ABSTRACT
PURPOSE: Nanosilver-silicone hydrogel (NAgSiH) composites for contact lenses were synthesized to asses the antimicrobial effects. METHODS: Silicone hydrogel (SiH) films were synthesized followed by impregnation in silver nitrate solutions (10, 20, 30, 40, 60, 80ppm) and in-situ chemical reduction of silver ions using sodium borohydride (NaBH4). The silver nano particles (AgNPS) were identified by UV-vis absorption spectroscopy, Energy-dispersive X-ray spectroscopy (EDX) mapping and EDX spectrum. Physico-mechanical and chemical properties of NAgSIH films were studied. The antimicrobial effect of the hydrogels against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus was evaluated. The numbers of viable bacterial cells on NAgSiH surface or in solution compared to control SiH were examined. RESULTS: The NAgSiH films were successfully synthesized. FTIR results indicated that AgNPS had no effect on the bulk structure of the prepared SiH films. From TGA analysis, NAgSiH(R80) and SiH(R0) films had the same maximum decomposition temperature (404°C). UV-vis absorption spectroscopy and EDX mapping and spectrum emphasized that AgNPS were in spherical shape. The maximum absorption wavelength of NAgSiH films were around 400nm. The light transmittance decreased as the concentration of AgNPS increased, but still greater than 90% at wavelength around 555nm. The Young's modulus increased gradually from 1.06MPa of SiH(R0) to highest value 1.38MPa of NAgSiH(R80). AgNPS incorporated into SiH films reduced the bacterial cell growth and prevented colonization. Groups NAgSiH(R60,R80) demonstrated an excellent reduction in bacterial viability in solution and on the SiH surface. CONCLUSIONS: NAgSiH composites were successfully synthesized and possessed an excellent antimicrobial effects.
Subject(s)
Bacteria/growth & development , Metal Nanoparticles/administration & dosage , Silicone Gels/chemistry , Silver/administration & dosage , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/chemical synthesis , Bacteria/drug effects , Cell Survival/drug effects , Dose-Response Relationship, Drug , Materials Testing , Metal Nanoparticles/chemistry , Metal Nanoparticles/ultrastructure , Nanocomposites/administration & dosage , Nanocomposites/chemistry , Nanocomposites/ultrastructure , Silver/chemistryABSTRACT
The present work deals with the preparation of innovative cotton textiles which act against blood sucking insects such as mosquitoes. Thus experiments were designed to incorporation of efficient insecticide (Permethrin, bioallethrin) in the macro-molecular structure of modified cotton fabrics. Chemical modification of cotton was realized by grafting with glycidyl methacrylate alone or in combination with ß-cyclodextrin by irradiation using fasting electron beam. Retreatment of the so obtained modified cotton was also made to increase the amount of CDs, and in turn, their cavities within the molecular structure of the modified cottons. Finished fabrics were though evaluated using chemical analysis; physical testing, bioassay tests and IR as well as SEM. Results obtained conclude that the amount of insecticide in the finished fabrics increases by increasing of the fixed amount of cyclodextrins which incorporate through their cavities the insecticide. The bioassay test shows that finished cotton fabrics display fast acting against mosquitoes.
Subject(s)
Aedes , Electrons , Epoxy Compounds/chemistry , Gossypium/chemistry , Insecticides , Methacrylates/chemistry , beta-Cyclodextrins/chemistry , Allethrins , Animals , Permethrin , Polymerization , Radiation, Ionizing , Textiles/radiation effectsABSTRACT
Organo-phosphorus compounds was prepared and applied onto cotton fabrics as flame retarding agent. methacryloloxyethylorthophoshor tetraethyl diamidate (MPD) was prepared and its structure was confirmed by IR, NMR and mass spectroscopy. Pyrovatex as commercial flame retardant was used for comparative study. Impregnation method was used as coating for the application of the organophosphorus compounds to cotton fabrics. The major factors affecting the reaction were studied. The results show that the prepared organophosphorus compound can be successfully used as flame retardant for cotton fabrics.
Subject(s)
Cotton Fiber , Flame Retardants , Organophosphorus Compounds/chemistry , Methacrylates/chemistryABSTRACT
Chitosan hybrid membranes were prepared in the presence of polyethylacrylate and polybutylacrylate and characterized by measuring stress, strain, Young's modulus, swelling behavior and antibacterial properties against gram-negative and gram-positive bacteria using IR spectroscopy and scanning electron microscopy (SEM). The results show that the mechanical properties of the hybrid membranes were enhanced using polybutylacrylate. SEM images showed homogeneity of the prepared membranes. The swelling degree was of the order chitosan > chitosan/polyethylacrylate > chitosan/polybutylacrylate. Antibacterial properties of the hybrid membranes with polybutylacrylate and polyethylacrylate were higher than those of chitosan membranes without any additives.
