Gel Emulsion Based on Amphiphilic Block Copolymer: A Template to Develop Porous Polymeric Monolith for the Efficient Adsorption of Volatile Organic Compounds

Abstract

The fabrication of adsorbents for volatile organic compounds (VOCs) always attains significant research interest for the industrialized civilization. Herein, we report the fabrication of a new class of porous polymeric monolith for the efficient adsorption of VOCs. In this case, a gel emulsion stabilized by poly­(oligo­(ethylene glycol) methyl ether methacrylate)-b-polystyrene (POEGMA-b-PS), an amphiphilic block copolymer (BCP), was successfully used as the template for the development of a porous monolith having a porosity in the range of 5–50 μm. A reversible addition–fragmentation chain transfer (RAFT) polymerization technique was adopted for the synthesis of BCP with varying PS block length. The BCPs were used as the stabilizer for water-in-oil gel emulsion consisting of >90% dispersed phase without using any costabilizer. Morphology and thermal and rheological behavior of the prepared gel emulsions were found to be dependent on the PS block length in the BCP as analyzed in FE-SEM, DSC, and rheometry. Porous polymeric monoliths were prepared by polymerizing gel emulsions with a mixed oil phase containing a styrene monomer, cross-linker, and radical initiator. The resulting monoliths had a minimum density of 0.08 g/cm3. Those monoliths were found to have very high resistance to water, showing a water contact angle of ∼120°, while they can effectively adsorb a wide range of VOCs like benzene, toluene, xylene, ethylbenzene, chloroform, tetrahydrofuran, acetone, formaldehyde, hexane, etc. and also attain reusability with similar efficiency.

High performance microwave absorption of light weight and porous non-carbon-based polymeric monoliths via a gel emulsion template

“…It is well known that the preparation of functional porous monoliths based on gel emulsions as templates is one of the most essential applications. [61][62][63][64] As exhibited in Fig. 1a, a series of gel emulsions were prepared.…”

Fundamentals and Design‐Led Synthesis of Emulsion‐Templated Porous Materials for Environmental Applications

“…After polymerization, washing and drying, the resulting white solid showed pore sizes in the range of 5-50 μm, a minimum density of 0.08 g cm −3 , very high resistance to water, and a water contact angle of ≈120°. [120] St/EHA/DVB-based emulsion-templated tubular membranes were prepared by molding a very viscous white HIPE into thin layers between flat plates, separated by poly(ethylene terephthalate) films, and subsequently polymerized. Afterward, the resulting membranes were impregnated with ionophores, graphite particles, electron mediators, and enzymes.…”

“…The adsorption capacities of these monoliths, 907 mg g −1 for benzene and 777 mg g −1 for toluene, were quite high. [120] The P(St-co-VBC-co-DVB) HIPE-templated monoliths were found to immobilize chemical warfare agents (CWAs) such as sulfur mustard, isopropyl methyl phosphonofluoridate, diethylaminoethyl O-ethyl methylphosphonothioate, diethylaminoethyl O-isobutyl methylphosphonothioate, diethylaminoethyl O-butyl methylphosphonothioate, diisopropylaminoethyl O-ethyl methylphosphonothioate, and bis(2-chloroethyl) sulfide. The adsorption of these CWAs was increased by increasing the VBC content and the volume of the internal phase emulsion, which could be positively correlated with the swelling.…”

“…The adsorption capacities of these monoliths, 907 mg g −1 for benzene and 777 mg g −1 for toluene, were quite high. [ 120 ]…”

“…After polymerization, washing and drying, the resulting white solid showed pore sizes in the range of 5–50 µm, a minimum density of 0.08 g cm −3 , very high resistance to water, and a water contact angle of ≈120°. [ 120 ]…”