Biomimetic hierarchical porous carbon fibers via block copolymer self-assembly

Abstract

Materials with well-defined porous structures, high conductivity and surface area are promising candidates in energy storage, oil absorption and catalysis applications. This work demonstrates, for the very first time, a new facile route to prepare carbon fibers exhibiting hierarchical porous designs that mimic deep-sea sponges. The fibres were prepared via wet spinning method using poly (acrylonitrile)-block-poly (methyl methacrylate) (ANMMA) block copolymers. The hierarchical porous morphologies were formed in carbon fibers due to the combined effect of self-assembly and solvent/non-solvent induced phase separation during the coagulation process. Continuous and interconnected macroporous features were observed in fibers with abundant small-sized nanopores and the fiber surface area was calculated to be 499 m2/g. Electrochemical analyses showed that the fibers possess a specific capacitance of 130 F/g at 10 A/g with excellent cyclic stability of 97% capacitance retention after 10,000 cycles. The porous fibers also exhibited excellent sorption properties with a range of organic solvents and oil, demonstrating high absorbent potential for oil/chemical clean-up. The absorption capacities were in the range of 70–92 g/g for different types of organic solvents and oil. This study paves the way towards a new class of porous carbon materials with nature mimicking designs for multifunctional applications.