Ueno Kazuhide, Fukai Toshimichi, Nagatsuka Tomomi, Yasuda Tomohiro, Watanabe Masayoshi
Department of Chemistry and Biotechnology, Yokohama National University , 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan.
Langmuir. 2014 Mar 25;30(11):3228-35. doi: 10.1021/la404797g. Epub 2014 Mar 11.
The solubility of poly(methyl methacrylate) (PMMA) in 1-alkyl-3-methylimidazolium ionic liquids (ILs) with different anionic structures has been explored. Nearly monodisperse PMMA-grafted silica nanoparticles (PMMA-g-NPs) were used as a measurement probe for evaluating the PMMA solubility in ILs. The hydrodynamic radius (Rh) of PMMA-g-NPs was measured in the ILs by dynamic light scattering (DLS). Changes in Rh and colloidal stability, that is, the PMMA-solubility change in the ILs, were observed depending on the ionic structures of the ILs. The solubility was mainly affected by the anionic structures of the ILs rather than by the alkyl chain length of the cationic structure. Solvent parameters, including Lewis basicity, solubility parameters, and a hydrophobicity parameter, were used to discuss the change in the PMMA solubility in ILs with different ionic structures. By considering the PMMA solubility in the ILs using these parameters, it was found that there is a good correlation between the PMMA solubility and the hydrophobicity parameter of the anions. Although the change in the PMMA solubility with different cationic structures was not remarkable, the hydrophobicity of the cations also played a role in the solvation of PMMA by providing a low-polarity environment adequate to dissolve PMMA.
人们已经探究了聚甲基丙烯酸甲酯（PMMA）在具有不同阴离子结构的1-烷基-3-甲基咪唑鎓离子液体（ILs）中的溶解度。使用近乎单分散的PMMA接枝二氧化硅纳米颗粒（PMMA-g-NPs）作为测量探针来评估PMMA在离子液体中的溶解度。通过动态光散射（DLS）在离子液体中测量PMMA-g-NPs的流体力学半径（Rh）。根据离子液体的离子结构，观察到Rh和胶体稳定性的变化，即离子液体中PMMA溶解度的变化。溶解度主要受离子液体的阴离子结构影响，而非阳离子结构的烷基链长度。使用包括路易斯碱度、溶解度参数和疏水性参数在内的溶剂参数来讨论具有不同离子结构的离子液体中PMMA溶解度的变化。通过使用这些参数考虑PMMA在离子液体中的溶解度，发现PMMA溶解度与阴离子的疏水性参数之间存在良好的相关性。尽管不同阳离子结构下PMMA溶解度的变化并不显著，但阳离子的疏水性通过提供足以溶解PMMA的低极性环境，也在PMMA的溶剂化过程中发挥了作用。
