Green Synthesis And Applications Of Sodium Carboxymethyl Cellulose Nanocomposite Materials

Cellulose fibers are natural polymer organic materials which are widely existed on earth and have the most advantages of biodegradability,good biocompatibility and renewability.Sodium carboxymethyl cellulose?CMC?is a class of polysaccharide which was modified by cellulose fibers,after modification,CMC not only has the characteristics of cellulose itself,but also has some special properties.In this paper,metal nanoparticles / CMC composites were synthesized by a method of in situ reduction from different metal precursors at different CMC concentration,reaction time,synthesis temperature and pH.The metal nanoparticles / CMC composites were characterized by UV-vis spectrophotometer,transmission electron microscopy?TEM?and particle size analyzer.The fluorescence,antibacterial and catalytic properties of the samples were also studied.The main contents and conclusions are as follows:?1?Using chloroauric acid?HAuCl₄?as metal precursor,CMC functioned as both reducing and stabilizing agent,gold nanoparticles / carboxymethyl cellulose?AuNPs/CMC?composites were prepared using situ reduction method,with their structure and properties also studied.The results showed that the reactive temperature,time,solution pH,and the concentration of CMC all had effects on the synthesis of gold nanoparticles,through a series of experiments,the 0.4% CMC,the appropriate temperature of 80?,the reaction time of 50 min and the optimum pH of 9 were chosen,the maximum absorption wavelengths of AuNPs/CMC composites were at 521-533 nm measured by UV–vis spectroscopy,the HRTEM measurements reveal that the AuNPs formed were spherical and quasi-spherical in shape,the size distribution of nanoparticles was in good agreement with the DLS and the diameter of particles mostly ranged from 14 nm to 26 nm.The AuNPs/CMC composites have good fluorescence property and Hg?II?has a quenching effect on its fluorescence.The fluorescence intensity decreased linearly with the Hg²⁺ concentration in the range of 0 to 0.32?mol/L,the detection limit was 3.6nmol/L.?2?Using silver nitrate?AgNO3?as metal precursor,CMC functioned as both reducing and stabilizing agent,silver nanoparticles / carboxymethyl cellulose?AgNPs/CMC?composites were prepared using situ reduction method,with their structure and properties also studied.The results showed that the reactive temperature,time,solution pH,and the concentration of CMC all had effects on the synthesis of silver nanoparticles,through a series of experiments,the 0.25% CMC,the appropriate temperature of 60?,the reaction time of 30 min and the optimum pH of 12 were chosen,the maximum absorption wavelengths of AgNPs/CMC composites were at 400-410 nm measured by UV–vis spectroscopy,the HRTEM measurements reveal that the AgNPs formed were spherical and quasi-spherical in shape,the size distribution of nanoparticles was in good agreement with the DLS and the diameter of particles mostly ranged from 7 nm to 16 nm.The AgNPs/CMC composites have good antibacterial property to C.perfringens and B.subtilis.?3?Using palladium chloride?PdCl₂?as metal precursor,CMC functioned as both reducing and stabilizing agent,palladium nanoparticles/carboxymethyl cellulose?PdNPs/CMC?composites were prepared using situ reduction method,with their structure and properties also studied.The results showed that the reactive temperature,time,solution pH,and the concentration of CMC all had effects on the synthesis of palladium nanoparticles,through a series of experiments,the 0.4% CMC,the appropriate temperature of 80?,the reaction time of 30 min and the optimum pH of 6 were chosen,the HRTEM measurements reveal that the PdNPs formed were spherical and quasi-spherical in shape,the size distribution of nanoparticles was in good agreement with the DLS and the diameter of particles mostly ranged from 1.5 nm to 4 nm.The PdNPs/CMC composites have excellent catalytic activity and it showed the excellent catalytic activity by reducing degradation of azo-dyes,such as p-Aminoazobenzene,scarlet 3G and reactive yellow 179,in the present of sodium borohydridesuch.