Cross-Linked Polymer−Ionic Liquid Composite Materials

Abstract

A series of composites, some with permanent porosity, comprising polymers and ionic liquids have been prepared by in-situ polymerization. The characteristics of both composites and isolated polymers have been investigated. Slow mass and phase transfer characterize the interaction with a range of polymers (1-17) in the N,N′-dialkylimidazolium ionic liquids, [emim]BF 4, [bmim]PF6, or [omim]N(SO2CF3)2. Freeradical homopolymerization of 1-vinyl-2-pyrrolidinone in [bmim]PF6 or of 4-vinylpyridine in [omim]N-(SO2CF3)2 gave viscous solutions from which polymer (Mw ) 162 500 and 71 500 g mol -1 , respectively) could be isolated. Detectable ionic liquid residues were retained in the isolated polymers despite five reprecipitations from methanol. Copolymerization of 4-vinylpyridine (VP) with >5% divinylbenzene (DVB) or trimethylolpropane trimethacrylate (TRIM) in [omim]N(SO2CF3)2, and homopolymerizations of the cross-linking monomers on their own, led with 90-100% monomer conversion to a series of gel-like composite materials, B-H, from which cross-linked polymers, B′-H′, could be isolated by Soxhlet extraction of the ionic liquid. Copolymers of VP with 5-30% DVB (E′, F′) showed a low degree of permanent porosity in the dry state. However, poly(DVB) (G′) and poly(TRIM) (H′) have bulk densities (<0.6 g cm -3 ), intrusion volumes (>0.9 cm 3 g -1 ), BET surface areas (70-320 m 2 g -1 ), and morphology (from SEM studies) which demonstrate the porogenic character of the ionic liquids used. Comparisons with the related products I and J obtained in toluene reveal the sensitivity of these systems both to the properties of the porogen solvent and to the monomer used.

Polymers in Ionic Liquids: Dawn of Neoteric Solvents and Innovative Materials

“…36 They screened the solubilities of 17 different polymers in three different ILs: 1-ethyl-3-methylimidazolium tetrafluoroborate, [C 2 mim]BF 4 , 1-butyl-3-methylimidazolium hexafluorophosphate, [C 4 mim]PF 6 , and 1-methyl-3-octylimidazolium bis(trifluoromethanesulfonyl)amide, [C 8 In this account, we present a solubility study of 24 different polymers (3 wt %) in four selected ILs. Scheme 2 shows the chemical structures of the polymers and the corresponding entry numbers and acronyms.…”

A transparent, flexible, ion conductive, and luminescent PMMA ionogel based on a Pt/Eu bimetallic complex and the ionic liquid [Bmim][N(Tf)2]

“…The matrix must immobilize the IL but should not interfere with the IL properties needed for the device to work. [13][14][15][16][17][18] There are essentially two approaches for IL immobilization: (1) chemical attachment of ionic species to a support 19,20 and (2) the physical fixation of ILs (without covalent linkage) within a polymeric, [21][22][23][24][25][26] carbonaceous, 15,27 or inorganic matrix. 28,29 The resulting materials have been termed ion-gels or ionogels.…”

“…Thermogravimetric analysis (TGA) was done in air on a Linseis L 81 thermal balance from 20 to 900 C and a Mettler Toledo TGA/SDTA 851e from 25 C to 800 C. Heating rate was 10 C min…”

Ionic Liquids in Photopolymerizable Holographic Materials

“…1.5 µm on the grating (Figure 9b). Possibly these are due to the different solubilization of polymers in ionic liquids [60,61]. Phase separation is often seen in the holographic polymer dispersed liquid crystal (H-PDLC) [62,63].…”