School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3216, Australia.
J Phys Chem B. 2013 Jul 18;117(28):8430-5. doi: 10.1021/jp4043232. Epub 2013 Jul 8.
We have investigated the influence of a series of triethylammonium-based protic ionic liquid-water solutions on the lower critical solution temperature (LCST) of poly(N-isopropylacrylamide) (PNIPAM). We find that kosmotropic anions lower the LCST of PNIPAM more dramatically when compared with chaotropic anions. In addition, we have probed the solvent properties of the hydrated protic ionic liquid solutions using (1)H NMR, polarity measurements, and solvatochromic analysis of the Kamlet-Taft parameters, β and π*. We find that the hydrogen bond character--more specifically, the interactions between water and pIL--is the dominant parameter responsible for lowering the LCST of PNIPAM. We have added choline dihydrogen phosphate (choline dhp) into this study on the basis of positive results from previously reported protein folding studies using this ionic liquid.
我们研究了一系列三乙铵基质子离子液体-水溶液对聚（N-异丙基丙烯酰胺）（PNIPAM）的低临界溶液温度（LCST）的影响。我们发现与离液性离子相比，亲液性离子使 PNIPAM 的 LCST 显著降低。此外，我们还使用（1）H NMR、极性测量和 Kamlet-Taft 参数β和π*的溶剂变色分析研究了水合质子离子液体溶液的溶剂性质。我们发现氢键特性——更具体地说，水与 pIL 之间的相互作用——是导致 PNIPAM 的 LCST 降低的主要因素。我们在以前使用这种离子液体进行蛋白质折叠研究的报告中得到了积极的结果的基础上，将磷酸二氢胆碱（choline dhp）添加到这项研究中。
