Facile Fabrication of Polymerizable Ionic Liquid Based-Gel Beads via Thiol–ene Chemistry

Abstract

Multipurpose gel beads prepared from natural or synthetic polymers have received significant attention in various applications such as drug delivery, coatings, and electrolytes because of their versatility and unique performance as micro- and nanocontainers.1 However, comparatively little work has been done on poly(ionic liquid)-based materials despite their unique ionic characteristics. Thus, in this contribution we report the facile preparation of polymerizable ionic liquid-based gel beads using thiol-ene click chemistry. This novel system incorporates pentaerythritol tetra (3-mercaptopropionate) (PETKMP) and 1,4-di(vinylimidazolium) butane bisbromide in a thiol-ene-based photopolymerization to fabricate the gel beads. Their chemical structure, thermal and mechanical properties have been investigated using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA). The gel beads possess low Tg and their ionic functionalities attribute self-healing properties and their ability to uptake small molecules or organic compounds offers their potential use as pH sensing material and macrocontainers.

Emerging Corrosion Inhibitors for Interfacial Coating

“…These chemically switchable stimulus-responsive PIL beads have potential applications in portable and preparative chemical analysis, separations and spatially addressed sensing ( Figure 7) and also have potential for use as cargo for corrosion inhibitors or slow release inhibitor. With the aim of using such PIL as corrosion inhibitors, we reported the novel and facile fabrication of multifunctional PIL gel beads using vinyl imidazolium based ionic liquid through click-type reactions (Figure 8) [75]. A detailed study into the effect of reactant ratios is examined.…”

“…These PIL gels exhibited multiple characteristics including (1) selfhealing characteristics due to their rubbery nature, (2) the ability to uptake active molecules which acts as corrosion inhibitors, and (3) pH sensing through the incorporation of indicator molecules. With the aim of using such PIL as corrosion inhibitors, we reported the novel and facile fabrication of multifunctional PIL gel beads using vinyl imidazolium based ionic liquid through click-type reactions (Figure 8) [75]. A detailed study into the effect of reactant ratios is examined.…”

Novel Thiol-Ene Hybrid Coating for Metal Protection

“…The FTIR spectra of MPTS, DVIMBr, and the PIL hybrid film (2:1 ratio) are shown in Figure 2. The bands at 2570 cm´1, 1644 cm´1, and 2928-3080 cm´1 that are present in the unreacted MPTS and DVIMBr monomers correspond to the thiol groups, C=C stretching of the vinyl group, stretching of´CH groups of the imidazole ring of the PIL, and vinylic proton =C-H stretching, respectively [16]. These bands disappeared in the cured PIL hybrid film indicating the reaction between double bond of vinyl group in PIL, and subsequent network formation through the thiol-ene photo-polymerization.…”

Extremely Soft, Conductive, and Transparent Ionic Gels by 3D Optical Printing

“…Use of IL in end‐crosslinked type thiol–ene polymerization has been out of focus and only very early stage reaction mechanism, kinetics, and information about their interaction are reported preliminarily . Very recently, some researchers have used crosslinkable ILs with multifunctional thiol end‐crosslinkers to develop polyionic liquids (PIL) by following the mechanism of thiol–ene reaction . In those reports, information about their bulk mechanical properties, stability, and structure–property relationships, along with the scope of 3D printability, have remained untouched.…”

“…[15,16] Very recently, some researchers have used crosslinkable ILs with multifunctional thiol end-crosslinkers to develop polyionic liquids (PIL) by following the mechanism of thiol-ene reaction. [17][18][19] In those reports, information about their bulk mechanical properties, stability, and structure-property relationships, along with the scope of 3D printability, have remained untouched. One of the very first approaches on making 3D-printed ionic structure of phosphonium-based PIL has been reported by Long et.…”