title: Preparation and characterization of SiO₂/CMC/Ag hybrids with antibacterial properties.
abstract: Amorphous hybrids based on sodium salt of carboxymethyl cellulose (CMC) and tetraethoxysilane (TEOS) containing silver nanoparticles were prepared by sol-gel method. The amorphous structure, morphology and antibacterial behavior were clarified. The thermal stability of obtained hybrids decreased with the increase in silver content from 0.5 to 1.5 wt%. Infrared spectra of the material suggest that the main interaction between the cellulose ether and silica network is via hydrogen bonds (bands at approximately 3,540 and 3,625 cm(-1)). According to UV-vis spectra the silver is present in two different states Ag(+) (absorption band at approximately 210 nm) and Ag(0) (band at approximately 300 nm). The different sizes of silver particles are present as clusters. It was demonstrated that these hybrids have a well pronounced antibacterial activity against B. subtilis and E. coli K12. Even the hybrid with 0.5 wt% Ag has efficient antibacterial activity for both Gram-positive and Gram-negative bacteria.
authors.affiliation: University of Chemical Technology and Metallurgy, Department of Fundamentals of Chemical Technology, str. bld. 8 Kl. Ohridski, 1756 Sofia, Bulgaria. Electronic address: rangelovang@gmail.com.
authors.forename: Nadezhda
authors.initials: N
authors.lastname: Rangelova
authors.forename: Lyubomir
authors.initials: L
authors.lastname: Aleksandrov
authors.forename: Tsvetelina
authors.initials: T
authors.lastname: Angelova
authors.forename: Nelly
authors.initials: N
authors.lastname: Georgieva
authors.forename: Rudolf
authors.initials: R
authors.lastname: Müller
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects; D002266:Carboxymethylcellulose Sodium / Q000737:chemistry* / Q000494:pharmacology*; D048168:Escherichia coli K12 / Q000187:drug effects; D053768:Metal Nanoparticles / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D012821:Silanes; D012834:Silver; C040733:tetraethoxysilane; D012822:Silicon Dioxide; D002266:Carboxymethylcellulose Sodium
keywords: Antibacterial activity; Carboxymethyl cellulose; Silver nanoparticles; Sol–gel method