Acid-Free Solution Process for Structurally Intact Carbon Fiber Paper with Long-Lasting Hydrophilicity

Background

Carbon fiber paper (CFP) is an inexpensive, electrically conductive, high surface area material that is additionally nontoxic, chemically inert, biocompatible, robust, and scalable; these beneficial properties make CFP desirable for use in many electrochemical, fuel cell, electrolyzer, supercapacitor, sensing, water desalination, tissue engineering, and wastewater treatment applications. However, as globally scalable clean energy and water purification technologies as well as biologic systems must operate in aqueous media, the hydrophobicity of CFP hampers its widespread use. Thus, hydrophilicity resulting from carbon surface modification is required in applications that rely on close electrical contact of CFP carbon with catalysts or the environment, but existing solutions—such as chemical vapor deposition of lithium ion conducting thin film polyelectrolyte coatings, etching, and acid treatment—suffer from high costs or severe structural damage to the CFP, minimizing its effectiveness.

Technology Overview

The university has invented an acid-free, aqueous process for imparting long-lasting hydrophilicity to initially hydrophobic carbon fiber paper, with exceptional utility in clean energy, water purification, electronics, sensing, and biomedical applications. The mesostructure of carbon fiber paper is preserved, and hydrophilicity lasts for over a year after implementation of our green chemistry process, which leads to the creation of graphitic edges by nanostructuring of carbon fibers, formation of surface oxygenates bound to these graphitic edges, and adsorption of surface water.

Benefits

This invention creates unprecedentedly long-lasting hydrophilicity of CFP without damaging carbon fiber network architectures or furnishing residues. The process is inexpensive, minimizes the generation of hazardous chemical waste, takes less than 30 minutes of preparation time, and is amenable to large-scale manufacturing, providing a substantial advantage over previously reported procedures.