A new nanotech polymer material developed by scientists in the US state of Virginia is capable of selectively capturing carbon dioxide from flue gas and natural gas.
The organic polymer material, developed by a team of scientists from Virginia Commonwealth University (VCU), possesses the remarkable ability to exclusively capture CO2 following exposure to flue gas or natural gas without impeding the passage of other key chemicals such as nitrogen or methane.
The key to this capability is the nano-engineering performed by the scientists on the chemical structure of the porous organic polymer. The material is comprised of minute particles, each of which are around 500 times smaller than the diameter of a human hair follicle. Each of these particles is in turn host to tiny pores a mere nanometre in width, which are equipped with nitrogen sites that are capable of capturing and tethering carbon dioxide molecules while simultaneously permitting the molecules of other chemical substances to pass by unaffected.
Hani El-Kaderi, associate professor of chemistry at VCU and leader of the team of scientists responsible for developing the material, said CO2 capture during the burning of fossil fuels is one of the most practical medium-term means of ameliorating the problem of global warming, at least until renewable energy and other zero-carbon power sources develop into fully viable options.
Porous organic polymers of the type developed by El-Kaderi's team are amongst the most promising of such carbon capture materials, possessing advantages including a lack of metallic materials, which reduces their adverse impact on the environment, as well as an extremely high surface area of around 1,200 square metres per gram, or around six times the area of a full tennis court.
According to El-Kaderi, in addition to enhancing the CO2 storage capacity and the chemical targeting ability of the material, the next key step could be using light as a trigger for the polymer to release the CO2 that it has sequestered.
El-Kaderi said the polymers could be configured so that following exposure to light their molecular structure shifts in such a way that the the carbon dioxide molecules are "squeezed" out of their nano-pores, providing an energy efficient method of flushing out the material.