Jeonbuk National University Researchers Develop Novel Eco-Friendly and Photo-Switchable Smart Adhesives

Researchers developed a reusable and eco-friendly smart light-responsive adhesives using biomass-derived materials

JEONBUK-DO, South Korea, Dec. 10, 2025 /PRNewswire/ -- Adhesives are essential in various industries, including aerospace, electronics, construction, marine, automotive, and biomedical fields. As these fields continue to advance, the demand for high-performance, multifunctional adhesives is also growing. However, such widespread use has also highlighted their environmental issues. Conventional adhesives, while effective and economical, release petroleum-based chemicals that are harmful to soil and water quality. Their production also contributes to environmental pollution, and the adhesives themselves are difficult to recycle or dispose of. Developing reusable and more eco-friendly alternatives is therefore becoming increasingly important.

At the same time, there is a growing demand for advanced adhesives with diverse functionalities. For example, stimuli-responsive adhesives that can vary their adhesive strength based on external stimuli are attracting significant attention. Among them, photo-responsive adhesives are especially attractive, as they allow localized wireless control of adhesion through light while also possessing non-invasive properties.

To meet both performance and sustainability goals, a research team led by Professor Kwang-Un Jeong, along with Ph.D. Student Mr. Mintaek Oh from the Department of Nano Convergence Engineering at Jeonbuk National University, South Korea, has developed a novel eco-friendly, photo-switchable smart adhesive. "We synthesized a tetrahydrogeraniol-based monomer, a derivative of rose oil, and successfully fabricated an eco-friendly adhesive containing 95% of it," explains Prof. Jeong. "It demonstrates light-responsive adhesion, and is eco-friendly, cost-effective, and reusable." Their study was made available online on July 15, 2025, and published in Volume 520 of the Chemical Engineering Journal on September 15, 2025.

To fabricate the adhesive, the researchers first synthesized two key components: an acid azobenzene-based methacrylate monomer (AAMM) and a biomass-based tetrahydrogeraniol methacrylate monomer (TGMM). AAMM consists of azobenzene, carboxylic acid, and methacrylate. Azobenzene derivatives are well known for their reversible photo-switchable behaviour, making them ideal for light-responsive systems. The carboxylic groups can form strong hydrogen bonds with a variety of substrates, facilitating strong adhesion.

By copolymerizing AAMM and TGMM through their methacrylate groups, the researchers successfully created a new eco-friendly and photo-switchable adhesive, termed the T/A adhesive.

During testing, the optimized T/A adhesive demonstrated excellent photo-switchable adhesion, with strong adhesion to a wide range of substrates, including metals, plastics, rubber, glass, cork, and paper. When exposed to ultravioletlight, the adhesive becomes more liquid-like, and its adhesion strength decreases. After subsequent exposure to visible light, it returns to its original adhesion strength and becomes more solid-like again, thus demonstrating fully reversible, light-controlled adhesion.

In addition, adhesion strength can also be switched using heat and chemicals. Heating to a temperature beyond 50⁰C significantly reduces adhesion strength, which returns on cooling. Similarly, the adhesive can be dissolved by solvents like chloroform and recovered when the solvent evaporates. Across repeated usage cycles in all three processes, the reused T/A adhesives were able to retain more than 90% of their original adhesive strength.

The researchers further demonstrated a smart UV sensor built using the new adhesive and a spring-based mechanism, that can serve as a UV-light sensitive switch in electrical circuits.

"Our smart, reusable, light-responsive adhesive is promising for a wide range of practical applications, including environmental monitoring, smart electronics, and adaptive assembly systems," remarks Mr. Oh.

Overall, by replacing petroleum-based adhesives with biomass-derived alternatives, this research paves the way for more sustainable and smart adhesive technologies.

Reference
Title of original paper: Eco-Friendly and Photo-Switchable Smart Adhesives from Biomass-Based Copolymers with Acid Azobenzene Functions
Journal: Chemical Engineering Journal
DOI: 10.1016/j.cej.2025.166035 

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SOURCE Jeonbuk National University