ABSTRACT
This work deals with the synthesis, structural characterization and applications of N-halamine glycinate functionalized silica-mesoporous silica coated ZnO-NPs/AC composite for water disinfection. Several nanocomposite materials were obtained: ZnO-NPs/AC, ZnO-NPs/AC@SiO2, ZnO-NPs/AC@SiO2@mSiO2, ZnO-NPs@SiO2@mSiO2-Gly and ZnO-NPs@SiO2@mSiO2-N-halamine-Gly. These nanocomposite materials were fully characterized via different physiochemical techniques including: FTIR, TGA, XPS, XRD, SEM, TEM and BET. XRD indicated a predominance of crystalline pattern of ZnO-NPs impregnated into activated carbon (AC) and their silica and m-mesoporous silica coating precursors. The FTIR spectra confirmed an immense combination between ZnO-NPs and AC of ZnO-NPs/AC nanocomposite as well as its interactions with coated silica precursors. SEM, TEM images illustrated that the fabricated ZnO-NPs/AC nanocomposites are well coated with silica-mesoporous silica functionalized N-halamine. The distinctive surface area has decreased from 800 m2/g for pristine AC to 772 m2/g for ZnO-NPs/AC and to 282 m2/g for ZnO-NPs/AC@SiO2 and to 139 m2/g for ZnO-NPs/AC@SiO2@mSiO2 and to 15.4 m2/g for ZnO-NPs@SiO2@mSiO2-N-Gly. All those nanocomposites showed good efficacy against all four bacterial species, with higher inhibition zones for the 2 g-positive bacteria than that of the 2 g-negative ones. The ZnO@SiO2@mSiO2-N-halamine-Gly exhibited the high zone inhibition against all tested bacteria except for E. Coli.
ABSTRACT
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
ABSTRACT
ZnO-NPs coated cotton or starched cotton fibers were successfully prepared via ultrasound irradiation. Different concentrations of soluble corn starch (1-3 starch wt.%) were used to stabilize ZnO-NPs onto the surface of cotton fabrics as entrapped species. The use of none-toxic biocompatible starch has improved the adhesion properties of the cotton fibers towards ZnO-NPs. This also enhanced the durability of ZnO-NPs onto the cotton fabrics and decreased their leaching from the surface of cotton fabrics. When 3 starch wt.% solution was used, deposition of ZnO-NP increased by 53% after 10 washing cycles. The antibacterial activity against Staphylococcus aureus and Escherichia coli increased by 50 and 21.5%, respectively. Functionalization of ZnO coated cotton with silver nanoparticles (Ag-NPs) and curcumin results in formation of ZnO-Ag/cotton and Zn(II) curcumin/cotton composites. The functionalized nanocomposites ZnO-Ag coated cotton material showed a synergistic antimicrobial behavior than that of individual ZnO/cotton material. The Zn(II) curcumin complex coated cotton showed higher antibacterial activities against both Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacteria than that of the ZnO/cotton material.
