Exceeding high concentration limits of aqueous dispersion of carbon nanotubes assisted by nanoscale xylan hydrate crystals

Abstract

Deacetylated xylan molecules with a low degree of branching can form crystals with water molecules, namely xylan hydrate crystals (XHC), leading to a low water solubility but other unique properties of xylan. However, cutting-edge applications of XHC have never been explored. Surface modified carboxymethylated xylan hydrate crystals (CmXhc) with great amphiphilic and rheological properties were produced through appropriate control of degree of substitution. Nanoscale CmXhc was successfully produced through ultrasonic treatments. Nanoscale CmXhc showed an ability to disperse multi-walled carbon nanotubes (MWCNT) in water with a recorded high CNT concentration of 40 mg/mL and a high dispersion efficiency of 91.7%. The CmXhc can also act as an anchoring agent to bind CNT to paper surfaces making the high concentration dispersion as a conductive paper coating or printing ink. The CmXhc-dispersed MWCNT coated paper demonstrated a high conductivity, specific capacity and capacitance stability, although subject to tuning for improvements, serving as a potential paper-based electrode for supercapacitors.