A group of researchers from China presented a method for automatically bonding and separating multiple strands of graphene oxide. In their work, published in the journal Science, the group describes this process and its possible applications.
Scientists noted that in recent years, materials scientists have been exploring the possibility of creating products using full or partial self-assembly as a fast and waste-free production method. In biological systems, where two materials self-assemble into a third material, scientists describe this as a synthesis process, borrowing terminology from physics.
In the case where one material is divided into two or more materials, they call it the fission process. In a new study, scientists have developed a technique for creating graphene oxide filaments that use both processes.
They created several strands of graphene oxide and then immersed them in the solution for 10 minutes. When the strands were taken out of the solution, they joined together to form a single strand. They also developed a means to reverse the process – to do this, you need to submerge the thread in a different solvent.
This method works because the graphene oxide filaments swell when placed in a solution. This causes the elements that make up the outer layer of each of the fibers to adhere more tightly to each other, resulting in a new density material. When the bundle of filaments is removed from the solution, surface tension pulls the filaments together into a cylindrical shape. The created cord dries up allowing the fibers to bond. Then, if you put the cord in a second solution, the threads relax, breaking the bonds and returning them to their original shape. Scientists believe that this process can be useful in the production of complex structures.