WASHINGTON, Nov. 18 (Xinhua) -- Researchers in the United States have developed a method that could reduce the amount of water needed to flush a conventional toilet by half.
The study, published Monday in the journal Nature Sustainability, describes a bio-inspired, sludge- and bacteria-repellent liquid coating that can make a toilet self-cleaning.
Researchers from the Pennsylvania State University developed a two-step spray. The first spray is created from molecularly grafted polymers, which can build a smooth and liquid-repellent surface on the bowl.
When the first spray dries, it grows molecules that look like little hairs, with a diameter of about 1 million times thinner than a human's. Then the second spray is applied, infusing a thin layer of lubricant around those "hairs" to create a super-slippery surface.
"When we put that coating on a toilet in the lab and dump synthetic fecal matter on it, it (the synthetic fecal matter) just completely slides down and nothing sticks to it (the toilet)," said Wang Jing, the paper's co-author and a PhD graduate from the university.
The researchers predict the coating could last for about 500 flushes in a conventional toilet before a reapplication of the lubricant layer is needed.
The two-step spray takes less than five minutes to make a slippery surface, and it repels bacteria, particularly those that spread infectious diseases and unpleasant odors, according to the study.