Recently, silver nanoparticles have gained significant interest due to their wide and excellent antibacterial properties, while the inadvertent harm caused by dissociative AgNPs greatly limited their applications in water disinfectant and wound treatment. Immobilization of the silver nanoparticles on a substrate or an upholder is the most probable solution to this problem.
Aerogels are porous non-crystalline nanomaterials which can be used to immobilize the silver nanoparticles. It has been observed that production of aerogels using raw biomass materials result in astronomical cost increase due to the complexity and high price for biomass purification and separation. Consequently, researchers have therefore turned their focus to abundant and renewable bagasse for direct use in aerogels.
A team of researchers led by Professor Xiaoying Wang from the State Key Laboratory of Pulp and Paper Engineering, South China University of Technology in China proposed a study on the application of bagasse as a reducing and stabilizing agent in the synthesis of silver nanoparticles and developed the bagasse-AgNP aerogel to immobilize and then reduce the dissociation of silver nanoparticles. They aimed at introducing a technique that directly utilizes bagasse as an ultra-light aerogel with silver nanoparticles for the first time. Their work is now published in Journal of Materials Chemistry B.
Foremost, the silver nanoparticles were synthesized in situ using a green route with depithing bagasse. The de-pithed bagasse was treated to remove sucrose, starch and wax and then ground into powders through ball milling, after which the bagasse powder was extracted. The research team then synthesized the bagasse-silver nanoparticle composite under microwave irradiation and fabricated the bagasse-AgNP aerogel. Finally, they antimicrobial tests using activated bacteria were done.
The research team observed that during the reaction, the crystalline region of cellulose in bagasse was destroyed and some groups of the bagasse were partly oxidized into carbonyl of ketone. This confirmed the reducing capacity of the bagasse. They then obtained the bagasse-silver nanoparticle composite and dissolve it into 1-Ethyl-3-methylimidazolium acetate so as to prepare the aerogel with silver nanoparticles. The aerogel piled up in slices and its weight multiplied by about 19 times its dry weight. It was then noted that the aerogel did not crush the flower branch since its density was very low due to the large interspaces between the aerogel slices.
The obtained aerogel is characterized by a strong antibacterial effect, especially against Escherichia Coli and Pseudomonas aeruginosa. This research work presents an interesting technique that proposes the direct use of bagasse in aerogel synthesis. A novel ultra-light antibacterial bagasse-AgNP aerogel without any silver-nanoparticle dissociation is presented herein using the new procedure.
Zuguang Shen, Guocheng Han, Xiaoying Wang, Jiwen Luo and Runcang Sun. An ultra-light antibacterial bagasse– silver nanoparticles aerogel. Journal of Materials Chemistry B volume 5 2017 pages 1155—1158.Go To Journal of Materials Chemistry B