INTRODUCTION

PREPARATION and FUSION are the two main methods

employed by various research workers to synthesize numerous

surfactants, particularly metal carboxylates. The former method involves

the reaction of a soluble salt of the metal with the solution of alkali soap

in water while the latter generally involves either, (i) a neutralization

reaction between the oxide or hydroxide of a metal with a fused fatty

acid, or alternatively (ii) a metathetic displacement reaction in which the

carbonate or some other salt of the metal (with volatile acids) such as

acetate, is treated with fatty acids in the fused state. The main advantage

of the last method is the possibility of getting directly anhydrous samples

of metal carboxylates, since attempts to remove the water of hydration

from soaps isolated from an aqueous medium often yield hydrolysed

products. Metal carboxylates have been prepared in the laboratory by the

reaction of aqueous or alcoholic solutions of various metal salts with

stoichiometric amounts of sodium, potassium, or ammonium soaps which

may be represented as,

XnMRMMnRMX nn ')CO('—CO 22 ; where ‗M’ represents Na, K,

NH4+

, and X denotes Cl, NO3, SO4 etc. When a solution of an appropriate

soluble metallic salt is treated with a solution of ammonium or alkali

metal soap, metathesis occurs and the (hydrated) insoluble metallic soap

is generally precipitated while a soluble alkali (ammonium) salt is

formed. Using this technique (1), carboxylates of a large number of

metals (1-5), eg. Cr (III) (2), Fe (II) (3), Zn (II), Cu (II), Mg (II) (4), La

(III), Ce (III) (5) etc. have been prepared. The metal soaps obtained by

this method in an aqueous medium are generally hydrated compounds.

Therefore, dehydration of hydrated compounds becomes an essential step.

21

Another method for preparation of such compounds involves reaction of

metal derivatives with fused carboxylic acids (fusion method). These

reactions are straight forward and the side-product(s) (water and carbon

dioxide) may easily be driven off, leaving the soaps in a pure state (1, 6).

A reaction of metal derivatives with carboxylic acids in organic solvents

is a useful method for the preparation of organometallic carboxylates in

particular which are strongly hydrolysed in aqueous medium. In this

method, the reactants are generally mixed together in the presence of

organic solvents and the reaction mixtures are refluxed to push the

reaction to completion. A large number of metal carboxylates of Cr and

Mo (7, 8), Mn, Co, Ni, Cu, Zn (9), Fe (10, 11), have been prepared by

treating the halides (generally the chlorides) with carboxylic acids or their

alkali metals, silver or thallium salts.

Infrared studies provide the preliminary information

concerning the structure of substances. The first reported collection of

valuable infrared spectra pertaining to surfactants was made by

Delsemme (12). The use of infrared spectra for identifying surfactants

was published by sadtler (13). The infrared spectra of Mg soaps (14) of

lower fatty acids show no peak in between 3650-3590 cm–1

which

confirm that these soaps are free from water of crystallisation. The

present chapter though deals with the preparation and analysis of alkaline

(Mg, Ca, Sr, Ba) earth metal stearates.

22

EXPERIMENTAL

Preparation of Compounds

GR grade magnesium, calcium, strontium and barium carbonates

were used. Stearic acid obtained from Sigma chemical Co. U.S.A. , of

stated high purity, was used as received. The conductivity water used for

experimental work was prepared by redistilling good quality distilled

water over alkaline KMnO4.

Alkaline earth metal stearates were prepared by direct metathesis.

The aqueous solution containing stoichiometric amount of respective

metal carbonate and potassium stearate were mixed at about 80°C under

constant stirring. As evolution of CO2 ceased and metathetic

displacement reaction completed (phenolphthalein indicator rendered

colourless from pink), the desired compound was separated from mother

liquor by vacuum filtration. The product washed several times with

benzene and then oven dried. All the compounds so prepared were further

purified by recrystallisation from 50% methanol + 50% chloroform

solvent-mixture. The pure and well dried compounds were then stored

over calcium chloride. The recrystallized pure compounds are found to

decompose between 190-205°C. The synthesis and purity of the

compounds were confirmed by CHNS (elemental) as recorded in table 1

(a), 1 (b) and IR techniques.

23

INFRARED SPECTRA OF ALKALINE EARTH METAL

STEARATES

Method: Infrared spectra were obtained with KBr and CsI pellets.

The spectra were also recorded with Nujol and Fluorolube mulls; these

spectra showed practically no differences from the pellet spectra. All

infrared spectra were recorded on a BOMEM DA3-02 Fourier transform

infrared spectrometer, equipped with a high-speed vector processor, and

a PDP 11-03 computer for data processing. A germanium coated KBr

beam splitter and a high sensitivity, liquid nitrogen cooled mercury

cadmium telluride detector were used for the 3500-500 cm–1

region.

RESULTS AND DISCUSSION

Since infrared spectra contain large number of bands, the

possibility that two different compounds will have the same IR spectrum

is exceedingly small. For this reason an infrared spectrum is called the

finger print of a molecule. Thus, if two pure samples give different

infrared spectra, the compounds must be different. If they give the

superimposable spectra then they represent the same compound. The

region from (4000-1500 cm–1

) (high frequency part) to the left in an

infrared spectrum is useful for the identification of functional groups.

This region shows absorption arising from stretching modes. The region

to the right of 1500 cm–1

(1500-500 cm–1

) is usually complex since both

stretching and bending modes give rise to absorption here. In this region

correlation of an individual band with a specific functional group is often

difficult. Even for organometallic compounds, the infrared region (4000-

24

500 cm–1

) is of prime importance. Table 2 however shows a clear-cut

comparison of IR spectra for potassium stearate and alkaline earth metal

stearates.

As no crystal structure information is available on alkali and

alkaline earth metal stearates, one has to make use of correlations which

have been established with known crystal structures of related

compounds. Thus it can be seen that the infrared spectra Fig. (1-5) of

these compounds when compared with IR wave numbers of n-

hexadecanol show clear splitting of the CH2 scissoring (1468-1465 cm–1

)

and the CH2 rocking modes (724-665 cm–1

). These spectra resemble with

those of n-alkanes (15-18).

The absorption maxima observed near 2660,1740,940,690,550,

and 430 nm in the spectrum of stearic acid are associated with the

carboxyl group of the acid molecule in the dimeric form and confirm the

existence of hydrogen bonding between the two molecules of stearic acid.

Dimeric form of stearic acid

The appearance of two absorption bands of carboxyl group

corresponding to the symmetric and asymmetric vibrations of carboxylate

ion near 1567-1558 cm–1

and 1723-1613 cm–1

respectively, in the spectra

of alkali and alkaline earth metal stearates indicate that there is a

25

complete resonance in the C-O bonds of carboxyl group of the soap

molecules. It is, therefore, concluded that the resonance character of the

ionized carboxyl group is retained in the metal soaps.

(Resonance hybrid structure of carboxylate ion)

The progressive bands with medium sharp intensity observed in the

region 1247-1213 cm–1

are assigned to the wagging and twisting

vibrations of the chains of successive methylene group of the molecule of

the soap. The absorption bands of C-H stretching vibrations, viz, the

symmetrical and asymmetrical vibrations of CH2 at 2850 and 1467 cm–1

,

respectively, are observed. C-H stretching asymmetrical vibrations and

rocking modes in CH3 in the vicinity of the regions 2956 and 1189 cm–1

,

respectively, are observed in the spectra of these metal soaps.

The spectra of metal soaps show a medium sharp peak in the

region 579-518 cm–1

for M-O stretching. The IR spectra of alkaline earth

metal stearates show prominent peaks between 3453-3418 cm–1

due to –OH stretching indicating the presence of water of crystallisation.

However, no such peaks are observed in case of alkali metal soaps. These

results correspond very well with thermodynamic analysis of the stated

metal soaps.

26

X-RAY DIFFRACTION OF ALKALINE EARTH METAL

STEARATES

INTRODUCTION

The physicochemical characteristics of alkaline earth metal

(Ba, Sr, Ca, and Mg) stearates and potassium stearate were carried out

just after their synthesis in pure dry form. IR, TGA have already been

discussed in earlier chapters of the thesis. The compounds under study

have also been examined and characterized through X-ray diffraction

(XRD) and FE-SEM methods of pure anhydrous form. While X-ray study

reveals that these compounds possess a single layer structure, FE-SEM

technique proves handy to establish both the presence of elements in

these compounds and their microstructures.

A survey of literature 19-24

on metal soaps revealed the

significance of physicochemical characterization and also the fact that

alkaline earth metal stearates have not been thoroughly investigated in

spite of their numerous applications in various industries. This prompted

us to undertake an integrated study on these compounds in solid state as

well as in solution. The IR, TGA and particularly XRD of the solid

samples were thus carried out in order to obtain structural information.

EXPERIMENTAL

The X-ray diffraction patterns for alkaline earth metal stearates were

recorded using an X-ray Diffractometer (Bruker, AXS, D8 Advance,

Germany) using CuKα radiation with 2 theta in the range of 5° to 80°.

The XRD curves were recorded under the applied voltage of 10 to 100

27

kV, using scanning speed of 1° min-1

. The wavelength of radiation was

taken as 1.542 Å.

RESULTS AND DISCUSSION

Generally, the crystals of metal soaps do not grow to give

large crystals sufficient for a detailed single crystal examination so that

X-ray diffraction patterns of alkaline earth metal stearates were

investigated to characterize the structure of these soaps.

The intensities of diffracted X-rays (I %) as a function of

diffraction angle (2 theta), full width at half maximum (FWHM) and d

values (Bragg‘s equation) are given in tables 1 to 5. The data were

recorded with help of spectrophotometer. Recorded curves for these

compounds were reproduced over the range of 5° to 80° (Figs 6 a-e). A

large number peaks, arising from the diffraction of X-rays by planes of

metal ions (known as basal planes) were observed over the range of 5° to

80° of the diffraction angle in the diffraction patterns of alkaline earth

metal soaps under study. The appearance of the diffraction upto 13th order

for stearates of alkaline earth metal confirms good crystallinity for these

compounds. The interplanar spacings calculated for 5th, 6

th, 7

th, 8

th, 9

th,

11th, 13

th, 20

th and 23

rd order of diffractions for alkaline earth metal

stearates are 45.620, 46.212, 46.242, 46.616, 46.944, 47.221, 47.056,

46.640 and 46.621Å respectively and average planar distance is 46.575

Å. The results are in agreement with the calculated values of long

spacings for stearates (52.0 Å) ions.

The values of the long spacings for these soaps are

approximately equal to double the length of the fatty acid radical of the

28

soap molecule. It is therefore suggested that the zig-zag chains of the

fatty acid radicals extend straight forward on both sides of each basal

planes.

The observed values of the long spacings for stearates

(46.575 Å) for alkaline earth metal soaps is smaller than the calculated

dimensions of stearates (52.0 Å) ions from Pauling‘s values of atomic

radii and bond angles and this suggest that the molecular axis of these

soaps are somewhat inclined to the basal planes. The metal ions fit into

spaces between O2 atoms of the ionized carboxylic groups without

putting great strain on the bonds. The values of the long spacings for

alkaline earth metal stearates show that the angle of inclination of

molecular axes of soap to the basal plane increases slightly with

decreasing number of carbon atoms in the fatty acid radical constituent of

the soap molecule.

A number of diffraction peaks in the intermediate range of

the diffraction angles were also observed in the diffraction patterns of

stearates soaps, these being attributed to the diffraction of X-rays by

planes of atoms of much smaller separation than the basal planes.

The calculated spacings from these peaks correspond to the

shorter side spacings i.e. the lateral distances between one soap molecule

and the next in a layer.

It is observed that the long spacing peaks are fairly intense

while the short spacing peaks are relatively weaker. On the basis of long

and short spacings, it is suggested that the metal ion in these compounds

are arranged in a parallel plane i.e. a basal plane equally spaced in the

soap crystal with fully extended zig-zag chains of fatty acid radicals on

both sides of each basal plane and these soaps have a double layer

structure as proposed by Vold and Hattiangdi [25].

29

TOPOGRAPHICAL STUDY OF ALKALINE EARTH

METAL STEARATES BY FIELD EMISSION SCANNING

ELECTRON MICROSCOPE (FE SEM) AND EDAX

ANALYSIS

INTRODUCTION

Field emission scanning electron microscope (FE-SEM) gives

information about the morphology and topographic examination. EDX

Analysis stands for Energy Dispersive X-ray analysis. It is also referred

to as EDS or EDAX analysis. It is a technique used for identifying the

elemental composition of the specimen. With Energy Dispersive X-ray, it

enables us to get information about surface composition (C, O, ions etc).

The EDX analysis system works as an integrated feature of a scanning

electron microscope (SEM), and can not operate on its own without the

latter.

EXPERIMENTAL

The alkaline earth metal (Mg, Ca, Sr and Ba) stearates and

potassium stearates were coated with gold / palladium to render them

conductive. The surface morphology of these compounds was evaluated

by Field Emission Scanning Electron Microscope (FESEM-QUANTA

200 F, FEI Netherlands). The micro analyses were carried out by an

Energy Dispersive X-ray spectroscopy (EDAX) attached to FESEM.

30

RESULTS AND DISCUSSION

FE-SEM micrographs are found to show the general features

of the alkaline earth metal stearates and potassium stearate. SEM

observation revealed that the potassium stearate has rough and irregular

textured surface (Fig.7a) whereas Fig. 7b shows the elemental

composition by weight percentage. The particles of magnesium stearate

are of smooth and spongy appearance (Fig.8 a). Magnesium stearate is a

very fine, light impalpable powder of low bulk density, having a faint

odor of stearic acid and a characteristic taste. The powder is greasy to the

touch and readily adheres to the skin. Elemental composition can be seen

in Fig 8 b.

It seems that calcium stearate has rod like, smoother, more

homogenous microstructures and lamellar morphology (Fig.9a). The

angular, irregular and fractured particles can be seen in strontium stearate

(Fig.10a). As it can be seen in the figure 11a, the barium stearate particles

are compact and irregular in shape and having varying particle size.

31

Table 1(a): Theoretical data of percentage content for elements (C, H, N, and S).

Sr. No. Name of Compounds Content Percentage

Carbon Hydrogen

1 Mg-Stearate 6.09 11.85

2 Ca-Stearate 5.93 11.54

3 Sr-Stearate 5.50 10.7

4 Ba-Stearate 5.11 9.94

32

Table (b): Experimental (Practical) data of percentage content for C,H,N,S elements

Sr.

No.

Name of

Compunds

Weight

[mg] Date/Day Time info 2

C/N

Ratio

Content

[%]

Peak

Area

Blank

Value

Daily

Factor

1 Mg-Stearate 3.0023 05.01.09/Mon 15.09

Hu

1

0.000N: 0.000 2537 27830 1.1402

C 6.000 23940 45 1.0338

S 0.000 2794 170 1.0970

H 11.320 6862 165 2.0016

2 Ca-Stearate 2.8234 05.01.09/Mon 15.15 1

0.000N: 0.000 25737 27830 1.1402

C 5.10 23940 45 1.0338

S 0.000 2794 170 1.0970

H 11.00 6862 165 2.0016

3 Sr-Stearate 2.6894 05.01.09/Mon 15.21 1

0.000N: 0.000 25737 27830 1.1402

C 5.00 23940 45 1.0338

S 0.000 2794 170 1.0970

H 9.65 6862 160 2.0016

4 Ba-Stearate 2.8912 05.01.09/Mon 15.28 1

0.00N: 0.000 25737 27830 1.1402

C 4.95 23940 45 1.0338

S 0.000 2794 170 1.0970

H 9.22 6862 165 2.0016

33

Table2: Assignment of frequencies (cm-1

) in the infrared spectra of alkaline earth metal stearates.

Compund

s

COO-

rock

M-O

str.

(CH2)

rock

C-C

and C-

O str.

C-C

str.

(CH3)

rock

CH2

twist

and

wag

Sym.

C-C

str.

C-H

defin

CH3

Sym.

C-H def.

in

CH2 asy.

COO-

C-O asy

str.

COO-

C-O

asy str.

C-H

str.

Sym.

In CH2

C-H

str.

Asy in

CH2

C-H

str.

Asy in

CH3

OH

str.

K-

Stearate

492.66

(MW)

529.71

(W)

719.85

(VS)

913.69

(MW)

1092.79

(S)

1189.81

(S)

1236.57

(S) -

1408.19

(S)

1469.20

(VS)

1560.43

(VS)

1683.80

(MS)

2849.28

(VS)

2917.30

(MS) - -

Mg-

Stearate

497.55

(VW)

518.50

(W)

722.40

(S)

918.12

(VW)

992.70

(S)

- - - 1214.05

(B) - -

1575.23

(S) -

2850.13

(S)

2918.45

(VS)

2956.28

(S)

3453.01

(VB)

Ca-

Stearate

497.40

(VW)

528.97

(W)

718.39

(S)

914.57

(MW)

1091.74

(VW)

1189.65

(W)

1238.18

(S) -

1420.10

(MS)

1470.28

(S) -

1638.14

(MB)

2850.34

(VS)

2917.92

(MS)

2956.52

(S)

3418.06

(VB)

Sr-

Stearate -

579.80

(MB)

722.05

(S)

907.26

(W)

1093.56

(W)

1189.69

(MS) -

1213.27

(MW)

1406.01

(MS) 1468.76

(VS)

1561.03

(S)

1643.91

(MS)

2849.13

(VS)

2917.97

(S)

2956.47

(S)

3427.71

(VB)

Ba-

Stearate -

534.85

(W)

722.75

(MS)

906.11

(W)

1213.04

(VW) -

1236.25

(S) -

1406.02

(MS)

1467.44

(S)

1556.41

(W)

1644.48

(MS)

2848.72

(VS)

2918.42

(S) -

3436.07

(VB)

S- Sharp

MS- Medium Sharp

VS- Very Sharp

B-Broad

MB-Medium

Broad

VB- Very Broad

W- Weak

WB- Weak Broad

VW- Very Weak

34

Table 3: XRD of Potassium Stearate

Peak Search Report (55 Peaks, Max P/N = 32.2)

