Materials science just produced one of those results that makes you do a double take.
Researchers at Japan’s Gifu University created a rubber — technically a “CO₂-curable elastomer” — that absorbs carbon dioxide from its surroundings and transforms into a rigid, acrylic-like plastic. Published in Nature Communications.
How It Works
The material combines polyethyleneimine (PEI), which reacts with CO₂, with polydimethylsiloxane (PDMS), a silicone polymer that CO₂ passes through easily. On its own, PEI absorbs ~1mg of CO₂ per gram. Bonded with PDMS, it absorbs 220mg per gram — the PDMS creates internal “passageways” that let CO₂ reach PEI deep inside the material.
After absorption, the rubber becomes more than 1,000 times harder. Slip-proof rubber surface → smooth plastic surface.
The most intriguing part: it’s reversible. Heat it to 70–100°C and the CO₂ escapes, reverting the plastic back to rubber. Under UV light, absorbed CO₂ produces blue fluorescence — a built-in visual indicator.
Carbon Removal or Carbon Utilization?
Let’s be clear: this isn’t a CDR technology. At 220mg per gram, you’d need roughly 4.5 tonnes of this rubber to capture a single kilogram of CO₂. And the CO₂ releases again when heated.
But it’s a fascinating CCU (carbon capture and utilization) concept. Imagine construction materials that harden by absorbing ambient CO₂. Or CO₂ sensors built from the material itself. The reversibility even suggests potential for CO₂ capture-release cycles in industrial settings.
The team at Gifu is now working on a version that retains CO₂ permanently and maintains its plastic state — which would push it closer to genuine carbon storage territory.
The Japan CDR Scene
This isn’t an isolated data point. Japan’s CDR ecosystem is growing fast. ENEOS (Japan’s largest energy company) just invested in Berkeley DAC startup AirMyne. Sumitomo partnered with Global Thermostat. Mitsui backed Heirloom. Japanese industrial conglomerates are quietly building CDR portfolios across multiple pathways.
For a country with limited land area but massive industrial capacity, materials-based carbon capture could be a natural fit.
Source: Japan Forward · Nature Communications