Capacitive Organic Dye Removal by Block Copolymer Based Porous Carbon Fibers

Abstract

Block copolymer based porous carbon fibers (PCFs) have hierarchical pores, high surface areas, and excellent electrical/ion conductivities. Herein, PCF is synthesized from poly(methyl methacrylate)‐block‐poly(acrylonitrile) and utilized for organic dye removal. The PCF contains hierarchical macro‐, meso‐, and micropores with a surface area of 780 m2 g−1. The electrosorptive behavior of PCF is well described by the Langmuir isotherm and the Weber–Morris model. Based on the model, the interconnected hierarchical pores contribute to easy accessibility of dye ions to the inner surface sites within PCF, resulting in a high electrosorption capacity of 1360 mg g−1, reaching ≈87% of the theoretical maximum. The PCF shows a capacity loss of <0.5% over ten cycles during a 240 h operation period. Thanks to the hierarchical pores that allow for rapid ion desorption, the PCF can easily be regenerated. Lastly, depending on the electrode configuration, the PCF can selectively remove anionic dye, cationic dye, or both. The findings herein provide a fundamental understanding of electrosorptive behavior of block copolymer based porous carbon fibers, enabling future development in filtration applications.

Structural design and mechanism analysis of hierarchical porous carbon fibers for advanced energy and environmental applications

“…61,76,97,383 Thus, to further explore the potential adsorption capability of PCFs, Liu's group employed hierarchical PCFs with controlled porosity for the removal of an organic dye through electrosorptive treatment, which exhibited an extremely high adsorption capacity and fast infiltration rates for both cationic and anionic dyes. 385 It was proved that the hierarchical porous structure formed by the coexistence of micropores, mesopores, and interfiber voids provided the dye ions with easy accessibility to the surface sites in the fibers, and the pore interconnectivity could further facilitate the diffusion of the dye ions. More importantly, the hierarchical pores allowed rapid ion desorption, which was advantageous to regenerate the PCF easily.…”

Humidity-Controlled Preparation of Flexible Porous Carbon Fibers from Block Copolymers

“…PMMA- b -PAN was synthesized via reversible addition–fragmentation chain-transfer (RAFT) polymerization modified from a previous report. ,,,, First, MMA (70.0 mL, 618 mmol), CDB (169 mg, 0.318 mmol), and AIBN (50.8 mg, 0.310 mmol) were dissolved in benzene (120 mL) in a 1 L Schlenk flask. The mixture was subjected to four cycles of freeze–pump–thaw (FPT) followed by back-filling with N 2 to remove the dissolved oxygen.…”

“…Owing to the block copolymer microphase separation and the narrowly dispersed mesopores, these PCFs have shown outstanding capabilities for energy storage . However, the mechanical properties remain to be elucidated . Interestingly, in the preparation of separation membranes, vapor-induced phase separation (VIPS) , has shown the potential to generate pores in polymers while retaining excellent mechanical strength .…”

Mesoporous carbons from self‐assembled polymers

“…Nevertheless, the BCP-derived fibers in this study exhibited interconnected porous structures with a pore size distribution centered around 9.3 nm and BET surface area of 503 m 2 /g. Building on this work, these materials have been employed in a number of different applications, showing their great utility for capacitive deionization, 165 electrochemical applications, 166,167 dye removal for wastewater treatment, 168 and fillers to enhance mechanical properties of nanocomposites. 169…”