吸附聚羧酸系与萘系超塑化剂水泥颗粒的电性行为研究

Study of Electric Behavior of Cement Particles Adsorbing Co-Polycarboxylate and Naphthalene Sulphonate Superplasticizer

水泥颗粒表面的电性质是新拌水泥浆体分散的重要因素之一。文章通过不同掺量萘系(UNF-5)和聚羧酸系(COPOCA202)超塑化剂的水泥颗粒表面电位试验和此两种超塑化剂饱和掺量以及未掺超塑化剂时水泥颗粒表面电位随时间变化试验,认为:超塑化剂的掺入使水泥颗粒电性统一,掺UNF-5带负电,掺COPOCA202则带正电,并随时间的延长其绝对值均逐渐降低;这种电性统一是新拌水泥浆体分散的重要来源;COPOCA202系比UNF-5对表面电位改变能力小。

Electric behavior on the surface of cement particles featured one of the important factors for dispersion of freshlymixed cement paste, By means of Zeta potential tests on the surface of cement particles with different addition of naphthalene sulphonate-based superplasticizer（UNF-5） and co-polycarboxylate-based superplasticizer（COPOCA202） as well as tests of zeta potential varied along with time on the surface of cement particles with saturated addition of superplasticizer and without addition of superplasticizer, it was determined that addition of superplasticizer facilitated consistence of electric behavior on the surface of cement particles, i.e., addition of UNF-5 charged negative whereas addition of COPOCA202 charged positive, both of their absolute values decreased with time elapsing. This consistence of electric behavior indicated an important impetus to dispersion of freshly-mixed cement paste, UNF-5 changed zeta potential more than COPOCA202.