Preparation of silica particles utilizing the sol-gel and the emulsion-gel processes

Autor:	Ritva Lindberg, Johan Sjöblom, Göran Sundholm
Rok vydání:	1995
Předmět:	Colloid and Surface Chemistry Aqueous solution Chemical engineering Pulmonary surfactant Chemistry Precipitation (chemistry) Dispersity Emulsion Concentration effect Organic chemistry Particle size Sol-gel
Zdroj:	Colloids and Surfaces A: Physicochemical and Engineering Aspects. 99:79-88
ISSN:	0927-7757
Popis:	The preparation of silica particles by means of the sol-gel or emulsion-gel techniques has been studied. In the case of precipitation from homogeneous solutions, we have studied the whole solution phase in the system tetraethyl orthosilicate-ethanol-aqueous ammonia and have mapped the region for monodisperse particles. These particles have a size of 70–640 nm. Their size and monodispersity are controlled by the composition of the system. Utilizing the emulsion-gel technique it is possible to increase the particle size to some tens of micrometers, but the polydispersity increases. In the emulsion-gel process the best results were obtained for small water contents (below 15 wt.%) and low amounts of surfactant (less than 0.5 wt.%) and for considerably longer reaction times than for the conventional sol-gel process.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c7bb1894af1f52aaa00fe3664ab47454 https://doi.org/10.1016/0927-7757(95)03117-v Zobrazit plný text záznamu Full Text from ScienceDirect