Video: Powdered glue is dry until you squish it
Dried-up glue may come in useful. A new powdered form of adhesive developed by researchers in Japan could help in building hard-to-reach parts of cars or smartphones.
Most glues are either liquids that dry to form a bond, or solids that are heated to make them viscous and sticky, and then bond when cooled. Nowof Osaka Institute of Technology in Japan and his colleagues have come up with a dry powder that becomes a sticky glue when squished.
The powder is made up of “” – beads of liquid coated in solid particles that trap the fluid inside. In this case, the team rolled spheres of a latex liquid in a layer of calcium-carbonate nanoparticles. The resulting drops are a few millimetres across and pour easily, but when put under pressure for a few seconds the nanoparticles are pushed inside, exposing the sticky liquid within to the surface.
The team’s tests show that the glue forms stronger bonds than other pressure-sensitive adhesives (PSAs) such as those found on Post-it notes or sticky tape. “Our PSA materials can adhere substrates with a rough surface like wood, which are difficult to be bonded using Scotch tape,” says Fujii.
Because the material can be poured before its stickiness is activated, Fujii thinks it would be particularly useful for getting glue into odd shapes or tight spots. “The PSA powder can flow into confined and intricate spaces,” he says. To satisfy desired design properties in the automobile, aerospace and electronics industries, there is a strong need to join parts with complicated shapes, he says.
Journal reference: Materials Horizons, DOI:
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