Cambridge researchers developing self-healing concrete
Researchers from the University of Cambridge are using microencapsulation technologies developed by Dolomite Microfluidics to create self-healing construction materials. The Geotechnical and Environmental Research Group are developing microcapsules containing ‘healing’ agents – such as exoxy or polyurethane – which can be added to building materials to allow self-repair of small cracks which develop over time. Cambridge University’s Dr Livia Ribeiro de Souza explained: “Many composite building materials used in the construction industry – such as concrete – suffer fatigue over time, developing small cracks. Our work helps overcome this problem by adding microcapsules filled with ‘healing’ agents to the concrete before it is used. The idea is that, as cracks begin to form, they rupture the microcapsules, releasing their payload and stabilizing the material.”
“This approach requires the formation and functionalization of double emulsion microcapsules, which we have been producing with the help of microfluidics. Microfluidics offers much better control of particle size and composition than traditional amplification polymerization techniques, simplifying the investigation and optimization of particle properties. We originally used a homemade microfluidic set-up for this, but we switched to Dolomite Microfluidics system in 2014. Using an optimized, commercially available system is both simpler and more reliable than an in-house developed set-up; it’s very reliable and robust.”
The system has enabled the researchers to create functionalized microcapsules that bind more strongly to the cement matrix while also having thinner shell walls and higher core retention. They have shown the microcapsules they can now produce have improved self-healing properties.
Dr Livia Ribeiro de Souza continued, “It is also good to be able to discuss any issues we’re having with the experts at Dolomite Microfluidics , helping to accelerate our research and move us a step closer to real world applications.”
Ribeiro de Souza, L. (2017). Design and synthesis of microcapsules using microfluidics for autonomic self-healing in cementitious materials (Doctoral thesis). https://doi.org/10.17863/CAM.16673