doi:10.1038/nindia.2013.21 Published online 12 February 2013
Researchers have synthesized nanowhiskers, rod-shaped cellulose nanoparticles using jute-derived cellulose. To make nanowhiskers, cellulose materials were exposed to varying concentrations of inorganic and organic acids at different temperatures.
These nanowhiskers will be useful as reinforcing agents in nanocomposites for energy storage devices, replacing costly carbon nanotubes.
In recent years, cellulose has emerged as a green substitute for synthetic polymers. Cellulose in the shape of microfibrils, microcrystals, nanocrystals, and nanowhiskers make excellent reinforcing agents for nanocomposites. Among these, nanowhiskers less than 100 nm wide are very popular. Cellulose nanowhiskers have been made using natural resources like wood, cotton, algae, sugarbeet, and rice husk. However, no previous studies have tried to produce cellulose nanowhiskers from jute.
To prepare nanowhiskers from jute cellulose, the researchers cut jute fibres into pieces, treated them with toluene and heated mildly. The fibres were then soaked in sodium hydroxide and heated to remove non-cellulosic materials, yielding only cellulose. This cellulose was bleached using hydrogen peroxide and washed with distilled water. The cellulose materials were then treated with varying concentrations of acids, changing exposure time and temperature to produce nanowhiskers.
After acid hydrolysis, cellulose nanowhiskers formed as uniform rod-like structures. Lengths of the whiskers were between 500 and 600 nm, with widths between 25 and 50 nm. After 2 hours of acid hydrolysis, morphology of the nanowhiskers changed from rod-like structures to triangular shapes with lengths of 400 nm and widths of 200 nm.
The study found that sulphuric acid at an optimum low concentration (27.7%) produced nanowhiskers with the desired shape and size. The researchers say that these nanowhiskers are suitable for nanocomposite application.