جستجوی مقالات مرتبط با کلیدواژه "nanosilver" در نشریات گروه "جنگلداری"

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.‎

Present research was conducted to investigate the effects of nanosilver and Nanocopper on physical (Water Absorption and Dimension Swelling) and mechanical properties (MOE، MOR، Compression strength parallel to the grain and Hardness) of Paulownia fortunei. Specimens were impregnated with Empty-cell method with a 400 ppm aqueous suspension of nanosilver and nanocopper، size range from 10 to 80 nm، in a pressure vessel at 2. 5 bar for 30 minutes. Results showed that modulus of rupture (MOR)، modulus of elasticity (MOE)، and compression strength parallel to the grain were significantly increased in impregnated samples and the most increased was showed in impregnated samples with Nanocopper. In mechanical properties، there was no significant difference in hardness between impregnated and control samples. Results shown that impregnated wood with Nanosilver and Nanocopper have positive significantly effect to decrease dimension swelling and water absorption in specimens. Cluster analysis on physical and mechanical properties showed that impregnated samples with nano-copper clustered differently. However، impregnated samples with nano-silver had improved some of the physical and mechanical properties of wood but they didn’t have significant difference in comparison control specimens.