Change in size and structure of monodisperse poly(N-isopropylacrylamide) microcapsules in response to varying temperature and ethyl gallate concentration

Research output: Contribution to journalArticlepeer-review

Authors

  • Chuan Lin Mou
  • Xiao Heng He
  • Xiao Jie Ju
  • Rui Xie
  • Zhuang Liu
  • Li Liu
  • Liang Yin Chu

Colleges, School and Institutes

External organisations

  • State Key Laboratory of Polymer Materials Engineering
  • Sichuan University

Abstract

The change in size and structure of monodisperse poly(. N-isopropylacrylamide) (PNIPAM) microcapsules in response to varying temperature and ethyl gallate (EG) concentration has been investigated systematically. Monodisperse PNIPAM microspheres and core-shell microcapsules were fabricated via a microfluidic approach. The volume phase transition temperature (VPTT) of PNIPAM microspheres in aqueous solutions with varying EG concentrations were investigated systematically, and the experimental results showed that the VPTT of PNIPAM microspheres in EG aqueous solution decreased with increasing the EG concentration, due to the hydrogen bonding between PNIPAM networks and EG molecules. The change in size and structure of core-shell PNIPAM microcapsules in response to varying temperature and EG concentration was investigated visually by using a confocal laser scanning microscope (CLSM). The core-shell PNIPAM microcapsules changed their volume from swollen to shrunken state upon heating or increasing the EG concentration, and released the colored oil cores suddenly when the environmental temperature was increased to just above the VPTT or the EG concentration was increased to above a critical concentration. From the experimental data, a state diagram of the intact-to-broken transformation of core-shell PNIPAM microcapsules in aqueous solution as a function of temperature and EG concentration has been constructed for the first time.

Details

Original languageEnglish
Pages (from-to)212-219
Number of pages8
JournalChemical Engineering Journal
Volume210
Publication statusPublished - 1 Nov 2012

Keywords

  • Ethyl gallate, Microfluidics, Phase transition, Poly(N-isopropylacrylamide), Responsive core-shell microcapsules