ORIGINAL PAPERA new surface modification method to improve the dispersityof nano-silica in organic solventsYulin Li • Zhengxing Chen • Xiaoxuan Li •Huawei ZengReceived: 30 November 2010/Accepted: 17 December 2010/Published online: 24 December 2010? Springer Science+Business Media, LLC 2010Abstract Different surface modification methods toimprove the dispersity of nano-silica in organic solvents byc-methacryloxypropyltrimethoxy silane (MOPTMS) anhy-drous alcohol solution were investigated. The possibleprinciples of these methods improving the dispersity ofnano-silicainorganicsolventswereproposed.Theoptimummodification method was that nano-silica powders werechemically modified by c-methacryloxypropyltrimethoxysilane anhydrous alcohol solution and c-methacrylox-ypropyltrimethoxy silane anhydrous alcohol solution wasdropwise added at 3 mL/min. The transparency of theoptimum modified nano-silica powder anhydrous alcoholsolution (0.1 wt. %) was 85.9%. The29 Si cross polarizationand magic-angle spinning nuclear magnetic resonancespectra suggested that nano-silica was chemically modifiedby c-methacryloxypropyltrimethoxy silane anhydrousalcohol solution. The transmission electron microscopyimages suggested that the optimum modified nano-silicawas well dispersed. The dispersity of nano-silica in anhy-drous alcohol, CH 2 Cl 2 , CCl 4 , cyclohexane, and liquid par-affin increased from 0, 0, 0, 0, and 0.1 to 9.4, 9.6, 9.8, 9.8,and 10.0 g/100 mL after surface modification.Keywords Surface modification ? Dispersity ?Nano-silica ? Organic solvent ? Transparency1 IntroductionImproving the dispersity of nano-silica in organic solventshad caused intensively interesting because nano-silicawell-dispersed in organic solvents could be extensivelyused in rubber, paint, and plastic industries [1–6]. In pre-vious investigations, to improve the dispersity of silica inorganic solvents, it was modified by titanate [7], oleic acid[8], vinyltriethoxysilane [9], and aminopropyltriethox-ysilane [10]. These modified silicas were not well dispersedin organic solvents yet [7–10]. Moreover, these modifiershad two disadvantages: (1) their unsaturated bonds couldnot react with the surface –OH groups of silica effectively[7, 8]; (2) once encountered a polar medium, these modi-fiers were easy to be separated from the surface of silica [9,10]. Therefore silane coupling agent was used as a newmodifier. Li et al. (2006) modified nano-silica gel by silanecoupling agent and silane coupling agent was dropwiseadded. He found that silane coupling agent could improvethe dispersity of nano-silica in organic solvents and c-methacryloxypropyltrimethoxy silane (MOPTMS) was thebest among all used silane coupling agents [11]. Theseresearchers used a modification method respectively anddid not demonstrate that which method was optimum.The aim of this study was to investigate a new surfacemodification method to improve the dispersity of nano-silica in organic solvents. The transparency of nano-silicaanhydrous alcohol solution was used as an index of eval-uating the modification effect. Nano-silica and the opti-mum modified nano-silica were characterized by the29 Sicross polarization and magic-angle spinning nuclearY. Li (&)The State Key Laboratory of Food Science and Technology,Jiangnan University, 1800 Lihu Rood, 214122 Wuxi, Chinae-mail: liyulin7226@163.comZ. Chen (&) ? X. LiThe School of Food Science and Technology, JiangnanUniversity, 1800 Lihu Rood, 214122 Wuxi, Chinae-mail: zxchen2007@126.comH. ZengThe Key Laboratory of Industrial Biotechnology of Ministerof Education, School of Biotechnology, Jiangnan University,1800 Lihu Rood, 214122 Wuxi, People’s Republic of China123J Sol-Gel Sci Technol (2011) 58:290–295DOI 10.1007/s10971-010-2389-0
