H_2O_2处理碳包覆铁纳米颗粒的表面特性及分散行为

采用体积分数30%的H2O2处理碳包覆铁纳米粒子外层的非晶态类石墨碳层,并将其超声分散于水介质中,通过改变pH值分析测定碳包覆铁纳米粒子表面zeta电位和粒径。结果表明:碳包覆铁纳米粒子非晶碳层的特殊结构可通过双氧水化学处理使其表面产生羧基和羟基;在强碱性介质下,羟基和羧基可强化颗粒间的静电斥力,提高碳包覆铁纳米粒子在水介质中的分散性能。当pH值约为11.5时,碳包覆铁纳米粒子表面zeta电位为48 mV,水合粒子粒径可达到110 nm。

Surface Properties and Dispersion Behavior of Carbon Coated Nano-particles Treated with H2O2

Carbon coated iron nano-particles with amorphous graphite carbon layer was treated with H2O2,the volume fraction was 30%.The sample was dispersed in aqueous media by ultrasonic vibration.Zeta potential and particle size of carbon-coated iron nano-particles were measured at different pH value.The results showed that the carboxyl and hydroxyl groups emerged on the surface of amorphous carbon layer of carbon coated iron nano-particles after chemical treatment by hydrogen peroxide.In strong alkaline medium,the hydroxyl and carboxyl groups enhanced the electrostatic repulsion between the particles and improved the dispersion of carbon coated iron nano-particles in water.Zeta potential of carbon coated iron nano-particles was 48 mV and the hydrated particle size was 110 nm at pH 11.5.