INNOVATIVE BIFUNCTIONAL MICROCAPSULE FOR HEAT STORAGE AND ANTIBACTERIAL PROPERTIES

It is well known that the microcapsules encapsulating heat storage or phase change materials are coated onto the fabrics for the thermoregulating property. To increase their function on the textile application, in this work, bifunctional microcapsules having both thermal energy storage and antibacterial properties were fabricated. Chitosan was used as surfactant of poly(methyl methacrylate-divinyl benzene) microcapsule encapsulated octadecane (OD) prepared by microsuspension iodine transfer polymerization. The nonspherical with dent microcapsules were prepared in acidic condition without any free polymethyl methacrylate particles nucleated by emulsion polymerization. Due to amino groups in chitosan chains were protonated in which presented positive charge, the microcapsules stabilized with such molecules were then obtained without any coalescence. In addition, percent yield of microcapsules decreased with chitosan concentration in the aqueous medium. It may be due to the high viscosity of the aqueous medium where the monomer droplets are unable to maintain the shape in the early stage of the polymerization. For thermal properties, the latent heats of the encapsulated octadecane (234 J/g-OD) were closed to those (233 J/g-OD) of bulk octadecane. For antibacterial property, 2 millimetres over control sample of the resulting inhibition zones of both S. aureus and E. coli were observed. Based on bifunctional feature derived from both microcapsule core and shell for thermal energy storage and antibacterial properties, respectively, the developed microcapsules would express a great potential for textile application.