A biaxially stretched cellulose film prepared from ionic liquid solution.

A biaxially stretched cellulose film with high performance was manufactured from ionic liquid solution through an environmentally friendly, cost effective and facile process. As the transverse stretching ratio (TSR) is increased, the tensile strength and elastic modulus of the biaxially stretched cellulose film in transverse direction (TD) are significantly improved and the coefficient of thermal expansion in TD is reduced while the performance achieves balance in the machine direction (MD) and TD. The transverse stretching regulates the microfibril orientation in the gel film from dominantly uniaxial orientation in MD to homogeneous planar orientation. This microfibril orientation may further play a role in the orientation of the chains in the films during gel drying as evidenced from the birefringence and 2D XRD results. These results indicate cellulose film prepared from ionic liquid process could be utilized with improved structural and mechanical properties by biaxial stretching, and thus serves in various applications.

Cellulose Aerogel Membranes with a Tunable Nanoporous Network as a Matrix of Gel Polymer Electrolytes for Safer Lithium-Ion Batteries.

Cellulose aerogel membranes (CAMs) are proposed as a matrix for gel polymer electrolyte to the fabrication of lithium-ion batteries (LIBs) with superior thermal stability. The CAMs are obtained from a cellulose-ionic liquid solution via a dissolution-regeneration-supercritical drying route. The presence of high porosity, the nanoporous network structure, and numerous polar hydroxyl groups benefits the quick absorption of liquid electrolytes for gelation of the CAMs and improves the ionic conductivity of the gelled CAMs. LIBs assembled with the gelled CAMs display excellent electrochemical performance at room temperature, and more importantly, the intrinsic thermal resistance of cellulose allows the LIBs to run stably for at least 30 min at working temperatures as high as 120 °C. The CAMs, with their excellent thermal stability, are promising for the development of highly safe, cost-effective, and high-performance LIBs.

Cellulose-based films prepared directly from waste newspapers via an ionic liquid.

Waste newspapers, composed of cellulose (>60wt%), lignin (∼15wt%), hemicellulose (∼10wt%) and other additives, are one kind of low-cost, easily collected and abundant resources. In order to get value-added products from this waste, in this work an attempt was made to directly convert waste newspapers into cellulose-based films by employing an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) as a solvent. Most of the organic substances in this waste were dissolved quickly in AmimCl under mild conditions, and then coagulated and dried. Although containing lignin, hemicellulose and inorganic additives, the regenerated cellulose-based films were smooth, compact and semi-transparent, and exhibited good mechanical properties. If the newspaper/AmimCl solution was filtered to remove undissolved inorganic substances, the regenerated films became transparent and had a tensile strength of 80MPa. Thus, this work provides a new, simple and highly efficient way to achieve a high-valued utilization of waste newspapers for packaging and wrapping.