Surface Organic Modification of TiO Powder and...

Research ArticleSurface Organic Modification of TiO2 Powder andRelevant Characterization

Hong Zhou Sijia Sun and Hao Ding

Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes National Laboratory of Mineral MaterialsSchool of Materials Science and Technology China University of Geosciences Beijing 100083 China

Correspondence should be addressed to Hao Ding dinghaocugbeducn

Received 9 November 2016 Revised 11 January 2017 Accepted 24 January 2017 Published 2 May 2017

Academic Editor Michele Iafisco

Copyright copy 2017 Hong Zhou et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Surface organic modification was conducted to TiO2with modifiers to improve the dispersity and comparability of pigment

TiO2in application system by adjusting particle surface characteristics Then modification effects were characterized according

to the changes in wetting contact angle and activation index of TiO2before and after modification Moreover the modification

mechanisms of sodium stearate and sodium oleate were studied by analyzing the characteristics of TiO2surface functional groups

inmodification system and effects ofmodifiersThe results showed that after beingwet-processedwith sodium stearate and sodiumoleate TiO

2could turn from surface hydrophilic to inductive hydrophobic with controllable degree The wetting contact angle of

modified TiO2increased from 7∘ to 1256∘ and 1213∘ respectively The dispersity of TiO

2in organic medium was stronger than

that in inorganic medium The modifiers formed absorption with chemical property on TiO2particle surface so the inductive

hydrophobicity of surface was stable

1 Introduction

Titanium dioxide (TiO2) is metallic oxide with excellent

physical and chemical properties Its particle in submicronscale (02ndash03120583m) is the component of the best whitepigment nanometer TiO

2(less than 100 nm) is excellent

photocatalytic materialTherefore TiO2draws general atten-

tion With properties of high refractive index no toxicitystrong stability high brightness high covering power andso forth TiO

2has been widely used in fields of coating

plastic papermaking printing ink chemical fiber and soforth [1ndash7] As the photocatalyst nanometer TiO

2is applied

in fields of water and air purification [8ndash11] breaking downprocedures of organic pollutant degradation [12 13] medicalwaste treatment [14 15] and so forth Actually above prop-erties and their roles are dependent on the control over thepurity crystal form and size distribution of TiO

2powder

in synthesis and preparation Moreover the postprocessingis also important in optimizing the surface morphologyand compatibility with application system Therefore theprocessing for TiO

2powder is necessary when improving the

application performance

Micro-nano TiO2is poor in compatibility with high

polymer material because of small grain size high surfaceenergy and especially strong hydrophilia for surface hydrox-ylation Actually the bad dispersity and agglomeration ofTiO2in organic system impede its pigment performance or

photocatalytic performance However this problem can besolved by improving the dispersity of TiO

2in application

system In the way of particle surface modification thesurface wettability can be adjusted and the morphologyof surface functional groups be changed Guosheng et alconducted surface organic modification to nano-TiO

2par-

ticle with silane coupling agent The results show that TiO2

turns from surface hydrophilic to surface hydrophobic [16]In addition TiO

2particle was also modified with sodium

stearate and polyethylene glycol lauryl sodium sulfate andtriethanolamine and sodium hexametaphosphate by Gang etal [17] Xihai et al [18] Hui [19] Ding et al [20ndash22] andWeng et al [23] respectively All of these studies show that thedispersity of TiO

2improves in corresponding medium This

work also indicates that the application effects of modifierswith carboxylic in structure are more ideal among abovemodifiers [24ndash26] Except for surface modifier it is also

HindawiAdvances in Materials Science and EngineeringVolume 2017 Article ID 9562612 8 pageshttpsdoiorg10115520179562612

2 Advances in Materials Science and Engineering

important to make preassessment for TiO2modification

effects At present the surface modification of powder ismainly evaluated by measurement with contact angle [2728] and activation index [29] However the modificationeffects and stability of changed surface wettability cannot beevaluated Moreover the modification mechanism cannot bereflected with the interaction between modifier and TiO

2

particle This work conducted surface modification to TiO2

particle in micrometer scale by wet-modification with mod-ifiers sodium stearate and sodium oleate Suspension wasprepared with TiO

2powder and water in the weight ratio of

1 1 and heated to and fixed at 65∘CThen appropriate dosageof modifier was added to adjust pH value of modifier equalto or smaller than 7 The modified suspension was obtainedafter 30 minutes of heat preservation and constant stirringAfter drying and dispersing the modified suspension mod-ified TiO

2powder can be obtained Then the modification

effects of TiO2were characterized according to the changes

of wetting contact angle and activation index in differentliquid mediums before and after modification Finally themodificationmechanisms of TiO

2were studied by testing the

infrared spectrums and analyzing the morphology of surfacefunctional groups before and after modification with sodiumstearate and sodium oleate

2 Experiments

21 Raw Materials and Reagent TiO2used in tests was

anatase-type titanium oxide powder manufactured by HenanBillions Chemicals Co Ltd In sample test the particle sizewas median diameter (119889

50) of 037 120583m specific surface area

was 6125m2gminus1 whiteness was 9880 covering powerwas 1299 gm2 oil absorption was 2440 g100 g and water-wetting contact angle was 7∘

Theorganicmodifiers in test sodium stearate and sodiumoleate were all chemically pure reagents provided by BeijingJingweiHuabo Co Ltd The reagents should be disposed as5 water solution by heating

22 Process of TiO2 Organic Modification Surface modifica-tion for TiO

2was conducted by water suspension wet surface

modification Suspension was prepared with TiO2powder

and water in weight ratio of 1 1 (solid content 50) andheated to constant temperature (65∘C) Then the modifiersolution was added to TiO

2water suspension by ratio to

adjust the pH value equal to or less than 7 Modified sus-pension was obtained after thermal insulation and constantstirring for 30 minutes TiO

2powder can be obtained after

drying and dispersing the modified suspension

23 Performance and Structural Characterization231 Wetting Contact Angle Contact angle (120579) refers to theincluded angle between gas-liquid surface and solid-liquidsurface (including liquid) in the junction of three phasesgas liquid and solid As the physical quantity quantitativelyreflecting the wetting degree on solid surface contact anglecan represent the change in surface characteristics of TiO

