Aruna Kumar Mohanty

Visible-light photoiniferter RAFT polymerization enables highly controlled block copolymer synthesis with low dead chain formation; however, distinguishing living from dead chains remains challenging. Here, an α,ω-dihydroxyl-functionalized trithiocarbonate was used as a photoiniferter to synthesize poly(benzyl acrylate) (pBzA) and poly(benzyl acrylate-b-tert-butyl acrylate) (p(BzA-b-tBA)) under blue-light irradiation. Solvent-gradient HPLC (SG-HPLC) using a bare silica column then separated RAFT agent-derived living chains from dead chains through end-group polarity contrast installed by the dihydroxyl iniferter design. Living fractions accounted for ∼96% of the integrated 260 nm signal and 94.9 wt % of the recovered block copolymer, with chain-end fidelity enriched from ∼95% to >99% upon SG-HPLC isolation. MALDI–TOF MS of the isolated fractions gave apparent dispersities (ĐMALDI = 1.02–1.03), close to 1 + 1/DPn, supporting a near-ideal single population. This study demonstrates SG-HPLC as a practical route to separate and quantify living and dead chains in photoiniferter-mediated acrylic block copolymers.

Here the synthesis of poly(3,4‐ethylenedioxythiophene) (PEDOT) aqueous dispersion using sulfonated poly(ether sulfone) (SPES) with hydrophobic fluorinated groups to improve the weather and water stability of the conductive film is reported. The conductivity and surface morphology of the fabricated PEDOT:SPES conductive thin films are investigated. The PEDOT:SPES film after the N,N‐dimethylformamide (DMF) treatment showed a 200 times increase in the conductivity and the transmittance is over 96.5%. Raman spectroscopy indicates conformational changes in PEDOT chains due to the solvent treatment. The PEDOT:SPES film shows better water and weather stability performance in terms of dimensional stability in comparison to the commercial PEDOT:poly(styrene sulfonic acid) (PSS). Further, the organic solar cells performance is tested using PEDOT:SPES as hole transport layer and poly(3‐hexylthiophene) (P₃HT):[6,6]‐phenyl C₇₁‐butyric acid methyl ester (PC₇₁BM) as active material. The PEDOT:SPES achieves a good power conversion efficiency (=3.36%), comparable with the conventional PEDOT:PSS (AI 4083).

Polymers containing cyclic derivatives are a new class of macromolecular topologies with unique properties. Herein, we report the synthesis of a triblock copolymer containing a spirocyclic mid-block. To achieve this, a spirocyclic polystyrene (cPS) mid-block was first synthesized by atom transfer radical polymerization (ATRP) using a tetra-functional initiator, followed by end-group azidation and a copper (I)-catalyzed azide-alkyne cycloaddition reaction. The resulting functional cPS was purified using liquid chromatography techniques. Following the esterification of cPS, a macro-ATRP initiator was obtained and used to synthesize a poly (methyl methacrylate)-block-cPS-block-poly (methyl methacrylate) (PMMA-b-cPS-b-PMMA) triblock copolymer. This work provides a synthetic strategy for the preparation of a spirocyclic macroinitiator for the ATRP technique and as well as liquid chromatographic techniques for the purification of (spiro) cyclic polymers.

We report for the first time in situ reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization in an epoxy resin mixture for toughening of epoxy. Good dispersion of latex particles in the epoxy resin by the selection of suitable monomers and block copolymerization eliminated the need for tedious re-dispersion of preformed particles.

A class of phenolphthalein anilide (PA)-based poly(ether sulfone) multiblock copolymers containing pendant quaternary ammonium (QA) and imidazolium (IM) groups were synthesized and evaluated as anion exchange membrane (AEM) materials. The AEMs were flexible and mechanically strong with good thermal stability. The ionomeric multiblock copolymer AEMs exhibited well-defined hydrophobic/hydrophilic phase-separated morphology in small-angle X-ray scattering and atomic force microscopy. The distinct nanophase separated membrane morphology in the AEMs resulted in higher conductivity (IECw = 1.3–1.5 mequiv./g, σ(OH⁻) = 30–38 mS/cm at 20 °C), lower water uptake and swelling. Finally, the membranes were compared in terms of microbial fuel cell performances with the commercial cation and anion exchange membranes. The membranes showed a maximum power density of ~310 mW/m² (at 0.82 A/m²); 1.7 and 2.8 times higher than the Nafion 117 and FAB-PK-130 membranes, respectively. These results demonstrated that the synthesized AEMs were superior to Nafion 117 and FAB-PK-130 membranes.