Nonsolvents-induced swelling of poly(methyl methacrylate) nanoparticles.
Nonsolvents-induced swelling of poly(methyl methacrylate) nanoparticles.
复制标题
DOI：
10.1039/c3cp52673a
复制
发表时间：
2013-09
期刊：
影响因子：
--
通讯作者：
A. Shundo;Koichiro Hori;D. Peñaloza;Kazuki Yoshihiro;M. Annaka;Keiji Tanaka
中科院分区：
文献类型：
--
作者：
A. Shundo;Koichiro Hori;D. Peñaloza;Kazuki Yoshihiro;M. Annaka;Keiji Tanaka
聚合物纳米颗粒已用于各种各样的应用中。在大多数这些应用中，它们通常分散在非溶剂中。然而，非溶剂对纳米粒子的结构、物理性质和功能的影响尚未被考虑。采用无皂乳液聚合法制备了单分散的聚甲基丙烯酸甲酯（PMMA）纳米粒子。将PMMA纳米粒子分散在水和甲醇中，这两种典型的PMMA非溶剂中，以便我们可以讨论非溶剂对纳米粒子的影响。动态光散射测量结果表明，在甲醇中的PMMA纳米粒子的流体动力学半径大于相同的PMMA分散在水中。它们的DLS值也大于通过原子力显微镜测量的纳米颗粒的半径。当芘与PMMA纳米颗粒一起分散在甲醇中时，它被掺入纳米颗粒中。这些结果清楚地表明，非溶剂分子可以被吸附到聚合物纳米颗粒中，因为聚合物链段可能溶解到液相中的界面区域对于此类纳米颗粒来说总体积相当大。因此，基于我们的发现，可以论证地确定，目前关于聚合物在其非溶剂中不溶胀的假设不一定是正确的。
Polymer nanoparticles have been used in a wide variety of applications. In most of these applications, they are generally dispersed in a non-solvent. However, the effect of the non-solvent on the structure, physical properties and function of the nanoparticles has not yet ever taken into account. In this study, monodispersed poly(methyl methacrylate) (PMMA) nanoparticles were prepared by a surfactant-free emulsion polymerization. The PMMA nanoparticles were dispersed in water and in methanol, both typical non-solvents for PMMA, so that we could discuss the effect of the non-solvent on the nanoparticles. Dynamic light scattering measurements revealed that the hydrodynamic radius of the PMMA nanoparticles in methanol was larger than the same PMMA dispersed in water. Their DLS values were also larger than the radius of the nanoparticles measured by atomic force microscopy. When pyrene was dispersed in methanol with the PMMA nanoparticles, it was incorporated into the nanoparticles. These results clearly indicate that non-solvent molecules can be sorbed into polymer nanoparticles because the area of the interface, where polymer segments might be dissolved into liquid phases, as the total volume is quite larger for such nanoparticles. Therefore, based on our findings, it can be arguably established that the present assumption for a polymer not to be swollen in its non-solvent is not necessarily true.