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An interesting wood-based all-solid-state supercapacitor is produced using reduced graphene oxide (RGO) coated on wood transverse section slice (WTSS) as electrode material by means of a low-cost, eco-friendly, and simple method for the first time. The RGO-coated WTSS electrode has a porous 3D honeycomb framework due to the hierarchical cellular structure of the WTSS substrate and can function as an electrolyte reservoir. This special construction endows this novel electrode with good areal capacitance (102 mF cm−2) and excellent cyclic stability (capacitance retention of 98.9% after 5000 cycles). In addition, the supercapacitors exhibit good mechanical flexibility and preserve almost constant capacitive behavior under different bending conditions. Our study introduces a new and eco-friendly material design for electrodes in future flexible energy storage devices that closely resemble natural materials. Open image in new window

We utilized a simple dipping-and-polymerization method to prepare an interesting electrode material consisting of polypyrrole (PPy) polymerized on a wood transverse section slice (WTSS), and fabricated a wood-based supercapacitor. The novel electrode has a 3D honeycomb porous framework, a high capacitance (0.61 F cm−2) and excellent flexibility. These make the PPy-coated WTSS electrode an excellent alternative candidate for flexible energy storage.

A carboxymethyl cellulose acetate (CMCA)/cellulose acetate (CA) blend ultrafiltration (UF) membrane was prepared via phase inversion in the absence and presence of 2.5 wt.% additive, namely polyethylene glycol 600 (PEG 600). CMCA was firstly synthesized from carboxymethyl cellulose sodium (CMC-Na) by acidifying and esterifying. The as-prepared blend membranes were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), mechanical analysis, contact angle, pure water flux (PWF), water content (WC), rejection and molecular weight cut off (MWCO) to understand the influence of polymer blend composition and additive on the properties of the modified membranes. SEM and AFM surface roughness analysis showed that CA/CMCA blend membranes possessed large size pore in the top layer and porous structures in the cross-section. Compared to the pure CA membrane, blending of CA with CMCA resulted in novel blend membranes with enhanced ultrafitration membrane characteristics such as lower contact angle and higher PWF coupled with higher water content. Bovine serum albumin (BSA) was subjected to rejection by the blend membranes. Meanwhile, the fouling resistant ability was studied and the UF experiments suggested that the modified membranes had more positive influence on membrane anti-fouling performance.

Cellulose derivative CMCAB was synthesized, and nanometer fiber composite material was obtained from lithium iron phosphate (LiFePO4, LFP)/CMCAB by electrospinning. Under the protection of inert gas, modified LFP/carbon nanofibers (CNF) nanometer material was obtained by carbonization in 600 °C. IR, TG-DSC, SEM and EDS were performed to characterize their morphologies and structures. LFP/CNF composite materials were assembled into lithium-ion battery and tested their performance. Specific capacity was increased from 147.6 mAh g−1 before modification to 160.8 mAh g−1 after modification for the first discharge at the rate of 2 C. After 200 charge–discharge cycles, when discharge rate was increased from 2 C to 5 C to 10 C, modified battery capacity was reduced from 152.4 mAh g−1 to 127.9 mAh g−1 to 106 mAh g−1. When the ratio was reduced from 10 C to 5 C to 2 C, battery capacity can be quickly approximate to the original level. Cellulose materials that were applied to lithium battery can improve battery performance by electrospinning.

Combining the microemulsion polymerization with UV direct initiation, an efficient method for polymerization of AM with high polymerization rate and conversion, low polymerization temperature, high purity of product and simple radiation equipment was developed. In the absence of initiator and under UV radiation, the polymerizations of AM inverse microemulsion system with high monomer content and low emulsifier content were successfully accomplished at low temperature (24~30 °C) and PAM with high purity and high limiting viscosity [η] was obtained. The polymerization rate was fast and the conversion reached to higher than 85% in 30 minutes. Based on the abundant experimental results, the reasonable polymerization mechanisms were proposed as follows: the AM participated in the initiation reaction and the main initiation locus was the emulsifier layer. Rp and [η] were weakly influenced by temperature due to the low apparent activation energy of the reaction (Ea = 12.98 kJ/mol). The polymerization kinetics of Rp was expressed as the following: Rp = [IUV]0.4972[M]1.5048[E]-0.5731. The Rp order with respect to [M] is equal 1.5048 which confirms the conclusion that the monomer participated in the initiation reaction.