Yoon Se-Young, Deng Yulin
School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 500 10th Street, NW, Atlanta, GA 30332-0620, USA.
J Colloid Interface Sci. 2004 Oct 1;278(1):139-45. doi: 10.1016/j.jcis.2004.05.011.
The focused beam reflectance measurement (FBRM), also known as scanning laser microscopy (SLM), was used as a real-time monitor to study the flocculation and reflocculation of clay suspensions under different shear conditions in the presence of single polymer, dual polymer, microparticle and poly(ethylene oxide)/phenolformaldehyde (PEO/PFR) flocculation systems. For initial flocculation, the high molecular weight PEO and cationic polyacrylamide (CPAM) produced larger flocs than others. However, reflocculation of clay suspensions formed by these non- or low-charged polymers was insignificant after the initial flocs were broken under high shear force. In contrast, high charge density polymers, such as poly(diallyldimethylammonium chloride) (PDADMAC), do not form large initial flocs, but they showed significant reflocculation ability under a continuous shear condition. It is concluded that high flocculation can be obtained by effective polymer bridging, but high reflocculation can only be induced by high electrostatic attractive forces between suspended particles.
聚焦光束反射测量（FBRM），也称为扫描激光显微镜（SLM），被用作实时监测手段，以研究在单一聚合物、二元聚合物、微粒和聚环氧乙烷/酚醛树脂（PEO/PFR）絮凝体系存在下，不同剪切条件下粘土悬浮液的絮凝和再絮凝情况。对于初始絮凝，高分子量的PEO和阳离子聚丙烯酰胺（CPAM）比其他物质产生的絮体更大。然而，在高剪切力作用下初始絮体破碎后，由这些非带电或低电荷聚合物形成的粘土悬浮液的再絮凝并不显著。相比之下，高电荷密度聚合物，如聚二烯丙基二甲基氯化铵（PDADMAC），不会形成大的初始絮体，但在连续剪切条件下它们表现出显著的再絮凝能力。得出的结论是，有效的聚合物架桥可实现高絮凝，但只有悬浮颗粒之间的高静电吸引力才能引发高再絮凝。
