Functionalization of nanocellulose to quaternized nanocellulose tri-iodide and its evaluation as an antimicrobial agent.

The reported research involves formation of quaternized nanocellulose triiodide for use as an agent for controlled release of iodine. Nanocellulose was extracted from bagasse and the extracted cellulose nanofibers (CNFs) were quaternized with 3-chloro-2-hydroxypropyltrimethyl ammonium chloride (CHPTAC) in NaOH/urea solution. This was followed by exchange of Cl- with I3- by reaction with KI/I2. Nanofibers having I3- anions were characterized by SEM, TEM, XRD, XRF and FTIR spectroscopy. The iodine content was estimated to be 33.42% and the fibers showed no leaching of molecular I2 in detectable amounts. The fibers showed a maximum activity of 94.73% and 99.86% against E. coli and S. aureus, respectively. These are capable of sustaining 100% antimicrobial activity over a period of six months. These fibers can thus find potential applications as a disinfectant agent in biomedical and water purification processes.

l-Cysteine functionalized bagasse cellulose nanofibers for mercury(II) ions adsorption.

Presence of mercury ions in water, even in trace amounts, is a serious environmental hazard. Hence, there is imperative need to develop innovative and environmentally-friendly materials for their removal from wastewaters. In the present study, cellulose nanofibers (CNFs) extracted from bagasse was esterified with l-cysteine to yield thiol and amine functionalized green material (Cys-CNFs) for removal of Hg2+ ions. The Cys-CNFs were well characterized by SEM, TEM, FTIR, EDS and XRD and evaluated for selective removal of Hg2+ ions from the simulated wastewater. It was observed that Cys-CNFs adsorb Hg2+ ions even at a very low concentration of 1.0mg/L and it exhibited a maximum adsorption capacity of 116.822mgg-1. Kinetic analysis of the data revealed that pseudo-second order kinetics and Langmuir isotherm were followed for adsorption of Hg2+ ions.

Extraction and functionalization of bagasse cellulose nanofibres to Schiff-base based antimicrobial membranes.

The work reported in this paper involves synthesis of a nanocellulose/chitosan composite and its further modification to antimicrobial films. Bagasse, an easily available biowaste, was used as source to extract nanocellulose fibres (CNFs) by subjecting it to mechanical and chemical treatments including alkaline steam explosion and high shear homogenization. The CNFs were subjected to periodate oxidation to obtain nanocellulose dialdehyde (CDA). The aldehyde groups of CDA were reacted with amino groups of chitosan to form Schiff-base. The resulting CDA/chitosan composite fibres were characterized at various steps. The fibres were then cast into films using cellulose acetate as a binder. The films have good physical strength. The composite films show excellent antimicrobial properties when tested against Staphylococcus aureus and Escherichia coli. Such antimicrobial films have potential applications in the formation of antimicrobial packaging material.