Composition Design of Block Copolymers for Porous Carbon Fibers

Block copolymer-based porous carbon fibers (PCFs) exhibit hierarchical porous structures, high surface areas, and exceptional electrochemical properties. However, the design of block copolymer for PCFs remains a challenge in advancing this type of fibrous material for energy storage applications. Herein we have systematically synthesized a series of poly(methyl methacrylate-block-acrylonitrile) (PMMA-b-PAN) with well-controlled molecular weights and compositions to study the physical and electrochemical properties of PCFs. PCFs are synthesized via electrospinning, self-assembly, oxidation, and pyrolysis with no additives or chemical activation. By adjusting the molecular weights of PAN and PMMA blocks, we have achieved tunable mesopore sizes ranging from 10.9 to 18.6 nm and specific capacitances varied from 144 to 345 F g-1 at 10 mV s-1. Interestingly, regardless of the volume fraction of PAN, all block copolymers produce hierarchical porous structures due to the self-assembly and crosslinking of PAN. Blo...