caa a22 4500 475764048 CHVBK 20180406123559.0 cr unu---uuuuu 170329e20001201xx s 000 0 eng 10.1007/s003960000380 doi (NATIONALLICENCE)springer-10.1007/s003960000380 Hydrocarbon dispersion of nanospherical silica by a sol-gel process. 1. Tetraethoxysilane homopolymerization [Elektronische Daten] [M. A. S. Pedroso, M. L. Dias, C. Azuma, C. G. Mothé] This study focused on the preparation of a hydrocarbon dispersion of nanospherical silica using tetraethoxysilane homopolymerization by a sol-gel process catalyzed by NH4OH 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 10-130 nm 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. Springer-Verlag Berlin Heidelberg, 2000 Key words Nanospheres nationallicence Sol-gel process nationallicence Colloidal dispersion nationallicence Tetraethoxysilane nationallicence Pedroso M. A. S. Depto de Processos Orgânicos Escola de Química Universidade Federal do Rio de Janeiro C.P. 68522, 21949-900 Rio de Janeiro, Brazil e-mail: cheila@h2o.eq.ufrj.br, BR aut Dias M. L. Instituto de Macromoléculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, C.P. 68525 21945-970 Rio de Janeiro, Brazil, BR aut Azuma C. The University of the Air Tokyo Daiichi Gakushu Center 4-1-1, Shimouma, Setagaya-Ku Tokyo 154-0002, Japan, JP aut Mothé C. G. Depto de Processos Orgânicos Escola de Química Universidade Federal do Rio de Janeiro C.P. 68522, 21949-900 Rio de Janeiro, Brazil e-mail: cheila@h2o.eq.ufrj.br, BR aut https://doi.org/10.1007/s003960000380 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s003960000380 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Pedroso M. A. S. Depto de Processos Orgânicos Escola de Química Universidade Federal do Rio de Janeiro C.P. 68522, 21949-900 Rio de Janeiro, Brazil e-mail: cheila@h2o.eq.ufrj.br, BR aut NATIONALLICENCE 700 1- Dias M. L. Instituto de Macromoléculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, C.P. 68525 21945-970 Rio de Janeiro, Brazil, BR aut NATIONALLICENCE 700 1- Azuma C. The University of the Air Tokyo Daiichi Gakushu Center 4-1-1, Shimouma, Setagaya-Ku Tokyo 154-0002, Japan, JP aut NATIONALLICENCE 700 1- Mothé C. G. Depto de Processos Orgânicos Escola de Química Universidade Federal do Rio de Janeiro C.P. 68522, 21949-900 Rio de Janeiro, Brazil e-mail: cheila@h2o.eq.ufrj.br, BR aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer