Multifunctional films composed of carbon nanotubes and cellulose regenerated from alkaline-urea solution

Multifunctional carbon nanotube (CNT)-cellulose films were fabricated by dissolving cellulose and dispersing CNTs homogeneously in aqueous alkaline-urea solution. We found that the resulting composite films with 2-10 wt% CNTs have both normal flexible paper and conducting CNT characteristics, which show a volume resistivity that can be controlled over a wide range of 1.35-540 Ohm cm. The composite films achieved multifunctional sensing ability for monitoring stress-strain, temperature and humidity. Both the mechanical properties and thermal stabilities of the composite films with CNTs were enhanced. This work provided a novel and simple pathway to regenerate cellulose films with carbon nanotubes as multifunctional biomaterials for electronic, magnetic, semiconducting and biotechnological applications.