2-Theta d(A) Height I% FWHM

5.517 16.0067 2912 66.5 0.170

6.578 13.4255 4382 100.0 0.264

7.358 12.0037 204 4.7 0.127

8.743 10.1058 471 10.7 0.360

9.199 9.6056 1044 23.8 0.251

10.961 8.0649 1043 23.8 0.265

12.542 7.0517 63 1.4 0.549

12.880 6.8675 284 6.5 0.314

15.399 5.7493 50 1.1 0.420

15.723 5.6314 72 1.6 0.326

16.019 5.5281 34 0.8 0.625

16.735 5.2932 68 1.6 0.254

17.578 5.0412 72 1.6 0.242

18.740 4.7313 990 22.6 0.293

20.059 4.4230 541 12.3 0.489

20.500 4.3288 771 17.6 0.360

21.496 4.1303 115 2.6 0.204

22.240 3.9939 385 8.8 0.270

22.883 3.8831 467 10.7 0.650

23.301 3.8144 687 15.7 0.409

24.455 3.6369 168 3.8 0.387

24.796 3.5876 100 2.3 0.234

25.940 3.4320 571 13.0 0.385

26.558 3.3536 181 4.1 0.371

28.111 3.1717 44 1.0 0.290

28.338 3.1468 65 1.5 0.196

28.782 3.0992 141 3.2 0.671

28.918 3.0850 178 4.1 0.560

29.400 3.0355 144 3.3 0.439

30.940 2.8878 97 2.2 0.410

31.238 2.8610 170 3.9 0.363

33.207 2.6956 69 1.6 0.716

33.500 2.6728 126 2.9 0.466

33.921 2.6406 87 2.0 0.850

35.780 2.5075 162 3.7 0.376

35.996 2.4929 82 1.9 0.997

37.708 2.3836 43 1.0 0.404

35

38.058 2.3625 132 3.0 0.494

38.159 2.3565 120 2.7 0.543

38.493 2.3368 52 1.2 0.620

39.985 2.2530 63 1.4 0.217

40.323 2.2349 140 3.2 0.473

40.540 2.2234 145 3.3 0.506

41.560 2.1712 130 3.0 0.321

42.464 2.1270 48 1.1 0.269

42.685 2.1165 54 1.2 0.238

43.901 2.0606 30 0.7 0.620

44.983 2.0136 67 1.5 0.456

45.356 1.9978 103 2.4 0.506

47.696 1.9052 54 1.2 0.284

47.920 1.8968 46 1.0 0.322

53.666 1.7065 40 0.9 0.308

56.321 1.6321 18 0.4 0.659

56.517 1.6270 28 0.6 0.437

58.564 1.5749 24 0.5 0.683

36

Table 4: XRD of Magnesium Stearate

Peak Search Report (33 Peaks, Max P/N = 45.3)

2-Theta d(A) Height I% FWHM

5.280 16.7228 6139 71.9 0.482

5.560 15.8813 8540 100.0 0.202

7.438 11.8750 603 7.1 0.274

8.820 10.0177 831 9.7 0.382

9.281 9.5207 1838 21.5 0.292

10.601 8.3385 488 5.7 0.380

12.284 7.1992 177 2.1 0.244

13.060 6.7732 151 1.8 0.246

14.060 6.2939 586 6.9 0.331

15.463 5.7258 115 1.3 0.495

15.796 5.6056 298 3.5 0.294

17.622 5.0288 285 3.3 0.340

19.341 4.5854 1100 12.9 0.387

21.220 4.1834 286 3.3 0.521

21.740 4.0846 971 11.4 0.373

23.359 3.8050 1607 18.8 0.372

24.982 3.5614 120 1.4 0.334

25.256 3.5234 133 1.6 0.303

26.641 3.3433 81 0.9 0.445

28.858 3.0913 77 0.9 0.554

30.040 2.9722 91 1.1 0.379

34.178 2.6212 85 1.0 0.394

34.178 2.6212 85 1.0 0.394

36.800 2.4403 67 0.8 0.736

37.020 2.4263 120 1.4 0.689

38.882 2.3143 223 2.6 0.350

40.683 2.2159 118 1.4 0.499

41.118 2.1934 281 3.3 0.486

42.184 2.1405 83 1.0 0.526

42.341 2.1329 107 1.3 0.411

42.480 2.1263 118 1.4 0.370

42.742 2.1138 50 0.6 0.876

48.160 1.8879 64 0.7 0.583

37

Table 5: XRD of Calcium Stearate

Peak Search Report (68 Peaks, Max P/N = 17.7)

