MANUFACTURED SUBTANCES IN INDUSTRYCHEMISTRY

NAME : NURUL NABILA HUDA BINTI SUMRI CLASS : 5 PERDAGANGAN 2 I.C NO : 921218-08-6166 CHEMISTRY TEACHER: PN. NOR ZAIROS

CONTENTS1. SULPHURIC ACID o Introduction o Objective o Information o Discussion o AMMONIA AND ITS SALTS o Introduction o Objective o Information o Discussion ALLOYS o Introduction o Objective o Information o Discussion o SYNTHETIC POLYMERS o Introduction o Objective o Information o Discussion o GLASS AND CERAMICS o Introduction o Objective o Information o Discussion o COMPOSITE MATERIALS o Introduction o Objective o Information o Discussion o CONCLUSION 1 2 3 -7 8 - 11

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REFERENCES

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TOPIC

MANUFACTURED SUBTANCES IN INDUSTRY

IntroductionWhat is manufactured substance in industry? Almost everything we see is a manufactured product. Industrial products are manufactured for our comfort. Spoons, forks, pots are industrial products used in the kitchen. Washing liquids such as detergents are manufactured from ammonia. Bucket bottles, plastic plates and bowls are example of synthetic polymer normally used in our daily life.

InformationSULPHURIC ACIDIntroductionA strong mineral acid with the chemical formula H2SO4. It is a colorless, oily liquid, sometimes called oil of vitriol or vitriolic acid. The pure acid has a density of 1.834 at 25C (77F) and freezes at 10.5C (50.90F). It is an important industrial commodity, used extensively in petroleum refining and in the manufacture of fertilizers, paints, pigments, dyes, and explosives. Sulphuric acid is produced on a large scale by two commercial processes, the Contact process and the lead-chamber process. In the Contact process, sulfur dioxide, SO2, is converted to sulphur trioxide, SO3, by reaction with oxygen in the presence of a catalyst. Sulphuric acid is produced by the reaction of the sulphur trioxide with water. The lead-chamber process depends upon the oxidation of sulfur dioxide by nitric acid in the presence of water, the reaction being carried out in large lead rooms. Sulphuric acid reacts vigorously with water to form several hydrates. The concentrated acid, therefore, acts as an efficient drying agent, taking up moisture from the air and even abstracting the elements of water from such compounds as sugar and starch. The concentrated acid also acts as a strong oxidizing agent. It reacts with most metals upon heating to produce sulphur dioxide. Concentrated Sulphuric Acid When heated, the pure 100% acid loses sulphur trioxide gas, SO3, until a constant-boiling solution, or azeotrope, containing about 98.5% H2SO4 is formed at 33 0C. Concentrated sulphuric acid is a weak acid and a poor electrolyte because relatively little of it is dissociated into ions at room temperature. When cold it does not react readily with such common metals as iron or copper. When hot it is an oxidizing agent, the sulphur in it being reduced; sulphur dioxide gas may be released. Hot concentrated sulphuric acid reacts with most metals and with several nonmetals, e.g., sulphur and carbon. Because the concentrated acid has a fairly high boiling point, it can be used to release more volatile acids from their salts, e.g., when sodium chloride (NaCl), or common salt, is heated with concentrated sulphuric acid, hydrogen chloride gas, HCl, is evolved. Concentrated sulphuric acid has a very strong affinity for water. It is sometimes used as a drying agent and can be used to dehydrate (chemically remove water from) many compounds,

e.g., carbohydrates. It reacts with the sugar sucrose, C12H22O11, removing eleven molecules of water, H2O, from each molecule of sucrose and leaving a brittle spongy black mass of carbon and diluted sulphuric acid. The acid reacts similarly with skin, cellulose, and other plant and animal matter. When the concentrated acid mixes with water, large amounts of heat are released; enough heat can be released at once to boil the water and spatter the acid. To dilute the acid, the acid should be added slowly to cold water with constant stirring to limit the buildup of heat. Sulphuric acid reacts with water to form hydrates with distinct properties. Dilute Sulphuric Acid Dilute sulphuric acid is a strong acid and a good electrolyte; it is highly ionized, much of the heat released in dilution coming from hydration of the hydrogen ions. The dilute acid has most of the properties of common strong acids. It turns blue litmus red. It reacts with many metals (e.g., with zinc), releasing hydrogen gas, H2, and forming the sulphate of the metal. It reacts with most hydroxides and oxides, with some carbonates and sulfides, and with some salts. Since it is dibasic (i.e., it has two replaceable hydrogen atoms in each molecule), it forms both normal sulphate (with both hydrogen replaced, e.g., sodium sulfate, Na2SO4) and acid sulfates, also called bisulphate or hydrogen sulphate (with only one hydrogen replaced, e.g., sodium bisulphate, NaHSO4).

Objectives

I. List the uses of sulphuric acid. II. Explain the industrial process involved in the manufacture of sulphuric acid. III. Explain that sulphur dioxide causes environmental pollution.

i)

Uses of sulphuric acid i. ii. iii. iv. v. vi. vii. Manufacture of fertilizers such as ammonium sulphate, (NH4)2SO4 Manufacture of electrolyte in lead-acid accumulators (car battery) Manufacture of soaps and detergents Manufacture of pesticides (insecticides) Manufacture of plastic items such as rayon and nylon Manufacture of paints Leather tanning

Manufacture of car batteries

Manufacture of detergents

Manufacture of detergents

Manufacture of paints

Manufacture of plastic items

Leather tanning

Manufacture of pesticides

ii)

Manufacture of sulphuric acid

Sulphuric acid, H2SO4, is manufactured in industry through the Contact process. The manufacture of sulphuric acid, H2SO4, is called Contact Process because sulphur dioxide SO2 reacts with oxygen in contact with the catalyst in several times. Catalysts are normally made from transition elements to speed up the rate of reaction. The raw materials used are sulphur, air and water. The manufacturing of sulphuric acid, H2SO4, in industry involves three stages.

The manufacture of sulphuric acid, H2SO4 in the Contact Process

STAGEStage 1Sulphur dioxide gas, SO2, can be produced by burning sulphur in air. The gas produced is purified and cooled. S + O2 SO2

AIMTo produce sulphur dioxide gas, SO2

Stage 2

To produce sulphur trioxide gas,

The gas mixture of sulphur dioxide, SO2, and oxygen, O2, is passed over vanadium (V) oxide, V2O5, (catalyst) at temperature 450 500oC and under the pressure of 1 atmosphere to produce sulphur trioxide, SO3. 2SO2 + O2 2SO3 SO3.

About 99.5% of the sulphur dioxide, SO2, is converted into sulphur trioxide, SO3, through this reversible reaction.

Stage 3In the absorber, the sulphur trioxide, SO3, is dissolved in concentrated sulphuric acid, H2SO4, to form a product called oleum, H2S2O7. SO3 + H2SO4 H2S2O7 To produce sulphuric acid, H2SO4.

The oleum, H2S2O7, is then diluted with water to produce concentrated sulphuric acid, H2SO4 in large quantities. H2S2O7 + H2O 2H2SO4

The three stages involved in the Contact Process.

iii)

Environmental pollution causes by sulphur dioxide.

Sulphur dioxide, SO2 is one of the by-products of the Contact Process. It can cause environmental pollution. Almost all sulphur dioxides, SO2 in the air comes from the burning of fossil fuels such as petrol containing sulphur. Below are the environmental pollution causes by sulphur dioxide :

Visibility Impairment - Haze occurs when light is scattered or absorbed by particles and gases in the air. Sulfate particles are the major cause of reduced visibility in many parts of the U.S., including our national parks.

Acid Rain SO2 and nitrogen oxides react with other substances in the air to form acids, which fall to earth as rain, fog, snow, or dry particles. Some may be carried by the wind for hundreds of miles. This due to the reaction of sulphur dioxide, SO2 with rainwater. Acid rain destroys trees in forest.

Plant and Water Damage - Acid rain damages forests and crops, changes the makeup of soil, and makes lakes and streams acidic and unsuitable for fish. Continued exposure over a long time changes the natural variety of plants and animals in an ecosystem. Lake and rivers become acidic. Aquatic organism dies. pH of soils decreases. Plants die of malnutrition and diseases.

Aesthetic Damage - SO2 accelerates the decay of building materials and paints, including irreplaceable monuments, statues, and sculptures that are part of our nation's cultural heritage.

Respiratory Effects from Gaseous SO2 - Peak levels of SO2 in the air can cause temporary breathing difficulty for people with asthma who are active outdoors. Longer-term exposures to high levels of SO2 gas and particles cause respiratory illness and aggravate existing heart disease. Respiratory Effects from Sulfate Particles - SO2 reacts with other chemicals in the air to form tiny sulfate particles. When these are breathed, they gather in the lungs and are associated with increased respiratory symptoms and disease, difficulty in breathing, and premature death.

