While so-called supergels may be useful, they are usually made from irritating chemicals and are difficult to dissolve once cured,media New Atlas reported. But now scientists have created a plant-based, powerful glue that can be easily removed when needed.
The experimental adhesive was designed by researchers from the University of Alto, The University of Tokyo, Sichuan University in China and the University of British Columbia in Canada. Its active ingredient is cellulose nanoparticles, which can be obtained from plants relatively cheaply. These particles can even be harvested from discarded plant materials, such as waste from agricultural or paper mills.
The scientists added water to the nanoparticles and then placed the resulting mixture between the two surfaces that needed to be connected. When heat is then applied to the solution, the water evaporates, creating bonds through the side-by-side layers converted into cellulose nanocrystals. Then, if someone tries to pull the two surfaces directly apart to exert force along the bonding plane, they will find it very difficult to do so – a drop of glue can withstand a pull of up to 90 kg.
That is, if the two surfaces are pulled in the opposite direction to the side – thus applying force perpendicular to the bonding plane – the bonding is relatively easy to break. In fact, the outside strength of the glue is only one-tenth of the strength of its plane. Simply apply lateral pressure with your thumb to roll the adhesive off the surface.
At present, the glue solidifies for about two hours, although it can be reduced by increasing heat. However, trade-offs need to be weighed because higher temperatures (more than 50oC/122oF) result in smaller bonding areas. Once the technology is further developed, scientists hope it will be useful in applications such as electronics or packaging, which remain intact for the duration of their intended use, but can be easily disassembled and reused when discarded.
A paper on the study was recently published in the journal Advanced Materials.