Self-condensing Atom Transfer Radical Polymerization from Surfaces: Nanocomposites of Multifunctional Hyperbranched Polymers

从二氧化硅（或金）纳米颗粒表面通过原子转移自由基聚合（ATRP）进行的自凝聚乙烯基聚合（SCVP）可以得到具有极高表面官能团密度和精确纳米尺寸的杂化纳米颗粒。为此，ATRP引发剂与二氧化硅颗粒共价连接，然后是在同一分子中同时具有丙烯酸单体和引发剂功能的引发剂单体（“引发剂”）的SCVP。平均而言，超支化聚合物每个单体单元携带一个溴酯功能。分支度和功能可以通过与丙烯酸单体共聚来调节。溴酯功能将通过化学转化或原子转移自由基加成得到表面密度比线性接枝聚合物高几个数量级的各种官能团。

Self-condensing vinyl polymerization (SCVP) via atom transfer radical polymerization (ATRP) from the surface of silica (or gold) nanoparticles leads to hybrid nanoparticles with an extremely high density of functional groups at the surface and precise nanoscopic dimensions. For this aim, ATRP initiators are covalently linked to silica particles, followed by SCVP of initiator-monomers ("inimers") having both an acrylic monomer and initiator function in the same molecule. On the average, the hyperbranched polymers carry one bromoester function per monomer unit. The degree of branching and functionality can be adjusted by copolymerization with acrylic monomers. The bromoester function will be further modified by chemical transformations or by atom transfer radical addition to result a variety of functional groups with surface densities which are by orders of magnitude higher than for linear grafted polymers.