Mechanical, optical and antibacterial properties improvement of paper using nanofibrillated ‎cellulose modified with nanosilver particles

The packaging industry is one of the most important consumers of paper, in that about one ‎third of materials used in the packaging industry are paper and paperboard. In general, ‎packaging papers need to have high barrier and mechanical properties. Regarding the importance ‎of sustainable development and debates on using petrochemical-based polymers in food ‎packaging, there is an increasing interest in replacing synthetic and fossil-based polymers with ‎more renewable and sustainable materials. A renewable biomaterial that may be a good ‎alternative for improving strength and barrier properties of paper and composites is ‎nanofibrillated cellulose (NFC).‎ Cellulose is the most abundant natural, renewable, biodegradable and biocompatible polymer. ‎Cellulose and its derivatives have been used in a variety of applications in several areas, such as ‎the textile industry, the paper industry and in the medical field, where they are used as tissue ‎engineering materials owing to their good biocompatibility and mechanical properties similar to ‎those of hard and soft tissue and easy fabrication into a variety of shapes with adjustable ‎interconnecting porosity. Cellulose and its derivatives are viable alternatives to alleviate such ‎issues, due to their inherent properties such as non-toxicity, hydrophilicity, and chemical ‎resistivity (1). The use of nanofibrillated cellulose (NFC) for the production of nanocomposites ‎containing inorganic nanoparticles has attracted the attention of the scientific community. ‎Nanofibrillated cellulose (NFC) and microbial cellulose, due to their nanosized dimensions can ‎impart improvement and in many cases new properties to the ensuing (nano) composite ‎materials (2). With the growing public health awareness of disease transmissions and cross-‎infection caused by microorganisms, use of antimicrobial materials has increased in many ‎application areas like protective clothing for medical and chemical works, other health related ‎products. The aim of this study was to produce NFC/Ag nanocomposites and used paper to ‎improve the mechanical and antibacterial properties. Silver nanoparticles reducing was used to ‎help NaBH4 on nanofibrillated cellulose at the level 5 and 10 ppm and finally, nanocomposite ‎NFC /Ag at 5, 10, 15% w/w of the paper were used to improve mechanical and antibacterial ‎properties. The results show an increase density and burst index. The brightness of paper treated ‎with nanocomposite NFC /Ag was low and opacity index was increased. Antibacterial properties ‎investigated towards gram negative (E.colie) and gram positive (S. aureus) bacteria. The results ‎indicated that the presence of few amounts of silver in treated paper were inhibited bacterial ‎growth. Lateral to target antibacterial properties was prepared of nanocomposite NFC/Ag ‎nanocomposite the immersion method used by the silver 5 and 10 ppm.‎