A Highly Conductive Cationic Wood Membrane. (25th August 2019) - Chen, Gegu
Abstract: Here, a highly conductive cationic membrane is developed directly from natural wood via a two‐step process, involving etherification and densification. Etherification bonds the cationic functional group ((CH3 )3 N + Cl − ) to the cellulose backbone, converting negatively charged (ξ‐potential of −27.9 mV) wood into positively charged wood (+37.7 mV). Densification eliminates the large pores of the natural wood, leading to a highly laminated structure with the oriented cellulose nanofiber and a high mechanical tensile strength of ≈350 MPa under dry conditions (20 times higher than the untreated counterpart) and ≈98 MPa under wet conditions (×5.5 increase compared to the untreated counterpart). The nanoscale gaps between the cellulose nanofibers act as narrow nanochannels with diameters smaller than the Debye length, which facilitates rapid ion transport that is 25 times higher than the ion conductance of the natural wood at a low KCl concentration of 10 × 10 −3 m . The demonstrated cationic wood membrane exhibits enhanced mechanical strength and excellent nanofluidic ion‐transport properties, representing a promising direction for developing high‐performance nanofluidic material from renewable, and abundant nature‐based materials. Abstract : A highly conductive cationic membrane is fabricated directly from natural wood. For the first time, a cationic functional group is grafted onto the wood structure. The cationic wood membrane with a dense laminated structure shows high mechanical strength and excellent nanofluidic ion‐transport properties, representing a promising direction for developing high‐performance nanofluidic materials from renewable and abundant natural resources.