Kelly M. Meek

Polymerized ionic liquid block copolymers for electrochemical energy

Polymerized ionic liquid (PIL) block copolymers are an emerging class of polymers that synergistically combine the benefits of both ionic liquids (ILs) and block copolymers into one, where the former possesses a unique set of physiochemical properties and the latter self assembles into a range of nanostructures. The potential to synthesize a vast array of new block copolymers is almost limitless with numerous IL cations and anions available. In this paper, we highlight the very recent work on PIL block copolymers, specifically, synthesis and unique solid-state properties for electrochemical energy.

Sulfonated Polymerized Ionic Liquid Block Copolymers.

The successful synthesis of a new diblock copolymer, referred to as sulfonated polymerized ionic liquid (PIL) block copolymer, poly(SS-Li-b-AEBIm-TFSI), is reported, which contains both sulfonated blocks (sulfonated styrene: SS) and PIL blocks (1-[(2-acryloyloxy)ethyl]-3-butylimidazolium: AEBIm) with both mobile cations (lithium: Li(+) ) and mobile anions (bis(trifluoromethylsulfonyl)imide: TFSI(-) ). Synthesis consists of polymerization via reversible addition-fragmentation chain transfer, followed by post-functionalization reactions to covalently attach the imidazolium cations and sulfonic acid anions to their respective blocks, followed by ion exchange metathesis resulting in mobile Li(+) cations and mobile TFSI(-) anions. Solid-state films containing 1 m Li-TFSI salt dissolved in ionic liquid result in an ion conductivity of >1.5 mS cm(-1) at 70 °C, where small-angle X-ray scattering data indicate a weakly ordered microphase-separated morphology. These results demonstrate a new ion-conducting block copolymer containing both mobile cations and mobile anions.

Correction: Polymerized ionic liquid block copolymers for electrochemical energy

Correction for ‘Polymerized ionic liquid block copolymers for electrochemical energy’ by Kelly M. Meek et al., J. Mater. Chem. A, 2015, DOI: 10.1039/c5ta07170d.

A Solvent‐Free Synthesis of Lignin‐Derived Renewable Carbon with Tunable Porosity for Supercapacitor Electrodes

Synthesis of multiphase materials from lignin, a biorefinery coproduct, offers limited success owing to the inherent difficulty in controlling dispersion of these renewable hyperbranched macromolecules in the product or its intermediates. Effective use of the chemically reactive functionalities in lignin, however, enables tuning morphologies of the materials. Here, we bind lignin oligomers with a rubbery macromolecule followed by thermal crosslinking to form a carbon precursor with phase contrasted morphology at submicron scale. The solvent-free mixing is conducted in a high-shear melt mixer. With this, the carbon precursor is further modified with potassium hydroxide for a single-step carbonization to yield activated carbon with tunable pore structure. A typical precursor with 90 % lignin yields porous carbon with 2120 m2  g-1 surface area and supercapacitor with 215 F g-1 capacitance. The results show a simple route towards manufacturing carbon-based energy-storage materials, eliminating the need for conventional template synthesis.