Amphiphilic comb-like polymer for harvest of conductive nano-cellulose

In this study, electrically conductive bacterial cellulose (BC) was prepared by culturing Gluconacetobacter xylinus in a carbon nanotube (CNT)-dispersed medium. The CNTs were dispersed by adopting a non-covalent approach in the presence of non-ionic amphiphilic comb-like polymer (CLP). Specifically, the hydrophobic backbone of CLP was chemophysically attached to the surface of the CNTs and the hydrophilic side chains were released freely toward the medium in an aqueous environment. CLP-modified CNTs were stable and did not show any noticeable sediment, even after centrifugation at 15,000 rpm for 30 min. Notably, the dispersion solution of CLP-modified CNTs was stable at room temperature for several months because the long-range entropic repulsion among polymer-decorated tubes acted as a barrier to aggregation. The morphology of the BC membrane was studied by field-emission scanning electron microscopy. The presence of CLP bound to the CNT surface was characterized by Fourier transform infrared spectroscopy and the conductivity of the CNT-incorporated BC membrane was measured by four-probe measurements.