本研究以三乙氧基乙烯基矽烷為前驅物,利用溶膠凝膠法製備出表面含乙烯基之二氧化矽顆粒,並以此顆粒作為粒種。因顆粒表面帶有乙烯官能基,可利用起始劑進行自由基聚合反應,將顆粒表面的乙烯基開鍵,形成以C-C單鍵鍵結而成的啞鈴形二氧化矽顆粒。由改變起始劑種類、起始劑濃度、反應時間及抑制劑濃度,探討對顆粒型態的影響,獲得製備高產率啞鈴形二氧化矽顆粒的聚合條件,並探討顆粒之熱性質及光學性質。 由研究結果得知,兩性型起始劑VA-057擁有較好的起始和穩定效能;在適當的起始劑濃度和反應時間下,配合適當濃度的抑制劑DPPH,可獲得高產率的啞鈴形二氧化矽顆粒。由IR、TGA、DSC分析結果可證明單球二氧化矽顆粒表面的乙烯基成功地被開鍵,形成啞鈴形二氧化矽顆粒。
In this study, Silica particles possessing vinyl groups were prepared by sol-gel method using Vinyltriethoxysilane as precursor. Because there are vinyl groups on silica particles, we can take these particles as seeds for polymerization. By using initiator to open vinyl groups and start the free radical polymerization, dumbbell silica particles linked by C-C bond were formed. By changing different kinds of initiators, initiator concentration, reaction time, and inhibitor concentration, the effect on particles morphology were investigated. System to prepare high yield dumbbell silica particles can be found. Thermal and optical property of these silica particles were be measured and tested. From the experimental results, the amphoteric initiator VA-057 has better initiating and stabilizing property. High yield of dumbbell silica particles were formed at appropriate initiator concentration, reaction time, and concentration of inhibitor DPPH. Analysis of IR, TGA, and DSC indicate that vinyl groups on single silica particles were successfully opened to form dumbbell silica particles.