DiscussionThere are two major processes (lead chamber and contact) for production of sulphuric acid, and it is available commercially in a number of grades and concentrations. The lead chamber process, the older of the two processes, is used to produce much of the acid used to make fertilizers; it produces a relatively dilute acid (62%78% H2SO4). The Contact process produces a purer, more concentrated acid but requires purer raw

materials and the use of expensive catalysts. In both processes sulphur dioxide is oxidized and dissolved in water. The sulphur dioxide is obtained by burning sulphur, by burning pyrites (iron sulphides), by roasting nonferrous sulphide ores preparatory to smelting, or by burning hydrogen sulphide gas. Some sulphuric acid is also made from ferrous sulphate waste solutions from pickling iron and steel and from waste acid sludge from oil refineries. Contact Process Sulphuric acid, H2SO4, is manufactured in industry through the Contact process. The manufacture of sulphuric acid, H2SO4, is called Contact Process because sulphur dioxide SO2 reacts with oxygen in contact with the catalyst in several times. Catalysts are normally made from transition elements to speed up the rate of reaction. The raw materials used are sulphur, air and water. The manufacturing of sulphuric acid, H2SO4, in industry involves three stages. In the contact process, purified sulfur dioxide and air are mixed, heated to about 450C, and passed over a catalyst; the sulfur dioxide is oxidized to sulfur trioxide. The catalyst is usually platinum on a silica or asbestos carrier or vanadium pentoxide on a silica carrier. The sulfur trioxide is cooled and passed through two towers. In the first tower it is washed with oleum (fuming sulfuric acid, 100% sulfuric acid with sulfur trioxide dissolved in it). In the second tower it is washed with 97% sulfuric acid; 98% sulfuric acid is usually produced in this tower. Waste gases are usually discharged into the atmosphere. Acid of any desired concentration may be produced by mixing or diluting the products of this process. Lead Chamber Process In the lead chamber process hot sulphur dioxide gas enters the bottom of a reactor called a Glover tower where it is washed with nitrous vitriol (sulphuric acid with nitric oxide, NO, and nitrogen dioxide, NO2, dissolved in it) and mixed with nitric oxide and nitrogen dioxide gases; some of the sulphur dioxide is oxidized to sulphur trioxide and dissolved in the acid wash to form tower acid or Glover acid (about 78% H2SO4). From the Glover tower a mixture of gases (including sulphur dioxide and trioxide, nitrogen oxides, nitrogen, oxygen, and steam) is transferred to a lead-lined chamber where it is reacted with more water. The chamber may be a large, boxlike room or an enclosure in the form of a truncated cone. sulphuric acid is formed by a complex series of reactions; it condenses on the walls and collects on the floor of the chamber. There may be from three to twelve chambers in a series; the succession. The acid produced in the chambers, often called chamber acid or fertilizer acid, contains 62% to 68% H2SO4. After the gases have passed through the chambers they are passed into a reactor called the Gay-Lussac tower where they are washed with cooled concentrated acid (from the Glover tower); the nitrogen oxides and unreacted sulphur dioxide dissolve in the acid to form the nitrous vitriol used in the Glover tower. Remaining waste gases are usually discharged into the atmosphere.

SafetyLaboratory harzard

The corrosive properties of sulphuric acid are accentuated by its highly exothermic reaction with water. Hence burns from sulphuric acid are potentially more serious than those of comparable strong acids (e.g. hydrochloric acid), as there is additional tissue damage due to dehydration and particularly due to the heat liberated by the reaction with water; i.e. secondary thermal damage. The danger is obviously greater with more concentrated preparations of sulphuric acid, but it should be remembered that even the normal laboratory "dilute" grade (approx. 1 M, 10%) will char paper by dehydration if left in contact for a sufficient time. Solutions equal to or stronger than 1.5 M should be labeled CORROSIVE, while solutions greater than 0.5 M but less than 1.5 M should be labeled IRRITANT. Fuming sulphuric acid (oleum) is not recommended for use in schools due to it being quite hazardous. The standard first aid treatment for acid spills on the skin is, as for other corrosive agents, irrigation with large quantities of water: Washing should be continued for at least ten to fifteen minutes in order to cool the tissue surrounding the acid burn and to prevent secondary damage. Contaminated clothing must be removed immediately and the underlying skin washed thoroughly. Preparation of the diluted acid can also be dangerous due to the heat released in the dilution process. It is essential that the concentrated acid is added to water and not the other way round, to take advantage of the relatively high heat capacity of water. Addition of water to concentrated sulphuric acid leads at best to the dispersal of a sulphuric acid aerosol, at worst to an explosion. Preparation of solutions greater than 6 M (35%) in concentration is the most dangerous, as the heat produced can be sufficient to boil the diluted acid: efficient mechanical stirring and external cooling (e.g. an ice bath) are essential.

Industrial hazardsAlthough sulphuric acid is non-flammable, contact with metals in the event of a spillage can lead to the liberation of hydrogen gas. The dispersal of acid aerosols and gaseous sulfur dioxide is an additional hazard of fires involving sulphuric acid. Sulphuric acid is not considered toxic besides its obvious corrosive hazard, and the main occupational risks are skin contact leading to burns (see above) and the inhalation of aerosols. Exposure to aerosols at high concentrations leads to immediate and severe irritation of the eyes, respiratory tract and mucous membranes: this ceases rapidly after exposure, although there is a risk of subsequent pulmonary edema if tissue damage has been more severe. At lower concentrations, the most commonly reported symptom of chronic exposure to sulphuric acid aerosols is erosion of the teeth, found in virtually all studies: indications of possible chronic damage to the respiratory tract are inconclusive as of 1997.

AMMONIA AND ITS SALTIntroduction

Ammonia is a compound with the formula NH3.Ammonia solution NH3 can be used to identify the presence of certain cation in aqueous soluiton in laboratory. It is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceuticals. Although in wide use, ammonia is both caustic and hazardous. In 2006, worldwide production was estimated at 146.5 million tonnes. Ammonia, as used commercially, is often called anhydrous ammonia. This term emphasizes the absence of water in the material. Because NH3 boils at -33 C, the liquid must be stored under high pressure or at low temperature. Its heat of vaporization is, however, sufficiently great that NH3 can be readily handled in ordinary beakers in a fume hood. "Household ammonia" or "ammonium hydroxide" is a solution of NH3 in water. The strength of such solutions is measured in units of baume (density), with 26 degrees baume (about 30 weight percent ammonia at 15.5 C) being the typical high concentration commercial product. Household ammonia ranges in concentration from 5 to 10 weight percent ammonia. Ammonia, NH3, is used to manufacture nitric acid, HNO3. Nitric acid, HNO3, is then used to manufacture explosives and nitrate fertilisers.

Objectives

I. List the uses of ammonia. II. State the properties of ammonia.

III. Explain the industrial process in the manufacture of ammonia. IV. Design an activity to prepare ammonium fertiliser.

Informationi) i. ii. iii. Uses of ammonia Manufacture of fertilisers Manufacture of nitric acid , HNO3, through the Ostwald Process Manufacture of electrolytes in dry cells

iv. v. vi.

Manufacture of cleaning agents such as washing powder and detergents Maufacture of explosives such as trinitroluene (TNT) Manufacture of dyes

ii)

Properties of ammonia

Has characteristic of weak alkali when dissolve in water. Produce thick white fumes with hydrogen chloride

Colorless gas

PROPERTIE S OF AMMONIA, NH3

Pungent smell

Less dense than air.

Very soluble in water

iii)

Manufacture of ammonia

Ammonnia, NH3 is manufactured on a large scale in factories through the Haber Process. There are three main stages in the manufacture of ammonia. The Haber process is the third stage and uses a catalyst. The three main stages in ammonia synthesis a) conversion of methane and steam to hydrogen and carbon monoxide b) removal of the carbon monoxide and the production of a mixture of hydrogen and nitrogen c) synthesis of ammonia in the Haber process The process combines nitrogen gas, N2, from the air with hydrogen gas, H2, derived mainly from natural gas to form ammonia, NH3. The two gases are mixed in the ratio of 1:3 volumes.

N2 + 3H2

2NH3

The hydrogen gas is obtained from methane CH4, a type of natural gas, while nitrogen gas is obtained from air by fractional distillation of liquified air. The gas mixture is passed over iron (catalyst) at a temperature of 450 550 0C to speed up the rate of reaction and compressed under a pressure of 200 500 atmospheres.

The manufacture of ammonia,NH3 through the Haber Process.

iv)

Preparation of ammonium fertiliser.

Aim To prepare ammonium sulphate, (NH4)2SO4, salts Materials Ammonia solution, NH3, 1 mol dm-3, sulphuric acid, H2SO4, 1 mol dm-3, red litmus paper Apparatus 250 cm3 beaker, glass rod, tripod stand, Bunsen burner, wire gauge, filter funnel, filter paper, measuring cylinder, dropper, asbestos tile

Preparation of ammonium sulphate, (NH4)2SO4, salts Procedure 1. 50 cm3 of sulphuric acid, H2SO4, 1 mol dm-3 is measured with a measuring cylinder and poured into a 250 cm3 beaker.

2. While stirring, ammonia solution, (NH4)2SO4, 1 mol dm-3, is added drop by drop from a dropper into the sulphuric acid, H2SO4, until an excess amount is used (when ammonia, NH4, can be smelled) 3. The mixture is then poured into an evaporating dish. 4. The mixture is boiled until it evaporates to form a saturated solution. 5. The saturated solution is then cooled to room temperature until crystals salts is formed. 6. The crystals are then filtered and rinsed with a little cold distilled water. 7. The salt crytals are then dried on filter paper. Analysis Neutaralisation occur between sulphuric acid, H2SO4, and ammonia solution or ammonia hydroxide, NH4OH, and can be represented by the chemical equation below : H2SO4 + 2NH4OH (NH4)2SO4 + 2H2O

Conclusion Ammonium sulphate, (NH4)2SO4, salt can be prepared from the reaction between sulphuric acid, H2SO4, amd ammonia solution NH3. Dicussion The mixture formed in the beaker is tested from time to time with red litmus paper. The adding of ammonia solution, NH3, drops are stopped when the red litmus paper turns blue.

Information

The most familiar compound composed of the elements nitrogen and hydrogen, NH3. It is formed as a result of the decomposition of most nitrogenous organic material, and its presence is indicated by its pungent and irritating odor. Ammonia has a wide range of industrial and agricultural applications. Examples of its use are the production of nitric acid and ammonium salts, particularly the sulfate, nitrate, carbonate, and chloride, and the synthesis of hundreds of organic compounds including many drugs, plastics, and dyes. Its dilute aqueous solution finds use as a household cleansing agent. Anhydrous ammonia and ammonium salts are used as fertilizers, and anhydrous ammonia also serves as a refrigerant, because of its high heat of vaporization and relative ease of liquefaction. The physical properties of ammonia are analogous to those of water and hydrogen fluoride in that the physical constants are abnormal with respect to those of the binary hydrogen compounds of the other members of the respective periodic families. These abnormalities may be related to the association of molecules through intermolecular hydrogen bonding. Ammonia is highly mobile in the liquid state and has a high thermal coefficient of expansion. Most of the chemical reactions of ammonia may be classified under three chief groups: (1) addition reactions, commonly called ammonation; (2) substitution reactions, commonly called ammonolysis; and (3) oxidation-reduction reactions. Ammonation reactions include those in which ammonia molecules add to other molecules or ions. Most familiar of the ammonation reactions is the reaction with water to form ammonium hydroxide. The strong tendency of water and ammonia to combine is evidenced by the very high solubility of ammonia in water. Ammonia reacts readily with strong acids to form ammonium salts. Ammonium salts of weak acids in the solid state dissociate readily into ammonia and the free acid. Ammonation occurs with a variety of molecules capable of acting as electron acceptors (Lewis acids), such as sulfur trioxide, sulfur dioxide, silicon tetrafluoride, and boron trifluoride. Included among ammonation reactions is the formation of complexes (called ammines) with many metal ions, particularly transition metal ions. Ammonolytic reactions include reactions of ammonia in which an amide group (NH2), an imide group), or a nitride group replaces one or more atoms or groups in the reacting molecule. Oxidation-reduction reactions may be subdivided into those which involve a change in the oxidation state of the nitrogen atom and those in which elemental hydrogen is liberated. An example of the first group is the catalytic oxidation of ammonia in air to form nitric oxide. In the absence of a catalyst, ammonia burns in oxygen to yield nitrogen. Another example is the reduction with ammonia of hot metal oxides such as cupric oxide. The physical and chemical properties of liquid ammonia make it appropriate for use as a solvent in certain types of chemical reactions. The solvent properties of liquid ammonia are, in many ways, qualitatively intermediate between those of water and of ethyl alcohol. This is particularly true with respect to dielectric constant; therefore, ammonia is generally superior to ethyl alcohol as a solvent for ionic substances but is inferior to water in this respect. On the other hand, ammonia is generally a better solvent for covalent substances than is water.

The Haber-Bosch synthesis is the major source of industrial ammonia. In a typical process, water gas (CO, H2, CO2) mixed with nitrogen is passed through a scrubber cooler to remove dust and undecomposed material. The CO2 and CO are removed by a CO2 purifier and ammoniacal cuprous solution, respectively. The remaining H2 and N2 gases are passed over a catalyst at high pressures (up to 1000 atm or 100 megapascals) and high temperatures (approx. 1300F or 700C). Other industrial sources of ammonia include its formation as a by-product of the destructive distillation of coal, and its synthesis through the Cyanamid process. In the laboratory, ammonia is usually formed by its displacement from ammonium salts (either dry or in solution) by strong bases. Another source is the hydrolysis of metal nitrides. History The Romans called the ammonium chloride deposits they collected from near the Temple of Jupiter Amun (Greek Ammon) in ancient Libya 'sal ammoniacus' (salt of Amun) because of proximity to the nearby temple. Salts of ammonia have been known from very early times; thus the term Hammoniacus sal appears in the writings of Pliny, although it is not known whether the term is identical with the more modern sal-ammoniac. In the form of sal-ammoniac, ammonia was known to the Arabic alchemists as early as the 8th century, first mentioned by Geber (Jabir ibn Hayyan), and to the European alchemists since the 13th century, being mentioned by Albertus Magnus. It was also used by dyers in the Middle Ages in the form of fermented urine to alter the colour of vegetable dyes. In the 15th century, Basilius Valentinus showed that ammonia could be obtained by the action of alkalis on sal-ammoniac. At a later period, when sal-ammoniac was obtained by distilling the hoofs and horns of oxen and neutralizing the resulting carbonate with hydrochloric acid, the name "spirit of hartshorn" was applied to ammonia. Gaseous ammonia was first isolated by Joseph Priestley in 1774 and was termed by him alkaline air; however it was acquired by the alchemist Basil Valentine. Eleven years later in 1785, Claude Louis Berthollet ascertained its composition. The Haber process to produce ammonia from the nitrogen in the air was developed by Fritz Haber and Carl Bosch in 1909 and patented in 1910. It was first used on an industrial scale by the Germans during World War I, following the allied blockade that cut off the supply of nitrates from Chile. The ammonia was used to produce explosives to sustain their war effort. Prior to the advent of cheap natural gas, hydrogen as a precursor to ammonia production was produced via the electrolysis of water. The Vemork 60 MW hydroelectric plant in Norway constructed in 1911 was used purely for this purpose and up until the second world war provided the majority of Europe's ammonia.

Discussion

The Haber process (also known as HaberBosch process) is the reaction of nitrogen and hydrogen, over an iron-substrate, to produce ammonia. The Haber process is important because ammonia is difficult to produce, on an industrial scale. Even though 78.1% of the air we breathe is nitrogen, the gas is relatively inert due to the strength of the triple bond that keeps the molecule together. It was not until the start of the twentieth century that this method was developed to harness the atmospheric abundance of nitrogen to create ammonia, which can then be oxidized to make the nitrates and nitrites essential for the production of nitrate fertilizer and munitions. It was developed immediately prior to World War I by Fritz Haber and Carl Bosch, German chemists. Haber won the Nobel Prize for Chemistry in 1918 for his discoveries, while Bosch shared a Nobel Prize with Friedrich Bergius in 1931 for his work on high-pressure chemical reactions. At first a German national secret, the chemistry and techniques behind the effective synthesis of ammonia spread to the rest of the world in the 20s and 30s. Ammonia is important because it is the primary ingredient in artificial fertilizers, without which modern-day agricultural yields would be impossible. Sometimes called the "Haber Ammonia process", the Haber-Bosch process was the first industrial chemical process to make use of extremely high pressures (200 to 400 atmospheres). In addition to high pressures, high temperatures (750 to 1200 degrees Fahrenheit or 400 to 650 degrees Celsius) are used. The efficiency of the reaction is a function of pressure and temperature - greater yields are produced at higher pressures and lower temperatures. In the first decade of the 20th century, the artificial synthesis of nitrates was being researched because the world's supply of fixed nitrogen was declining rapidly relative to the demand. While nitrogen in its inactive, atmospheric gas form is very plentiful, agriculturally useful "fixed" nitrogen compounds were harder to come by at that time in history. Agricultural operations require liberal amounts of fixed nitrogen to produce good yields. At the turn of the century, all the world's developed countries were required to mass import nitrates from the largest available source - Chilean saltpeter (NaNO3). Many scientists started worrying about the declining supply of nitrogen compounds. The Haber-Bosch process provided a solution to the shortage of fixed nitrogen. Using extremely high pressures and a catalyst composed mostly of iron, critical chemicals used in both the production of fertilizers and explosives were made highly accessible to German industry, making it possible for them to continue fighting WWI effectively. As the HaberBosch process branched out in global use, it became the primary procedure responsible for the production of fertilizer to feed the world's population. Without it, billions of people might not exist. Today, the Haber-Bosch process is used to produce more than 500 million tons (453 billion kilograms) of artificial fertilizer per year; roughly 1% of the world's energy is used for it, and it sustains about 40% of our planetary population.

