摘要
采用水悬浮法对蒙脱石原土进行钠离子交换反应和提纯处理得到纯度较高的钠型蒙脱石。研究了钠型蒙脱石在水中的溶胀行为。用MC1粘度仪研究了蒙脱石水悬浮液的流变特性,考察了蒙脱石的固相含量、在水中的溶胀时间以及电解质对悬浮液流变行为的影响。研究发现:当固相含量较低(≤3.0%,质量分数,下同)时,悬浮液为Newton流体,随着蒙脱石含量的提高(≥5.0%),悬浮液由Newton流体向假塑性流体转变。根据蒙脱石含量的不同,蒙脱石在水中的溶胀剥离需要数小时到数十小时不等,而超声波分散处理使蒙脱石溶胀剥离的时间缩短到10min左右。向蒙脱石水悬浮液中加入电解质NaCl会导致蒙脱石的片层聚并在一起并形成网络结构,悬浮液的粘度特别是在低剪切速率下的粘度有数倍的增加。对不同固液分散相比例的悬浮乳液的流变性能测定表明:蒙脱石片层双电层与乳液液滴的双电层之间存在相互作用,导致悬浮乳液产生独特的粘度变化。
An Na-montmorillonite with high purity was obtained by the water suspension method using the ion exchange reaction and suspension purification treatment. The swelling behavior of montmorillonite in water was studied. The effects of the mass fraction of montmorillonite, swelling time and the addition of NaCI on the rheological behavior of the suspension were investigated by a MC - l rheometer. The results show that when the solids content is lower ≤3.0%, mass fraction, the same below）, the suspension is a Newton liquid, and the suspension becomes a pre-plastic liquid when the montmorillonite content is ≥5.0%. According to the change of the content of montmorillonite in water, it takes several to tens hours for montmorillonite to realize full swelling and exfoliation. But the time for the exfoliation of montmorillonite in water can be shortened to 10 min by using ultrasonic wave dispersion treatment. The flocculation and network structure of montmorillonite layers can he formed by the addition of NaCl. The suspension liquid viscosity, especially under a low shear rate, can be increased for several times. The measurement result for the rheological behaviors of the suspension liquids with different solid fluid dispersed phase ratios indicates that there is an interaction between the double electric layers of the montmorillonite lamellar and the double electric layers of the emulsion droplets, resulting in the particular viscosity change.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2005年第12期1457-1463,共7页
Journal of The Chinese Ceramic Society
基金
国家杰出青年科学基金(20125617)资助项目。~~
关键词
蒙脱石
悬浮液
悬浮乳液
流变行为
montmorillonite
suspension
blend of suspension and emulsion
rheological behavior