2

before and aftermodificationTherefore contact angle can be

used to determine the modification effects When measuringthe angle the sample to be tested should be pressed asthe solid slice with smooth surface Then contact anglegauge (JC2000D Shanghai powereach digital technologyequipment Co Ltd) should be used to measure and takephoto of wetting contact angle

232 Activation Index Activation index refers to the per-centage of powder floating on the water-gas interfaceaccounting for the total volume after mixing the modifiedpowder in water Particles with surface hydrophobicity mayfloat on the interface in the comprehensive action of adhesiveforce gravity buoyancy water pressure and so forth inmoist periphery of three phases The stronger the surfacehydrophobicity of particle is the greater the adhesive forcein moist periphery and the larger the floating trend willbe Therefore the floating powder can intuitively reflect thesurface modification effects

2 g modified sample was correctly weighed and placedin pear-shaped funnel with 200mL water After oscillationand stewing the sedimentation at bottom in hierarchy wasintroduced to beaker for drying and weighingThe activationindex of sample119867 could be calculated by following formula

119867 =Sedimentation quantity in total quality

Total qualitytimes 100 (1)

233 Infrared Spectroscopy Infrared spectroscopy analysiscan be used to detect various keys in molecule structureof functional group and binding characteristics of differentparts in composite materials After compressing the sampleto be tested and KBr Spectrum 100 infrared spectrometricanalyzer manufactured by Shanghai PerkinElmer Co Ltdwas used for infrared spectrometry and analysis The scan-ning scope of instrument was 4000 cmminus1ndash400 cmminus1 and theresolution ratio was 3 cmminus1

3 Results and Discussion

31 Change of Modified TiO2 Wetting Contact Angle withModifiers and Dosage Figure 1 shows the influences ofmodifier dosage on the contact angle of TiO

2wetted by

water after TiO2particles weremodifiedwith sodium stearate

and sodium oleate Figure 2 shows the microscopic image ofwetting contact angle

According to Figure 1 the contact angle continuouslyenlarged with the increase of modifier dosage after TiO

2is

modified with sodium stearate and sodium oleateThe anglesare 1256∘ (modified with sodium stearate) and 1213∘ (mod-ified with sodium oleate) larger than 90∘ critical betweenhydrophile and hydrophobicity when modifier dosage is15 The contact angle of TiO

2is 7∘ before modification

Obviously TiO2surface has turned from strong hydrophilia

to hydrophobicity after modification However the wettingcontact angle on TiO

2surface decreases in small range when

the dosage further increasesThe results show that bothmod-ifiers can change the wettability of TiO

2surface Moreover

the hydrophobicity formed in modification can be controlledwith modifier dosage In other words the wettability on

Advances in Materials Science and Engineering 3

00 05 10 15 20 25 30

0

50

100

150

Sodium stearateSodium oleate

Dosage of modier ()

Wet

cont

act a

ngle

(∘)

Figure 1 The wetting contact angle of modified TiO2in water

TiO2particle surface and its degree are controllable Figure 2

intuitively reflects the changes in Figure 1In this work TiO

2wasmodifiedwith sodium stearate and

sodiumoleate (in dosage of 15) respectively Figure 3 showsthe contact angles of modified product and unmodified TiO

2

wetted by water absolute ethyl alcohol and kerosene It canbe seen that the contact angle of modified TiO

2wetted by

absolute ethyl alcohol is about 21∘ while the angle wettedby water is larger than 120∘ (see Figure 1) This means thatthe hydrophilia of TiO

2with alcohol is stronger than that

with water because alcohol has double characters of organicsand water Therefore modified TiO

2with surface strong

hydrophobicity has stronger wetting action than water Thewetting contact angle of modified TiO

2in kerosene (organic

nonpolar solvent) is slightly smaller than that in ethyl alcohol(less than 20∘) In other words the hydrophilia of modifiedTiO2in kerosene is much stronger than that in alcohol

It means that the surface of modified TiO2particle has

stronger organic nonpolarity Moreover the above resultsfurther specify that modifiers form the effective absorptionon the surface of TiO

2particle so the particle turns from

surface hydrophilia to hydrophobicity Figure 3 also showsthat the contact angle of unmodified TiO

2wetted by alcohol

and kerosene is about 20∘ larger than that wetted by waterIn other words the wetness degree of alcohol and keroseneis lower than water This means that unmodified TiO

2has

strong surface hydrophilicityBefore and after modification wetting contact angle of

TiO2particles changed in differentmediumsThismeans that

TiO2particle has extremely strong hydrophilia which may

turn to strong hydrophobicity after organicmodificationThewettability of modified TiO

2particle in organic medium is

stronger than that in inorganic medium which is beneficialto the improvement of dispersity in organic medium

32 Changes in Activation Index of Modified TiO2 Activationindex is an important index evaluating modification The

stronger the hydrophobicity TiO2particles are the larger

the activation index will be Figure 4 shows the changes inactivation index of TiO

2powdermodified by sodium stearate

and sodium oleate According to the figure the activationindex of modified TiO

2greatly increases with the dosages

of sodium stearate and sodium oleate increasing from 0to 15 and from 0 to 1 respectively Moreover theactivation index reached the maximum 986 and 897when the dosages of sodium stearate and sodium oleatewere 15 and 1 respectively However with the furtherincrease of sodium stearate and sodium oleate the activationindex of TiO

2may slightly decrease or keep stable This is

because the surface modification of TiO2is incomplete if the

modifier dosage is little so the activation index is small Withthe increase of modifier dosage however the unimolecularcoverage is realized with modifier on the surface of TiO

2

to make the modifier dosage saturated At this time theactivation index is the maximum If the modifier dosagefurther increases multilayer coats will form on the surfaceof TiO

2particles to make some types of group outward and

reduce the hydrophobicity of TiO2 Therefore the activation

index will decrease The change of activation index showsthat after modifying the sodium stearate and sodium oleateof TiO

2 the hydrophilia on surface will turn to strong

hydrophobic effectsThis is obviously the interaction betweenTiO2particle andmodifiermolecule as well as the coating on

the surface of TiO2[30 31]

This means that TiO2surface turns from hydrophilia

to strong hydrophobicity after being modified with sodiumstearate and sodiumoleateThis is obviously the result of TiO

