Even if soy sauce, ketchup, or engine oil gets on a white shirt, it becomes clean with just a water rinse. That is because the fabric has a self-cleaning coating that blocks stains. Shorter wash times significantly cut water and electricity use. If commercialized, it is expected to save resources and also greatly reduce microplastic pollution from the laundry process.
A research team led by chemistry professor Wang Dayang at Jilin University in China said on the 19th that it developed a sprayable fabric coating that allows clothes to be washed with only water, in Communications Chemistry, a sister journal of Nature. The team said the stain-blocking coating can be applied to both natural and synthetic fibers and can reduce water and energy consumption during washing by more than 80%.
◇Polymer layer repels grease
The team created a kind of protective shield on fabric using two polymer materials. Alternately spraying positively charged poly(diallyldimethylammonium chloride) (PDADMAC) and negatively charged poly(vinyl sulfonic acid) (PVSA) causes them to attract each other and form a robust polymer layer.
The polymer layer formed on the fabric is rich in hydroxyl (-OH) groups, each consisting of one hydrogen and one oxygen atom, making it highly hydrophilic. When a soiled fabric is rinsed, the hydroxyl groups in the polymer layer immediately form strong hydrogen bonds with water. A thin water film then forms between the fiber surface and the grease. If the grease cannot penetrate into the fibers and instead floats in the water, a light rinse is enough to clean the garment.
The team said that in tests on garments made of three materials—cotton, silk, and polyester—the coating removed a variety of stains, including soy sauce, engine oil, Zanthoxylum bungeanum oil, vinegar, and ketchup, with performance equal to or better than conventional washing. On ordinary cotton fabric, most grease remains after rinsing with water alone, but with the self-cleaning coating, the cleaning efficiency exceeded 90%, the team said.
Conventional washing machines wash by rubbing clothes with water and detergent, then rinsing several times and spinning. Clothes with the self-cleaning coating are finished by simply rinsing with water without detergent. That cuts water and electricity use and shortens wash time. Compared with a standard cycle of one wash and four rinses in a conventional machine, the team estimated that each wash could reduce water, electricity, and time consumption by more than 80%.
◇Likely economical and helpful for the environment
The team also tested whether the self-cleaning coating affects humans or the environment. When cowpea plants were grown separately with water used to rinse the coated clothes and with ordinary tap water, there was no difference in plant growth. Tests of the self-cleaning coating on mouse skin cells also found no issues. The coating delivered the same washing effect in hard water rich in minerals, such as groundwater or spring water, as in tap water. Conventional detergents foam poorly in hard water and lose much of their cleaning power.
Of course, applying a polymer layer to block contamination on fabric incurs additional cost. But the team estimated that, depending on the detergent type, the initial coating cost is offset after 15 to 50 washes. Given that a person does at least 100 washes a year, the self-cleaning coating can be considered sufficiently economical. The team said the coating did not degrade after more than 100 washes.
Considering the environmental protection effect, the benefits would be immediate. Surfactants, which separate grease in detergents, are a major source of water pollution. Surfactants do not readily break down in nature. When they flow into rivers, they form a foamy film that blocks sunlight and oxygen. Washing with only water, without detergent, can prevent such problems. Domestic wastewater treatment also becomes simpler. The team noted that rinsing simply with water greatly reduces the amount of microplastics shed from synthetic fibers.
◇Self-cleaning fabrics inspired by lotus leaves
Nature also offers a famous example of staying unstained: the lotus. Although it lives in muddy water, its leaves remain spotless. In 1997, Wilhelm Barthlott, a botanist at the University of Bonn, discovered that microscopic protrusions on lotus leaves prevent water droplets from permeating, causing them to roll off. In the process, dust on the surface is washed away.
The surfaces of the microscopic protrusions on lotus leaves have a waxy layer that repels water. Air layers between the protrusions block other substances from entering. As a result, water droplets containing contaminants cannot slip between the protrusions; they hang on the tips and fall off with a slight movement. Scientists call this the "lotus effect."
Schoeller Textil, a Swiss textile company, developed NanoSphere technology in 2001 by mimicking lotus leaves to create a finely corrugated structure on fabric surfaces. Several sportswear companies sell waterproof and stain-repellent products using this technology. Like lotus leaves, when beverages or ketchup spill on clothes, the liquid slides along the surface before staining.
Oil does not respond to the lotus effect. That is because the protrusion surfaces on lotus leaves are covered with a waxy layer that is oleophilic. In 2008, a team led by Gareth McKinley of the Massachusetts Institute of Technology (MIT) Department of Mechanical Engineering reported a micro-protrusion structure that even oil cannot penetrate in the Proceedings of the National Academy of Sciences of the United States of America (PNAS). The team calculated the optimal spacing to maintain an air layer between the protrusions. When the gaps were made narrower than those of lotus leaves, oil dropped from a height did not soak in but fell off like water droplets.
The microscopic protrusion structure of lotus leaves is also vulnerable to impact. In heavy rain, the self-cleaning function is damaged. The Wyss Institute for Biologically Inspired Engineering at Harvard University found an answer in the pitcher plant, which uses sticky secretions to make insects slide inward. In 2014, the team reported in Nanotechnology a fabric using SLIPS coating technology, short for "slippery liquid-infused porous surfaces." A lubricating liquid was applied to the protrusion surfaces to let contaminants slide off. Kim Pil-seok, then at the Wyss Institute and now chief technology officer of SK Innovation and head of the Environmental Science and Technology Institute, was a co-author of the paper.
Self-cleaning garments are expensive. That is because creating microscopic structures on fabric surfaces is costly. They are still sold only in niche markets such as high-performance sportswear and outdoor gear. But as microplastics from clothing emerge as a serious environmental issue, interest in self-cleaning technology is growing. Lotus leaves or pitcher plants may soon feature frequently in apparel ads.
References
Communications Chemistry (2026), DOI: https://doi.org/10.1038/s42004-026-01942-7
Nanotechnology (2014), DOI: https://doi.org/10.1088/0957-4484/25/1/014019
PNAS (2008), DOI: https://doi.org/10.1073/pnas.0804872105