ALLOYSIntroduction

An alloy is a partial or complete solid solution of one or more elements in a metallic matrix. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may be homogeneous in distribution depending on thermal (heat treatment) history. Alloys usually have different properties from those of the component elements. Alloying one metal with other metal(s) or non metal(s) often enhances its properties. For instance, steel is stronger than iron, its primary element. The physical properties, such as density, reactivity, Young's modulus, and electrical and thermal conductivity, of an alloy may not differ greatly from those of its elements, but engineering properties, such as tensile strength and shear strength may be substantially different from those of the constituent materials. This is sometimes due to the sizes of the atoms in the alloy, since larger atoms exert a compressive force on neighboring atoms, and smaller atoms exert a tensile force on their neighbors, helping the alloy resist deformation. Alloys may exhibit marked differences in behavior even when small amounts of one element occur. For example, impurities in semi-conducting ferromagnetic alloys lead to different properties, as first predicted by White, Hogan, Suhl, Tian Abrie and Nakamura. Some alloys are made by melting and mixing two or more metals. Brass is an alloy made from copper and zinc. Bronze, used for bearings, statues, ornaments and church bells, is an alloy of tin and copper. Unlike pure metals, most alloys do not have a single melting point. Instead, they have a melting range in which the material is a mixture of solid and liquid phases. The temperature at which melting begins is called the solidus and the temperature when melting is complete is called the liquidus. However, for most alloys there is a particular proportion of constituents which give them a single melting point or (rarely) two. This is called the alloy's eutectic mixture.

Objectives

I. Relate the arrangement of atoms in metals to their ductile and malleable properties. II. State the meaning of alloy. III. State the aim of making alloys. IV. List the composition and properties of alloys. V. Relate the properties of alloys to their uses. VI. Relate the arrangement of atoms in alloys to their strength and hardness.

Informationi) Arrangement of atoms in metals

Most metals are solid. Pure metal is soft and not very strong. Pure metal have similar size and shape and are arranged closely but there is still space between the atoms. The arrangement of the atoms in metals gives the metals their ductile and malleable properties. o When force is applied to pure metals, the atoms slide along one another easily. This property causes pure metal to be ductile, that is, it can be stretched into wire.

Metals are ductile o When knocked or hammered, metal atoms slide along one another to fill spaces between the metal atoms. This property causes pure metal to be malleable, that is, it can be knocked or pressed into various desired shapes.

Metals are malleable

ii)

Alloys

Two soft metals can be mixed together to make stronger metal called alloy. An alloy is a mixture of two or more elements with a certain fixed composition on which the major

component is a metal. Most pure metals are weak and soft. The properties of pure metals can be improved by making them into alloys. The aim of making alloys is to make them into alloys. The process of mixing atoms of impurities with atoms of pure metal by melting is called alloying. iii) Aims of alloying are to : a) increase the strength and hardness of the metal b) prevent corrosion of the metal c) have a better furnish and lustre iv) Composition and properties of alloy ALLOY Steel Bronze o o o o COMPOSITION 99% iron 1% carbon 90% copper 10% tin o o o o o o o o o o o o o o PROPERTIES Hard and strong Withstand corrosion Hard and strong Withstand corrosion Has shiny surface Strong Shiny Harder than copper Shiny Strong Does not rust Light Strong Withsand corrosion

Brass

o 70% copper o 30% zinc o o o o o o o o o o 74% iron 8% carbon 18% chromium 93% aluminium 3% copper 3% magnesium 1% manganese 96% tin 3% copper 1% antimony

Stainless steel

Duralumin

Pewter

Copper nickel

o 75% copper o 25% nickel

o Lustre o Smooth and shiny surface o Strong o Withstand corrosion o Strong o Shiny silver colour

v)

Uses of alloy

Properties of alloys and their uses.

vi)

Arrangement of atoms in alloys.

Impurity atoms which are mixed may be larger or smaller than atoms of pure metal. Impurity atoms will fill the empty spaces between the atoms in pure metal. Impurity atoms can prevent

the layers of metal atoms from sliding along one another easily. Due to this, an alloy is harder and stronger than pure metal.

The formation of alloy

DiscussionAlloy is a metal product containing two or more elements as a solid solution, as an intermetallic compound, or as a mixture of metallic phases. Alloys are frequently described

on the basis of their technical applications. They may also be categorized and described on the basis of compositional groups. For example,Beryllium alloys; Iron alloys. Except for native copper and gold, the first metals of technological importance were alloys. Bronze, an alloy of copper and tin, is appreciably harder than copper. This quality made bronze so important an alloy that it left a permanent imprint on the civilization of several millennia ago now known as the Bronze Age. Today the tens of thousands of alloys involve almost every metallic element of the periodic table. Alloys are used because they have specific properties or production characteristics that are more attractive than those of the pure, elemental metals. For example, some alloys possess high strength; others have low melting points; others are refractory with high melting temperatures; some are especially resistant to corrosion; and others have desirable magnetic, thermal, or electrical properties. These characteristics arise from both the internal and the electronic structure of the alloy. An alloy is usually harder than a pure metal and may have a much lower conductivity. Bearing alloys are used for metals that encounter sliding contact under pressure with another surface; the steel of a rotating shaft is a common example. Most bearing alloys contain particles of a hard intermetallic compound that resist wear. These particles, however, are embedded in a matrix of softer material which adjusts to the hard particles so that the shaft is uniformly loaded over the total surface. The most familiar bearing alloy is babbitt. Bearings made by powder metallurgy techniques are widely used because they permit the combination of materials which are incompatible as liquids, for example, bronze and graphite, and also permit controlled porosity within the bearings so that they can be saturated with oil before being used, the so-called oilless bearings. Certain alloys resist corrosion because they are noble metals. Among these alloys are the precious-metal alloys. Other alloys resist corrosion because a protective film develops on the metal surface. This passive film is an oxide which separates the metal from the corrosive environment. Stainless steels and aluminum alloys exemplify metals with this type of protection. The bronzes, alloys of copper and tin, also may be considered to be corrosionresisting. Dental alloys contain precious metals. Amalgams are predominantly silver-mercury alloys, but they may contain minor amounts of tin, copper, and zinc for hardening purposes. Liquid mercury is added to a powder of a precursor alloy of the other metals. After being compacted, the mercury diffuses into the silver-base metal to give a completely solid alloy. Gold-base dental alloys are preferred over pure gold because gold is relatively soft. The most common dental gold alloy contains gold, silver, and copper. For higher strengths and hardnesses, palladium and platinum are added, and the copper and silver are increased so that the gold content drops. Vitallium and other corrosion-resistant alloys are used for bridgework and special applications. Die-casting alloys have melting temperatures low enough so that in the liquid form they can be injected under pressure into steel dies. Such castings are used for automotive parts and for office and household appliances which have moderately complex shapes. Most die castings are made from zinc-base or aluminum-base alloys. Magnesium-base alloys also find some

application when weight reduction is paramount. Low-melting alloys of lead and tin are not common because they lack the necessary strength for the above applications. In certain alloy systems a liquid of a fixed composition freezes to form a mixture of two basically different solids or phases. An alloy that undergoes this type of solidification process is called a eutectic alloy. A homogeneous liquid of this composition on slow cooling freezes to form a mixture of particles of nearly pure copper embedded in a matrix (background) of nearly pure silver. High-temperature alloys have high strengths at high temperatures. In addition to having strength, these alloys must resist oxidation by fuel-air mixtures and by steam vapor. At temperatures up to about 1380F (750C), the austenitic stainless steels serve well. An additional 180F (100C) may be realized if the steels also contain 3% molybdenum. Both nickel-base and cobalt-base alloys, commonly categorized as superalloys, may serve useful functions up to 2000F (1100C). Nichrome, a nickel-base alloy containing chromium and iron, is a fairly simple superalloy. More sophisticated alloys invariably contain five, six, or more components; for example, an alloy called Ren-41 contains Cr, Al, Ti, Co, Mo, Fe, C, B, and Ni. Other alloys are equally complex. A group of materials called cermets, which are mixtures of metals and compounds such as oxides and carbides, have high strength at high temperatures, and although their ductility is low, they have been found to be usable. One of the better-known cermets consists of a mixture of titanium carbide and nickel, the nickel acting as a binder or cement for the carbide. Metals are bonded by three principal procedures: welding, brazing, and soldering. Welded joints melt the contact region of the adjacent metal; thus the filler material is chosen to approximate the composition of the parts being joined. Brazing and soldering alloys are chosen to provide filler metal with an appreciably lower melting point than that of the joined parts. Typically, brazing alloys melt above 750F (400C), whereas solders melt at lower temperatures. As discussed here, prosthetic alloys are alloys used in internal prostheses, that is, surgical implants such as artificial hips and knees. External prostheses are devices that are worn by patients outside the body; alloy selection criteria are different from those for internal prostheses. Alloy selection criteria for surgical implants can be stringent primarily because of biomechanical and chemical aspects of the service environment. The most widely used prosthetic alloys therefore include high-strength, corrosion-resistant ferrous, cobalt-based, or titanium-based alloys: for example, cold-worked stainless steel; cast Vitallium; a wrought alloy of cobalt, nickel, chromium, molybdenum, and titanium; titanium alloyed with aluminium and vanadium; and commercial-purity titanium.

SYHTHETIC POLYMERSIntroduction

A polymer is a large molecule (macromolecule) composed of repeating structural units typically connected by covalent chemical bonds. While polymer in popular usage suggests plastic, the term actually refers to a large class of natural and synthetic materials with a variety of properties and purposes Well-known examples of polymers include plastics and proteins. A simple example is polypropylene, whose repeating unit structure is shown at the right. However, polymers are not just limited to having predominantly carbon backbones, elements such as silicon form familiar materials such as silicones, examples being silly putty and waterproof plumbing sealant. The backbone of DNA is in fact based on a phosphodiester bond. Natural polymer materials such as shellac and amber have been in use for centuries. Biopolymers such as proteins and nucleic acids play crucial roles in biological processes. A variety of other natural polymers exist, such as cellulose, which is the main constituent of wood and paper. The list of synthetic polymers includes Bakelite, neoprene, nylon, PVC, polystyrene, polyacrylonitrile, PVB, silicone, and many more. Polymers are studied in the fields of polymer chemistry, polymer physics, and polymer science.

Objectives

I. State the meaning of polymers. II. List the naturally occuring polymers and their uses. III. Identify the monomers in the synthetic polymers. IV. Justify the uses of synthetic polymers in daily life.

Informationi) Meaning of polymers

Polymers are long chains of molecules made from combination of many small molecules. Small molecules that combine together by covalent bond to form polymers are called monomers. Polymerisation is a process of combining monomers to form a long chain of molecules.

Formation of polymer Polymers can be divided into two types: a) natural polymer b) synthetic polymer NATURAL POLYMER A natural polymer is a polymer that occurs naturally. Naturals polymer are normally made by living organism. NATURAL POLYMER MONOMER (small molecules) Rubber Isoprene Cellulose Glucose Starch Glucose Protein Amino acid Fat Fatty acid and glycerol Nucleic acid Nucleotides Examples of natural polymers and their monomers

SYNTHETIC POLYMER

Synthetic polymers are man-made polymers that are produced from chemical compunds through polymerisation. Plastic, synthetic fibres and synthetic rubbers are three examples of synthetic polymers. There are two types of polymerisation: a) Additon polymerisation b) Condensation polymerisation Addition polymerisation Unsaturated monomers that contain double bonds between two carbon atoms undergo addition polymerisation. Condesation polymerisation Small molecules such as water, H2O, and ammonia, NH3, are released in condensation polymerisation. Examples of synthetic polymers (products of condensation polymerisation, with their monomers) MONOMER POLYMER a) Adipic acid and hexanediamine Nylon b) 1,4-dicarboxylbenzene and ethene-1,2diol Terylene

ii)

Natural polymers and their uses

NATURAL POLYMER Rubber Cellulose Starch Protein Fat

USE Tyres, eraser, condom, electric insulation, elastic bands and belts. Paper, textiles, pharmaceuticals, and explosives To stiffen cloth (as in laundering), used in cooking to thicken foods, manufactured of adhesives, paper, textiles and as a mold in the manufacture of sweets. Essential in the diet of animals for the growth and repair of tissue, Maintaining healthy skin and hair, insulating body organs against shock, promoting healthy cell function and serve as energy stores for the body

iii)

Monomers in the synthetic polymers SYNTHETIC POLYMER Polythene Polyvinyl chloride (PVC) Polypropene Perspex Polystyrene Nylon Terylene MONOMER Ethene Chloroethene (Vinylchloride) Propene Methyl-2-methylpropenoate (Methyl metacrylate) Styrene Adipic acid and hexanediamine 1,4-dicarboxylbenzene and ethene-1,2diol

iv)

Uses of synthetic polymers in daily life

TYPE OF POLYMER Polythene

USE a) b) c) d) e) a) b) c) d) e) a) b) c) d) e) a) b) c) a) b) c) d) a) b) c) a) Make buckets Make plastic bags Make raincoats Make films Make rubbish bins Make water pipes Make electric cables Make mats Make vinyl records Make clothes hangers Make ropes Make bottles Make chairs Make drink cans Make carpets Make car windows Make plane windows Make spectacle lenses (optical instruments) Make ropes Make curtains Make stockings Make clothes Make packing boxes Make buttons Make noticeboards Make textile items such as clothes and cloths

Polyvinyl chloride (PVC)

Polypropene

Perspex Nylon

Polystyrene Terylene

Discussion

Etymology The word polymer is derived from the Greek words (poly), meaning "many"; and (meros), meaning "part". The term was coined in 1833 by Jns Jakob Berzelius, although his definition of a polymer was quite different from the modern definition. Historical development Starting in 1811, Henri Braconnot did pioneering work in derivative cellulose compounds, perhaps the earliest important work in polymer science. The development of vulcanization later in the nineteenth century improved the durability of the natural polymer rubber, signifying the first popularized semi-synthetic polymer. In 1907, Leo Baekeland created the first completely synthetic polymer, Bakelite, by reacting phenol and formaldehyde at precisely controlled temperature and pressure. Bakelite was then publicly introduced in 1909. Despite significant advances in synthesis and characterization of polymers, a correct understanding of polymer molecular structure did not emerge until the 1920s. Before that, scientists believed that polymers were clusters of small molecules (called colloids), without definite molecular weights, held together by an unknown force, a concept known as association theory. In 1922, Hermann Staudinger proposed that polymers consisted of long chains of atoms held together by covalent bonds, an idea which did not gain wide acceptance for over a decade and for which Staudinger was ultimately awarded the Nobel Prize. Work by Wallace Carothers in the 1920s also demonstrated that polymers could be synthesized rationally from their constituent monomers. An important contribution to synthetic polymer science was made by the Italian chemist Giulio Natta and the German chemist Karl Ziegler, who won the Nobel Prize in Chemistry in 1963 for the development of the Ziegler-Natta catalyst. Further recognition of the importance of polymers came with the award of the Nobel Prize in Chemistry in 1974 to Paul Flory, whose extensive work on polymers included the kinetics of step-growth polymerization and of addition polymerization, chain transfer, excluded volume, the Flory-Huggins solution theory, and the Flory convention. Synthetic polymer materials such as nylon, polyethylene, Teflon, and silicone have formed the basis for a burgeoning polymer industry. These years have also shown significant developments in rational polymer synthesis. Most commercially important polymers today are entirely synthetic and produced in high volume on appropriately scaled organic synthetic techniques. Synthetic polymers today find application in nearly every industry and area of life. Polymers are widely used as adhesives and lubricants, as well as structural components for products ranging from children's toys to aircraft. They have been employed in a variety of biomedical applications ranging from implantable devices to controlled drug delivery. Polymers such as poly (methyl methacrylate) find application as photoresist materials used in semiconductor manufacturing and low-k dielectrics for use in high-performance microprocessors. Recently, polymers have also been employed in the development of flexible polymer-based substrates for electronic displays.

Polymer synthesis Polymerization is the process of combining many small molecules known as monomers into a covalently bonded chain. During the polymerization process, some chemical groups may be lost from each monomer. The distinct piece of each monomer that is incorporated into the polymer is known as a repeat unit or monomer residue. Polymer structure The structural properties of a polymer relate to the physical arrangement of monomer residues along the backbone of the chain. Structure has a strong influence on the other properties of a polymer. For example, a linear chain polymer may be soluble or insoluble in water depending on whether it is composed of polar monomers (such as ethylene oxide) or nonpolar monomers (such as styrene). On the other hand, two samples of natural rubber may exhibit different durability, even though their molecules comprise the same monomers. Polymer scientists have developed terminology to describe precisely both the nature of the monomers as well as their relative arrangement. Polymer properties Types of polymer properties can be broadly divided into several categories based upon scale. At the nano-micro scale there are properties that directly describe the chain itself, and can be thought of as polymer structure. At an intermediate mesoscopic level there are properties that describe the morphology of the polymer matrix in space. At the macroscopic level properties describe the bulk behavior of the polymer. The bulk properties of a polymer are those most often of end-use interest. These are the properties that dictate how the polymer actually behaves on a macroscopic scale. Melting point The term melting point, when applied to polymers, suggests not a solid-liquid phase transition but a transition from a crystalline or semi-crystalline phase to a solid amorphous phase. Though abbreviated as simply Tm, the property in question is more properly called the crystalline melting temperature. Among synthetic polymers, crystalline melting is only discussed with regards to thermoplastics, as thermosetting polymers will decompose at high temperatures rather than melt. Boiling point The boiling point of a polymer substance is never defined because polymers will decompose before reaching theoretical boiling temperatures.

Chemical properties of polymers The attractive forces between polymer chains play a large part in determining a polymer's properties. Because polymer chains are so long, these interchain forces are amplified far beyond the attractions between conventional molecules. Different side groups on the polymer can lend the polymer to ionic bonding or hydrogen bonding between its own chains. These stronger forces typically result in higher tensile strength and melting points. The intermolecular forces in polymers can be affected by dipoles in the monomer units. Polymers containing amide or carbonyl groups can form hydrogen bonds between adjacent chains; the partially positively charged hydrogen atoms in N-H groups of one chain are strongly attracted to the partially negatively charged oxygen atoms in C=O groups on another. These strong hydrogen bonds, for example, result in the high tensile strength and melting point of polymers containing urethane or urea linkages. Polyesters have dipoledipole bonding between the oxygen atoms in C=O groups and the hydrogen atoms in H-C groups. Dipole bonding is not as strong as hydrogen bonding, so a polyester's melting point and strength are lower than Kevlar's (Twaron), but polyesters have greater flexibility. Ethene, however, has no permanent dipole. The attractive forces between polyethylene chains arise from weak Van der Waals forces. Molecules can be thought of as being surrounded by a cloud of negative electrons. As two polymer chains approach, their electron clouds repel one another. This has the effect of lowering the electron density on one side of a polymer chain, creating a slight positive dipole on this side. This charge is enough to attract the second polymer chain. Van der Waals forces are quite weak, however, so polyethene can have a lower melting temperature compared to other polymers.