2-Theta d(A) Height I% FWHM

5.557 15.8895 1662 100.0 0.234

6.300 14.0186 442 26.6 0.551

6.580 13.4211 452 27.2 0.539

7.402 11.9338 120 7.2 0.193

9.240 9.5631 474 28.5 0.368

10.279 8.5985 42 2.5 0.580

10.479 8.4349 75 4.5 0.437

10.824 8.1666 112 6.7 0.440

11.039 8.0082 113 6.8 0.271

12.702 6.9634 55 3.3 0.340

12.957 6.8267 113 6.8 0.383

15.587 5.6805 29 1.7 0.353

16.062 5.5134 36 2.2 0.183

18.799 4.7164 332 20.0 0.269

20.062 4.4224 413 24.8 0.682

20.480 4.3330 436 26.2 0.637

21.307 4.1666 54 3.2 0.380

21.562 4.1179 139 8.4 0.441

22.084 4.0218 109 6.6 0.379

22.260 3.9903 102 6.1 0.225

22.806 3.8960 156 9.4 0.849

22.960 3.8703 222 13.4 0.594

23.400 3.7985 289 17.4 0.470

24.231 3.6701 35 2.1 0.303

24.476 3.6339 37 2.2 0.282

26.139 3.4064 428 25.8 0.387

26.562 3.3530 75 4.5 0.774

27.138 3.2832 164 9.9 0.235

29.321 3.0435 323 19.4 0.257

31.378 2.8485 39 2.3 0.255

33.022 2.7103 143 8.6 0.297

33.945 2.6388 26 1.6 0.167

35.943 2.4965 169 10.2 0.258

36.170 2.4813 90 5.4 0.353

37.817 2.3770 139 8.4 0.310

38.380 2.3434 118 7.1 0.360

38.926 2.3118 25 1.5 0.209

38

39.847 2.2604 34 2.0 0.257

40.469 2.2271 27 1.6 0.320

40.702 2.2149 37 2.2 0.388

40.983 2.2004 36 2.2 0.432

41.176 2.1905 42 2.5 0.367

41.580 2.1702 44 2.6 0.345

42.546 2.1231 33 2.0 0.494

42.781 2.1120 72 4.3 0.353

43.058 2.0990 63 3.8 0.390

45.258 2.0020 28 1.7 0.426

45.817 1.9788 185 11.1 0.348

47.386 1.9169 83 5.0 0.143

48.399 1.8791 152 9.1 0.305

50.119 1.8186 75 4.5 0.242

52.300 1.7478 66 4.0 0.492

52.912 1.7290 55 3.3 0.259

53.034 1.7253 49 2.9 0.286

58.878 1.5672 20 1.2 0.507

59.127 1.5612 35 2.1 0.286

59.276 1.5576 25 1.5 0.410

60.237 1.5351 27 1.6 0.228

60.605 1.5266 27 1.6 0.225

60.894 1.5201 22 1.3 0.267

63.066 1.4728 33 2.0 0.322

69.039 1.3593 20 1.2 0.200

70.851 1.3289 21 1.3 0.329

72.448 1.3035 21 1.3 0.373

73.068 1.2939 23 1.4 0.272

73.250 1.2912 16 1.0 0.388

76.939 1.2382 30 1.8 0.260

79.238 1.2079 26 1.6 0.207

39

Table 6: XRD of Strontiun Stearate

Peak Search Report (64 Peaks, Max P/N = 25.3)

