ONE POT TREATMENT OF CELLULOSE TO OBTAIN NANOCELLULOSE FIBRES AND WATER-SOLUBLE OXIDISED CELLULOSE

Poornima Vijay
School of Chemistry, Monash University, Clayton Campus, Vic, Australia

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Keywords: Nanocellulose, One-pot process, Green oxidation.

The conventional production of nanocellulose from cellulose demands the usage of either halogenated compounds, strong corrosive acids, or high mechanical energy. The objective of this research was to find a greener approach to produce nanocellulose from bulk cellulose.

This research explains the sustainable process of fibrillation to procure renewable nanocellulose fibres and water-soluble oligomeric oxidised cellulose from BEK (Bleached Eucalyptus Kraft) cellulose. One-pot treatment of cellulose was conducted using iron oxide catalysts, namely, hematite and magnetite with hydrogen peroxide. The research has also shown that the reaction of cellulose with iron oxide, hydrogen peroxide catalytic system involved three stages. First, cellulose underwent depolymerisation to form highly crystalline nanocellulose fibres. Second, the nanocellulose was oxidised to produce a water-soluble product, and the final stage was the complete decomposition of the reaction mixture to carbon dioxide and water. Thus, we have found that either nanocellulose fibres or water soluble oxidised cellulose could be produced in one-pot treatment by controlling the reaction conditions.

Multiple factors such as the valency of ions in the crystal lattice of catalyst, particle size, and reaction time influenced the cellulose treatment.

The reaction of BEK Cellulose with 1 µm size Fe2O3 and H2O2 at 90oC gave an 83% yield of nanocellulose fibres, when the reaction was carried out for 1.5 hours. Nanocellulose was having high crystallinity of 73% and low DP (degree of polymerisation), 150. The SEM image confirmed the nanostructure of the product with the dimension of 30-110 nm thickness and 1-5 µm in length. Water soluble oxidised product was obtained with 38% yield in 9-hour reaction using the same catalytic system. This highly oxidised product was having a carboxyl content of 2.9 mmol/g with DP, 25. This research gave an alternative method to produce nanocellulose fibres and oxidised cellulose, and eliminated the need for halogenated reagents, strong corrosive acids, high energy-consuming mechanical pretreatment methods.

A dedicated, detailed and result focused research student with 8+ years’ experience in development and analysis of quality compounds efficacious for the academic and industrial organisation. A confident presenter at conferences and teaching in classrooms, able to explain complex information to audiences of all levels. Currently pursuing doctorate in Biopolymers.

CORE SKILLS
Biomass treatment
Cellulose nanofiber synthesis
Biopolymer characterization
Grafting synthetic polymers from cellulose nanofibers
EDUCATION AND QUALIFICATION:
PhD in Biopolymers, October 2018- Present
Monash University, Melbourne, Australia.
Master of Science (M.Sc) in Chemistry, June 2002 – May 2004
Mangalore University, Mangala Gangotri, Karnataka, India
Bachelor of Science, June 1999 – April 2002.
Mangalore University, Mangala Gangotri, Karnataka, India