Key Laboratory of Applied Chemistry of Hebei Province, College of Environmental and Chemical Engineering, Yanshan University, 066004, Qinhuangdao, P. R. China.
Key Laboratory for Special Fiber and Fiber Sensor of Hebei Province, School of Information Science and Engineering, Yanshan University, 066004, Qinhuangdao, P. R. China.
Macromol Rapid Commun. 2017 Nov;38(22). doi: 10.1002/marc.201700494. Epub 2017 Oct 13.
Functional polymer-grafting silica nanoparticles hold great promise in diverse applications such as molecule recognition, drug delivery, and heterogeneous catalysis due to high density and uniform distribution of functional groups and their tunable spatial distance. However, conventional grafting methods from monomers mainly consist of one or more extra surface modification steps and a subsequent surface polymerization step. A monomer protonation-dependent surface polymerization strategy is proposed to achieve one-step uniform surface grafting of cross-linked poly(4-vinylpyridine) (P4VP) onto core-shell Fe O @SiO nanostructures. At an approximate pH, partially protonated 4VP sites in aqueous solution can be strongly adsorbed onto deprotonated silanol groups (SiO ) onto Fe O @SiO nanospheres to ensure prior polymerization of these protonated 4VP sites exclusively onto Fe O @SiO nanoparticles and subsequent polymerization of other 4VP and divinylbenzene monomers harvested by these protonated 4VP monomers onto Fe O @SiO nanoparticles, thereby achieving direct grafting of cross-linked P4VP macromolecules onto Fe O @SiO nanoparticles.
功能化聚合物接枝二氧化硅纳米粒子由于其高浓度和功能基团的均匀分布以及可调谐的空间距离，在分子识别、药物传递和多相催化等多种应用中具有广阔的应用前景。然而，传统的单体接枝方法主要包括一个或多个额外的表面改性步骤和随后的表面聚合步骤。本研究提出了一种单体质子化依赖的表面聚合策略，实现了交联聚（4-乙烯基吡啶）（P4VP）在核壳 Fe O @SiO 纳米结构上的一步均匀表面接枝。在近似 pH 值下，水溶液中部分质子化的 4VP 位点可以强烈吸附到 Fe O @SiO 纳米球上的去质子化硅醇基团（SiO ）上，以确保这些质子化的 4VP 位点优先单独聚合到 Fe O @SiO 纳米颗粒上，然后聚合其他 4VP 和二乙烯基苯单体，这些单体是由这些质子化的 4VP 单体收集到的，从而实现交联 P4VP 大分子直接接枝到 Fe O @SiO 纳米颗粒上。
