Novel nanofibrillated cellulose/chitosan nanoparticles nanocomposites films and their use for paper coating

• Rice straw nanofibrillated cellulose (NFC)/chitosan nanoparticles (CHNP) glycerol-plasticized nanocomposites films were prepared.
• The NFC/CHNP films had good tensile, antimicrobial, and grease-proof properties.
• CHNP improved tensile strength properties and reduced porosity of NFC films.
• CHNP imparted NFC films good antimicrobial properties at ≥10% CHNP loading.
• Coating of paper sheets with NFC/CHNP was briefly tested.

Novel nanocomposites films were prepared from TEMPO-oxidized nanofibrillated cellulose isolated from rice straw, chitosan nanoparticles (CHNP), and glycerol by solution casting. The percentage of chitosan nanoparticles ranged from 2.5 to 20% while a fixed ratio of glycerol (25%) was added. The effect of chitosan nanoparticles on porosity, tensile strength properties, water vapor permeability, grease-proof, and antimicrobial properties was studied. The results showed that addition of chitosan nanoparticles can improve tensile strength properties, reduce porosity, and impart NFC antimicrobial properties against Gram-positive bacteria (Staphylococcus aureus), Gram-negative bacteria (Escherichia coli), and yeast (Saccharomyces cervisiae). CHNP did not affect WVP or grease-proof properties of NFC films.The mixture containing CNF and 10% CHNP was used for paper coating and the effect of coating on tensile strength, porosity, water vapor permeability, water absorption, and grease-proof properties of paper sheets was studied. The results showed coating of paper sheets with thin film of NFC or NFC/CHNP can improve tensile strength properties, decrease porosity and water absorption, and increase grease-proof properties of paper sheets but did not affect their WVP. Presence of CHNP in the coating mixture resulted in higher tensile strength properties of coated paper sheets than in case of using NFC alone but no noticeable differences were found regarding porosity, WVP, grease proof, and water absorption of paper sheets coated with NFC or NFC/CHNP under the conditions used.