Fabrication, Mechanical Testing and Structural Simulation of Regenerated Cellulose Fabric Elium® Thermoplastic Composite System

Regenerated cellulose fibres are an important part of the forest industry, and they can be used in the form of fabrics as reinforcement materials. Similar to the natural fibres (NFs), such as flax, hemp and jute, that are widely used in the automotive industry, these fibres possess good potential to be used for semi-structural applications. In this work, the mechanical properties of regenerated cellulose fabric-reinforced poly methyl methacrylate (PMMA) (Elium®) composite were investigated and compared with those of its natural fibre composite counterparts. The developed composite demonstrated higher tensile strength and ductility, as well as comparable flexural properties with those of NF-reinforced epoxy and Elium® composite systems, whereas the Young’s modulus was lower. The glass transition temperature demonstrated a value competitive (107.7 °C) with that of other NF composites. Then, the behavior of the bio-composite under bending and loading was simulated, and a materials model was used to simulate the behavior of a car door panel in a flexural scenario. Modelling can contribute to predicting the structural behavior of the bio-based thermoplastic composite for secondary applications, which is the aim of this work. Finite element simulations were performed to assess the deflection and force transfer mechanism for the car door interior.

Development of a superhydrophobic cellulose fabric via enzyme treatment and surface hydrophobization

Enzymatic hydrolysis is a common finishing method for cellulosic materials, to improve fabric softness, appearance, and surface properties. However, its potential to trigger superhydrophobicity has not been studied in depth. In this study, a superhydrophobic cellulose fabric was fabricated in two steps. Micro-/nano-hierarchical roughness on the fabric surface was achieved by cellulase from Aspergillus niger, through enzymatic hydrolysis. Subsequently, hydrophobization was carried out by a dip coating method, using polydimethylsiloxane (PDMS). Enzyme concentration and treatment temperature were varied to find the values that provided the greatest superhydrophobicity. As enzyme concentration and temperature increased, the nano-scale roughness increased, along with weight reduction. The degree of crystallinity and reduction in tensile strength were also increased with weight loss via enzyme hydrolysis. As air pockets were formed by micro-/nano-structures on the fiber surface, the water contact angle increased and the shedding angle tended to decrease. The sample treated with 5 g/l enzyme at 60 ℃ for 60 min and coated with PDMS 1 wt.% coating solution had the greatest superhydrophobicity, with a water contact angle of 162° and a shedding angle of 7.0°. The weight loss and reduction in tensile strength of the developed superhydrophobic fabrics were 2.9% and 39.0%, respectively. This approach reduces the necessity for an additional process to introduce nano-scale roughness, and it has the potential to produce superhydrophobic cellulosic biomass for outdoor clothing.

Graphene decorated carbonized cellulose fabric for physiological signal monitoring and energy harvesting

A multifunctional graphene decorated carbonized cellulose fabric was fabricated for human physiological signal monitoring and energy harvesting.