Institut Charles Gerhardt, UMR 5253 CNRS/UM/ENSCM, Ingénierie et Architectures Macromoléculaires, Université Montpellier, CC1702, Place Eugène Bataillon, F-34095 Montpellier Cedex 5, France.
Soft Matter. 2017 Jun 28;13(25):4507-4519. doi: 10.1039/c7sm00682a.
A series of amphiphilic photo-responsive heterografted copolymers have been successfully synthesized. The random copolymers were composed of a methacrylate backbone, with various compositions of hydrophilic oligomeric 2-methyl-2-oxazoline side chains (OMOx) and hydrophobic long alkyl chains terminated by a coumarin moiety (Cm). Using dynamic (DLS) and static light scattering (SLS), and transmission electron microscopy (TEM), their self-assembling behavior was studied in water using the nanoprecipitation method. Depending on the system, one, two or three particle size distributions co-exist in solution. However, DLS measurements showed that monomodal and slightly polydisperse self-assemblies were obtained with the more hydrophobic copolymers (i.e., 85% of hydrophobic monomers with a long alkyl chain terminated by a coumarin moiety (MCm) per molecule) with hydrodynamic diameters ranging from ca. 130 to 300 nm. Morphological information on these self-assembly structures was obtained using SLS: a Gaussian behavior has thus been evidenced. Finally, these heterografted copolymers were illuminated using UV light at λ = 350 nm inducing photo-crosslinking of the coumarin units. The influence of UV illumination on the thus-formed nanoparticles was investigated by carrying out complementarily DLS-measurements and UV spectroscopy.
已成功合成了一系列两亲光响应杂化接枝共聚物。无规共聚物由甲基丙烯酸酯主链组成，具有不同组成的亲水性低聚物 2-甲基-2-恶唑啉侧链（OMOx）和由香豆素部分（Cm）封端的疏水性长烷基链。使用动态光散射（DLS）和静态光散射（SLS）以及透射电子显微镜（TEM），通过纳米沉淀法在水中研究了它们的自组装行为。根据系统的不同，溶液中存在一种、两种或三种粒径分布。然而，DLS 测量表明，具有疏水性更强的共聚物（即每个分子中含有 85%的疏水性单体和由香豆素部分封端的长烷基链（MCm））可得到单分散且轻微多分散的自组装体，其水动力直径在约 130 至 300nm 范围内。使用 SLS 获得了这些自组装结构的形态信息：因此证明了高斯行为。最后，使用 350nm 的 UV 光照射这些杂化接枝共聚物，诱导香豆素单元的光交联。通过互补地进行 DLS 测量和 UV 光谱研究，研究了 UV 照射对由此形成的纳米粒子的影响。
