分散剂和超剪切对二氧化硅的协同分散作用

Synergistic dispersion of SiO_(2) by dispersant and supershear

为了提高纳米二氧化硅粉体的分散性,拓展其应用领域,以丙烯酸(AA)、丙烯酸丁酯(BA)为主单体,丙烯酰胺(AM)为功能单体,经自由基溶液聚合法合成了一系列三元共聚物分散剂。采用红外光谱、核磁共振氢谱等对分散剂的分子结构进行了表征,验证了其结构。将此分散剂应用于二氧化硅纳米粉体的表面改性以提高其分散性,同时考察了外加超剪切力场对纳米二氧化硅粉体的分散效果,研究了分散剂用量、超剪切力场强度和分散时间等因素对纳米二氧化硅平均粒径的影响,优化了工艺参数。激光粒度和透射电镜分析结果表明,在分散剂用量为二氧化硅质量的1%、超剪切设备转速为18000 r/min、分散时间为30 min条件下,由于分散剂和超剪切的协同作用,纳米二氧化硅悬浮液的分散性能最佳。

In order to improve the dispersion of nano SiO_(2)powder to extend its application,a series of terpolymer dispersants were synthesized by free radical solution polymerization with acrylic acid(AA)and butyl acrylate(BA)as main monomers and acrylamide(AM)as functional monomer.The molecular structure of the dispersant was characterized by FT-IR and^(1)H-NMR,and its structure was verified.The dispersants were applied to the surface modification of nano-SiO_(2)powder to promote its dispersion,and the role of super shear force field on the dispersion of nano SiO_(2)powder was also studied.The effects of dispersant dosage,the strength of super shear force field and the time of dispersion on the average particle size of nano-SiO_(2)were examined,and the process parameters were optimized.The results of laser diffraction particle size analysis and TEM showed that when the mass proportion of dispersant was 1%of SiO_(2),the stiring speed of the super shear force field was 18000 r/min,and the time of dispersion was 30 min,the dispersion performance of nano SiO_(2)suspension was the best,which was due to the synergistic effects of dispersant and super shear.