2-Theta d(A) Height I% FWHM

5.520 15.9954 2962 100.0 0.203

6.151 14.3562 83 2.8 0.385

6.582 13.4188 725 24.5 0.188

7.361 11.9997 288 9.7 0.189

8.863 9.9695 270 9.1 0.517

9.218 9. 5856 1015 34.3 0.319

10.313 8.5707 31 1.0 0.554

11.001 8.0362 276 9.3 0.274

12.899 6.8573 284 9.6 0.346

16.089 5.5043 30 1.0 0.375

18.200 4.8704 41 1.4 0.334

18.761 4.7258 215 7.3 0.250

20.259 4.3797 198 6.7 0.532

20.681 4.2914 227 7.7 0.608

22.478 3.9521 132 4.5 0.268

25.080 3.5477 1956 66.0 0.373

25.641 3.4713 803 27.1 0.395

29.037 3.0726 95 3.2 0.499

29.342 3.0414 160 5.4 0.549

29.483 3.0272 281 9.5 0.350

31.359 2.8502 264 8.9 0.388

34.359 2.6079 89 3.0 0.137

35.062 2.5572 176 5.9 0.249

36.063 2.4885 576 19.4 0.628

36.440 2.4636 596 20.1 0.598

37.636 2.3880 38 1.3 0.262

38.247 2.3512 47 1.6 0.295

39.539 2.2773 66 2.2 0.250

40.660 2.2171 68 2.3 0.430

41.221 2.1882 205 6.9 0.494

41.376 2.1804 172 5.8 0.524

44.001 2.0562 694 23.4 0.320

45.520 1.9911 240 8.1 0.339

46.559 1.9490 179 6.0 0.256

47.640 1.9073 365 12.3 0.353

49.840 1.8281 372 12.6 0.465

50.179 1.8166 212 7.2 0.464

40

50.474 1.8066 57 1.9 0.359

51.324 1.7787 56 1.9 0.330

51.580 1.7705 80 2.7 0.239

51.814 1.7630 33 1.1 0.579

52.942 1.7281 31 1.0 0.443

53.317 1.7168 29 1.0 0.543

54.900 1.6710 44 1.5 0.230

55.095 1.6655 39 1.3 0.265

57.219 1.6086 101 3.4 0.516

57.339 1.6056 86 2.9 0.560

58.818 1.5687 80 2.7 0.287

59.739 1.5467 70 2.4 0.236

62.500 1.4848 51 1.7 0.371

62.683 1.4809 55 1.9 0.347

63.277 1.4684 15 0.5 0.703

63.801 1.4576 101 3.4 0.338

65.165 1.4304 47 1.6 0.620

65.381 1.4262 90 3.0 0.457

65.980 1.4147 29 1.0 0.475

71.919 1.3118 91 3.1 0.170

73.387 1.2891 69 2.3 0.586

73.735 1.2839 95 3.2 0.457

73.841 1.2823 67 2.3 0.645

74.099 1.2785 45 1.5 0.470

74.986 1.2655 60 2.0 0.190

77.458 1.2312 64 2.2 0.372

77.758 1.2272 65 2.2 0.488

41

Table 7: XRD of Barium Stearate

Peak Search Report (59 Peaks, Max P/N = 23.2)

2-Theta d(A) Height I% FWHM

5.523 15.9893 1271 55.6 0.183

6.582 13.4172 101 4.4 0.139

7.343 12.0289 102 20.9 0.246

9.677 9.1326 28 1.2 0.262

10.865 8.1363 40 1.7 0.284

11.058 7.9949 38 1.7 0.243

12.540 7.0529 45 2.0 0.233

12.864 6.8760 119 5.2 0.224

19.439 4.5626 220 9.6 0.165

19.902 4.4575 92 4.0 0.445

20.201 4.3922 60 2.6 0.836

20.582 4.3117 191 8.4 0.416

22.334 3.9774 79 3.5 0.309

23.041 3.8569 58 2.5 0.264

23.881 3.7230 2287 100.0 0.276

24.280 3.6628 1093 47.8 0.289

25.668 3.4677 26 1.1 0.260

25.939 3.4321 30 1.3 0.364

27.682 3.2198 278 12.2 0.206

29.480 3.0274 131 5.7 0.226

32.464 2.7556 55 2.4 0.196

33.703 2.6572 375 16.4 0.260

34.080 2.6286 499 21.8 0.412

34.562 2.5931 686 30.0 0.352

39.460 2.2817 198 8.7 0.217

40.500 2.2255 76 3.3 0.204

41.980 2.1504 748 32.7 0.213

42.940 2.1045 322 14.1 0.219

44.161 2.0491 250 10.9 0.254

44.842 2.0196 517 22.6 0.265

46.722 1.9426 365 16.0 0.363

48.884 1.8616 88 3.8 0.212

49.743 1.8315 49 2.1 0.231

52.679 1.7361 53 2.3 0.181

53.697 1.7055 37 1.6 0.219

54.307 1.6878 34 1.5 0.241

54.663 1.6777 161 7.0 0.262

42

55.622 1.6510 136 5.9 0.329

56.300 1.6327 161 7.0 0.268

59.137 1.5610 72 3.1 0.265

60.531 1.5283 60 2.6 0.199

60.839 1.5213 112 4.9 0.499

61.401 1.5087 45 2.0 0.393

62.099 1.4934 29 1.3 0.284

62.520 1.4844 49 2.1 0.348

68.101 1.3757 147 6.4 0.496

68.542 1.3679 97 4.2 0.608

69.621 1.3493 103 4.5 0.265

70.457 1.3354 57 2.5 0.375

70.959 1.3271 109 4.8 0.367

72.940 1.2959 69 3.0 0.315

76.143 1.2491 40 1.7 0.300

76.308 1.2469 44 1.9 0.269

76.805 1.2400 37 1.6 1.138

76.968 1.2378 51 2.2 0.494

77.318 1.2331 61 2.7 0.556

77.561 1.2298 41 1.8 0.456

78.740 1.2143 40 1.7 0.272

43

Fig 1: Infrared spectrum of K- stearate

44

Fig 2: Infrared spectrum of Mg- stearate

45

Fig 3: Infrared spectrum of Ca- stearate

46

Fig 4: Infrared spectrum of Sr- stearate

47

Fig 5: Infrared spectrum of Ba- stearate

48

(b)