2

particle and modifier molecule covering TiO2surface Above

results are consistent with the analysis on contact angle test

33 Function Mechanism of Modifiers and TiO2 Particle

331 IR Analysis on TiO2 Modified with Sodium Stearate andSodium Oleate The mechanism of TiO

2surface showing

strong hydrophobicity can be further understood and hydro-phobicity stability be determined by studying the proper-ties of interaction between modifiers sodium stearate andsodium oleate and TiO

2surfaceTherefore the infrared spec-

troscopies were measured for sodium stearate and sodiumoleate as well as TiO

2modified by these two modifiers

Figures 5 and 6 show the measurement resultsFigure 5 shows that there are symmetrical and dis-

symmetrical characteristic absorption peaks of -CH2- at

2917 cmminus1 and 2849 cmminus1 in the infrared spectroscopy ofsodium stearate (see Figure 5(a)) Moreover there is charac-teristic absorption peak of -CH

3at 2956 cmminus1 and stretching

absorption peaks of carbonyl (C=O) and carboxyl (COO-) at1557 cmminus1 and 1470 cmminus1 All of these reflect the structuralcharacteristics of sodium stearate Compared with raw mate-rial of sodium stearate and TiO

2 there are absorption peaks

at 2996 cmminus1 and 2885 cmminus1 in the infrared spectroscopy ofmodified TiO

2 This is obviously the characteristics of -CH

2-

and -CH3 showing that sodium stearate has attached to TiO

2

surfaceAccording to the comparison the absorption peak of

modified TiO2at 1504 cmminus1 resulted from the displacement


(a) (b) (c)

Figure 2 Microscopic image of wet contact angle of TiO2 (a)Wet contact angle of TiO

2 (b) wet contact angle of modified TiO

2with sodium

stearate and (c) wet contact angle of modified TiO2with sodium oleate

Water Ethanol Kerosene0

20

40

60

80

100

120

140

Medium

Wet

cont

act a

ngle

(∘)

Ti2

Ti2 modied by sodium stearate Ti2 modied by sodium oleate

Figure 3 Change of wet contact angle of TiO2

00 05 10 15 20 25 30 35 40 4550

60

70

80

90

100


Dosage of modier ()

Activ

atio

n in

dex

()

Figure 4 Activation index of modified TiO2with the amount of

modifier

of absorption peaks at 1557 cmminus1 and 1470 cmminus1 in theinfrared spectrum of sodium stearate It means that thechemical environment of C=O and -COOminus had significantchange after sodium stearate reacted with TiO

2 This may

result from the chemical action between functional group ofsodium stearate and surface functional group of TiO

2(the

hydroxide radical produced in Ti or Ti hydrolysis)Thereforeit is believed that the attachment of sodium stearate to TiO

2

particle surface has chemical properties Sodium stearateis closely and firmly combined with TiO

2particle so the

changes in surface characteristics of TiO2formodification are

stableAs shown in Figure 6 the infrared spectral features of

TiO2modified with sodium oleate are similar to those of

TiO2modified with sodium stearate In the infrared spec-

troscopy ofmodifiedTiO2 there are characteristic absorption

peaks representing methylene and methyl at 2852 cmminus1 and2922 cmminus1 This means that sodium oleate has attached toTiO2surface The absorption peak at 1465 cmminus1 indicates

that chemical action occurred between -COOminus and TiO2

in sodium oleate Therefore sodium oleate is also closelycombined with TiO

2particle for stable modification of TiO

2

332 Functional Group Morphology of TiO2 Particle Surfacein Water Medium TiO

2is one of the most typical oxides

of surface hydroxylation while the surface hydroxylation ofTiO2as the semiconductor material is complex with various

hydroxyl groups Perrinmade quantitative analysis on hydra-tion reaction of titanium ion (Ti4+) in water medium Thehydration reactions of Ti4+ in different levels and constantsare as follows [32]

Ti4+ +H2O 999445999468 Ti (OH)3+ +H+ p119896

1= 1415 (2)

Ti (OH)3+ +H2O 999445999468 Ti(OH)22+ +H+ p119896

2= 1373 (3)

Ti(OH)22+ +H

2O 999445999468 Ti(OH)3

+ +H+ p1198963= 1339 (4)

Ti(OH)3+ +H

2O 999445999468 Ti (OH)4 +H

+ p1198964= 1306 (5)

p1198961= log[Ti (OH)3+] [H+][Ti4+]

(6)


(a)

(b)

(c)

295645291743

284997206118 155795

162936

147050

144221

142101

11878771908

345844

107579 61339

7944046433

344800292663

285714 206239

162797155804

109379

79554

61028

5174846357

4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400(cＧminus1)

Figure 5 IR of TiO2modified by sodium stearate (a) Sodium stearate (b) TiO

2 (c) modified TiO

2

(a)

(b)

(c)

4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400

206118

162936

345844

107579

79440

61339

46433

343790

292771285714 206184

162797155804

105300

79581

61101

4632351748

1094

59

965

1192

366

823

7572

194 69

884 537

24

1345

91

1318

01

1378

181

1278

58

1233

75

1560

90

1462

65

1446

29

1425

05

(cＧminus1)

2851

2830

095

5

2921

60

Figure 6 IR of TiO2modified by sodium oleate (a) Sodium oleate (b) TiO

2 (c) modified TiO

2


p1198962= log[Ti(OH)2

2+] [H+]

[Ti (OH)3+](7)

p1198963= log[Ti(OH)3

+] [H+][Ti (OH)2

2+](8)

p1198964= log[Ti (OH)4] [H

+][Ti(OH)3

+](9)

Therefore the relationship between components Ti4+Ti(OH)3+ Ti(OH)

2

2+ Ti(OH)3

+ and Ti(OH)4 and pH value

(minus log[H+]) is shown in Figure 7 [32]Figure 7 shows that with the increase of pH value in

system Ti4+ tends to generate polyhydroxy When pH lt 1Ti(OH)

2

2+ is taken as the principal when pH=2 Ti(OH)3

+ istaken as the principal when pHgt 4 Ti4+ will turn to Ti(OH)

4

component The result also shows that even when pH = 0sim1the concentration of OHminus in system is extremely small If theexternal action of hydrolysis is weak no Ti4+ and Ti(OH)3+

component is representedmeaning that the capability of Ti4+is strong in generating various hydroxylates It is obviousbecause the constants (pk

1simpk4) of Ti4+ hydrolysis reaction

in different levels keep in very high value (1306sim1415)The hydroxylation characteristic of unsaturated Ti on

