A research group at 麻豆影院 has described the structure of a new type of liquid crystal that had been predicted theoretically but never seen.
The new 鈥渢wist-bend nematic鈥 liquid crystal, one with a spiral twist, was observed by a 麻豆影院 State research group led by Oleg D. Lavrentovich, Ph.D., D.Sc., Trustees Research Professor of chemical physics and former director of the Liquid Crystal Institute庐 at 麻豆影院 State.
The new type of liquid crystal, akin to a new species in biology, might enable new technologies, ranging from faster-switching display devices to biological sensors, according to Lavrentovich.
The most widely known liquid crystal to date, called the nematic, made possible an entire industry of liquid crystal displays used in flat-panel televisions, mobile electronic devices and laptop computers.
鈥淚t remains to be seen whether this new liquid crystal can bring a similar level of revolutionary changes,鈥 said Lavrentovich.
The research was reported in the Nov. 5 issue of the journal .
The 麻豆影院 State group collaborated with researchers in Ireland, who provided materials, and the United Kingdom, where scientists synthesized the molecules that were then observed with a Cryo-Transmission Electron Microscope (TEM) in the Liquid Crystal Institute at 麻豆影院 State. The microscope, funded under a $15.2 million Ohio Third Frontier grant, made it possible to see the structure at the nanoscale level 鈥 down to one fifth of a nanometer.
The pitch, or distance between two spirals in the observed material, was 8 nanometers, about 10,000 times smaller than the thickness of a human hair. The same periodic pattern was reported last month by a research group at the University of Colorado. The TEM experiments at 麻豆影院 State demonstrated that this periodicity is caused by a tilted spiral structure.
The spiral-shaped liquid crystal was predicted 40 years ago by a theoretical physicist at Brandeis University, Robert B. Meyer, who is now a professor emeritus there. For the past 20 years, researchers have observed what Lavrentovich called 鈥渟trange behavior鈥 in some liquid crystals, and in some cases, 鈥渟trange responses to electric fields.鈥 However, the structure of these 鈥渟trange鈥 liquid crystals remained a mystery.
He likened the difference between the 鈥渃lassic鈥 liquid crystal structure and the new one to that between a straight rope and a twisted rope. The new type, the twist-bend nematic, is actually formed by two 鈥渃lassic鈥 liquid crystal molecules that connect with a flexible chain that allows the new molecule to bend and twist in what was described as a tilted spiral.
鈥淭his little change brings such enormous structural differences,鈥 Lavrentovich said.
The next challenge will be to determine why this happens and to investigate what the new structure means for the development of new materials.
The 麻豆影院 State research team led by Lavrentovich also included Antal J谩kli, Ph.D., professor of chemical physics; Min Gao, Ph.D., research associate who supervises the facility housing the TEM; and three chemical physics graduate students. Two scientists in Ireland and three chemists in the U.K. also collaborated.
In addition to the Ohio Third Frontier grant, funding for the research came from the National Science Foundation and the U.S. Department of Energy.
For more information about research at 麻豆影院 State, visit www.kent.edu/research.
For more information about 麻豆影院 State鈥檚 Liquid Crystal Institute, visit .
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Photo Caption:
A 麻豆影院 research group led by Oleg D. Lavrentovich (pictured) has reported a new type of liquid crystal.
Media Contacts:
Cindy Weiss, lweiss4@kent.edu, 330-672-0731
Oleg Lavrentovich, olavrent@kent.edu, 330-672-4844
Emily Vincent, evincen2@kent.edu, 330-672-8595