The structures and properties of nanosilica materials prepared via reverse micelle method

• Main Authors: Li-Tzuen Hong, 洪笠尊
• Other Authors: 賴偉淇
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/05820613873939177541

碩士 === 淡江大學 === 化學工程與材料工程學系碩士班 === 102 === In this study, sodium bis(2-ethylhexyl) sulfosuccinate (AOT) / water / hexane reverse micelle system was regarded as microreactor ,and then adding the precursor of silica,Tetraethylorthosilicate(TEOS),into the reverse micelle system then hydrolysis and condensation reaction occurred in alkaline conditions .Therefore,reverse micelles was regarded as a template which can control the growth structure of silica,then evaporating the solvent to change the system into high concentration gel material. By FTIR analysis,we observed the characteristic peaks of the silica in the gel at the band 465 ,792,and 1102cm-1 which means the formation of the silica.By rheometer analysis,the rheological property transformed from gel-like state (Multi relaxatuon model) to gel state (G’>G”at all frequency)after the formation of silica in the reverse micelle.Whith increase of AOT concentration,the amount of TEOS,and lower value of wo,the material has better solid elastic properties(G’).By SAXS analysis,when AOT/water/ hexane reverse micelle system in 6m AOT concentration ,the structure of reverse micelle is no long-range cylindrical structure.When AOT concentration increase to 72m,the structure transform to hexagonally closed-packed cylindrical structure.However,the SAXS results showed no long-range cylindrical structure after the hydrolysis and condensation reaction at low and high concentration .By POM and TEM analysis,the fiber bundle which composed of cylindrical fiber were found at high concentration AOT reverse micelle system .As the silica was generated in reverse micelle,the fiber bundle were randomly oriented.By TGA analysis, with increase of wo value ,the material had poor thermal stability because excess water caused AOT and silica arranged loosely and had weakened interation between each other. With the addition of more TEOS, the more residual silica,which means that the more convertion ratio of silica.