On August 2nd, a joint research team led by Song Jang-kun, a professor of Electronic and Electrical Engineering, Whang Dong-mok, a professor of Advanced Materials Science and Engineering, and Lee Jae-hyun, a professor at Ajou University, identified the sequence direction principles of liquid crystal (LC) molecules on graphene electrodes, conductors that are highly flexible, transparent, and electrical. It was discovered that the sequential direction of the LC molecules was controlled by a LC during the definite moment its surface touched the graphene. Previous to this finding, scientists believed that graphene determined the orientation of LC molecules.
|Six Domains of the Liquid Crystal (LC) Drop on a Clean and Pure Graphene (yonhapnews.co.kr)|
Whenever LCs were coated on graphene, the molecules of the rod-shaped LCs consistently arranged to one side and in the same direction. Although LC molecules can be arranged in one of three directions, its directional point cannot be predicted prior to coating. Despite coating LCs on graphene, the observed sample can be contaminated by foreign substances on the graphene surface. If there is a presence of an unwanted substance on the graphene, the LC molecules are formed in only one direction. To inspect the three possible directions of LC molecules, the research team experimented on pure graphene that had a high degree of cleanliness. LC molecules have an equal likelihood of facing one of the three directions when coated on a profoundly clean and pure graphene. The level of cleanliness cannot be analyzed by a simple method. Fortunately for the research team, the minuscule amount of the unknown substance on the graphene surface helped determine that pure graphene was clean by working backwards and examining the arrangement of the LC molecules. In addition, the research team also developed a technology that obtains the equal LC sequence in the preferred direction from the area of single crystal graphene. This technology was applied to a liquid crystal display (LCD), a thin electrically generated visual display and devices to prevent quality deterioration and innovatively shorten the stages of process. To minimize the LCD process, the research team proceeded with the simple stamping method of replicating the complex structure of LC sequences from one surface of graphene to another. The research result was published in the materials science journal Advanced Materials on August 2nd.
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