炭黑表面氧化改性及其水分散性研究

Study of surface oxidation of carbon black and its water dispersion

在水介质中利用过硫酸铵对炭黑表面进行氧化改性,考察了炭黑种类、氧化剂含量、反应时间和温度等参数对改性效果的影响。采用XPS和pH计测定分析了炭黑表面基团含量变化,通过膜过滤、激光粒度分析、透射电子显微镜(TEM)观察及炭黑水分散液离心分离等方法考察了改性炭黑的水分散性及分散稳定性。结果表明,过硫酸铵质量分数为0.018%,反应温度为30℃,反应时间为20 h时,炭黑粒度由315.6 nm降至146.8 nm,其水分散液的分散性及稳定性最好,静置一年后无表观沉降。

A simple and environmentally friendly method for the oxidization of carbon black in water, using ammonium persulfate （APS） as an oxidant, has been proposed. The parameters affecting the dispersity and stability of carbon black samples were studied systematically. The functional groups present on the surface of carbon black samples were characterized by X-ray photoelectron spectroscopy （XPS） and pH value measurement. The dispersity was examined by determining the degree of retention of carbon black on filter paper and the stability was examined by measuring the absorbance of the decantate after separation by centrifugation. Furthermore, the particle size of oxidized carbon black was measured with a laser light scattering system and the morphology of the particles was ob- served by transmission electron microscopy （TEM）. The results indicated that the optimum oxidation conditions are an APS content of 0. 018%, an oxidation temperature of 30 ℃ and an oxidation time of 20 h ; under these conditions, Key w the modal particle size of the carbon black decreased from 315.6 nm to 146.8 nm.