凹土在水中的纳米化及晶束解离行为研究

Nano-dispersion behavior and crystal-bundles dissociation of palygorskite under water

采用玻片提拉法对新鲜浆料在线取样,扫描电子显微镜(SEM)直观展示凹土在水中的纳米化及晶束解离的微观形貌变化,结合粒度和沉降行为分析,评价了现行凹土纳米化的工艺条件.结果表明,水化作用促进致密凹土颗粒崩解并蓬松化,同时凹凸棒晶束逐步解离;在凹土微纳米化及晶束解离过程中,分散剂的位阻效应强于静电斥力;解离后的凹凸棒晶仍倾向成束和相互架靠,形成疏松透水的水稳性团聚体.浆料浓度为0.1%,在高速搅拌、协同分散剂共同作用下,也难以获得单分散的凹凸棒晶纤维.

The scanning electron microscope （SEM） was used to display the change of microcosmic morphology sampled from fresh pulp stock by online glass slides pulling. The objective evaluation to present nano-dispersion technology of palygorskite was achieved based on SEM, sedimentation experiment and size characterization. The results indicate that the hydration pro- moted the compact particle disintegrating and fluffing, which came with the crystal-bundles dispersing of palygorskite. The steric hindrance effect of the dispersants was more than its electrostatic repulsion effect on this dispersing system. The dispersed nanorods tended to be assemble into bundles, interweaved with each other, and further formed permeable water stable aggregates. It was very hard to get single crystal even for 0.1% concentration pulp while being cooperated with high speed stirring and fine dispersant.