Discarded nitrile gloves can be chemically transformed into carbon capture materials, according to new research published in Chem. Chemists at Aarhus University demonstrated a proof-of-concept method to convert nitrile rubber—widely used in laboratory and medical nitrile gloves—into solid amine-based carbon capture materials capable of capturing carbon dioxide (CO₂) under flue gas–relevant conditions. The work combines catalytic chemistry and polymer upcycling to address both the demand for carbon capture and the challenge of rubber waste.
Carbon capture materials are engineered sorbents designed to bind and release CO₂ from industrial emission streams. Most commercial carbon capture systems rely on amine chemistry, in which amine functional groups reversibly react with CO₂ to form carbamates or bicarbonates.
Carbon capture materials derived from nitrile gloves
Nitrile-butadiene rubber contains nitrile functional groups (–C≡N) that can be reduced to primary amines (–CH₂NH₂), the reactive groups commonly used in carbon capture materials. The researchers applied transition-metal–catalyzed hydrogenation to convert the nitrile groups in commercial nitrile gloves into amine-rich polymers.
Using a commercially available ruthenium pincer complex, the team hydrogenated the nitrile rubber under elevated hydrogen pressure and temperature. The method was validated using both model rubber samples and a commercially manufactured nitrile glove.
To extend the approach, the researchers also performed nickel-catalyzed hydrocyanation on styrene-butadiene-styrene rubber prior to hydrogenation. This two-step sequence introduced additional nitrile groups into the polymer backbone before conversion to amines, expanding the polymer upcycling concept beyond nitrile gloves.
Structural confirmation was obtained using Fourier transform infrared spectroscopy and solid-state 13C cross-polarization magic-angle-spinning nuclear magnetic resonance to verify the conversion of nitrile groups into amines. Thermogravimetric analysis quantified CO₂ adsorption capacity, while differential scanning calorimetry evaluated thermal transitions relevant to gas transport.
Performance of carbon capture materials under flue gas conditions
The hydrogenated rubber-derived carbon capture materials were tested under simulated flue gas conditions, typically defined as approximately 10 percent CO₂ in nitrogen at elevated temperatures.
Despite lacking porosity and exhibiting minimal surface area by Brunauer-Emmett-Teller analysis, the materials demonstrated measurable adsorption capacity. Under 100 percent CO₂ at 90°C, one hydrogenated nitrile rubber sample achieved an average adsorption capacity of 3.05 mmol/g. Under 10 percent CO₂ at 90°C, capacities between approximately 0.50 and 1.25 mmol/g were observed after short adsorption periods.
The researchers observed improved adsorption performance at higher temperatures. They attribute this effect to increased polymer chain mobility above the material’s glass transition temperature, which facilitates CO₂ migration between amine sites within the polymer matrix.
The materials retained most of their working capacity over 40 adsorption–desorption cycles under simulated flue-gas conditions.
Comparison to established adsorbents
The study compared the rubber-derived carbon capture materials to Calgary Framework 20, a commercially deployed metal-organic framework. While Calgary Framework 20 exhibits higher adsorption capacity under optimal low-temperature conditions, the rubber-derived carbon capture materials demonstrated complementary performance at elevated temperatures.
The authors describe the work as proof-of-concept. The hydrogenation relies on ruthenium catalysts, which would require optimization for cost and scalability. In addition, the non-porous structure limits adsorption kinetics relative to engineered porous carbon capture materials.
Relevance for laboratories
Nitrile gloves represent a significant waste stream in research and clinical laboratories. Although the catalytic hydrogenation and hydrocyanation steps require controlled reaction systems and specialized instrumentation not available in standard laboratory waste workflows, the study demonstrates that nitrile gloves can be chemically converted into functional carbon capture materials.
For laboratory managers monitoring sustainability initiatives, advanced catalysis research, and polymer upcycling strategies, the work highlights how common laboratory consumables intersect with the development of emerging carbon capture materials.
This article was created with the assistance of Generative AI and has undergone editorial review before publishing.
