Magnetic field cures adhesives faster with less energy

Conventional adhesives, such as epoxy, are designed to cure using moisture, heat and light. Curing is necessary to cross-link and bond the glue with the two secured surfaces as the glue crystallizes and hardens. Now, scientists from Nanyang Technological University (Singapore; www.ntu.edu.sg), led by professor Raju V. Ramanujan and associate professor Terry Steele, have developed a new adhesive that can be cured using a magnetic field.

The new adhesive is made by combining a commercially available epoxy adhesive with specially tailored oxide nanoparticles made from a chemical combination including manganese, zinc and iron. These nanoparticles are designed to heat up when electromagnetic energy is passed through them, activating the curing process. The temperature and rate of heating can be controlled, eliminating overheating and hotspot formation.

One gram of the new adhesive can be cured by a 200-W electromagnetic device in 5 min. In contrast, a conventional epoxy requires 1 h to cure in a traditional 2,000-W oven. “Our temperature-controlled magnetic nanoparticles are designed to be mixed with existing one-pot adhesive formulations, so many of the epoxy-based adhesives on the market could be converted into magnetic field-activated glue,” says Ramanujan.

The new adhesive should be of considerable interest in the sports, medical, automotive and aerospace industries. The scientists have filed for a patent through NTUitive, the university’s innovation and enterprise company.