Preparation of free-standing thermosensitive composite gel particles incorporating ionic liquids
Preparation of free-standing thermosensitive composite gel particles incorporating ionic liquids
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DOI：
10.1039/c2sm27393d
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发表时间：
2013-01
期刊：
影响因子：
3.4
通讯作者：
Toyoko Suzuki;H. Ichikawa;M. Nakai;H. Minami
中科院分区：
文献类型：
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作者：
Toyoko Suzuki;H. Ichikawa;M. Nakai;H. Minami
以甲基丙烯酸-2-苯乙酯(P(PhEMA-VT)/1-丁基-3-甲基咪唑双([Bmim][TFSA]，IL)凝胶粒子为催化剂，采用种子聚合法合成了甲基丙烯酸-2-苯乙酯-乙烯基甲苯(VT)共聚物(P(PhEMA-VT))与聚甲基丙烯酸甲酯(PMMA)的复合凝胶粒子，其中P(PhEMA-VT)具有较低的临界溶液温度(LCST)型相变行为。在70℃(LcST以上)得到的粒子呈雪人状相分离，并明显表现出P(PhEMA-VT)相尺寸减小，PMMA相尺寸增大的体积-相变行为。P(PhEMA-VT)相表现为LCST型的体积-相变行为，发生了IL的分离。相反，PMMA相膨胀，IL从P(PhEMA-VT)相中分离出来，PMMA相可以作为IL的保存剂。有趣的是，复合凝胶粒子在空气和真空中都表现出相似的体积-相变行为，没有IL从凝胶粒子中泄漏出来，这应该是独立的热敏性凝胶粒子。
Composite gel particles consisting of 2-phenylethyl methacrylate (PhEMA)-vinyl toluene (VT) copolymer (P(PhEMA-VT)) and poly(methyl methacrylate) (PMMA) were prepared by seeded polymerization of MMA in the presence of P(PhEMA-VT)/1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([Bmim][TFSA], IL) gel particles, in which P(PhEMA-VT) exhibited lower critical solution temperature (LCST)-type phase transition behavior in IL. The particles obtained at 70 °C (above the LCST) adopted a phase-separated snowman-like shape and clearly exhibited volume–phase transition behavior in which the P(PhEMA-VT) phase reduced in size and the PMMA phase increased in size above the LCST. The P(PhEMA-VT) phase exhibited LCST-type volume–phase transition behavior and separation of IL occurred. In contrast, the PMMA phase was swollen with IL separated from the P(PhEMA-VT) phase, in which the PMMA phase could act as a preserver of IL. Interestingly, the composite gel particles exhibited similar volume–phase transition behavior in both air and vacuum without leakage of IL from the gel particles, which should be free-standing thermosensitive gel particles.