Department of Chemistry, Technical University of Denmark , 2800 Kgs. Lyngby, Denmark.
Langmuir. 2017 May 16;33(19):4806-4815. doi: 10.1021/acs.langmuir.7b00953. Epub 2017 May 3.
The effect of sodium fluoride, sodium trichloroacetate, and sodium thiocyanate on the stability and conformation of poly(N-isopropylacrylamide), in bulk solution and at the gold-aqueous interface, is investigated by differential scanning calorimetry, dynamic light scattering, quartz crystal microbalance, and atomic force microscopy. The results indicate a surface partitioning of the weakly hydrated anions, i.e., thiocyanate and trichloroacetate, and the findings are discussed in terms of anion-induced electrostatic stabilization. Although attractive polymer-ion interactions are suggested for thiocyanate and trichloroacetate, a salting-out effect is found for sodium trichloroacetate. This apparent contradiction is explained by a combination of previously suggested mechanisms for the salting-out effect by weakly hydrated anions.
通过差示扫描量热法、动态光散射、石英晶体微天平以及原子力显微镜研究了氟酸钠、三氯乙酸钠和硫氰酸钠对聚（N-异丙基丙烯酰胺）在本体溶液和金-水界面的稳定性和构象的影响。结果表明，弱水合阴离子（即硫氰酸根和三氯乙酸根）发生表面分配，根据阴离子诱导的静电稳定化作用对结果进行了讨论。尽管硫氰酸根和三氯乙酸根与聚合物离子之间存在吸引力相互作用，但三氯乙酸钠却表现出盐析效应。通过将之前提出的弱水合阴离子盐析效应的机制进行组合，对这种明显的矛盾进行了解释。
