星型聚羧酸分散剂对纳米水化硅酸钙特性调控研究

Study on the Regulation of the Characteristics of Nano-calcium-silicate-hydrate by Star Shaped Polycarboxylate Dispersant

采用自由基聚合方法合成了梳型和星型聚羧酸分散剂(PCE),将其作为沉淀底料合成纳米水化硅酸钙晶核(C-S-H/PCE),研究C-S-H/PCE晶核粒径分布和形貌、PCE在C-S-H/PCE晶核表面的吸附量、C-S-H/PCE晶核对硅酸盐水泥水化的影响规律。结果表明:星型PCE较梳型PCE在C-S-H晶核表面具有更大的吸附量,能更好地调控C-S-H/PCE晶核粒径的生长;C-S-H/PCE晶核粒径越小,对硅酸盐水泥水化进程促进越剧烈,更小粒径的C-S-H/PCE晶核使28d硬化水泥浆体具有更少的缺陷孔和更高的抗压强度。

This article synthesizes comb and star shaped polycarboxylate dispersants(PCE)using free radical polymerization method,and uses them as precipitation substrates to synthesize nano-calcium-silicate-hydrate nuclei(C-S-H/PCE),studies the particle size distribution and morphology of C-S-H/PCE nuclei,the adsorption amount of PCE on the surface of C-S-H/PCE nuclei,and the influence of C-S-H/PCE nuclei on the hydration of Portland cement.The results show that the star shaped PCE has a larger adsorption capacity on the surface of C-S-H crystal nuclei than the comb shaped PCE,which can better regulate the growth of C-S-H/PCE crystal nucleus particle size;the smaller the particle size of the C-S-H/PCE crystal nucleus,the more intense the promotion of the hydration process of Portland cement.The smaller the particle size of the C-S-H/PCE crystal nucleus,the less defect pores and higher compressive strength of the 28 days hardened cement slurry.