An innovative discovery from Japan promises to revolutionize the way we deal with the yellow spots under the armpits and other obstinate signs on the fabrics. Instead of resorting to aggressive bleachings or washing at high temperatures that often ruin the garments, the researchers have developed a surprisingly delicate method based on the use of blue light.
According to a study published on ACS Sustainable Chemistry & Engineering And led by Dr. Tomohiro Sugahara, materials of the materials at the Asahi Kasei Corporation company, a LED light at 445 nanometers, in the visible blue band, is able to degrade the molecules responsible for the injection without affecting even the most delicate tissues, as Sugahara pointed out:
We did not expect such an effective result. Seeing the process operating so well on real stained shirts was impressive.
The unsightly yellow spots in the armpits are among the most difficult to eliminate: they are not only sweat, but a combination of sebums, squalene, oleic acid and food pigments such as beta-carotene or lycopene, present in foods such as tomatoes and citrus fruits.
Conventional methods such as bleach, hydrogen peroxide or ultraviolet light can partly solve the problem, but at a high price. In fact, these techniques weaken the fibers, degrade the colors and have a significant environmental impact, requesting chemicals, water and energy.
The Sugahara team, together with colleague Hisanari Yones, wondered if the same blue light they had already used to remove yellowing from plastic materials could also work on the fabrics. The first experiments gave promising results.
The blue light acts with oxygen to destroy the stains
In the laboratory, the researchers treated solutions containing square and other typical compounds of the spots, exposing them to the LED blue light in the presence of atmospheric oxygen. Within three hours, the colored compounds were completely decomposed. The molecular analyzes confirmed that the light, in synergy with oxygen, broke the double bonds of the molecules, transforming them into aldehydes and colorless carboxylic acids, as Sugahara explained:
Our method uses light visible in combination with environmental oxygen, which acts as a natural oxidant. This eliminates the need for aggressive chemical agents, making the process much more sustainable.
But how does this technology behave on real clothing?
After only 10 minutes, the blue light eliminates the stains better than bleach
The researchers simulated real spots on cotton samples, using square and aging the fabrics with heat. They then compared three treatments: hydrogen peroxide, UV light and LED blue light.
The result was clear: the blue light removed more yellowing in just 10 minutes than the other methods, without damaging the fabric. Even delicate materials such as silk and polyester have not shown signs of discoloring, wear or fragility. In addition, the treatment has proven effective also on difficult food spots such as orange juice and tomato sauce.
Another advantage? The colored garments, such as blue or black paintings, remained unchanged. This suggests that the technique could adapt to a wide range of clothing, not only to white ones.
According to Professor Juan Hinestroza, fiber expert at Cornell University:
This method could reduce the need for intense mechanical washing, thus limiting the production of microplastics and lengthening the life of clothes.
When will this technology be available?
For now, this technique is not yet ready for domestic use. It is not enough to turn on any blue torch: a specific lamp with a precise wavelength is needed, and the technology has not yet been converted into a commercial product.
However, researchers are optimistic: within five years the blue light could be adopted by professional laundries, wedding dresses or theaters. In a second moment, it could also enter the household appliances, but first it will be necessary to complete further tests on the safety and resistance of colors.
While the world seeks more ecological and delicate solutions for the care of fabrics, this innovative blue light technology could become a turning point in the fight against stains without compromising the environment or integrity of the garments.
You may also be interested in:
