Bio-Treatment of Natural Fibers in Isolation of Cellulose Nanofibres: Impact of Pre-Refining of Fibers on Bio-Treatment Efficiency and Nanofiber Yield

Biodegradability, renewability and high specific strength properties of cellulose nanofibres and microfibrils have made them very attractive in nano-biocomposite science. Treatment of natural fibers with suitable enzymes or fungus has been found to substantially alleviate the high energy requirement associated with the isolation of cellulose nanofibers via high shear refining and subsequent cryocrushing. This article briefly describes a novel enzymatic fiber pretreatment developed to facilitate the isolation of cellulose nanofibres and explores the effect of pre-refining of fibers on the effectiveness of bio-treatment. Soft wood Kraft pulp was pre-sheared to different degree and treated with a genetically modified fungus isolated from fungus infected Dutch elm tree. Cellulose nanofibres were isolated from these treated fibers by high shear refining. The percentage yield of nanofibres from pre-refined fibers in the less than 50 nm range showed a substantial increase and at the same time the number of revolutions required during the high shear refining to attain a comparable level of nanofibres isolation decreased. This observation may be attributed to the better fiber internal accessibility of the enzymes due to loosening up of the fibers and increased number of fiber ends as a result of pre-refining.     

Polymeric Materials as Potential Inhibitors Against SARS-CoV-2

Journal of Polymers and the Environment - Recently discovered SARS-CoV-2 caused a pandemic that triggered researchers worldwide to focus their research on all aspects of this new peril to humanity....     

Effect of Glycerol on the Properties of 100 % Biodegradable Thermoplastic Based on Wheat Flour

This paper reports the effect of glycerol on thermal, mechanical and morphology of the wheat-flour based thermoplastic sheets (<3 mm) fabricated using single screw extrusion followed by compression molding. The amount of glycerol (plasticizer) added during the formulation varies from 20 to 35 % w/w (20, 23, 25, 30 and 35 % w/w). Results indicate that increase in the amount of glycerol in the starch based thermoplastic sheets, lowers its hardness and tensile properties while an increase in the melt flow index. Variation in the glycerol content from 20 to 25 % w/w increases the impact strength of the thermoplastic sheets beyond this limit it decreases. The contact angle analysis shows that glycerol has effect on the surface energy and work of adhesion of the thermoplastic sheets. However, the presence of glycerol has no significant influence on the thermal stability of thermoplastic sheets above 200 °C.