ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Copolymerization of silicon alkoxides in alcoholic basic medium usingtrialkyl- or triarylchlorosilanes as terminator was investigated. Tetraethoxysilane(TEOS), phenyltriethoxysilane (PTEOS) and vinyltriethoxysilane (VTEOS) wereused as monomers and triphenylchlorosilane (TPCS) and trimethylchlorosilane(TMCS) as terminator. The copolymerization of TEOS with PTEOS and VTEOSproduces core-shell silica-silicone nanospherical hybrids containing large amounts offunctional groups in the structure of their external layer. The structure is the result ofthe fast hopolymerization of TEOS in a first stage of the reaction, forming the core,followed by copolymerization of TEOS and the alkyl- or vinyl-trialkoxysilanecomonomer in its last stage. The structure was confirmed by Raman and FTIRspectroscopy, wide angle X-ray scattering (WAXS) and thermogravimetry. Thecontrol of particle size is effectively made by the termination reaction and particleswith average diameter between 20 and 100 nm were obtained. Introduction of otherchemical functions on the surface of these nanoparticles can be carried out bycommon reactions with the functional surface groups. As an example, sulfonation ofparticles containing phenyl groups on the surface by direct sulfuric acid andchlorosulfonic acid was investigated and the results discussed
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/18/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.570.24.pdf
