DWI-Leibniz-Institute for Interactive Materials, e.V. , RWTH-Aachen University , Forckenbeckstraße 50 , D-52074 Aachen , Germany.
Technical University of Cluj-Napoca , Department of Physics and Chemistry , 25 G. Baritiu Str. , RO-400027 Cluj-Napoca , Romania.
Langmuir. 2018 Jul 10;34(27):8031-8041. doi: 10.1021/acs.langmuir.8b01289. Epub 2018 Jun 25.
Understanding the diffusion of gold nanorods (AuNRs) and their composites in dispersion is important at fundamental level and in fields as diverse as material science, nanobiotechnology to drug delivery. The translational and rotational diffusion of AuNRs decorated with thermoresponsive poly( N-isopropylacrylamide) brushes having hydrophilic and hydrophobic end groups was investigated in the dilute regime by dynamic light scattering. The same series of functionalized AuNRs were studied in the isotropic concentrated dispersions by high-resolution NMR diffusometry. The dependence of translational and rotational diffusivity upon molecular weight and polymer end group were measured as a function of temperature in the region of the brush phase transition. The effective hydrodynamic radius of AuNR composites proved to be the most sensitive quantity to the temperature-induced phase transition of brushes, allowing the evaluation of the brush thickness in the swollen and collapsed states.
了解金纳米棒（AuNRs）及其复合材料在分散体中的扩散对于基础研究和材料科学、纳米生物技术到药物输送等各个领域都非常重要。通过动态光散射研究了具有亲水性和疏水性端基的热响应性聚（N-异丙基丙烯酰胺）刷修饰的 AuNRs 在稀释状态下的平移和旋转扩散。通过高分辨率 NMR 扩散测量法研究了同一系列功能化 AuNRs 在各向同性浓缩分散体中的扩散。作为温度的函数，在刷相转变区域测量了平移和旋转扩散系数对分子量和聚合物端基的依赖性。AuNR 复合材料的有效水动力半径被证明是对刷相转变最敏感的量，允许在溶胀和塌陷状态下评估刷的厚度。
