The carbon dioxide that’s to be captured from the atmosphere by various innovative means has proved itself of having multiple uses, from producing fertilizers to aspirin. Now, German from the Fraunhofer Institute researchers found that it also can be used as a non-toxic solvent for dyes.
Carbon dioxide can enter a supercritical state at a temperature of 30.1 degrees Celsius and a pressure of 73.8 bar, when it acts like a solvent. Thus it can be inserted into polymers.
“We pump liquid carbon dioxide into a high-pressure container with the plastic components that are to be impregnated, then steadily increase the temperature and the pressure until the gas reaches the supercritical state. When that state is reached, we increase the pressure further. At 170 bar, pigment in powder form dissolves completely in the CO2 and then diffuses with the gas into the plastic. The whole process only takes a few minutes. When the container is opened, the gas escapes through the surface of the polymer but the pigment stays behind and cannot subsequently be wiped off,” explains Dipl.-Ing. Manfred Renner, a scientist at Fraunhofer UMSICHT in Oberhausen.
Furthermore, the polycarbonate has been impregnated with nanoparticles that gave it antibacterial properties, and even killed all of the E-coli bacteria placed on the plastic’s surface. This could make up for the cleanest door handles the world has even seen. Another health-related fact about this solvent is that it’s not toxic. Furthermore, it is non-flammable and inexpensive.
Recovering carbon dioxide from the tailpipes or from the factories’ emissions and sequestering it into plastics is the best idea yet. Not only we can get rid of this potent greenhouse gas, but also put it to good use.