Kevlar fabrics treated with MTMS modified silica based STF showed better impact energy absorption as compared to APTES modified and control silica based STF treated fabrics, attributed to changes in interactions between fabrics and silica particles.

Paper matrices showing antibacterial activity were prepared by immobilizing ZnO nanowires (NWs) of diameter ca. 130–500 nm and length up to 2.5 μm on the surface of cellulose fibers by a single-step hydrothermal method. The antibacterial activity of the paper matrices has been investigated versus the visible light exposure time and ZnO contents (2.0 to 18.0 wt%). A complete inhibition of E. coli growth (i.e. 99.99%) was observed with the ZnO-immobilized paper matrices for 6 to 9 h exposure. A possible growth mechanism for the ZnO NW growth on the surface of the cellulose fibers has been proposed. The immobilization of ZnO NWs in paper matrices was characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), X-ray photoluminescence spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy.

Metal oxide nanostructures of TiO₂, ZnO, Fe₂O₃/Fe₃O₄, Bi₂O₃, CeO₂, ITO, SiO₂, MoO₂, and WO₃ have shown great potential for applications in various fields such as piezoelectric, magnetic, gas sensors, and dye sensitized solar cells due to their unique optical, electronic, conductivity, catalytic and antimicrobial properties. However, recovery and reuse of these nanostructures pose big threats from cost and environmental perspectives. Thus, various substrates have been employed for incorporating or immobilizing them but finding suitable substrate is still a big challenge. Paper, being a natural biopolymer, has been used recently to incorporate/immobilize various metal oxide nanostructures. The metal oxide nanostructures are normally adhered to the cellulose matrices through weak interactions such as van der Waals force and hence, usually have retention related issues. This was circumvented to a great extent by using suitable linkers, binders, or retention aids for the incorporation/immobilization of the nanostructures in paper matrices. Although these reagents improve retention, as well as some of the properties, they ultimately add cost to the final product. Additionally, these retention aids and linkers hinder accessibility of active surface sites of metal oxide nanostructures for their various applications. Very recently our group developed an in situ single step hydrothermal method to immobilize metal oxide nanostructures such as TiO₂, ZnO, and Bi₂O₃ without using any binder, linker or retention aid. In this review a comprehensive account of the development of methodology for incorporation/immobilization of metal oxide nanostructures is discussed. Furthermore, how the immobilization of nanostructures evolved without using any binder, linker or retention aid is thoroughly discussed based on the chemistry of the cellulose and metal oxides. Applications of nanostructure immobilized paper matrices are highlighted and critical challenges are discussed along with directions for future research.