Hydrocarbon dispersion of nanospherical silica by a sol-gel process. 1. Tetraethoxysilane homopolymerization

• Published in: Colloid and polymer science Vol. 278; no. 12; pp. 1180 - 1186
• Main Authors: PEDROSO, M. A. S, DIAS, M. L, AZUMA, C, MOTHE, C. G
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01-12-2000; Springer Nature B.V
• Subjects: Applied sciences; Dispersions; Ethyl alcohol; Exact sciences and technology; Hydrocarbons; Inorganic and organomineral polymers; Nanocomposites; Nanomaterials; Nanostructure; Physicochemistry of polymers; Preparation; Silicon dioxide; Sol-gel processes; Tetraethoxysilane; Organic solvent; Particle size; Sol gel process; Preparation; Condensation polymerization; Spherical particle; Colloidal dispersion; Experimental study; Property processing relationship; Silica; Submicron particle; Organic silicate
• ISSN: 0303-402X; 1435-1536
• DOI: 10.1007/s003960000380

This study focused on the preparation of a hydrocarbon dispersion of nanospherical silica using tetraethoxysilane homopolymerization by a sol-gel process catalyzed by NH^sub 4^OH in ethanol. The silica surface was rendered hydrophobic by the introduction of trimethylchlorosilane or trimethylethoxysilane as a terminator. Organophilic particles with diameters in the range 10-130nm were obtained under controlled conditions. Nevertheless, the organophilic fraction dispersed in hexane was not greater than 62%. The homopolymerization reaction time was directly related to the particle size and, in some cases, its insolubility. High terminator concentration and low termination temperature favored the increase in the number of organophilic particles. The chlorine-containing terminator was more efficient in promoting the production of hydrocarbon hydrophobic nanospheres.[PUBLICATION ABSTRACT]