TiO2surface can be deducted according to the hydrolysis

behavior of Ti4+ In other words Ti is covered by a largeamount of hydroxyl so surface functional groups of TiO

2are

mainly OH-group as shown in Figure 8 [33] This is similarwith the molecule model of TiO

2with surface attached with

water proposed by Huaxiang and Xuxu [33]

333 DissociationMorphology of SodiumStearate and SodiumOleate in Water Solution The molecular formula of sodiumstearate is CH

3(CH2)16COONa while that of sodium oleate

is CH3(CH2)7CH=CH(CH

2)7COONa (R-COONa for short)

Both of them are composed of long chain of polar hydrophiliccarboxyl and nonpolar hydrophobic alkane They can dis-solve in water solution and then the dissolved componentsare rehydrated The reaction formula is as follows

R-COONa 997888rarr R-COOminus + Na+ (10)

R-COOminus +H2O 997888rarr R-COOH +OHminus (11)

Dianzuo and Yuehua [34] studied the relationshipbetween the concentration of R-COO and R-COOH insodium oleate solution and pH value (see Figure 9) [34] Thefigure shows that the main morphology of R-COONa is R-COOH in the modification condition of TiO

2 and only few

R-COONa have coexistence of R-COOHandR-COOminus in thiswork Therefore it is believed that the action groups of TiO

2

modified with sodium stearate and sodium oleate are mainlyR-COOH followed by R-COOminus

334 Model of Action between Modifier and TiO2 SurfaceThemodification mechanism of sodium stearate and sodiumoleate can be obtained according to above analysis on surfacefunctional groups of TiO

2particle and the dissociation

0 1 2 3 4 50

20

40

60

80

100

pH

Dist

ribut

ion

rate

Ti(OH)4４Ｃ(（)2

2+

４Ｃ(（)3+

Figure 7 Distribution of Ti4+ hydrolysis component with pH value

O

O

H

OH

Ti

Ti

O OHTi

O HTi

TiO OH

Figure 8 Schematic diagram of TiO2surface adsorbed hydroxyl

0 2 4 6 8 10 12 14pH

middotmiddotmiddot

ＦＩＡC

RCOO（()

RCOO（(Ｋ)

RCOminus

RCOOH-RCOminus

(２minus)22minus

Figure 9 Distribution of sodium oleic acid in aqueous solution

morphology ofmodifiers Firstly R-COOH forms a hydrogenbond with OHminus on TiO

2particle surface for combination by

dihydroxylation reaction The combination can be realizedby forming hydrogen bond with C=O and OHminus on TiO

2

surface throughR-COOminusTherefore themodifier R-COONafirmly attaches to TiO

2particle surface to make organic


Ti

O

Ti

O

Ti

OH

H

OH

O

OH

O

Ti

O

Ti

O

HOOC-R

O=C-R

HOOC-R

O=C-R

HOOC-R

O

Ti

O

Ti

O

Ti

O

Ti

O

Ti

O

H

O

O

O

OC-R

O=C-R

OC-R

O=C-R

OC-R

minus minus

minusminus

（2O

（2O

（2O

Figure 10 Schematic diagram of TiO2modified by sodium stearate and sodium oleate

hydrocarbon chain distribute externally on particle surfaceTherefore TiO

2has strong hydrophobicity OHminus onTiO

2sur-

face is covered by R-COOH and R-COOminus attachment so theabsorption peaks reflect hydroxyl in infrared spectroscopy ofTiO2after modification

The reaction model of modifier on TiO2particle surface

in wet process is established as according to above resultanalysis (See Figure 10)

4 Conclusions

Surface modification was conducted to TiO2particle with

sodium stearate and sodium oleate TiO2particle surface

turns from hydrophilia to hydrophobicity while the hydro-phobicity degree can be controlled by changing modifierdosage

In aqueous medium wetting contact angle of TiO2

particle greatly enlarges after modifying sodium stearate andsodium oleate The increase of activation index shows thatwettability in water medium becomes poor The wettingcontact angle of modified TiO

2particle in absolute ethyl

alcohol and kerosene is significantly lower than that in watermedium showing the good compatibility of organic matrix

TiO2infrared spectroscopic analysis before and after

modification shows that the modifier forms effective attach-ment on TiO

2particle surface With such attachment induc-

tive hydrophobicity forms on TiO2particle surface It is

relatively stable because attachment of modifier has certainchemical propertiesThe actionmodel of TiO

2modified with

sodium stearate and sodium oleate was established based onthe analysis on the functional groups of TiO

2particle surface

and the dissociation morphology of modifiers

Disclosure

Zhou Hong is the first author

Conflicts of Interest

The authors declare that they have no conflicts of interest

Acknowledgments

The work was supported by National Natural Science Foun-dation of China ldquoFundamental Researches of Theory and

Technology for Self-Assembly Compound of Calcium Car-bonate and TiO

2driven by Particle-Induced Hydrophobic

Effectrdquo (Grant no 51474194)

References

[1] E Reck and M Richards ldquoTiO2manufacture and life cycle

analysisrdquo Pigment and Resin Technology vol 28 no s3 pp 149ndash157 1999

[2] S-R Lu H-L Zhang C-X Zhao et al ldquoStudies on the prop-erties of a new hybridmaterials containing chain-extended ureaand SiO

2-TiO2particlesrdquo Polymer vol 46 no 23 pp 10484ndash

10492 2005[3] A Chatterjee ldquoEffect of nanoTiO

2addition on poly(methyl

methacrylate) an exciting nanocompositerdquo Journal of AppliedPolymer Science vol 116 no 6 pp 3396ndash3407 2010

[4] F Loffredo I A Grimaldi A De Girolamo Del Mauro et alldquoPolyethylenimineN-doped titanium dioxide nanoparticlebased inks for ink-jet printing applicationsrdquo Journal of AppliedPolymer Science vol 122 no 6 pp 3630ndash3636 2011

[5] C Xiaoquan and SWenhao ldquoResearch progress on the prepara-tion and application of nano titanium dioxide in papermakingrdquoPaper Science and technology vol 6 pp 109ndash114 2010

[6] A Sotto A Boromand R Zhang et al ldquoEffect of nanoparticleaggregation at low concentrations of TiO

