(643c) A Novel Smart Microsphere with K+-Induced Shrinking and Aggregating Property Based on Responsive Host-Guest System Conference: AIChE Annual MeetingYear: 2015Proceeding: 2015 AIChE Annual MeetingGroup: Particle Technology ForumSession: Functional Nanoparticles Time: Thursday, November 12, 2015 - 9:08am-9:27am Authors: Jiang, M. Y., Sichuan University Chu, L., Sichuan University Ju, X. J., Sichuan University Liu, Z., Yu, H. R., Jiang, L., Wang, W., Sichuan University Xie, R., Sichuan University Chen, Q. M., Fang, L., A novel type of smart microspheres with K+-induced shrinking and aggregating properties is designed and developed based on K+-recognition host-guest system. The microspheres are composed of crosslinked poly(N-isopropylacrylamide-co-acryloylamidobenzo-15-crown-5) (P(NIPAM-co-AAB15C5)) networks. Due to the formation of stable 2:1 “sandwich-type” host-guest complexes between 15-crown-5 units and K+ ions, the P(NIPAM-co-AAB15C5) microspheres significantly exhibit isothermally and synchronously K+-induced shrinking and aggregating properties at a low K+ concentration; while other cations (e.g., Na+, H+, NH4+, Mg2+ or Ca2+) can not trigger such response behaviors. Effects of chemical compositions of microspheres on the K+-induced shrinking and aggregating behaviors are investigated systematically. The K+-induced aggregating sensitivity of the P(NIPAM-co-AAB15C5) microspheres can be enhanced by increasing the content of crown ether units in the polymeric networks; however, it is nearly not influenced by varying the monomer and crosslinker concentrations in the microsphere preparation. State diagrams of the dispersed-to-aggregated transformation of P(NIPAM-co-AAB15C5) microspheres in aqueous solutions as a function of temperature and K+ concentration are constructed, which provide valuable information for tuning the dispersed/aggregated states of microspheres by varying environmental K+ concentration and temperature. The microspheres with synchronously K+-induced shrinking and aggregating properties proposed in this study provide a brand-new model for designing novel targeted drug delivery systems.