Klimkevicius Vaidas, Graule Thomas, Makuska Ricardas
Department of Polymer Chemistry, Vilnius University , Naugarduko 24, LT-03225, Vilnius, Lithuania.
Langmuir. 2015 Feb 24;31(7):2074-83. doi: 10.1021/la504213t. Epub 2015 Feb 11.
Cationic linear polymer poly([2-(methacryloyloxy)ethyl] trimethylammonium chloride) p(METAC), neutral brush polymer poly(poly(ethylene glycol) methyl ether methacrylate) p(PEO22MEMA), and cationic comb copolymers p(METAC-PEO(x)MEMA) were used for the stabilization of titania dispersions under neutral and alkaline conditions. Random comb copolymers p(METAC-PEO(x)MEMA) differing in charge density and length of PEO side chains were synthesized by RAFT. The adsorption of cationic polymers on titania nanoparticles was evaluated by thermogravimetric analysis; changes in surface potential, by measuring the zeta potential; and the stability of the treated TiO2 dispersions, by laser diffraction and DLS. Cationic linear and comb copolymers containing relatively short PEO side chains promoted the inversion of nanoparticle surface potential from strongly negative (-60 mV) to moderately positive (10-35 mV). Cationic comb copolymers containing longer PEO side chains increased the zeta potential of the treated nanoparticles but did not invert it to positive. Aqueous dispersions of titania nanoparticles stabilized by cationic comb copolymers under alkaline conditions (pH 10) were dispersed by high-energy planetary ball milling up to a primary particle size of 20 nm and were stable for at least 2 days.
阳离子线性聚合物聚（[2 - （甲基丙烯酰氧基）乙基]三甲基氯化铵）p（METAC）、中性刷状聚合物聚（聚乙二醇甲基醚甲基丙烯酸酯）p（PEO22MEMA）以及阳离子梳状共聚物p（METAC - PEO(x)MEMA）用于在中性和碱性条件下稳定二氧化钛分散体。通过可逆加成 - 断裂链转移聚合（RAFT）合成了电荷密度和聚环氧乙烷（PEO）侧链长度不同的无规梳状共聚物p（METAC - PEO(x)MEMA）。通过热重分析评估阳离子聚合物在二氧化钛纳米颗粒上的吸附；通过测量zeta电位评估表面电位的变化；通过激光衍射和动态光散射（DLS）评估处理后的二氧化钛分散体的稳定性。含有相对较短PEO侧链的阳离子线性和梳状共聚物促使纳米颗粒表面电位从强负（-60 mV）转变为中等正（10 - 35 mV）。含有较长PEO侧链的阳离子梳状共聚物增加了处理后纳米颗粒的zeta电位，但未将其转变为正值。在碱性条件（pH 10）下由阳离子梳状共聚物稳定的二氧化钛纳米颗粒水分散体通过高能行星球磨分散至初级粒径为20 nm，并至少稳定2天。
