以溶凝膠法製作SiO2奈米多孔質載體之加工特性的初步探討

Abstract

無機多孔質材料因其高強度與耐熱性廣為各領域所應用，而近年發展迅速的溶膠凝膠法由於能以化學法製作出擁有奈米等級微孔的無機多孔質材料而深受各界重視，其可利用作生物、觸媒、過濾及吸附的載體或母材等等應用。本研究的目的便是要建立利用溶膠凝膠法製作二氧化矽多孔質塊材的製程技術基礎與找出各項製程參數的影響趨勢，然後再加入乾燥控制化學添加劑(DCCA)以測試其效果。最後藉由孔隙分析瞭解實驗獲得的樣本之孔隙大小、孔徑分佈與表面積的資料，藉以找出可以製作具有奈米級孔徑、集中的孔徑分佈與大表面積之載體的加工條件，以作為未來開發功能性材料的參考。研究結果顯示，莫耳水量多、酸催化、低溫反應、低轉速及較短攪拌時間有獲得較小粒徑的趨勢，而DCCA的添加明顯地縮短結膠時間、減少裂痕與增加成形性。本研究獲得的樣本平均孔隙大小約6nm、孔徑分佈集中於4.5nm且表面積為308.6185m2/g。

The sol-gel processing route to advanced glasses and ceramics is a way of manipulating molecular precursors to form bulk oxide materials. The nanoporous bulk oxide materials can be used as filters, catalytic matrices, and sensors. The purpose of this thesis is using sol-gel method to synthesize silica bulk and to compare the influence of the parameters in this process consist of solvents, catalysis, reaction temperature, stirring speed, and reaction times. Then, the use of drying control chemical additives to avoid fracture and crack formation in the conversion of the wet gel to dry gel is favorable. The pore’s structure changes were studied by BET analysis, which were prepared to be the reference of the future further research. A sample study is presented here: from the composition chosen, the pore distribution is very well monodispersed and centred on 4.5nm. The average pore diameter is 58.9497 Å and the surface area is 308.6185m2/g.