GLASS AND CERAMICSIntroductionGlass Materials made by cooling certain molten materials in such a manner that they do not crystallize but remain in an amorphous state, their viscosity increasing to such high values that, for all practical purposes, they are solid. Materials having this ability to cool without crystallizing is relatively rare, silica, SiO2, being the most common example. Although glasses can be made without silica, most commercially important glasses are based on it. The most important properties are viscosity; strength; index of refraction; dispersion; light transmission (both total and as a function of wavelength); corrosion resistance; and electrical properties. Chemically, most glasses are silicates. Silica by itself makes a good glass (fused silica), but its high melting point (1723C or 3133F) and its high viscosity in the liquid state make it difficult to melt and work. To lower the melting temperature of silica to a more convenient level, soda, Na2O, is added in the form of sodium carbonate or nitrate, for example. This has the desired effect, but unfortunately the resulting glass has no chemical durability and is soluble even in water (water glass). To overcome this problem, lime, CaO, is added to the glass to form the basic soda-lime-silica glass composition which is used for the bulk of common glass articles, such as bottles and sheet (window) glass. Although these are the main ingredients, commercial glass contains other oxides (aluminum and magnesium oxides) and ingredients to help in oxidizing, fining, or decolorizing the glass batch. Special kinds of glass have other oxides as major ingredients. For example, boron oxide is added to silicate glass to make a low-thermal-expansion glass for chemical glassware which must stand rapid temperature changes, for example, Pyrex glass. Also, lead oxide is used in optical glass because it gives a high index of refraction.

Ceramics Inorganic, nonmetallic materials processed or consolidated at high temperature. This definition includes a wide range of materials known as advanced ceramics and is much broader than the common dictionary definition, which includes only pottery, tile, porcelain, and so forth. The classes of materials generally considered to be ceramics are oxides, nitrides, borides, carbides, silicides, and sulfides. Intermetallic compounds such as aluminides and beryllides are also considered ceramics, as are phosphides, antimonides, and arsenides. Ceramic materials can be subdivided into traditional and advanced ceramics. Traditional ceramics include clay-base materials such as brick, tile, sanitary ware, dinnerware, clay pipe, and electrical porcelain. Common-usage glass, cement, abrasives, and refractories are also important classes of traditional ceramics. Advanced materials technology is often cited as an enabling technology, enabling engineers to design and build advanced systems for applications in fields such as aerospace, automotive, and electronics. Advanced ceramics are tailored to have premium properties through application of advanced materials science and technology to control composition and internal structure. Examples of advanced ceramic materials are silicon nitride, silicon carbide, toughened zirconia, zirconia-toughened alumina, aluminum nitride, lead magnesium niobate, lead lanthanum zirconate titanate, silicon-carbide-whisker-reinforced alumina, carbon-fiber-reinforced glass ceramic, silicon-carbide-fiber-reinforced silicon carbide, and high-temperature superconductors. Advanced ceramics can be viewed as a class of the broader field of advanced materials, which can be divided into ceramics, metals, polymers, composites, and electronic materials. There is considerable overlap among these classes of materials

Objectives

I. List the type of glass and their properties. II. List the uses of glass. III. State the properties of ceramics. IV. List the uses of ceramics.

Informationi) Types of glasses and their properties TYPE OF GLASSES Fused silica glass PROPERTIES o Very high melting point o Not easy to change its shape o Does not easily expand or shrink with changes of temperature o o o o o o o o o Transparent to ultraviolet ray Transparent Low melting point Easily to be shaped Easily broken Cannot withstand heat and chemical reactions Withstand heat and chemical reactions High melting point Transparent to light and infrared ray but not to ultraviolet ray

Soda-lime glass

Borosilicate glass

Lead crystal glass

o Expand and shrink very little and only when temperature changes o Very transparent o Shiny o High refractive index o High density

ii)

Uses of glass TYPE OF GLASS Fused silica glass Soda-lime glass Borosilicate glass USES Lenses, spectacles, laboratory glassware, ultraviolet column. Bottles, glass containers, mirrors, electrical bulbs, glass windows Bowls, plates, saucers, pots and laboratory glassware

Lead crystal glass

such as test tubes, beakers and flasks Lenses, prisms, glasses and ornamental items (crystals)

iii)

Properties of ceramics o o o o o o o Brittle Extremely hard High melting point Withstand compression Crack when temperature changes drastically Inert to chemicals ( withstand corrosion) Good insulator of heat and electricity

iv)

Uses of ceramics Manufacture of computer microchips Make porcelaine vase and ornamental items Make plates, bowls and pots Make dentures enamel Used in the manufacturing of car engines, spacecraft, superconductors and nuclear reactors o Make construction materials such as bricks, cement, tiles, underground piping or roof tiles. o o o o o

DiscussionGeneral properties, uses, occurrence

Flat panel display, using thin sheets of special alkali-free glass

Ordinary glass is prevalent due to its transparency to visible light. This transparency is due to an absence of electronic transition states in the range of visible light. The homogeneity of the glass on length scales greater than the wavelength of visible light also contributes to its transparency as heterogeneities would cause light to be scattered, breaking up any coherent image transmission. Many household objects are made of glass. Drinking glasses, bowls and bottles are often made of glass, as are light bulbs, mirrors, aquaria, cathode ray tubes, computer flat panel displays, and windows. In research laboratories, flasks, test tubes, and other laboratory equipment are often made of borosilicate glass for its low coefficient of thermal expansion, giving greater resistance to thermal shock and greater accuracy in measurements. For high-temperature applications, quartz glass is used, although it is very difficult to work. Most laboratory glassware is massproduced, but large laboratories also keep a glassblower on staff for preparing custom made glass equipment. Sometimes, glass is created naturally from volcanic lava, lightning strikes, or meteorite impacts (e.g., Lechatelierite, Fulgurite, Darwin Glass, Volcanic Glass, Tektites). If the lava is felsic this glass is called obsidian, and is usually black with impurities. Obsidian is a raw material for flintknappers, who have used it to make extremely sharp glass knives since the stone age. Glass sometimes occurs in nature resulting from human activity, for example trinitite (from nuclear testing) and beach glass. Glass in buildings Glass is commonly used in buildings as transparent windows, internal glazed partitions, and as architectural features. It is also possible to use glass as a structural material, for example, in beams and columns, as well as in the form of "fins" for wind reinforcement, which are visible in many glass frontages like large shop windows. Safe load capacity is, however,

limited; although glass has a high theoretical yield stress, it is very susceptible to brittle (sudden) failure, and has a tendency to shatter upon localized impact. This particularly limits its use in columns, as there is a risk of vehicles or other heavy objects colliding with and shattering the structural element. One well-known example of a structure made entirely from glass is the northern entrance to Buchanan Street subway station in Glasgow. Glass in buildings can be of a safety type, including wired, heat strengthened (tempered) and laminated glass. Glass fibre insulation is common in roofs and walls. Foamed glass, made from waste glass, can be used as lightweight, closed-cell insulation. As insulation, glass (e.g., fiberglass) is also used. In the form of long, fluffy-looking sheets, it is commonly found in homes. Fiberglass insulation is used particularly in attics, and is given an R-rating, denoting the insulating ability. Glass production Glass ingredients

Quartz sand (silica) as main raw material for commercial glass production

Oldest mouth-blown window-glass from 1742 from Kosta Glasbruk, Smland, Sweden. In the middle is the mark from the glass blower's pipe

Pure silica (SiO2) has a "glass melting point" at a viscosity of 10 Pas (100 P) of over 2300 C (4200 F). While pure silica can be made into glass for special applications (see fused quartz), other substances are added to common glass to simplify processing. One is sodium carbonate (Na2CO3), which lowers the melting point to about 1500 C (2700 F) in soda-lime glass; "soda" refers to the original source of sodium carbonate in the soda ash obtained from certain plants. However, the soda makes the glass water soluble, which is usually undesirable, so lime (calcium oxide (CaO), generally obtained from limestone), some magnesium oxide (MgO) and aluminium oxide are added to provide for a better chemical durability. The resulting glass contains about 70 to 74 percent silica by weight and is called a soda-lime glass. Soda-lime glasses account for about 90 percent of manufactured glass. As well as soda and lime, most common glass has other ingredients added to change its properties. Lead glass, such as lead crystal or flint glass, is more 'brilliant' because the increased refractive index causes noticeably more "sparkles", while boron may be added to change the thermal and electrical properties, as in Pyrex. Adding barium also increases the refractive index. Thorium oxide gives glass a high refractive index and low dispersion, and was formerly used in producing high-quality lenses, but due to its radioactivity has been replaced by lanthanum oxide in modern eye glasses. Large amounts of iron are used in glass

that absorbs infrared energy, such as heat absorbing filters for movie projectors, while cerium(IV) oxide can be used for glass that absorbs UV wavelengths (biologically damaging ionizing radiation). Besides the chemicals mentioned, in some furnaces recycled glass ("cullet") is added, originating from the same factory or other sources. Cullet leads to savings not only in the raw materials, but also in the energy consumption of the glass furnace. However, impurities in the cullet may lead to product and equipment failure. Fining agents such as sodium sulfate, sodium chloride, or antimony oxide are added to reduce the bubble content in the glass. A further raw material used in the production of soda-lime and fiber glass is calumite, which is a glassy granular by-product of the iron making industry, containing mainly silica, calcium oxide, alumina, magnesium oxide (and traces of iron oxide). For obtaining the desired glass composition, the correct raw material mixture (batch) must be determined by glass batch calculation. Silica-free glasses Besides common silica-based glasses, many other inorganic and organic materials may also form glasses, including plastics (e.g., acrylic glass), carbon, metals, carbon dioxide (see below), phosphates, borates, chalcogenides, fluorides, germanates (glasses based on GeO2), tellurites (glasses based on TeO2), antimonates (glasses based on Sb2O3), arsenates (glasses based on As2O3), titanates (glasses based on TiO2), tantalates (glasses based on Ta2O5), nitrates, carbonates and many other substances. Some glasses that do not include silica as a major constituent may have physico-chemical properties useful for their application in fibre optics and other specialized technical applications. These include fluorozirconate, fluoroaluminate, aluminosilicate, phosphate and chalcogenide glasses. Under extremes of pressure and temperature solids may exhibit large structural and physical changes which can lead to polyamorphic phase transitions. In 2006 Italian scientists created an amorphous phase of carbon dioxide using extreme pressure. The substance was named amorphous carbonia(a-CO2) and exhibits an atomic structure resembling that of Silica. Physical properties The following table lists some physical properties of common glasses. Unless otherwise stated, the technical glass compositions and many experimentally determined properties are taken from one large study. Unless stated otherwise, the properties of fused silica (quartz glass) and germania glass are derived from the SciGlass glass database by forming the arithmetic mean of all the experimental values from different authors (in general more than 10 independent sources for quartz glass and Tg of germanium oxide glass). Those values marked in italic font have been interpolated from similar glass compositions (see Calculation of glass properties) due to the lack of experimental data.

History

Roman Cage Cup from the 4th century A.D.

Roman glass

Naturally occurring glass, especially obsidian, has been used by many Stone Age societies across the globe for the production of sharp cutting tools and, due to its limited source areas, was extensively traded. According to Pliny the Elder, Phoenician traders were the first to stumble upon glass manufacturing techniques at the site of the Belus River. Georgius Agricola, in De re metallica, reported a traditional serendipitous "discovery" tale of familiar type: "The tradition is that a merchant ship laden with nitrum being moored at this place, the merchants were preparing their meal on the beach, and not having stones to prop up their pots, they used lumps of nitrum from the ship, which fused and mixed with the sands of the shore, and there flowed streams of a new translucent liquid, and thus was the origin of glass." This account is more a reflection of Roman experience of glass production, however, as white silica sand from this area was used in the production of Roman glass due to its low impurity levels. But in general archaeological evidence suggests that the first true glass was made in coastal north Syria, Mesopotamia or Old Kingdom Egypt. Due to Egypt's favourable environment for preservation, the majority of well-studied early glass is found in Egypt, although some of this is likely to have been imported. The earliest known glass objects, of the mid third millennium BC, were beads, perhaps initially created as accidental by-products of metal-working slags or during the production of faience, a pre-glass vitreous material made by a process similar to glazing. During the Late Bronze Age in Egypt and Western Asia there was an explosion in glassmaking technology. Archaeological finds from this period include coloured glass ingots, vessels (often coloured and shaped in imitation of highly prized wares of semi-precious stones) and the ubiquitous beads. The alkali of Syrian and Egyptian glass was soda ash, sodium carbonate, which can be extracted from the ashes of many plants, notably halophile seashore plants: (see saltwort). The earliest vessels were 'core-wound', produced by winding a ductile rope of metal round a shaped core of sand and clay over a metal rod, then fusing it with repeated reheatings. Threads of thin glass of different colours made with admixtures of oxides were subsequently wound around these to create patterns, which could be drawn into festoons by using metal raking tools. The vessel would then be rolled flat ('marvered') on a

slab in order to press the decorative threads into its body. Handles and feet were applied separately. The rod was subsequently allowed to cool as the glass slowly annealed and was eventually removed from the centre of the vessel, after which the core material was scraped out. Glass shapes for inlays were also often created in moulds. Much early glass production, however, relied on grinding techniques borrowed from stone working. This meant that the glass was ground and carved in a cold state. By the 15th century BC extensive glass production was occurring in Western Asia and Egypt. It is thought the techniques and recipes required for the initial fusing of glass from raw materials was a closely guarded technological secret reserved for the large palace industries of powerful states. Glass workers in other areas therefore relied on imports of pre-formed glass, often in the form of cast ingots such as those found on the Ulu Burun shipwreck off the coast of Turkey. Glass remained a luxury material, and the disasters that overtook Late Bronze Age civilisations seem to have brought glass-making to a halt. It picked up again in its former sites, in Syria and Cyprus, in the ninth century BC, when the techniques for making colourless glass were discovered. In Egypt glass-making did not revive until it was reintroduced in Ptolemaic Alexandria. Core-formed vessels and beads were still widely produced, but other techniques came to the fore with experimentation and technological advancements. During the Hellenistic period many new techniques of glass production were introduced and glass began to be used to make larger pieces, notably table wares. Techniques developed during this period include 'slumping' viscous (but not fully molten) glass over a mould in order to form a dish and 'millefiori' (meaning 'thousand flowers') technique, where canes of multi-coloured glass were sliced and the slices arranged together and fused in a mould to create a mosaic-like effect. It was also during this period that colourless or decoloured glass began to be prized and methods for achieving this effect were investigated more fully. During the first century BC glass blowing was discovered on the Syro-Palestinian coast, revolutionising the industry and laying the way for the explosion of glass production that occurred throughout the Roman world. Over the next 1000 years glass making and working continued and spread through southern Europe and beyond.

Types of ceramic materials For convenience ceramic products are usually divided into four sectors, and these are shown below with some examples:

Structural, including bricks, pipes, floor and roof tiles Refractory, such as kiln linings, gas fire radiant, steel and glass making crucibles White wares, including tableware, wall tiles, decorative art objects and sanitary ware

Examples of white ware ceramics

Bone china Earthenware, which is often made from clay, quartz and feldspar. Porcelain, which are often made from kaolin Stoneware

Other applications of ceramics

Ceramics are used in the manufacture of knives. The blade of the ceramic knife will stay sharp for much longer than that of a steel knife, although it is more brittle and can be snapped by dropping it on a hard surface. Ceramics such as alumina and boron carbide have been used in ballistic armored vests to repel large-caliber rifle fire. Such plates are known commonly as small-arms protective inserts (SAPI). Similar material is used to protect cockpits of some military airplanes, because of the low weight of the material. Ceramic balls can be used to replace steel in ball bearings. Their higher hardness means that they are much less susceptible to wear and can offer more than triple lifetimes. They also deform less under load meaning they have less contact with the bearing retainer walls and can roll faster. In very high speed applications, heat from friction during rolling can cause problems for metal bearings; problems which are reduced by the use of ceramics. Ceramics are also more chemically resistant and can be used in wet environments where steel bearings would rust. The major drawback to using ceramics is a significantly higher cost. In many cases their electrically insulating properties may also be valuable in bearings. In the early 1980s, Toyota researched production of an adiabatic ceramic engine which can run at a temperature of over 6000 F (3300 C). Ceramic engines do not require a cooling system and hence allow a major weight reduction and therefore greater fuel efficiency. Fuel efficiency of the engine is also higher at high temperature, as shown by Carnot's theorem. In a conventional metallic engine, much of the energy released from the fuel must be dissipated as waste heat in order to prevent a meltdown of the metallic parts. Despite all of these desirable properties,

such engines are not in production because the manufacturing of ceramic parts in the requisite precision and durability is difficult. Imperfection in the ceramic leads to cracks, which can lead to potentially dangerous equipment failure. Such engines are possible in laboratory settings, but mass-production is not feasible with current technology.

COMPOSITE MATERIALIntroductionAy material made from at least two discrete substances, such as concrete. Many materials are produced as composites, such as the fiberglass-reinforced plastics used for automobile bodies and boat hulls, but the term usually is used to describe any of various modern industrially manufactured composites, such as carbon fiberreinforced plastics. Composite materials allow a blending of properties of the separate components. Carbon fiberreinforced plastics combine the high strength and stiffness of the fiber with the low weight and resistance to fracture of the polymeric matrix. Glass, wood, and other kinds of fibers are also used, and the fibers may be layered or woven. Other modern composites include wood fiber or chunks in a concrete matrix and silicon carbide, a ceramic, in a titanium matrix.

Objectives

I. Describe the needs to produce new materials for specific purposes. II. State the meaning of composite materials. III. List examples of composite materials and their components. IV. Compare and contrast the properties of composite materials with those of their original components. V. Justify the use of composite materials. VI. Generate ideas to produce advanced materials to fulfill specific needs. VII. Describe the importance of synthetic materials in daily life. VIII. Justify the importance of doing research and development continuously. IX. Practice being responsible when handling synthetic materials and their wastes.

