Scalable production of high-quality carbon nanotube dispersion in aqueous solution using cellulose as dispersant by a freezing/thawing process

Abstract

Carbon nanotube (CNT) dispersion, which enables scalable fabrication of printed and flexible electronic materials, has brought a revolutionary improvement in CNT-based devices. To progress from the laboratory to commercial applications, it will be necessary to develop simple and scalable methods to produce high-quality CNT dispersions. Here, we propose a freezing/thawing strategy assisted by cellulose to produce high-quality CNT dispersion in an aqueous solution on a large scale. The freezing/thawing process simultaneously serves two purposes: (1) one is to cleave CNTs from their bulk via water-freezing expansion force; (2) the other is to dissolve cellulose in NaOH/urea aqueous solution, facilitating the wrapping of cellulose on the surface of CNTs to improve the stability of the dispersion. The obtained cellulose-dispersed CNT (CDCNT) dispersion is highly homogeneous and stable because of the formation of CNT/cellulose/NaOH/urea inclusion complexes. Importantly, the freezing/thawing strategy using cellulose promises scalable production, including a high CNT concentration of 11.3 mg/mL, high yield of 75%, high production capacity, and unlimited system size, much superior to common ultrasonication. Furthermore, it is demonstrated that the CDCNT dispersion can be used as a precursor solution for fabricating different CNT-based materials via various techniques, such as spinning, dyeing, screen printing, and 3D printing, indicating versatile applications.