Wang Chen, Lu Si-Xian, Wang Liang, Hui Yao, Lu Yan-Ru, Chen Wei-Jia
School of Materials Science and Engineering, Xi'an Polytechnic University, Xi'an 710048, China.
School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Materials (Basel). 2019 Jul 30;12(15):2428. doi: 10.3390/ma12152428.
In recent years, thermosensitive poly(N-isopropylacrylamide) (PNIPAM) microspheres have received extensive attention due to their many advantages, and their size and swelling ratio are two crucial factors. In this paper, homogeneous and hollow thermosensitive microspheres were prepared by free radical polymerization in an aqueous solution. The effects of the process parameters on the size of the microspheres were studied. The results indicated that the change in size during reaction at different temperatures was not obvious. The size of the microspheres ranged from 802 ± 35.4 nm to 423 ± 33.7 nm with the changes in the dosage of the initiator. Meanwhile, it was observed that the size of microspheres was slightly reduced due to the increase of reaction time. When the dosage of methyl methacrylate (MAA) is increased, the size of the hollow microspheres increased by more than 110%. The average size of the microspheres was smaller when the content of sodium dodecyl sulfate (SDS) was 3 wt%. The microspheres with varying reaction parameters showed a continuous decreasing swelling ratio when the temperatures were changed from 28 °C to 35 °C. In comparison with homogeneous microspheres, the average swelling ratio of hollow microspheres was larger.
近年来，热敏性聚（N-异丙基丙烯酰胺）（PNIPAM）微球因其诸多优点而受到广泛关注，其尺寸和溶胀率是两个关键因素。本文通过水溶液中的自由基聚合制备了均相和中空热敏微球。研究了工艺参数对微球尺寸的影响。结果表明，在不同温度下反应过程中尺寸变化不明显。随着引发剂用量的变化，微球尺寸在802±35.4nm至423±33.7nm范围内变化。同时，观察到微球尺寸因反应时间的增加而略有减小。当甲基丙烯酸甲酯（MAA）用量增加时，中空微球尺寸增加超过110%。当十二烷基硫酸钠（SDS）含量为3wt%时，微球的平均尺寸较小。当温度从28℃变化到35℃时，具有不同反应参数的微球溶胀率持续下降。与均相微球相比，中空微球的平均溶胀率更大。
