Surface modification of SiO₂ coated ZnO nanoparticles for multifunctional cotton fabrics

A simple chemical synthetic route was designed to prepare zinc oxide nanoparticles (ZnO-NPs) by using sodium alginate as anti-agglomeration agent in the presence of sodium hydroxide as alkali. Next, surface modification of ZnO-NPs with SiO₂ nanoparticles was achieved as per to sol-gel process. Further enhancing of the multifunctional properties of SiO₂@ZnO-NPs was conducted successfully thanks to (aminopropyl)triethoxysilan (APTES) and vinyltriethoxysilan (VTES) which, in turns, increase the affinity of the SiO₂@ZnO-NPs nanocomposite towards glycosidic chains of cotton fabrics. Thorough characterizations of synthesized ZnO-NPs, SiO₂@ZnO-NPs, SiO₂@ZnO-NPs/APTES and SiO₂@ZnO-NPs/VTES were conducted by the making use of well advanced techniques such as FT-IR, XRD, TEM, DLS and SEM-EDX. The data obtained clarified the formation of an interfacial chemical bond between ZnO and SiO₂ as affirmed by FT-IR and XRD analysis. In addition, the results revealed by TEM, zeta sizer and SEM-EDX techniques, declared that the amorphous layers of SiO₂, APTES or VTES evenly coated the surface of ZnO-NPs. For these nanocomposites, the work was extended to render cotton fabrics multifunctional properties such as antibacterial and UV protection with high durability even after 20 washing cycles using pad dry cure method. Taking the advantages of the silane compounds terminated by active groups such as OH, NH₂, etc., open the door for further functionalization of the cotton fabrics' surfaces by durable multifunctional agents applied in various applications.