Application of nano silver in the production of antibacterial banknote paper

Bank-note during in its lifetime exposed to different environments and various applicationns with high frequency. As it is confirmed in scientific studies, bank-note can be one of the most important and perhaps rarest of disease and parasites carriers in society. The goal of this study is evaluation of the appropriate solution for antibacterial banknote paper production using silver nanoparticles as an antibacterial agent and a cationic polyacrylamide as retention aid. Laboratory pulp of cotton fibers bleached with hydrogen peroxide with freeness of 34 °SR, consistency of 3.1% and neutral pH were prepared and then above additives were added with specified conditions (nano silver with 25, 50, 75 and 100 ppm with 0.3% percent cationic polyacrylamide) and finally 90 g/m2 standard handsheets made from above mentioned pulp. To verify the presence of silver particles in paper structure, the hand sheet papers were characterized by SEM. UV-vis spectrophotometric method was used to evaluate of antibacterial properties of paper. Also, papers were analyzed in strength and optical properties. The results showed that with increasing the silver nanoparticles consumption, paper strength properties and brightness were decreased, and opacity increased. The biological test results showed that the antibacterial properties of paper were improved with silver nanoparticles consumption. Based on the results of strength, optical and biological tests and also economic and environmental overviews, 25ppm consumption of nano-silver was determined as optimized treatment.