2on the hydrophilicity

morphology and fouling resistance of PES-TiO2membranesrdquo

Journal of Colloid and Interface Science vol 363 no 2 pp 540ndash550 2011

[7] J C Yu J Yu W Ho et al ldquoLight-induced super-hydrophilicityand photocatalytic activity of mesoporous TiO

2thin filmsrdquo

Journal of Photochemistry and Photobiology A Chemistry vol148 no 1 pp 331ndash339 2002

[8] Y Gao G Chen Y Oli et al ldquoStudy on tribological properties ofoleic acid-modified TiO

2nanoparticle in waterrdquoWear vol 252

no 5 pp 454ndash458 2002[9] NMaximous GNakhlaWWan et al ldquoPerformance of a novel

ZrO2PESmembrane forwastewater filtrationrdquo Journal ofMem-

brane Science vol 352 no 1 pp 222ndash230 2010[10] N Maximous G Nakhla W Wan et al ldquoPreparation charac-

terization and performance of Al2O3PESmembrane for waste-

water filtrationrdquo Journal of Membrane Science vol 341 no 1 pp67ndash75 2009

[11] Z Wanzhong Q Xueliang Q Lin et al ldquoPhotocatalytic mech-anism of nano titanium dioxide and its application in thetreatment of organic wastewaterrdquo Journal of Synthetic Crystalsvol 35 pp 1026ndash1031 2006


[12] C Hanlin Study on Photoelectrochemical degradation of organicpollutants and hydrogen production bymodified titania nanotubearray electrode South China University of Technology 2015

[13] L Daohui Ji Jing L Tian et al ldquoEnvironmental behavior andbiological toxicity of nanomaterialsrdquo Science Bulletin vol 23 pp3590ndash3604 2009

[14] Li Shugan and J Xiaoning ldquoTreatment method of medicalpolypropylene nonwoven fabricrdquo Industrial Textiles vol 29 pp30ndash33 2011

[15] H Park Y Park W Kim et al ldquoSurface modification ofTiO2photocatalyst for environmental applicationsrdquo Journal of

Photochemistry and Photobiology C Photochemistry Reviewsvol 15 no 1 pp 1ndash20 2013

[16] C Yao G-S Gao X-P Lin X-J Yang L-D Lu and X WangldquoSurface modification of nanosized TiO

2with silane coupling

reagentrdquo Journal of Inorganic Materials vol 21 no 2 pp 315ndash321 2006

[17] X Gang Z Huashan Z Haodong et al ldquoStudy on surfacemodification of nano titanium dioxiderdquo Journal of KunmingUniversity of Science and Technology (Science and Engineering)vol 29 no 4 pp 39ndash42 2004

[18] H Xihai L Huimin L Fei et al ldquoStudy on surfacemodificationof nano titanium dioxiderdquo inorganic salt industry vol 44 no 1pp 30ndash32 2012

[19] F Hui Study on Surface Treatment and Application Performanceof Rutile Titanium Dioxide Jiangsu University 2007

[20] H Ding S-C Lu Y-X Deng and G-X Du ldquoMechano-activated surface modification of calcium carbonate in wetstirred mill and its propertiesrdquo Transactions of NonferrousMetals Society of China (English Edition) vol 17 no 5 pp 1100ndash1104 2007

[21] H Ding H Yushu and L shouci Ore sodium stearatemodifiedheavy calcium carbonate of non metallic mines wet ultrafinegrinding 1997 (4) 37-40

[22] H Ding H Zhou Y X Zheng and M M Wang ldquoEffect ofsodium stearate on grinding behaviour of calcium carbonate inwet stirred millrdquo Materials Research Innovations vol 17 no 1pp s292ndashs296 2013

[23] Y-X Weng L Li Y Liu L Wang and G-Z Yang ldquoSurface-binding forms of carboxylic groups on nanoparticulate TiO

2

surface studied by the interface-sensitive transient triplet-statemolecular proberdquo Journal of Physical Chemistry B vol 107 no18 pp 4356ndash4363 2003

[24] S Mallakpour and E Nikkhoo ldquoSurface modification of nano-TiO2with trimellitylimido-amino acid-based diacids for pre-

venting aggregation of nanoparticlesrdquo Advanced Powder Tech-nology vol 25 no 1 pp 348ndash353 2014

[25] D Q Vo E-J Kim and S Kim ldquoSurfacemodification of hydro-phobic nanocrystals using short-chain carboxylic acidsrdquo Jour-nal of Colloid and Interface Science vol 337 no 1 pp 75ndash802009

[26] Y Wang W Eli L Zhang H Gao Y Liu and P Li ldquoA newmethod for surface modification of nano-CaCO

3and nano-

Al2O3at room temperaturerdquo Advanced Powder Technology vol

21 no 2 pp 203ndash205 2010[27] T Zhisong L Runjing G Fen et al ldquoThe effect of coupling

agent on the surface modification of nano CaCO3rdquo Journal of

Beijing University of Chemical Technology 2004[28] W Shuzhong M Yixuan H Fuzeng et al ldquoStudy on inorganic

nano particlesstyrene butadiene latex composite technologyrdquoEncyclopedic Dictionary of Polymers vol 15 no 4 pp 437ndash4412002

[29] L Qinfu and X Xu ldquoEvaluation and Mechanism Study on theeffect of surface modification of kaolin in coal seriesrdquo Journal ofMaterials Science vol 14 no 3 pp 325ndash328 2009

[30] N Li G-z Ma and B-s Xu ldquoStudy on modification and prop-erties of calcined kaolin with stearic acidrdquo Applied ChemicalIndustry vol 38 no 8 pp 1136ndash1138 2009

[31] L Lihua ldquoStudy on surfacemodification of zinc boraterdquo Journalof Tangshan Normal University vol 38 pp 44ndash47 2016

[32] D D Perrin ldquoStability constants of metal-ion-complexesrdquoIUPAC vol 22 no Chemical Data Series 1979

[33] L huaxiang and W Xuxu ldquoTiO2surface hydroxyl groups and

their propertiesrdquo Progress in Chemistry vol 19 no 5 pp 665ndash670 2007

[34] W Dianzuo and H Yuehua Flotation Solution ChemistryHunan science and Technology Press Changsha Hunan 1988

Submit your manuscripts athttpswwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of



