Fabrication of Solid-State Asymmetric Supercapacitors Based on Aniline Oligomers and Graphene Electrodes with Enhanced Electrochemical Performances.

This work describes solid-state asymmetric supercapacitors (ASCs), composed of aniline oligomers as a cathode, nonoxidative graphene sheet as an anode, and polyvinyl alcohol-potassium hydroxide gel as an electrolyte. The synergistic effects resulting from the combination of aniline oligomer and graphene sheet have greatly enhanced the electrical and electrochemical performance of ASCs. The electrical and electrochemical properties of ASCs were highly dependent on the protonation levels of aniline oligomers including aniline tetramer, aniline trimer, and aniline dimer.

Preparation and Characterization of Transparent Polyimide⁻Silica Composite Films Using Polyimide with Carboxylic Acid Groups.

Polyimide (PI) composite films with thicknesses of approximately 100 µm were prepared via a sol⁻gel reaction of 3-aminopropyltrimethoxysilane (APTMS) with poly(amic acid) (PAA) composite solutions using a thermal imidization process. PAA was synthesized by a conventional condensation reaction of two diamines, 3,5-diaminobenzoic acid (DABA), which has a carboxylic acid side group, and 2,2'-bis(trifluoromethyl)benzidine (TFMB), with 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) in N,N-dimethylacetamide (DMAc). The PAA⁻silica composite solutions were prepared by mixing PAA with carboxylic acid side groups and various amounts of APTMS in a sol⁻gel process in DMAc using hydrochloric acid as a catalyst.