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通过可逆断裂链转移加成聚合,制备了单分散的聚甲基丙烯酸叔丁酯,并一步水解获得了具有硫醇端基的聚甲基丙烯酸(PMAA).在还原氯金酸为金纳米粒子的同时,利用硫醇端基与金纳米粒子(GNPs)的耦合作用,一步获得了聚甲基丙烯酸单层保护的金纳米粒子.通过紫外光谱和透射电镜表征证实,金纳米粒子为单分散的球型颗粒,在水溶液中具有长期稳定性.聚甲基丙烯酸单层保护的金纳米粒子的光学性质和聚集状态,具有明显的pH响应性.在酸性条件下,由于PMAA被质子化发生疏水性转变,聚合物链收缩聚集,促使金纳米粒子之间互相靠近并聚集,其表面等离子共振吸收峰发生红移.从酸性调节为碱性后,(PMAA-@-GNPs)能重新分散,吸收峰发生蓝移.在多次循环后,溶液的光学信号能可逆互变且变化不大.
The monodispersed poly (t-butylmethacrylate) was prepared by reversible fragmentation and chain transfer addition polymerization, and polymethylmethacrylate (PMAA) with thiol end groups was obtained by one-step hydrolysis. The gold nanoparticles protected by poly (methacrylic acid) monolayer were obtained in one step by the coupling of thiol end groups and gold nanoparticles (GNPs) .Using UV spectroscopy and transmission electron microscopy, gold nanoparticles were monodispersed Spherical particles with long-term stability in aqueous solution.The polymethacrylate monolayer protected the optical properties and aggregation state of the gold nanoparticles with obvious pH responsiveness Under acidic conditions, PMAA is protonated to be hydrophobic (PMAA - @ - GNPs) can be redispersed and the absorption peak (PMAA - @ - GNPs) redisplays after the surface plasmon resonance absorption peaks shift from acidic to basic. Blue shift occurred.After many cycles, the optical signal of the solution could reversibly change and change little.