CeramicsJournal of


CompositesJournal of

NanoparticlesJournal of



International Journal of

Biomaterials


NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research



MetallurgyJournal of


BioMed Research International

MaterialsJournal of



important to make preassessment for TiO2modification

effects At present the surface modification of powder ismainly evaluated by measurement with contact angle [2728] and activation index [29] However the modificationeffects and stability of changed surface wettability cannot beevaluated Moreover the modification mechanism cannot bereflected with the interaction between modifier and TiO

2

particle This work conducted surface modification to TiO2

particle in micrometer scale by wet-modification with mod-ifiers sodium stearate and sodium oleate Suspension wasprepared with TiO

2powder and water in the weight ratio of

1 1 and heated to and fixed at 65∘CThen appropriate dosageof modifier was added to adjust pH value of modifier equalto or smaller than 7 The modified suspension was obtainedafter 30 minutes of heat preservation and constant stirringAfter drying and dispersing the modified suspension mod-ified TiO

2powder can be obtained Then the modification

effects of TiO2were characterized according to the changes

of wetting contact angle and activation index in differentliquid mediums before and after modification Finally themodificationmechanisms of TiO

2were studied by testing the

infrared spectrums and analyzing the morphology of surfacefunctional groups before and after modification with sodiumstearate and sodium oleate

2 Experiments

21 Raw Materials and Reagent TiO2used in tests was

anatase-type titanium oxide powder manufactured by HenanBillions Chemicals Co Ltd In sample test the particle sizewas median diameter (119889

50) of 037 120583m specific surface area

was 6125m2gminus1 whiteness was 9880 covering powerwas 1299 gm2 oil absorption was 2440 g100 g and water-wetting contact angle was 7∘

Theorganicmodifiers in test sodium stearate and sodiumoleate were all chemically pure reagents provided by BeijingJingweiHuabo Co Ltd The reagents should be disposed as5 water solution by heating

22 Process of TiO2 Organic Modification Surface modifica-tion for TiO

2was conducted by water suspension wet surface

modification Suspension was prepared with TiO2powder

and water in weight ratio of 1 1 (solid content 50) andheated to constant temperature (65∘C) Then the modifiersolution was added to TiO

2water suspension by ratio to

adjust the pH value equal to or less than 7 Modified sus-pension was obtained after thermal insulation and constantstirring for 30 minutes TiO

2powder can be obtained after

drying and dispersing the modified suspension

23 Performance and Structural Characterization231 Wetting Contact Angle Contact angle (120579) refers to theincluded angle between gas-liquid surface and solid-liquidsurface (including liquid) in the junction of three phasesgas liquid and solid As the physical quantity quantitativelyreflecting the wetting degree on solid surface contact anglecan represent the change in surface characteristics of TiO

2

before and aftermodificationTherefore contact angle can be

used to determine the modification effects When measuringthe angle the sample to be tested should be pressed asthe solid slice with smooth surface Then contact anglegauge (JC2000D Shanghai powereach digital technologyequipment Co Ltd) should be used to measure and takephoto of wetting contact angle

232 Activation Index Activation index refers to the per-centage of powder floating on the water-gas interfaceaccounting for the total volume after mixing the modifiedpowder in water Particles with surface hydrophobicity mayfloat on the interface in the comprehensive action of adhesiveforce gravity buoyancy water pressure and so forth inmoist periphery of three phases The stronger the surfacehydrophobicity of particle is the greater the adhesive forcein moist periphery and the larger the floating trend willbe Therefore the floating powder can intuitively reflect thesurface modification effects

2 g modified sample was correctly weighed and placedin pear-shaped funnel with 200mL water After oscillationand stewing the sedimentation at bottom in hierarchy wasintroduced to beaker for drying and weighingThe activationindex of sample119867 could be calculated by following formula

119867 =Sedimentation quantity in total quality

Total qualitytimes 100 (1)

233 Infrared Spectroscopy Infrared spectroscopy analysiscan be used to detect various keys in molecule structureof functional group and binding characteristics of differentparts in composite materials After compressing the sampleto be tested and KBr Spectrum 100 infrared spectrometricanalyzer manufactured by Shanghai PerkinElmer Co Ltdwas used for infrared spectrometry and analysis The scan-ning scope of instrument was 4000 cmminus1ndash400 cmminus1 and theresolution ratio was 3 cmminus1

3 Results and Discussion

31 Change of Modified TiO2 Wetting Contact Angle withModifiers and Dosage Figure 1 shows the influences ofmodifier dosage on the contact angle of TiO

2wetted by

water after TiO2particles weremodifiedwith sodium stearate

and sodium oleate Figure 2 shows the microscopic image ofwetting contact angle

According to Figure 1 the contact angle continuouslyenlarged with the increase of modifier dosage after TiO

2is

modified with sodium stearate and sodium oleateThe anglesare 1256∘ (modified with sodium stearate) and 1213∘ (mod-ified with sodium oleate) larger than 90∘ critical betweenhydrophile and hydrophobicity when modifier dosage is15 The contact angle of TiO

2is 7∘ before modification

Obviously TiO2surface has turned from strong hydrophilia

to hydrophobicity after modification However the wettingcontact angle on TiO

2surface decreases in small range when

the dosage further increasesThe results show that bothmod-ifiers can change the wettability of TiO

2surface Moreover

the hydrophobicity formed in modification can be controlledwith modifier dosage In other words the wettability on


00 05 10 15 20 25 30

0

50

100

150


Dosage of modier ()

Wet

cont

act a

ngle

(∘)






2


2wetted by












2wetted by alcohol


2has

















2










2





2surface showing













2-


2




(a) (b) (c)



2with sodium



20

40

60

80

100

120

140

Medium

Wet

cont

act a

ngle

(∘)

Ti2



00 05 10 15 20 25 30 35 40 4550

60

70

80

90

100


Dosage of modier ()

Activ

atio

n in

dex

()


modifier


2 This may


2(the


2


2particle so the










2





Ti4+ +H2O 999445999468 Ti (OH)3+ +H+ p119896

1= 1415 (2)

Ti (OH)3+ +H2O 999445999468 Ti(OH)22+ +H+ p119896

2= 1373 (3)

Ti(OH)22+ +H

2O 999445999468 Ti(OH)3

+ +H+ p1198963= 1339 (4)

Ti(OH)3+ +H

2O 999445999468 Ti (OH)4 +H

+ p1198964= 1306 (5)

p1198961= log[Ti (OH)3+] [H+][Ti4+]

