物理化学学报2012，Vol.28Issue(6)：1411-1417,7.DOI:10.3866/PKU.WHXB201203262
嵌段共聚物L64在1-丁基-3-甲基咪唑四氟硼酸盐离子液体中形成的层状液晶
Lamellar Liquid Crystalline Phase Formed by Triblock Copolymer L64 in 1-Butyl-3-methylimidazolium Tetrafluoroborate Ionic Liquid
摘要
Abstract
The aggregation behavior of the triblock copolymer poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (L64, PE013PP03oPEO,3) in the room-temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim] [BFJ) was investigated using polarized optical microscopy (POM), small-angle X-ray scattering (SAXS), and Fourier transform infrared (FTIR) spectroscopy. The phase diagram of the L64/[Bmim] [BF4] system is described, where the micellar phase (L1), a mixture of lamellar liquid crystalline (Lo) and L, phases, theLo phase, a mixture of Lo and reverse micellar (L2) phases, and the Lo phase are sequentially mapped. Among these phases, the behavior of the Lo phase formed in the L64/[Bmim][BF4] system in the L64 concentration region of 40%-65% (w, mass fraction) was focused on because it forms highly-ordered structures. The Maltese cross texture was found through POM characterization, and was typical for the Lo phase. The SAXS patterns further confirm the formation of the Lo phase. In addition, the lattice spacings of the Lo phase were obtained from the SAXS patterns. The effect of temperature on the microstructure of the Lo phase was also elucidated. As the temperature was increased, the lattice spacing and ordering of the Lo phase increased, while the interfacial area decreased for a certain temperature range. However, the birefringence of the Lo phase disappeared when the temperature reached a certain level, which was attributed to the breakdown of hydrogen bonding between [Bmim] [BF4] and polyethylene oxide) chains, so the ordering of the Lo phase was decreased. The formation mechanism of the Lo phase is also discussed. Hydrogen bonding, electrostatic and solvophobic interactions are believed to be the main driving forces for the formation of Lo phase in the L64/[Bmim][BF4] system.关键词
离子液体/嵌段共聚物/层状液晶/聚集行为/形成机理Key words
Ionic liquid/ Block copolymer/ Lamellar liquid crystalline/ Aggregation behavior/ Formation mechanism分类
化学化工引用本文复制引用
赵学艳,曹宇容,曹桂荣,肖瑞杰..嵌段共聚物L64在1-丁基-3-甲基咪唑四氟硼酸盐离子液体中形成的层状液晶[J].物理化学学报,2012,28(6):1411-1417,7.基金项目
中国地震局教师科研基金(20110123)和中央高校基本科研业务费创新项目团队计划(ZY20110103)资助 （20110123）
