Abstract: Quaternary ammonium type cationic starch with low degree of substitution was used to modify the surface of fly ash fibres (FAFs) which was pretreated by hydrochloric acid first. The optimization of acid pretreatment condition, and cationic modification and the effects of surface zeta potential on the dispersion of FAFs in water were examined. The results showed that the cationic FAFs with the maximum surface Zeta potential of 19.00 mV could be obtained under the conditions of 30 min pretreatment with 0.3 mol/L HCl and 40 min cationic modification with cationic starch at the water concentration of 0.06% in 40 min stirring time under normal temperature. SEM analysis showed good coating status of FAFs. The dispersion and settling experiments proved that the higher the surface Zeta potential was, the longer the settling time would be and the better the dispersion would turn, when Zeta potential increased to 17.20 mV, the anti-flocculation was improved obviously.

Key words: fly ash fibre, hydrochloric acid pretreatment, cationic surface modification, zeta potential, dispersion

摘要： 将粉煤灰纤维通过盐酸预处理后，采用低取代度季铵型阳离子淀粉对其进行表面阳离子化改性，研究了粉煤灰纤维的酸化条件筛选、阳离子化改性的工艺条件及纤维表面Zeta电位对其在水中分散的影响. 结果表明，经0.3 mol/L HCl预处理30 min后，常温下加入粉煤灰纤维质量3%的阳离子淀粉(水相浓度0.06%)，作用40 min，所得阳离子化粉煤灰纤维的Zeta电位达最高值19.00 mV；由SEM观测到其包覆状况较好，水中分散和沉降实验证实了其表面Zeta电位越高，沉降时间越长，分散性越好，当Zeta电位增至17.20 mV以上时，纤维的抗絮凝性明显改善.

关键词: 粉煤灰纤维, 酸处理, 阳离子化改性, zeta电位, 分散