(6)


(a)

(b)

(c)

295645291743

284997206118 155795

162936

147050

144221

142101

11878771908

345844

107579 61339

7944046433

344800292663

285714 206239

162797155804

109379

79554

61028

5174846357

4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400(cＧminus1)


2 (c) modified TiO

2

(a)

(b)

(c)

4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400

206118

162936

345844

107579

79440

61339

46433

343790

292771285714 206184

162797155804

105300

79581

61101

4632351748

1094

59

965

1192

366

823

7572

194 69

884 537

24

1345

91

1318

01

1378

181

1278

58

1233

75

1560

90

1462

65

1446

29

1425

05

(cＧminus1)

2851

2830

095

5

2921

60


2 (c) modified TiO

2


p1198962= log[Ti(OH)2

2+] [H+]

[Ti (OH)3+](7)

p1198963= log[Ti(OH)3

+] [H+][Ti (OH)2

2+](8)

p1198964= log[Ti (OH)4] [H

+][Ti(OH)3

+](9)


2

2+ Ti(OH)3




2



4







2are












2 and only few


2




0 1 2 3 4 50

20

40

60

80

100

pH

Dist

ribut

ion

rate

Ti(OH)4４Ｃ(（)2

2+

４Ｃ(（)3+


O

O

H

OH

Ti

Ti

O OHTi

O HTi

TiO OH


0 2 4 6 8 10 12 14pH

middotmiddotmiddot

ＦＩＡC

RCOO（()

RCOO（(Ｋ)

RCOminus

RCOOH-RCOminus

(２minus)22minus





2




Ti

O

Ti

O

Ti

OH

H

OH

O

OH

O

Ti

O

Ti

O

HOOC-R

O=C-R

HOOC-R

O=C-R

HOOC-R

O

Ti

O

Ti

O

Ti

O

Ti

O

Ti

O

H

O

O

O

OC-R

O=C-R

OC-R

O=C-R

OC-R

minus minus

minusminus

（2O

（2O

（2O




2sur-




4 Conclusions













2modified with


2particle surface


Disclosure




Acknowledgments





References















2thin filmsrdquo


























2






3and nano-




















CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



00 05 10 15 20 25 30

0

50

100

150


Dosage of modier ()

Wet

cont

act a

ngle

(∘)






2


2wetted by












2wetted by alcohol


2has

















2










2





2surface showing













2-


2




(a) (b) (c)



2with sodium



20

40

60

80

100

120

140

Medium

Wet

cont

act a

ngle

(∘)

Ti2



00 05 10 15 20 25 30 35 40 4550

60

70

80

90

100


Dosage of modier ()

Activ

atio

n in

dex

()


modifier


2 This may


2(the


2


2particle so the










2





Ti4+ +H2O 999445999468 Ti (OH)3+ +H+ p119896

1= 1415 (2)

Ti (OH)3+ +H2O 999445999468 Ti(OH)22+ +H+ p119896

2= 1373 (3)

Ti(OH)22+ +H

2O 999445999468 Ti(OH)3

+ +H+ p1198963= 1339 (4)

Ti(OH)3+ +H

2O 999445999468 Ti (OH)4 +H

+ p1198964= 1306 (5)

p1198961= log[Ti (OH)3+] [H+][Ti4+]

(6)


(a)

(b)

(c)

295645291743

284997206118 155795

162936

147050

144221

142101

11878771908

345844

107579 61339

7944046433

344800292663

285714 206239

162797155804

109379

79554

61028

5174846357

4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400(cＧminus1)


2 (c) modified TiO

2

(a)

(b)

(c)

4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400

206118

162936

345844

107579

79440

61339

46433

343790

292771285714 206184

162797155804

105300

79581

61101

4632351748

1094

59

965

1192

366

823

7572

194 69

884 537

24

1345

91

1318

01

1378

181

1278

58

1233

75

1560

90

1462

65

1446

29

1425

05

(cＧminus1)

2851

2830

095

5

2921

60


2 (c) modified TiO

2


p1198962= log[Ti(OH)2

2+] [H+]

[Ti (OH)3+](7)

p1198963= log[Ti(OH)3

+] [H+][Ti (OH)2

2+](8)

p1198964= log[Ti (OH)4] [H

+][Ti(OH)3

+](9)


2

2+ Ti(OH)3




2



4







2are












2 and only few


2




0 1 2 3 4 50

20

40

60

80

100

pH

Dist

ribut

ion

rate

Ti(OH)4４Ｃ(（)2

2+

４Ｃ(（)3+


O

O

H

OH

Ti

Ti

O OHTi

O HTi

TiO OH


0 2 4 6 8 10 12 14pH

middotmiddotmiddot

ＦＩＡC

RCOO（()

RCOO（(Ｋ)

RCOminus

RCOOH-RCOminus

(２minus)22minus





2




Ti

O

Ti

O

Ti

OH

H

OH

O

OH

O

Ti

O

Ti

O

HOOC-R

O=C-R

HOOC-R

O=C-R

HOOC-R

O

Ti

O

Ti

O

Ti

O

Ti

O

Ti

O

H

O

O

O

OC-R

O=C-R

OC-R

O=C-R

OC-R

minus minus

minusminus

（2O

（2O

（2O




2sur-




4 Conclusions













2modified with


2particle surface


Disclosure




Acknowledgments





References















2thin filmsrdquo


























2






3and nano-




















CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



(a) (b) (c)



2with sodium



20

40

60

80

100

120

140

Medium

Wet

cont

act a

ngle

(∘)

Ti2



00 05 10 15 20 25 30 35 40 4550

60

70

80

90

100


Dosage of modier ()

Activ

atio

n in

dex

()


modifier


2 This may


2(the


2


2particle so the










2





Ti4+ +H2O 999445999468 Ti (OH)3+ +H+ p119896

1= 1415 (2)

Ti (OH)3+ +H2O 999445999468 Ti(OH)22+ +H+ p119896

2= 1373 (3)

Ti(OH)22+ +H

2O 999445999468 Ti(OH)3

+ +H+ p1198963= 1339 (4)

Ti(OH)3+ +H

2O 999445999468 Ti (OH)4 +H

+ p1198964= 1306 (5)

p1198961= log[Ti (OH)3+] [H+][Ti4+]

(6)


(a)

(b)

(c)

