【正文】 covery angle increased whenthe increase in sol pH was from 4 to 6 and from 7to . When the pH was increased from 6 to 7,sis of TEOS was catalyzed with the hydrochloride orthe ammonia. The sol with the pH of 7 was preparedwithout catalyst and the hydrolysis at the same timewas probably not su?cient. The degree of the polymer anchored onto the fabric surface might be lowerand the ?lm could be thinner. When the fabric wasbended for an external force, the capacity of restoring its original shape might be weaker because ofless intermolecular forces and the value of the creaserecovery angle was lower. While the pH of the solwas between 4 and 6, for the existence of H+, afterbeing baked at high temperature, the glycoside bondbetween the adjacent glucose monomers of the cellulosic macromolecular chains would breakup to bringabout the degradation of the cotton ?bers. This wasbound to cause the crease recovery angles and thetensile strengths of the fabrics to decrease. And themore acidic the sol, the greater the extent of degradation of the ?bers and the lower the values of thecrease recovery angle and the tensile strength. Onthe other hand, when alkaline sols were prepared, the?bers swelled and underwent reduced degradations.The forces between and in the macromolecular chainsreceive less negative impacts. In addition, the hydrolysis of TEOS resulted in the nucleophilic attack ofhydroxide ion to the silicon atom in alkaline environment. Higher pH values lead to more hydroxideions and more TEOS were hydrolyzed. The thicker?exible ?lms were formed onto the treated cottonfabrics. Therefore, the values of the crease recoveryangle were enhanced with the increase in the pH ofthe sol in alkaline medium.For the tensile strength, it can be seen in Fig. 6that the value decreased with increasing pH of the solCrease recovery angle/176。Surface Review and Letters, Vol. 16, No. 5 (2009) 715–721c World Scienti?c Publishing CompanySURFACE TREATMENT OF ANTICREASE FINISHEDCOTTON FABRIC BASED ON SOL–GEL TECHNOLOGYCharles Q. Yang,*,? Qingliang He,? and Bojana Voncina?Department of Textiles, Merchandising and Interiors, The University of Georgia, Athens, Georgia 30602, United States Faculty of Mechanical Engineering, Department of Textiles, University of Maribor, Maribor, SloveniaAbstract:The silica sol was applied onto 1, 2, 3, 4butanetetracarboxylic acid (BTCA) ?nished cottonfabrics with the attempt to improve the physical properties especially the tensile strength whichhad a big loss in the previous anticrease ?nishing processing. The parameters including thedosage of the coupling agent, the concentration and pH of the sol and the processing methodswere studied in detail. Compared to the sample ?nished with BTCA, % of the increase inthe crease recovery angle and % of the enhancement in the tensile strength of the cottonfabric also treated with silica sol in the better selected conditions were obtained. The abrasionresistance was also improved. Keywords:Sol–gel。720640620600580560not adequately contact and react with the fabric.Method 1 seemed to be the most e?ective approachto improve the crease recovery angle. BTCA couldfully crosslink with the fabric and the silica ?lmalso improved the ?exibility of the fabric. Compared to Method 1, in Method 3, the paddedBTCA ?nishing solution was only dried and then34567pH891011padded with silica sol. The BTCA available waslesser. In Method 5, the sample which paddedFig. 6. E?ect of pH values on the tensile strengths offabrics treated with MPTS mol/L and concentrationof the sol 100%.in alkaline medium. That might be because the overrapid speed of hydrolysis of TEOS in higher pH leadto uneven distribution of ?lm onto the fabric surface. The higher the pH value of the sol, the higherthe speed of the hydrolysis. That might result ingreater uneven distribution of ?lms. When an external force was imparted, the resulting internal stresswould concentrate on the weaker areas. Then the tensile strength would decrease with the increase in thepH value.. Processing methodsThe sequences were illustrated in Table 1. In Fig. 7,the crease recovery angles of the samples ?rstly ?nished with BTCA (Methods 1, 3 and 5) were higherthan those ?rstly treated with silica sol (Methods2, 4 and 6). That might be because with Methods 1, 3 and 5, BTCA could better crosslink withthe fabrics. Whereas with Methods 2, 4 and 6,for the obstruction of the silica sol, BTCA could280260240220200with BTCA ?nishing solution was directly paddedwith silica sol solution. The BTCA available forcrosslinking with the fabric was much lesser andwas likely to weaken the e?ect of the anticrease?nishing.In Fig. 8, samples treated with Methods 1 and 2seemed to have much lower tensile strengths thanother processes. This might be attributed to thetwo times of curing. When curing at 160?C,