photovoltaic devices and solar cells. The use of nanoparticles of ZnO has been seen as a possible solution to stop infectious diseases due to their antimicrobial properties. Many researchers work in the field of ZnO nanoparticles synthesis and their application to textile materials where ZnO nanoparticles have been used for imparting antibacterial properties, UV-blocking and self-cleaning properties to textile materials [4–7]. The main problem when coating textiles with formulations containing nanoparticles is the control over the dispersion and surface distribution of the nanoparticles. If agglomeration occurs, the actual particle sizes lie in the range of several micrometers or even higher, so that the typical properties of nano sized object might be lost. The particles properties no longer behave like nanomaterials [1].

There are usually two possible ways for preparing coatings of textile materials with Nanosized particles. One is ex situ, e.g initially the nanoparticles are synthesized and then applied over a textile material [18]. Agglomeration is prevented by stabilization of the nanoparticles with a high molecular binding agent during the preparation of the nanoparticles and their application over fabric. Chitosan [19], acrylicbinder [20, 21] or soluble starch [22] is used as a binding agent. The other method, which ensures the more uniform distribution of nanoparticles, is in situ preparation and binding to a textile surface. ZnO nanostructures were in situ synthesized on the surface of a cotton fabric through a simple and efficient wet chemical method of Shateri-Khalilabad et al. [23]. However, further agglomeration is observed when using the approach they proposed. The synthesized particles are in two different structures: bundle-like and flower-like, and are composed of a few rods. This is the reason for the actual particle sizes to be higher than 100 nm or even in the range of several micro metres. To prevent the agglomeration there is need of a stabilizing agent [24]. For the past decade the different synthetic methods have been used to attain precise control over the properties of ZnO and the other nanoparticles, to attain the required properties, hydrogels are introduced.

Hydrogels are cross linked polymer networks that absorb substantial amounts of aqueous solutions. Hydrogels can be divided into two categories based on the chemical or physical nature of the crosslink junctions. Chemically cross linked networks have permanent junctions, while physical networks have transient junctions that arise from either polymer chain entanglements or physical interactions such as ionic interactions, hydrogen bonds, or hydrophobic interactions. Hydrogels are water swollen, cross-linked polymeric structures produced by the simple reaction of one or more co-monomers, physically cross-linked from entanglements, association bonds such as hydrogen bonds or strong van der Waals interactions between chains or crystallites bringing together two or more macromolecular chains. Hydrogels have received significant attention because of their exceptional promise in biomedical applications.