- 學位論文
二苯亞甲基山梨醇與醇系統有機膠之結構與性質研究
Studies on the structure-property of the organogels composed of dibenzylidene sorbitol and alcohol system
摘要
本研究以二苯亞甲基山梨醇(DBS)之衍生物與醇類極性溶劑所形成有機膠分別形成兩個系統，一方面改變溶劑極性基團與分子量，另一方面改變二苯亞甲基山梨醇分子上的基團作探討;討論其有機膠之結構型態、流變性質、熱性質、分子間作用力。 由結構與型態中可觀察到DBS形成之馬爾他十字類似球晶外觀，並由SEM與TEM中觀察到DBS與其衍生物自組裝所形成網狀纖維之外觀，DBS有機膠可由SAXS觀察到可能為層狀堆積。由流變性質與熱性質可發現，因PEG溶劑鏈長較長末端基影響相對明顯;長碳鏈與OH末端基使DBS不易自組裝，形成之有機膠強度較弱且有機膠相變化較慢。IR與UV分析可知道雖小分子溶劑OH末端基較多，但分子無長碳鏈阻礙有助於DBS的自組裝。在DBS與其衍生物系統中，由流變性質與熱性質可得知DBS衍生物分子上的碳基團對於自組裝型成立體障礙，阻礙PEG的OH末端基團影響使其較易自組裝並使有機膠易相變化，但不易形成整齊的結構。IR分析可得知1wt%DBS有機膠雖有較強的氫鍵，但形成的纖維強度不足以成膠。藉由UV與文獻推測出DBS苯環為T-shape堆疊而DMDBS為邊對平面之堆疊模式。
並列摘要
We study the organogels of structure, rheology and thermal Properties in two systems by 1,3:2,4 -Dibenzylidene sorbitol(DBS) and alcohol systems. One system is the difference between molecular weight and different end groups of alcohol solvents and another is the structure difference between DBS and its derivers. By POM analysis, we found the spherulite-like structure and the 3-D network of DBS by TEM and SEM. We also found the DBS organogels aggregate as lamellar type by SAXS. By rheology and thermal Properties analysis, we found the long carbon chains of PEG make the OH end groups more influential ;the long carbon chains of PEG and the OH end groups made DBS cannot self-assemble easily result in weaker organogels and slower phase transition . By IR and UV analysis we found though small molecular weight solvents have more OH end groups, DBS still self-assemble easily in these solvents without long carbon chains barrier. By rheology and thermal properties analysis, we found the alkyl groups steric resistance of DBS derivers keep the molecules away from PEG OH end groups then made organogelaters self-assemble and phase transition easily. By IR analysis we found though 1wt% DBS organogel has stronger hydrogen bond, the fibers of DBS were too weak to form gel. By UV analysis, we can simulate DBS phenyl rings stack as T-shape (point to face) and DMDBS stack as face to edge structure.