(a)

(c)

49

Fig.6 XRD profiles of (a) potassium stearate (b) magnesium stearate

(c) calcium stearate (d) strontium stearate (e) barium stearate

(e)

(d)

50

KV 20.0 MAG 3000 TILT 0.0 MICRONSPERPIXY 0.083

(a) (b)

KV 20.0 MAG 3000 TILT 0.0 MICRONSPERPIXY 0.083

(a) (b)

Fig.8

Fig.7

(a) (b)

KV 20.0 MAG 3000 TILT 0.0 MICRONSPERPIXY 0.083

Fig.9

51

Fig.7 (a) FE SEM image (b) EDAX of potassium stearate

Fig.8 (a) FE SEM image (b) EDAX of magnesium stearate

Fig.9 (a) FE SEM image (b) EDAX of calcium stearate

Fig.10 (a) FE SEM image (b) EDAX of strontium stearate

Fig.11 (a) FE SEM image (b) EDAX of barium stearate

KV 20.0 MAG 3000 TILT 0.0 MICRONSPERPIXY 0.083

Fig.10

Fig.11

(a) (b)

KV 20.0 MAG 3000 TILT 0.0 MICRONSPERPIXY 0.083

(a) (b)

52

REFERENCES

1. S.B. Elliott, "The Alkaline Earth and Heavy Metal Soaps".

Reinhold, New York (1946).

2. M.R. Hatfield, Inorg. Synth., 3, 148 (1950).

3. T. Golgotiv, I. Rosca and V.Petracovschi, Bul. Inst. Politch. Iasi,

18, 21 (1972); chem. Abstr. 79, 86925w (1973).

4. T. Hokoma, U.S. Patent, 3, 910, 974 (1975); chem. Abstr., 84,

73912t (1976).

5. S.N. Misra, T.N. Misra and R.C. Mehrotra, J. Inorg. Nucl. Chem.,

25, 195 (1963).

6. R. Hara and G.H. Cady, J. Am. Chem. Soc., 76, 4285 (1954).

7. A. Suszer, Rev. Chim (Bucharest). 9, 262 (1959); Chem. Abstr.,

54, 5320g (1960).

8. G. Doyle, J. Organometal. Chem., 84, 323 (1975).

9. M. J. Baillie, D.H. Brown, K.C. Moss and D.W.A. Sharp, J.

Chem. Soc. (A), 3110 (1968) and references therein.

10. A. Earnshaw, B.N. Figgis and J. Lewis, J. Chem. Soc. (A), 1656

(1966).

11. R. Young and G. Wilkinson, Inorg. Synth., 17, 79 (1974).

12. A.H. Delsemme, Mendedeel Vlaam. Chem. Ver., 13(4), 152

(1951).

13. P. Sadtler, Am. Soc. Testing Materials Bull, 190, 55 (1953).

14. R.P. Varma and K. Kumar, J. Indian Chem. Soc., LV., 675, (1978).

15. R.F. Holland and J.R. Neilsen, J. Mol. Spectrosc., 8, 383 (1962); 9,

436 (1962).

16. R.G. Synder, J. Chem. Phys., 71, 4229 (1979).

17. R.G. Synder, S.L. Hsu and S. Krlmm. Spectrochim. Acta, 34A, 395

(1978).

53

18. H.L. Casal, H.H. Mantsch, D.G. Cameron and R.G. Synder, J.

Chem. Phys., 77, 2825 (1982).

19. R.P. Varma and S. Shukla, Tenside Detergent., 20(4) (1983) 192.

20. K.N. Mehrotra, V.P. Mehta and T.N. Nagar, J. prakt. Chem., 545

(1970)312.

21. W.C. Roots, J. Am. Chem. Soc, 55 (1933) 850.

22. L.G. Pardeshi, J. Indian Chem. Soc., 59(1982) 1050.

23. W.U. Malik, A.K. Jain, V.K. Velu and A.K. Chhibbar, J. Indian

Chem. Soc.,61 (1984) 687.

24. K.N. Mehrotra, K. Tandon and M.K. Rawat, Bull Electrochem, 7

(5) (1991) 237.

25. R.D. Vold and G.S. Hattiangdi, Ind. Eng. Chem., 41(1949) 2311.

54