Informationi. The needs to produce new materials for specific purposes. Since the old days, human beings have been using clay, wood, stones or metals as building materials. These substances either corrode or decay easily. Otherwise, they are too heavy, bulky or difficult to be shaped or carved. Many of our modern technologies require materials with unusual combinations of properties that cannot be met by the conventional metal alloys, ceramics and polymeric materials. Therefore, continuous research and development have been done in search of new structural materials. Today, many of such materials are created and used for various fields. New materials are needed today to supply high demand for the new industries. To fulfil the needs, these building materials must have properties like: Low density Strong Resistance to heat and corrosion Last longer Easier and more convenient to use Able to withstand high pressure

ii.

Meaning of composite materials. A composite material is a structural material that is formed by combining two or more different substances such as metal, alloys, glass, ceramics and polymers. The different materials work together to give composite unique properties. The resulting material has properties that are superior than those of original components. Composite materials are created for specific application. Composite exist in nature. A piece of wood is a composite, with long fibres of cellulose (a very complex form of starch) held together by a much weaker substances called lignin. Cellulose is also found in cotton and linen, but it is the binding power of the lignin that make a piece of timber much stronger than bundle of cotton fibres.

iii.

Examples of composite materials and their components.

COMPOSITE MATERIALS Mixture of : Fibre glass Photochromic glass Cement Gravel Sand Water Iron

COMPONENTS

Reinforced concrete

Superconductor

Steel Yttrium oxide Barium carbonate Copper (II) oxide Silica Sodium carbonate Calcium oxide Glass fibre Polyester (a type of plastic) Glass Silver chloride or silver bromide

Fibre optic

iv.

Comparison the properties of composite materials and their original components.

ORIGINAL COMPONENTS

COMPOSITE MATERIALS

Low tensile strength

Concrete

Reinforced concrete

Very strong

Nonconductor electric

Yttrium oxide, Barium carbonate, Superconductor Copper (II) oxide

Very good conductor

Non transparent

Silica, Sodium carbonate, Calcium oxide

Fibre optic

Transparent

Transparent but not sensitive to the intensity of light rays Sensitive to the intensity of light rays

Glass Photochromic glass Silver chloride Transparent but sensitive to the intensity of light rays

v.

Uses of composite materials

COMPOSITE MATERIALSReinforced concrete

USESConstruction of large structures like o Highways o High-rise buildings o Bridges o Oil platforms o Airport runners o Dams o Transportation o Telecommunication o Astronomy o Industry o Medical fields o Used in medical field to observe internal organs (endoscope) o Transmit data, voice, images in a digital format o Water storage tanks o Badminton rackets o Small boats o Skis o Helmets o Used to make protective apparel for astronauts and firefighters. o To make optical lenses o Glass windows (windshields) of vehicles o Lens in camera o Information display panels o Optical switches o Light intensity meters

Superconductor

Fibre optic

Fibre glass

Photochromic glass

Bridge are is used to reinfrorced concrete

Magnetic resonance imaging, MRI in hospitals

A helmet that is made from fibre glass

A fibre optic cable

Lenses made from photochromic glass can protect our eyes from harmful ultaviolet rays

Advanced materials and the futureA lot of time and resources have to be invested through a series of research and tests to produce a new composite materials. This is essential to fulfil the ever expamdaing needs especially to help Malaysia to achieve a status of developed country in year 2020. With the abundant natural resources, dynamic workforce and advance infrastructure that we have, we are certain that Malaysia will produce outstanding materials of worlds standard. There are so many synthetic materials being produced and used in our daily lives. Synthetic materials may have improve our standard of living but at the same time, they may cause adverse effects on human beings and the environment. Therefore it is very important to do research and develepmont continuosly.

Importance of doing research and development continuously The phrase research and development (also R and D or, more often, R&D), according to the Organization for Economic Co-operation and Development, refers to "creative work undertaken on a systematic basis in order to increase the stock of knowledge, including knowledge of human, culture and society, and the use of this stock of knowledge to devise new applications R&D New product design and development is more than often a crucial factor in the survival of a company. In an industry that is fast changing, firms must continually revise their design and range of products. This is necessary due to continuous technology change and development as well as other competitors and the changing preference of customers. A system driven by marketing is one that puts the customer needs first, and only produces goods that are known to sell. Market research is carried out, which establishes what is needed. If the development is technology driven then it is a matter of selling what it is possible to make. The product range is developed so that production processes are as efficient as possible and the products are technically superior, hence possessing a natural advantage in the market place.

R&D has a special economic significance apart from its conventional association with scientific and technological development. R&D investment generally reflects a government's or organization's willingness to forgo current operations or profit to improve future performance or returns, and its abilities to conduct research and development. In 2006, the world's four largest spenders of R&D were the United States (US$343 billion), the EU (US$231 billion), Japan (US$130 billion), and China (US$115 billion). In terms of percentage of GDP, the order of these spenders for 2006 was China (US$115 billion of US$2,668 billion GDP), Japan, United States, EU with approximate percentages of 4.3, 3.2, 2.6, and 1.8 respectively. The top spenders in terms of percentage of GDP were China, Sweden, Finland, Japan, South Korea, Switzerland, Iceland, United States, followed by 9 other countries, and then the EU. In general, R&D activities are conducted by specialized units or centers belonging to companies, universities and state agencies. In the context of commerce, "research and development" normally refers to future-oriented, longer-term activities in science or technology, using similar techniques to scientific research without predetermined outcomes and with broad forecasts of commercial yield. Statistics on organizations devoted to "R&D" may express the state of an industry, the degree of competition or the lure of progress. Some common measures include: budgets, numbers of patents or on rates of peer-reviewed publications. Bank ratios are one of the best measures, because they are continuously maintained, public and reflect risk. In the U.S., a typical ratio of research and development for an industrial company is about 3.5% of revenues. A high technology company such as a computer manufacturer might spend 7%. Although Allergan (a biotech company) tops the spending table 43.4% investment, anything over 15% is remarkable and usually gains a reputation for being a high technology company. Companies in this category include pharmaceutical companies such as Merck & Co. (14.1%) or Novartis (15.1%), and engineering companies like Ericsson (24.9%). Such companies are often seen as poor credit risks because their spending ratios are so unusual. Generally such firms prosper only in markets whose customers have extreme needs, such as medicine, scientific instruments, safety-critical mechanisms (aircraft) or high technology military armaments. The extreme needs justify the high risk of failure and consequently high gross margins from 60% to 90% of revenues. That is, gross profits will be as much as 90% of the sales cost, with manufacturing costing only 10% of the product price, because so many individual projects yield no exploitable product. Most industrial companies get only 40% revenues. On a technical level, high tech organization explore ways to re-purpose and repackage advanced technologies as a way of amortizing the high overhead. They often reuse advanced manufacturing processes, expensive safety certifications, specialized embedded software, computer-aided design software, electronic designs and mechanical subsystems.

Pharmaceuticals Research often refers to basic experimental research; development refers to the exploitation of discoveries. Research involves the identification of possible chemical compounds or theoretical mechanisms. In the United States, universities are the main provider of research level products. In the United States, corporations buy licenses from universities or hire scientists directly when economically solid research level products emerge and the development phase of drug delivery is almost entirely managed by private enterprise. Development is concerned with proof of concept, safety testing, and determining ideal levels and delivery mechanisms. Development often occurs in phases that are defined by drug safety regulators in the country of interest. In the United States, the development phase can cost between $10 to $200 million and approximately one in ten compounds identified by basic research pass all development phases and reach market. Business Research and development is nowadays of great importance in business as the level of competition, production processes and methods are rapidly increasing. It is of especial importance in the field of Marketing where companies keep an eagle eye on competitors and customers in order to keep pace with modern trends and analyze the needs, demands and desires of their customers. R&D alliance An R&D alliance is a mutually beneficial formal relationship formed between two or more parties to pursue a set of agreed upon goals while remaining independent organizations, where acquiring new knowledge is a goal by itself. The different parties agree to combine their knowledge to create new innovative products.

Importance of synthetic materials in daily lifeMaterials science plays a pivotal role in determining and improving economic performance and the quality of life, particularly in the following areas: Living Environment: Because of pressing environmental concerns more efficient use of material and energy resources is urgently required. Materials science is helping to develop new energy generation technologies, more energy efficient devices, and easily recyclable, less toxic materials. Health: Overcoming disease and providing worldwide medical care are high priorities. Materials science, in conjunction with biotechnology, can meet this challenge by, e.g., developing artificial bones and organ implants, safe drug delivery systems, water filtration systems, etc. Communication: The increasing interconnectedness of our world requires faster and more reliable means of communication. The information and associated computer revolutions closely depend on advances made by scientists working on new electronic, optical, and magnetic materials.

Consumer Goods: Consumers have come to expect global products/services that are delivered rapidly at reasonable prices. Materials science can improve not only the products but also the way they are handled (e.g., packaging), resulting in faster production and delivery times and higher quality goods. Transport: Whether for business, holidays, or space exploration, materials science is needed to provide durable, high-performance materials that make traveling faster, safer, and more comfortable. Examples are the development of light-weight aluminium bodies for automobiles, brake systems for high-speed trains, quieter aircrafts, and insulation tiles for reentry spacecrafts.

Handling synthetic materials and their wastes Recycling

Recycling involves processing used materials into new products in order to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usage, reduce air pollution (from incineration) and water pollution (from landfilling) by reduc