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As the requirements for wearable electronic devices continue to increase, the development of bendable and foldable supercapacitors is becoming critical. However, it is still challenging to design free-standing electrodes with flexibility and high electrical conductivity. Herein, using carboxymethylcellulose (CMC) as the biological template and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) as the electroactive material, a flexible CMC/PEDOT:PSS membrane with a cross-linked mesh structure was firstly synthesized by a facile in-situ polymerization and vacuum filtration process. Subsequently, the CMC/PEDOT:PSS membrane was further treated with dimethyl sulfoxide (DMSO) to remove the excess PSS, thereby enhancing their electrochemical performance. The results showed that the best performing hybrid membrane had good mechanical properties (tensile strength of 48.1 MPa) and high electrical conductivity (45.1 S cm -1 ). The assembled asymmetric supercapacitor (ASC) is capable of delivering an energy density of 181.9 μW h cm -2 at a power density of 750 μW cm -2 and maintains an initial capacitance of 93.4 % and a coulombic efficiency of 100 % after 10,000 GCD cycles, demonstrating an ultra-long cycle life. Moreover, good electrochemical properties can be retained even in the bent and folded state. Therefore, the hybrid membrane electrode with both flexibility and high electrochemical performance has great potential for application in wearable electronics., Competing Interests: Declaration of competing interest No conflict of interest exits in the submission of this manuscript, and the manuscript is approved by all authors for publication., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Lignocellulosic biomass is mainly composed of polysaccharides and lignin. The complexity and diversity of the plant cell wall polymers makes it difficult to isolate the components in pure form for characterization. Many current approaches to analyzing the structure of lignocellulose, which involve sequential extraction and characterization of the resulting fractions, are time-consuming and labor-intensive. The present study describes a new and facile system for rationally derivatizing and dissolving coarsely ground plant cell wall materials. Using ionic liquids (EmimAc) and dichloroacetyl chloride as a solvent/reagent produced mildly acetylated whole cell walls without significant degradation. The acetylated products were soluble in DMSO- d 6 from which they can be characterized by solution-state two-dimensional nuclear magnetic resonance (2D NMR) spectrometry. A distinct advantage of the procedure is that it realizes the dissolution of whole lignocellulosic materials without requiring harsh ball milling, thereby allowing the acquisition of high-resolution 2D NMR spectra to revealing structural details of the main components (lignin and polysaccharides). The method is therefore beneficial to understanding the composition and structure of biomass aimed at its improved utilization.

Recently, IL/cosolvent systems have generated a lot of interest as cellulose-dissolving solvents and reaction media for various kinds of cellulose modification. In the present study, both 1-allyl-3-methylimidazolium chloride (AmimCl)/dimethyl sulfoxide (DMSO) and AmimCl/ N , N -dimethylformamide (DMF) systems were employed to synthesize cellulose acetate by transesterification. Microcrystalline cellulose, 1,8-diazabicyclo[5.4.0]undec-7-ene and isopropenyl acetate were chosen as the raw material, catalyst and acetylation reagent, respectively. The results revealed that DMSO was a suitable cosolvent for the transesterification in the homogeneous solution. Moreover, DMSO had a positive effect on the reaction as the cosolvent under the given conditions and the degree of the substitution of cellulose acetate could be significantly enhanced through increasing the molar ratio of DMSO. The synthesized products were characterized by Fourier transform infrared (FT-IR) spectroscopy, ¹H and 13 C nuclear magnetic resonance spectroscopy (¹H-NMR and 13 C-NMR), correlation spectroscopy (COSY), heteronuclear single quantum correlation (HSQC) spectroscopy, and X-ray diffraction (XRD) to confirm the chemical and physical structure of the cellulose acetate generated. The thermal properties were also evaluated using thermogravimetric analysis (TGA)/derivative thermogravimetry (DTG)., Competing Interests: The authors declare no conflict of interest.

Cellulose acetylation was investigated in dimethyl sulfoxide (DMSO) with isopropenyl acetate (IPA) as acetylating reagent and 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU) as catalyst at 70-130 °C for 3-12 h. The degree of substitution (DS) of acetylated cellulose was comparatively determined by titration and ¹H NMR and confirmed by FT-IR analysis. The results indicated that per-O-acetylation was achieved at >90 °C for a relatively long duration. The three well-resolved peaks of carbonyl carbons in ¹³C NMR spectra also provided evidence of per-O-acetylation. The solubility of cellulose acetates in common organic solvents was examined, and the result showed that chloroform can be an alternative choice as a solvent for fully acetylated cellulose formed in this study besides DMSO. The intrinsic viscosity of acetylated cellulose solution implied almost no degradation of cellulose during acetylation in DMSO except at higher temperature (130 °C) for a long time.