Preparation and properties of the single-walled carbon nanotube/cellulose nanocomposites using N-methylmorpholine-N-oxide monohydrate

Single-walled carbon nanotube (SWNT)/cellulose nanocomposite films were prepared using N-methylmorpholine-N-oxide (NMMO) monohydrate as a dispersing agent for the acid-treated SWNTs (A-SWNTs) as well as a cellulose solvent. The A-SWNTs were dispersed in both NMMO monohydrate and the nanocomposite film (as confirmed by scanning electron microscopy) because of the strong hydrogen bonds of the A-SWNTs with NMMO and cellulose. The mechanical properties, thermal properties, and electric conductivity of the nanocomposite films were improved by adding a small amount of the A-SWNTs to the cellulose. For example, by adding 1 wt % of the A-SWNTs to the cellulose, tensile strain at break point, Young's modulus, and toughness increased ∼ 5.4, ∼ 2.2, and ∼ 6 times, respectively, the degradation temperature increased to 9°C as compared with those of the pure cellulose film, and the electric conductivities at φ (the wt % of A-SWNTs in the composite) = 1 and 9 were 4.97 × 10^-4 and 3.74 × 10^-2 S/cm, respectively. Thus, the A-SWNT/cellulose nanocomposites are a promising material and can be used for many applications, such as toughened Lyocell fibers, transparent electrodes, and soforth.