A versatile and inexpensive photochemical platform for the preparation of high-order multiblock functional materials.

Herein we report the photoinduced living radical polymerization of acrylates in a variety of ionic liquids (ILs). 1-Ethyl-3-methylimidazolium ethyl sulfate [emim][EtSO 4 ], 1-heptyl-3-methylimidazolium bromide [C 7 mim][Br], 1-hexyl-3-methylimidazolium tetrafluoroborate [C 6 mim][BF 4 ], 1-hexyl-3-methylimidazolium hexafluorophosphate [C 6 mim][PF 6 ], and 1-octyl-3-methylimidazolium hexafluorophosphate [C 8 mim][PF 6 ] were employed as solvents for the homopolymerization of a variety of acrylates including methyl acrylate (MA), n-butyl acrylate (n-BA), ethylene glycol methyl ether acrylate (EGA), and poly(ethylene glycol) methyl ether acrylate (PEGA, M n ≈ 480). Polymerization of MA, EGA, and PEGA in [C 6 mim][BF 4 ], [C 6 mim][PF 6 ], and [C 8 mim][PF 6 ] proceeded in a controlled manner, as evidenced by kinetic studies, narrow molecular weight distributions (Đ ≈ 1.1), and quantitative conversions (>99%) within 30 min. MALDI-ToF-MS and 1 H NMR confirmed very high end-group fidelity, which was further exemplified by in situ chain extensions and block copolymerizations, yielding welldefined block copolymers in a quantitative manner. While polymerization of n-BA in [C 6 mim] [BF 4 ] and [C 6 mim][PF 6 ] yielded polymers with bimodal molecular weight distribution (potentially due to poor solubility), polymerization of the same monomer in [C 8 mim][PF 6 ] was well-controlled yielding materials with a monomodal polymer peak distribution and low dispersity. Interestingly, all polymerizations in ILs experienced a significant acceleration on the rate of polymerization without compromising the end-group fidelity, as opposed to the slower rates observed when DMSO was used as the solvent. The versatility of the approach was also demonstrated by polymerization of MA to a number of chain lengths (M n ≈ 4500−40 000 g mol −1 ) furnishing poly(acrylates) with low dispersities in all cases (Đ ≈ 1.1). Importantly, extraction of the obtained polymer with toluene allowed the IL/catalyst solution to be reused as the solvent for further polymerizations without affecting the living nature of the polymerization. Moreover, the polymer extracted into the toluene (copper-free) can be used directly for postpolymerization modifications (e.g., click reactions).

Copies of full items can be used for personal research or study, educational, or not-for-profit purposes without prior permission or charge. Provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way. Publisher statement:First published by Royal Society of Chemistry 2016 http://dx.doi.org/10.1039/C6CP06788C A note on versions:The version presented here may differ from the published version or, version of record, if you wish to cite this item you are advised to consult the publisher's version. Please see the 'permanent WRAP URL' above for details on accessing the published version and note that access may require a subscription. Hybrid anode materials consisting of micro-sized silicon (Si) interconnected with few-layer graphene (FLG) nanoplatelets and sodium-modified poly (acrylic acid) (PAA) as a binder were evaluated for Li-ion batteries. The hybrid film has demonstrated a reversible discharge capacity of ~1800 mAh/g with a capacity retention of 97% after 200 cycles. The superior electrochemical properties of the hybrid anodes are attributed to a durable, hierarchical conductive network formed between Si particles and the multi-scale carbon additives, with enhanced cohesion by the functionalized polymer binder. Furthermore, improved SEI stability is achieved from the electrolyte additives, due to the formation of a kinetically stable film on the surface of the Si.