Silanated nano ZnO hybrid embedded PMMA polymer coatings on cotton fabrics for near-IR reflective, antifungal cool-textiles†
Textile surfaces engineered with infrared/ultraviolet energy shielding coatings are an emerging technology in the processing of solar heat protective cool-textiles. In this work, such multifunctional coatings were prepared using silane treated nano ZnO hybrid embedded PMMA colloids on a model black colored cotton textile. Black cotton fabrics were selected for the study because they exhibit a high heat-build up tendency due to the inherent black body radiation effect. 3-(Aminopropyl)trimethoxy silane modified nano ZnO hybrids (APZO NHs) were first prepared and transformed into a stable colloidal dispersion in a PMMA medium to obtain an APZO NHs/PMMA sol. This hybrid–polymer colloidal sol was dip-coated on the fabric surface to form multilayer coatings. This surface engineered black cotton was subjected to studies of its phase analysis, chemical interaction, and morphological features in addition to its NIR reflectance, UV shielding efficiency and antifungal properties. The NIR/UV reflectance performance was analyzed with respect to the number of coatings and compared with the standard white cotton fabric which has roughly 50% NIR reflectance. When silane treated ZnO hybrid particulates are embedded in the PMMA matrix, the polymer coatings offer mechanically stable, UV/NIR radiation shielding textile surfaces in the wavelength region between 360 to 1600 nm that eventually turns the black cotton to cool-black textiles. The coatings also offer hydrophobic functionality as well as strong protection against the growth of Aspergillus flavus and Aspergillus niger fungi species resulting in biosafe textiles.