Hierarchically Porous Polymers from Hyper-cross-linked Block Polymer Precursors

Abstract

We report synthesis of hierarchically porous polymers (HPPs) consisting of micropores and well-defined 3D continuous mesopores by combination of hyper-cross-linking and block polymer self-assembly. Copolymerization of 4-vinylbenzyl chloride (VBzCl) with divinylbenzene (DVB) in the presence of polylactide (PLA) macro-chain-transfer agent produced a cross-linked block polymer precursor PLA-b-P(VBzCl-co-DVB) via reversible addition-fragmentation chain transfer polymerization. A nanoscopic bicontinuous morphology containing PLA and P(VBzCl-co-DVB) microdomains was obtained as a result of polymerization-induced microphase separation. While a basic treatment of the precursor selectively removed PLA to yield a reticulated mesoporous polymer, hyper-cross-linking of the precursor by FeCl3 generated micropores in the P(VBzCl-co-DVB) microdomain via Friedel-Crafts alkylation and simultaneously degraded PLA to produce the HPP containing micropores in the mesoporous framework. The mesopore size of the HPP could be precisely controlled from 6 to 15 nm by controlling the molar mass of PLA. We demonstrate acceleration in adsorption rate in the HPP compared to a hyper-cross-linked microporous polymer.

CO2-in-PEG emulsion-templating synthesis of poly(acrylamide) with controllable porosity and their use as efficient catalyst supports

“…It was found that the distribution of the macropores was wide. 16 This is a proof that both the internal CO 2 and the continuum phase PEG could play a role as porogen, which is similar to Peng and Zhang's report. 3 indicated that the pore size distribution of the PAM was narrowed and moved to the small pore diameter with the increase of the pressure, which is consistent with that observed from the SEM and TEM images ( Fig.…”

Special wettable nanostructured copper mesh achieved by a facile hot water treatment process

“…Porous materials, such as foams, meshes, and sponges, can easily gain multiscale surface structures [19][20][21][22], which is the favorable surface topography for a materials to obtain superhydrophobicity or special wettability after reducing their surface energy. For example, mesh texture with sub-micrometer scaled pores (opening areas) and mesh wires serve as a micro level template for subsequent multiscale structures.…”

Sugar-based micro/mesoporous hypercross-linked polymers with in situ embedded silver nanoparticles for catalytic reduction

“…The preparation of HCPs mainly includes three different synthesis strategies, namely postcross-linking of polymeric precursors containing functional groups [3], the “knitting” of rigid aromatic building blocks by external cross-linkers [4], and self-polycondensation of small molecular monomers [5]. Since the Tan group proposed the new synthetic strategy that "knits" low functionality rigid aromatic compounds with formaldehyde dimethyl acetal (FDA) as an external cross-linking agent through a Friedel–Crafts reaction to synthesize a polymer network with a high SSA [6], HCPs with knitted building blocks have been widely utilized because of their high SSA [7–8], mild synthesis conditions [9–10], and wide range of monomers [11].…”