Scientists invented glue that is activated by magnetic fields

The curing process is very important in bonding and sealing two surfaces with glue, because the adhesive will crystallize and harden to achieve the highest strength.

The magnetocuring adhesive developed by scientists at Nanyang Technological University (NTU, Singapore) can harden when applied through a magnetic field. This is extremely useful under certain environmental conditions, where current adhesives are not effective. In addition, when adhesive is applied between insulating materials such as wood or rubber, activators such as heat, light, and air cannot easily access the adhesive.

Products such as bicycle frames, helmets, and compound golf clubs are now made using a two-part epoxy adhesive, in which the resin and hardener are mixed together, resulting in a Chemical reactions take place immediately.

For carbon fiber manufacturers – thin strips of carbon glued together in layers – and sports equipment manufacturers that use carbon fiber, their factories use large, heat-resistant furnaces. high, to harden the epoxy adhesive for many hours. This energy-intensive curing process is the main reason why the cost of carbon fiber is so high.

The new magnetocuring adhesive is made by combining a conventional epoxy adhesive with specialized magnetic nanoparticles developed by NTU scientists. It does not need to be mixed with any hardener or accelerator (cure accelerator), unlike two-component adhesives (which consist of two liquids that must be mixed together. before use), making production and application easier.

This new type of adhesive can bind materials when activated by passing through a magnetic field, which is easily generated with only a small electromagnetic device. This process will consume less energy than a traditional large oven.

For example, 1 gram of magnetocuring adhesive can be easily hardened by a 200-watt electromagnetic device for 5 minutes (16.6 Wh consumption). This energy level is 120 times lower than that of a traditional 2,000-watt oven, which takes 1 hour (2,000Wh of consumption) to harden traditional epoxy.

Associate Professors Steele and Dr. Richa are hardening magnetocuring glue in a cotton ball using an electromagnetic field

Developed by Professor Raju V. Ramanujan, Associate Professor Terry Steele, and Dr. Richa Chaudhary from NTU’s University of Engineering and Materials Science, this invention has been published in the scientific journal Applied Materials Today. and offers potential applications in a wide range of fields, including high-end sports equipment manufacturing, automotive products, electronics, energy, aerospace, and healthcare. Laboratory tests show this new adhesive has a durability of up to 7 megapascals, equivalent to many epoxy adhesives on the market.

“Our research focus is to find a way to harden adhesive within minutes of exposure to a magnetic field, while also preventing the phenomenon from occurring ,” explains Associate Professor Steele, an expert on many advanced adhesives. overheating of adhesive surfaces This is very important when some of the surfaces we want to mount are extremely sensitive to heat, such as flexible electronics and biodegradable resins. study ”

How magnetocuring adhesives work

The new adhesive is made up of two main components – a conventional epoxy, heat-hardened, and the oxide nanoparticles made of a chemical compound consisting of manganese, zinc and iron.

These nanoparticles are designed to heat up when electromagnetic energy is passed through them, activating the drying process. The maximum heating temperature and frequency can be controlled by these special nanoparticles, solving the problem of overheating and the formation of high temperature points.

Since there is no need for a large industrial oven, activation of the adhesive will be possible in smaller spaces and with less energy consumption. Energy efficiency in the drying process is critically important for green production, a model in which products are produced at lower temperatures, and use less energy. on heating and cooling.

Sports shoe manufacturers, for example, often find it difficult to heat the adhesive between the rubber sole and the upper half of the shoe, because the rubber is an insulator and hinders the transfer of heat to the traditional epoxy. . An industrial oven is needed to heat shoes for a long time before heat can be transferred to the glue.

Using a magnetic activated glue helps to overcome this barrier when it only does one thing that directly activates the hardening process of the glue.

The magnetic field can also be embedded in the bottom part of a conveyor system, so that products with pre-glued adhesive can be dried as they pass through the magnetic field.

Professor Raju flexed two sticks held together with magnetocuring to demonstrate its strong bonding force.

Improve efficiency in production

Professor Raju Ramanujan, a world-renowned expert on magnetic materials, led the project and predicted that this technology could improve efficiency in the manufacture of products with glue coupling.

” Our temperature controlled magnetic nanoparticles are designed to blend with existing single component adhesive formulations, so many of the epoxy adhesives on the market can be converted into magnetically activated glues. school “- he said.

” The speed and temperature of the drying process can be controlled, so manufacturers of existing products can now redesign or improve their existing production methods. Since gluing and drying it partially in a traditional assembly line, the new process could be pre-gluing onto every component and then drying them while they move along the conveyor belt. In industrial furnaces, this process will take less time and be more efficient ”.

Study co-author, Dr. Richa Chaudhary, said: ” Our newly developed magnetocuring hardening process takes only minutes instead of hours, but still secures surfaces with force. Strong bonding, crucial in the sports, medical, automotive, and aerospace industries This efficient process also saves money because of the space and energy required for traditional thermal hardening of glue. will be significantly reduced .

In the past, there have been some studies on how to activate the glue with an electric current flowing through the coil, called “induction-curing”, in which the glue is heated and hardened from the outside. Its downside, however, is that the surfaces can be overheated and the bonding force is uneven due to the formation of hot spots within the glue.

In the coming time, researchers hope to work with adhesive manufacturers to cooperate with commercialization of this technology. They have also filed for a patent and have received interest from sports product manufacturers.

Reference: Phys