Prof. Kim Sang-wook develops graphene fiber with improved performance using mussel adhesive

Professor Kim Sang-wook and his colleagues in the new materials engineering department of our university developed a new concept carbon fiber with excellent physical properties using graphite graphene.

The carbon fiber developed by the team has high strength and high conductivity by increasing the adhesion between the graphene layers by using poly-dopamine, which is well known as mussel adhesive. The new material is expected to be used as a source material for various wearable devices in the form of a fabric.

“Despite technological potential, carbon fiber using graphene liquid crystal has had a limit to overcome the structural limitations.”

Kim In-ho, a researcher who participated as an author, was selected as a cover paper on “Advanced Materials,” an international journal of materials science. (Magnetic Resonance Imaging of Graphene Liquid Crystalline Fibers for Synergistic Enhancement of Mechanical Strength and Electrical Conductivity, Mussel-Inspired Defect Engineering of Graphene Liquid Crystalline Fibers for Synergistic Enhancement of Mechanical Strength and Electrical Conductivity)

Professor Kim Sang-wook and his team first discovered a new phenomenon of liquid crystal formation when graphene is dispersed in a liquid, and have related original patents. Since then, we have been leading the field through subsequent research on various new materials based on graphene liquid crystals.

In recent years, it has been found that the cheapest wet fiber process using graphene liquid crystal makes it possible to manufacture carbon fibers much cheaper than conventional carbon fibers.

Synthesis, Properties and Application of Graphene Woven Fabrics

However, in the process up to now, the graphene layer is folded during the fiber formation process, and pores are generated. These structural defects make the electrical properties as well as the mechanical properties of the carbon fibers vulnerable.

Professor Kim’s team focused on the adhesion properties of dopamine, a polymer developed with the inspiration of the natural mussel to solve the problem. This dopamine, which is studied in various fields, can increase the adhesion between the graphene layers and prevent the structural defects.

The researchers succeeded in fabricating high-strength carbon fibers with controlled structural defects. It also succeeded in fabricating fibers with improved electrical conductivity through the carbonization process of polypodamine.

Based on the theory that graphene has a structure similar to that of dopamine doped with dopamine, the team optimized dopamine polymerization conditions on graphene liquid crystals and solved the inherent defect control problems of existing graphene fibers by fiberizing them.

We also confirmed that the physical properties of dopamine are improved in terms of electrical conductivity due to the influence of nitrogen in dopamine molecules, without damaging the conductivity, which is the fundamental limit of conventional polymers.

Professor Kim Sang-wook, who led the research, said, “Despite technological potential, carbon fiber using graphene liquid crystal has had a limit to overcome the structural limitations.” This technology will be applied to composite fiber fabrication and various wearable textile based application devices “He said.

Source: KAIST