Synthesis of poly(N-isopropylacrylamide)/poly(ethyl-2-cyanoacrylate) composite hollow particles

Abstract

Recently, synthesis of hollow particles has received great interest due to their potential applications in controlled drug delivery, cosmetics, paint, electronic inks, heterogeneous catalytic or enzymatic reactions. In most cases, however, the syntheses include sacrificial templates and subsequent delicate removal steps, and which leads to detrimental effects such as, uses of toxic solvents, high impurities, and collapsed shell morphology. In order to resolve such drawbacks, several techniques have been developed. Among the techniques, the Shirasu Porous Glass (SPG) membrane emulsification seems not new but promising due to versatility in material selection, morphology control, energy cost, and mass productions. Herein, we aimed to fabricate monodisperse composite hollow particles of poly(N-isopropylacrylamide)/poly(ethyl-2cyanoacrylate) (namely, poly(NIPAAm)/ poly(E2CA)) by using SPG emulsification, ionic, and photo-polymerization techniques. Poly(NIPAAm) is well known biocompatible polymer exhibiting volume phase transition temperature (VPTT) near lower critical solution temperature (LCST) around 35 C. Poly(E2CA), known as one of ‘instant’ adhesive family, is both biocompatible and biodegradable. In this work, we found that shell morphology of the composite hollow particles was changed from semi-interpenetrating network (semi-IPN) to double shell structure depending on the mass ratio of NIPAAm and E2CA monomers.