Harvard Researchers Develop Transparent, Tough Self-healing Rubber
| Subj: Press-releses
Imagine a tire that could heal after being punctured or a rubber band that never snapped.
Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a new type of rubber that is as tough as natural rubber but can also self-heal. Potential applications include more durable tires, wearable electronics and medical devices.
The research is published in Advanced Materials.
Making of Rubber Self-healable
Self-healing materials aren’t new—researchers at SEAS have developed self-healing hydrogels, which rely on water to incorporate reversible bonds that can promote healing. However, engineering self-healing properties in dry materials—such as rubber—has proven more challenging. That is because rubber is made of polymers often connected by permanent, covalent bonds. While these bonds are incredibly strong, they will never reconnect once broken.
In order to make a rubber self-healable, the team needed to make the bonds connecting the polymers reversible, so that the bonds could break and reform.
Li-Heng Cai, a postdoctoral fellow at SEAS and corresponding author of the paper, said:
Cai, along with Jinrong Wu, a visiting professor from Sichuan University, China, and senior author David A. Weitz, Mallinckrodt Professor of Physics and Applied Physics, developed a hybrid rubber with both covalent and reversible bonds.
The concept of mixing both covalent and reversible bonds to make a tough, self-healing rubber was proposed in theory by Cai but never shown experimentally because covalent and reversible bonds don’t like to mix.
Li-Heng Cai said:
So, the researchers developed a molecular rope to tie these two types of bonds together. This rope, called randomly branched polymers, allows two previously unmixable bonds to be mixed homogeneously on a molecular scale. In doing so, they were able to create a transparent, tough, self-healing rubber.
Harvard’s Office of Technology Development has filed a patent application for the technology and is actively seeking commercialization opportunities.
The self-healing ability is appealing for a wide variety of rubber products.
Jinrong Wu said:
David A. Weitz said:
In addition to his role on the faculty at SEAS, Weitz is the director of Harvard’s Materials Research Science and Engineering Center, co-director of the BASF Advanced Research Initiative, a member of the Kavli Institute for Bionano Science and Technology, and a Core Faculty Member at the Wyss Institute for Biologically Inspired Engineering.
The research was supported by the National Science Foundation, Harvard Materials Research Science and Engineering Center (MRSEC) and the National Institute of Health/National Heart, Lung and Blood Institute.