Professor Yossi Weizmann and his team at Ben-Gurion University of the Negev have developed a revolutionary class of smart polymer materials using stable “latent monomers” that remain liquid for weeks but solidify on demand with a flash of light or gentle warmth. Published in Nature Chemistry, this breakthrough overturns 30 years of research focused on sensitive “sleeping” catalysts, promising safer, more efficient industrial curing, 3D printing, and material repair.
For decades, chemists trying to control when and where plastics harden have pursued a frustrating path: designing finicky “sleeping” catalysts. These molecules, dormant until triggered by light or heat, are often expensive, sensitive, and difficult to handle. Now, a team in Israel has flipped the script entirely. “Instead of a ‘sleeping’ catalyst, we created ‘sleeping’ building blocks of the material itself,” explains Prof. Yossi Weizmann of the Department of Chemistry at Ben-Gurion University, who led the study. The result is a user-friendly liquid that sits inert on a shelf but snaps into a solid plastic precisely when and where you want it to.
The innovation, reported by the university, lies in novel “latent monomers” built from small molecules called norbornadienes. Here’s the clever switch: in their normal form, these molecules can be linked into long chains using a standard industrial catalyst. But when hit with UV light, they morph into an inert form called quadricyclane—the “off” state. The magic happens when you apply a trigger. Gentle heat, supplied by tiny gold nanoparticles that warm up when illuminated with near-infrared light, flips the molecules back to their reactive “on” state. Only then does the catalyst spring into action, rapidly forming a solid material.
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This approach solves numerous practical problems. Manufacturers could store a ready-to-use liquid formula for weeks without fear of it hardening prematurely. They could fill a mold, coat a surface, or complete a 3D print layer, and then cure the entire object—or just specific sections—with a precise pattern of light. “That kind of on-demand, light-driven curing could make industrial production, printing, and repair processes safer, simpler and more energy-efficient,” Prof. Weizmann stated. It significantly reduces waste and the energy needed to heat large volumes or constantly mix new batches.
The potential goes far beyond a simple on/off switch. As demonstrated in their Nature Chemistry paper, the team can create advanced, multi-property materials by mixing active monomers with latent ones. They can produce a soft, easily shaped material and then later lock it into a tough, durable solid in a single process. PhD student Nir Lemcoff, a lead author, noted this “new way of thinking” could inspire solutions across polymer science. Because chemists can design many variations of the core norbornadiene molecule, this platform could yield hundreds of new tailor-made materials with properties difficult or impossible to achieve with current methods.
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From adhesives that cure only under a repair laser to 3D-printed medical implants that harden with gentle body heat, the applications are vast. By moving the control switch from a fragile catalyst to the robust building blocks themselves, Ben-Gurion University researchers haven’t just created a new material—they’ve illuminated a smarter path forward for the entire field of polymer chemistry.
