Preparation of Flattened Cross-Linked Hollow Particles by Suspension Polymerization in a Solid Dispersion Medium

Abstract

Flattened cross-linked hollow poly(divinylbenzene) (PDVB) particles with encapsulated n-hexadecane (HD) were successfully prepared through suspension polymerization using the self-assembling of phase-separated polymer (SaPSeP) method, in which the solid dispersion medium was gelled by gellan gum and compressed. The solid phase induced by gellan gum can be easily changed to a liquid state by heating, allowing the obtained particles to be easily recovered after polymerization. When the polymerization was conducted in the solid dispersion medium without compression, spherical hollow PDVB/HD composite particles were obtained. In contrast, when the polymerization was conducted with the compression of the solid dispersion medium, flattened hollow PDVB/HD composite particles were obtained. The shape of the flattened hollow polymer particles was controlled by changing the compression ratio of the solid phase, and the size could also be controlled by changing the DVB/HD droplet size using the Shirasu porous glass membrane-emulsification technique. Furthermore, flattened hollow particles larger than 20 μm in size were obtained, but it was difficult to obtain spherical hollow particles of such large size using the SaPSeP method.

Hollow Microcapsules with Controlled Mechanical Properties Templated from Pickering Emulsion Droplets

“…Many approaches have been developed to fabricate hollow microcapsules, such as layer-by-layer technique, [10,11] microfluidics, [12][13][14] template methods, [15,16] suspen sion polymerization [17][18][19] etc. However, it proves to be difficult to obtain hollow microcapsules with controllable mechanical properties merely by the methods mentioned above.…”

Efficient adsorption of oil in water by hydrophobic nonwoven fabrics coated with cross‐linked polydivinylbenzene fibers

“…Up to now, several superhydrophobic adsorbents have been developed to adsorb oil from aqueous solution, such as polydimethylsiloxane (PDMS), polymethylsilsesquioxane (PMSQ), polytetrafluoroethylene (PTFE), and tetranitro‐9‐fluorenone (TENF) . Among them, polydivinylbenzene (PDVB), a kind of novel superhydrophobic material, has been attracting considerable attentions because of its high specific surface area, hollow structure and high cross‐linking degree, which were favourable to the adsorption of many pollutants in environment . Although the possibility of oil adsorption by PDVB has been confirmed, recent studies focused mainly on the synthesis method of PDVB, painting PDVB onto different surfaces, and its usage as cross‐linkers .…”

“…Moreover, PDVB was generally synthesized by a solvothermal method, which takes a long time and needs complex conditions at high temperature in the presence of nitrogen . In contrast, the cationic polymerization method was considered as a good alternative for PDVB synthesis …”

“…18 Among them, polydivinylbenzene (PDVB), a kind of novel superhydrophobic material, has been attracting considerable attentions because of its high specific surface area, hollow structure and high cross-linking degree, which were favourable to the adsorption of many pollutants in environment. 19,20 Although the possibility of oil adsorption by PDVB has been confirmed, recent studies focused mainly on the synthesis method of PDVB, painting PDVB onto different surfaces, and its usage as cross-linkers. [21][22][23] Moreover, PDVB was generally synthesized by a solvothermal method, which takes a long time and needs complex conditions at high temperature in the presence of nitrogen.…”

“…22,23 In contrast, the cationic polymerization method was considered as a good alternative for PDVB synthesis. 19,24 In addition, there were several other points that needed to be addressed for PDVB use as oil adsorbent, including how to recycle the PDVB from water effectively, its capacity for adsorption and stability when used repeatedly, and how to regenerate it conveniently. Strategies were proposed by researchers to solve these problems, such as fabricating magnetic adsorbents or decorating polymers onto substrates to facilitate the collection from water, 2,23 generating macropores or combining sponge to expand adsorption capacity, 25,26 and recovering by heat or solvent extraction.…”