Preparation of Microcapsules Containing Water and Effect of Water Content on Expansion Behavior

Abstract

The research work was conducted in order to establish the optimum conditions for preparing the expanded polystyrene beads without harmful substances and was aimed at the preparation of the microcapsules containing water and investigation of the effect of the water content on the expansion behavior of microcapsules. Microcapsules were prepared with the suspension polymerization method and the suspension polymerization in parallel with interfacial polycondensation method using the multiple emulsion (W/O)/W and adding a few additives. With increasing the crosslinking agent concentration in the suspension polymerization method, the water content increased from R = 5.8 wt% (C T = 0) to R = 8.2 wt% (C T = 4 wt%) and then, decreased to R = 7.5 wt% (C T = 9.0 wt%), while the expansion ratio increased from E = 1.01 (C T = 0) to E = 2.20 (C T = 4 wt%) and then, decreased to E = 1.01 (C T = 7.0 wt%). With increasing the added amount of wax in the suspension polymerization method, the water content gradually increased from R = 2.5 wt% to R = 8.0 wt%, while the expansion ratio increased from E = 1.01 to E = 1.5 and then, decreased. The water content and the expansion ratio could be increased by conducting suspension polymerization in parallel with interfacial polycondensation reaction from R = 5.0 wt % to R = 8.0 wt % and from E = 1.01 to E = 1.3, respectively. The maximum expansion ratio of E = 2.58 in this work was obtained under the conditions of crosslinking agent concentration of C T = 4.0 wt %, the added amount of wax of 3.0 g, addition of Agarose and the expansion temperature of T = 150˚C.

Rapid and Highly Controlled Generation of Monodisperse Multiple Emulsions via a One-Step Hybrid Microfluidic Device

“…These materials include but not limited to liquid crystals 21–23 and lecithin 24 ; synthesized graphene oxide-polystyrene 25 ; glycerol to produce polyols-in-oil-in-water 26 ; natural glycyrrhizic nanofibrils assembling into a fibrillary hydrogel network to produce gelled MEs 20 ; bioactive materials dispersed in glycerol with the components of glycerol and organogel matrix of sitosterol-oryzanol in sunflower oil gels to produce oleogel capsules 27 ; graphene micro-aerogels embedded within soft MEs for electrochemical sensing 28 ; mix of oil, toluene, water and microparticles of poly benzyl methacrylate to produce porous polystyrene monoliths MEs 29 ; short-chain fatty acid within dietary fibers MEs 30 ; bacterial celluloses encapsulated within protein and polyglycerol polyricinoleate MEs 31 ; and eucalyptus oil, ubiquinone and fine water interfacing with hydroxy methyl cellulose and tannic acid to produce soft microcapsules of MEs 32 . Also, several emulsifiers 33 , silica nanoparticles 34–37 , colloidal materials 8,38,39 , pH stimuli-responsive polymers 40,41 , biomacromolecules 42 , surfactants 43,44 and physical parameters 45,46 have been incorporated to improve the MEs stability and performance 8,39,47–49 .…”

Fundamental investigation on effect of microencapsulated water on expansion behavior of microcapsules

“…Also, Tanaka et al have prepared the microcapsules containing water with two kinds of microencapsulation methods in order to form the stable (W/O)/W emulsion and to obtain the higher water content. In this report, the first method was the suspension polymerization method using the (W/O)/W, and the second method was the suspension polymerization method in parallel with interfacial polycondensation reaction.…”

“…Also, Tanaka et al 15 have prepared the microcapsules containing water with two kinds of microencapsulation methods in order to form the stable (W/O)/W emulsion and to obtain the higher water content.…”