Eco-friendly CityU invention lets boaters paint the town red

Henry Siu

Boats can potentially reduce their energy consumption by 30 to 40 percent with a cost-effective and environmentally friendly paint spray developed by CAT, a company established by City University.

The Nano-Photocatalytic Marine Antifouling/Anticorrosion Paint (Nano-MAP), CAT's inaugural product, is designed to replace traditional heavy metal-based antifouling paints that prevent the growth of parasitic organisms on ships.

The team also applied Nano-MAP to sluice gates in seawater systems to inhibit the growth of organisms.

Energy and environmental expert Michael Leung Kwok-ki, who led in the breakthrough, said fouling by marine organisms can significantly impair performance, resulting in a 30-40 percent increase in energy consumption.

"Traditional antifouling paints often contain heavy metals, which can effectively prevent marine organisms from adhering to the hull. However, these coatings release toxic metal ions upon contact with seawater, leading to marine pollution," Leung said.

"In contrast, Nano-MAP releases electrons that inhibit the chemical reaction between metals and oxygen, reducing rust and preventing the growth of marine organisms."

Leung said the spray, priced at HK$120 for 450 milliliters, can significantly reduce the frequency of boat maintenance by up to two years.

"Typically, boat maintenance costs around HK$200,000 a month for divers to clean organisms and debris from the hull. With our spray, a total of HK$4.8 million can be saved over two years," he explained.

Chief marketing officer Leung Tze-kei said the paint is also being considered for use in construction materials.

"This spray can help prevent dust and rain stains from tarnishing the exteriors of transportation and buildings, enhancing their appearance. It also reduces the need for frequent cleaning, minimizing risks faced by outdoor workers," she said.

Richard Li Huaicheng, another chief marketing officer at CAT, reported that about 3,000 units of the spray have been sold since its launch late last month.