A most interesting nano research study into self-cleaning textiles by a team from RMIT University in Melbourne, Australia, has devised a cheap and efficient technique for growing nanostructures that can degrade organic matter when exposed to small amounts of light directly on the textiles. Such nano-enhanced textiles could do away with the need to wash clothes as they could spontaneously clean themselves just by being put under a light bulb or worn when out in the sun.

The findings could aid the design of new multi-functional fabrics that can absorb visible light and thereby enhance light-activated catalytic processes. As researcher Rajesh Ramanathan points out, “The advantage of textiles is they already have a 3D structure so they are great at absorbing light, which in turn speeds up the process of degrading organic matter.” As well as textiles, the process offers a range of applications for catalysis-based industries, including agrochemicals, pharmaceuticals and natural products.

"There’s more work to do to before we can start throwing out our washing machines, but this advance lays a strong foundation for the future development of fully self-cleaning textiles"Rajesh Ramanathan

With functional textiles now an intensive area of research, the study, which was published in the journal Advanced Materials Interfaces [Anderson et al., Adv. Mater. Interfaces (2016) DOI: 10.1002/admi.201500632], could prove significant for the development of fully functioning self-cleaning textiles. The key issue in the novel approach was to identify the best way to grow the nanostructures on an industrial scale and also to permanently attach them to textiles. The team used copper and silver-based nanostructures, which offer the ability to absorb visible light; when the nanostructures are exposed to light, they receive an energy boost that creates “hot electrons”, which in turn release a burst of energy that enables the nanostructures to degrade organic matter.

The scientists managed to build the nanostructures directly onto cotton textiles by dipping them into different solutions, allowing them to produce stable nanostructures within only half an hour. When exposed to light, the nanostructures took under six minutes for some of the nano-enhanced textiles to spontaneously clean themselves.

The work is significant as it shows the potential for growing nanomaterials directly onto textile surfaces using simple and efficient processes, and understanding the underlying mechanistic aspect on the influence of light could help tailor the materials for other applications apart from catalysis. The next step for the team will be to test the nano-enhanced textiles with commercially significant organic stains such as wine or food to examine the optimum loading of nanoparticles required for efficient degradation.