Ever noticed how raindrops simply bead-up and slide off from gabi (taro) leaves? This is made possible by numerous tiny waxy spikes on the surface of its leaves that cause the extreme water-shedding preventing it from getting wet. This phenomenon is called the “lotus effect” referring to the same water repelling characteristic exhibited by the lotus leaves. This is also present in other insects and birds, notice how butterfly wings don’t get drenched from the rain and how water gently rolls off a duck’s back.
Inspired by this common occurrence in nature, a team of chemists from the Philippine Textile Research Institute (PTRI) endeavored to mimic this process and apply it to textiles. With persistent research, the team from the Research and Development Division (RDD) of the Institute successfully rendered pineapple and cotton blend fabrics water-repellent using a familiar material: silver. The team submerged silver nanoparticles into silicone oxide solution before applying it to various textiles. These nano-coatings create a bond with the fabric creating hair-like structures as that of the gabi leaves.
“Compared with conventional water repellent finishes which literally forms a coating on textile surfaces leaving them stiff, this PTRI-developed technology entails nanofinishing which imparts nano-sized coating to the fabric maintaining the softness and breathability of the material,” explained Mr. Julius Leaño, head of the Chemical, Dyes, Auxiliaries, and By-Product Utilization Section (CDABUS) of RDD.
Known for its anti-bacterial properties, silver nanoparticles are now being incorporated in garments, beddings, pillows, and other fabrics. With careful research led by Ms. Jeannie Lyn Cabansag of RDD, silver was also found to be active against common pathogens causing pneumonia and skin infections, Klebsiella pneumonia and Staphylococcus aureus, respectively.
“We have established a novel and very simple process of application that could readily be adopted by textile industries, even the small and micro enterprises, to add value to their products,” shared Ms. Cabansag. “The combination of water repellence and anti-microbial property of textiles could find potential application in outdoor garments and packaging materials,” she added.
This development is part of the Institute’s new set of R & D programs which aims to respond to the market’s increasing demand for highly specialized textiles. These programs involve advanced textile technologies from nanotechnology to bionano-fiber and composites technology to develop intelligent, bio-functional and nano-functional textiles and materials as well as green processing technologies. (Joy Camille Baldo, S&T MediaService)