title: Influences of Ag-NPs doping chitosan/calcium silicate nanocomposites for optical and antibacterial activity.
abstract: Chitosan (CS)/calcium silicate nanocomposites pure and doped with Ag ions (1, 2mol%) were prepared via sol-gel method. The prepared CS/calcium silicate nanocomposites were investigated through X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The XRD results, indicating that after increasing the Ag ions in the CS/calcium silicate nanocomposite the crystallinity degree increased regularly in the prepared nanocomposites accompanying to the continuously rearrangement in the internal structure of nanocomposite under the effect of inorganic nanoparticles. Correspondingly, the optical properties of the prepared nanocomposites films were measured using UV/vis spectroscopy. The reflectance increased while the energy band gap decreased from 3.96eV to 2.43eV with Ag-ions concentration. More over the transition type changed from direct into indirect by adding Ag-ions, indicate that new band between valence and conduction band were formed. In addition, the optical parameters showed an increase in refractive indices and decrease in the surface and volume energies losses with increasing Ag-ions. Correspondingly, the prepared nanocomposites exhibited good antibacterial activity against gram positive (Staphylococcus aureus), gram negative (Pseudomonas aeruginosa) bacteria and fungi (Candidia albicans). The results suggested that the prepared CS/calcium silicate nanocomposites can be a promised candidate for optical sensors applications and smart packaging materials.
authors.affiliation: Solid State Physics Department, National Research Centre, 33 El Bohouth St. (former El Tahrir St.), Dokki, Giza 12622, Egypt.
authors.forename: Amany M
authors.initials: AM
authors.lastname: El-Nahrawy
authors.affiliation: Basic Science Department, Faculty of Industrial Education, Helwan University, Sray El-Quba, 11281 Cairo, Egypt.
authors.forename: Ahmed I
authors.initials: AI
authors.lastname: Ali
authors.affiliation: Solid State Physics Department, National Research Centre, 33 El Bohouth St. (former El Tahrir St.), Dokki, Giza 12622, Egypt.
authors.forename: Ali B
authors.initials: AB
authors.lastname: Abou Hammad
authors.affiliation: Packing and Packaging Materials Department, National Research Centre, 33 El Bohouth St. (former El Tahrir St.), Dokki, Giza 12622, Egypt. Electronic address: amyoussef27@yahoo.com.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Youssef
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D017610:Calcium Compounds / Q000737:chemistry*; D002176:Candida albicans / Q000187:drug effects; D048271:Chitosan / Q000737:chemistry* / Q000494:pharmacology*; D053768:Metal Nanoparticles / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D055620:Optical Phenomena; D017640:Silicates / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D000890:Anti-Infective Agents; D017610:Calcium Compounds; D017640:Silicates; D012834:Silver; D048271:Chitosan; C031293:calcium silicate
keywords: Ag-doping; Antibacterial activity; Chitosan/calcium silicate nanocomposites; Optical properties; Optical sensors; Sol-gel growth