Properties of differently charged poly(N‐isopropylacrylamide) Latex dispersions in alcohol‐water mixtures
Properties of differently charged poly(N‐isopropylacrylamide) Latex dispersions in alcohol‐water mixtures
复制标题
不同电荷的聚（N-异丙基丙烯酰胺）乳胶分散体在醇-水混合物中的性能
DOI：
10.1002/bbpc.19981021135
复制
发表时间：
1998
期刊：
影响因子：
--
通讯作者：
R. Zimehl
中科院分区：
文献类型：
--
作者：
M. Mielke;R. Zimehl
Results of size control experiments, TEM and viscosity measurements on both negatively and positively charged poly(N-isopropylacrylamide) (PNIPAAM) latex dispersions are reported. In alcohol-water mixtures containing low weight fractions of alcohols higher than methanol, negatively and positively charged PNIPAAM particles exhibit both opposite swelling behaviour and flow characteristics at 20°C. Negatively charged particles shrink due to cononsolvency. Shrinking leads to a decreased viscosity. Conversely, positively charged particles swell dramatically and exhibit an increased viscosity. At 40°C, the negatively charged particles collapse and show a similar behaviour to those with positive charge. We observed with TEM that positively charged particles form random flocks after drying on the grid whereas negatively charged ones form arrays of separated particles. This underlines our general concept that the positively charged particles are in general more hydrophobic.