295645291743

284997206118 155795

162936

147050

144221

142101

11878771908

345844

107579 61339

7944046433

344800292663

285714 206239

162797155804

109379

79554

61028

5174846357

4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400(cＧminus1)


2 (c) modified TiO

2

(a)

(b)

(c)

4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400

206118

162936

345844

107579

79440

61339

46433

343790

292771285714 206184

162797155804

105300

79581

61101

4632351748

1094

59

965

1192

366

823

7572

194 69

884 537

24

1345

91

1318

01

1378

181

1278

58

1233

75

1560

90

1462

65

1446

29

1425

05

(cＧminus1)

2851

2830

095

5

2921

60


2 (c) modified TiO

2


p1198962= log[Ti(OH)2

2+] [H+]

[Ti (OH)3+](7)

p1198963= log[Ti(OH)3

+] [H+][Ti (OH)2

2+](8)

p1198964= log[Ti (OH)4] [H

+][Ti(OH)3

+](9)


2

2+ Ti(OH)3




2



4







2are












2 and only few


2




0 1 2 3 4 50

20

40

60

80

100

pH

Dist

ribut

ion

rate

Ti(OH)4４Ｃ(（)2

2+

４Ｃ(（)3+


O

O

H

OH

Ti

Ti

O OHTi

O HTi

TiO OH


0 2 4 6 8 10 12 14pH

middotmiddotmiddot

ＦＩＡC

RCOO（()

RCOO（(Ｋ)

RCOminus

RCOOH-RCOminus

(２minus)22minus





2




Ti

O

Ti

O

Ti

OH

H

OH

O

OH

O

Ti

O

Ti

O

HOOC-R

O=C-R

HOOC-R

O=C-R

HOOC-R

O

Ti

O

Ti

O

Ti

O

Ti

O

Ti

O

H

O

O

O

OC-R

O=C-R

OC-R

O=C-R

OC-R

minus minus

minusminus

（2O

（2O

（2O




2sur-




4 Conclusions













2modified with


2particle surface


Disclosure




Acknowledgments





References















2thin filmsrdquo


























2






3and nano-




















CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



(a)

(b)

(c)

295645291743

284997206118 155795

162936

147050

144221

142101

11878771908

345844

107579 61339

7944046433

344800292663

285714 206239

162797155804

109379

79554

61028

5174846357

4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400(cＧminus1)


2 (c) modified TiO

2

(a)

(b)

(c)

4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400

206118

162936

345844

107579

79440

61339

46433

343790

292771285714 206184

162797155804

105300

79581

61101

4632351748

1094

59

965

1192

366

823

7572

194 69

884 537

24

1345

91

1318

01

1378

181

1278

58

1233

75

1560

90

1462

65

1446

29

1425

05

(cＧminus1)

2851

2830

095

5

2921

60


2 (c) modified TiO

2


p1198962= log[Ti(OH)2

2+] [H+]

[Ti (OH)3+](7)

p1198963= log[Ti(OH)3

+] [H+][Ti (OH)2

2+](8)

p1198964= log[Ti (OH)4] [H

+][Ti(OH)3

+](9)


2

2+ Ti(OH)3




2



4







2are












2 and only few


2




0 1 2 3 4 50

20

40

60

80

100

pH

Dist

ribut

ion

rate

Ti(OH)4４Ｃ(（)2

2+

４Ｃ(（)3+


O

O

H

OH

Ti

Ti

O OHTi

O HTi

TiO OH


0 2 4 6 8 10 12 14pH

middotmiddotmiddot

ＦＩＡC

RCOO（()

RCOO（(Ｋ)

RCOminus

RCOOH-RCOminus

(２minus)22minus





2




Ti

O

Ti

O

Ti

OH

H

OH

O

OH

O

Ti

O

Ti

O

HOOC-R

O=C-R

HOOC-R

O=C-R

HOOC-R

O

Ti

O

Ti

O

Ti

O

Ti

O

Ti

O

H

O

O

O

OC-R

O=C-R

OC-R

O=C-R

OC-R

minus minus

minusminus

（2O

（2O

（2O




2sur-




4 Conclusions













2modified with


2particle surface


Disclosure




Acknowledgments





References















2thin filmsrdquo


























2






3and nano-




















CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



p1198962= log[Ti(OH)2

2+] [H+]

[Ti (OH)3+](7)

p1198963= log[Ti(OH)3

+] [H+][Ti (OH)2

2+](8)

p1198964= log[Ti (OH)4] [H

+][Ti(OH)3

+](9)


2

2+ Ti(OH)3




2



4







2are












2 and only few


2




0 1 2 3 4 50

20

40

60

80

100

pH

Dist

ribut

ion

rate

Ti(OH)4４Ｃ(（)2

2+

４Ｃ(（)3+


O

O

H

OH

Ti

Ti

O OHTi

O HTi

TiO OH


0 2 4 6 8 10 12 14pH

middotmiddotmiddot

ＦＩＡC

RCOO（()

RCOO（(Ｋ)

RCOminus

RCOOH-RCOminus

(２minus)22minus





2




Ti

O

Ti

O

Ti

OH

H

OH

O

OH

O

Ti

O

Ti

O

HOOC-R

O=C-R

HOOC-R

O=C-R

HOOC-R

O

Ti

O

Ti

O

Ti

O

Ti

O

Ti

O

H

O

O

O

OC-R

O=C-R

OC-R

O=C-R

OC-R

minus minus

minusminus

（2O

（2O

（2O




2sur-




4 Conclusions













2modified with


2particle surface


Disclosure




Acknowledgments





References















2thin filmsrdquo


























2






3and nano-




















CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



Ti

O

Ti

O

Ti

OH

H

OH

O

OH

O

Ti

O

Ti

O

HOOC-R

O=C-R

HOOC-R

O=C-R

HOOC-R

O

Ti

O

Ti

O

Ti

O

Ti

O

Ti

O

H

O

O

O

OC-R

O=C-R

OC-R

O=C-R

OC-R

minus minus

minusminus

（2O

（2O

（2O




2sur-




4 Conclusions













2modified with


2particle surface


Disclosure




Acknowledgments





References















2thin filmsrdquo


























2






3and nano-




















CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


















2






3and nano-




















CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of









CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Surface Organic Modification of TiO Powder and...

Documents

Transcript of Surface Organic Modification of TiO Powder and...