Liquid crystal displays have already provided the basis for successful technologies such as LCD displays, and researchers continue to create specific types of liquid crystals for even better optical devices and applications.
Juan de Pablo, a professor of the Liew family at the University of Chicago’s Pritzker School of Molecular Engineering (PME), and his team have found a way to create and stabilize so-called “blue phase LCDs.”Both liquid and crystalline properties, in some cases can be reflected visible light It is superior to ordinary LCDs.
Result is, ACS Nano, May lead to new optical technologies with better response times.
A new way to stabilize blue phase crystals
Thanks to the uniform molecular orientation, liquid crystals are the basis of many display technologies, including digital displays for computers and televisions. In this study, de Pablo and his team are interested in chiral LCDs that have certain asymmetric “dominant hands” such as right-handed and left-handed and can exhibit a wider and more interesting range of optical behavior. I did.
Importantly, these crystals can form blue-phase crystals. Due to its unique structure, it reflects blue and green light and can be turned on and off incredibly quickly. However, these crystals exist only in a narrow range of temperatures and are inherently unstable. Heating even once can destroy its properties. As a result, its use in technology is limited.
Through simulations and experiments, the team was able to stabilize the blue phase crystals through the formation of so-called double emulsions.They used small core droplets of water-based solution surrounded by outer droplets of oily chiral. liquid crystal, Which creates a “core and shell” structure. The structure itself was suspended in another aqueous liquid that could not be mixed with the liquid crystal. Within the proper temperature range, the chiral LCD was able to be trapped in the shell in a “blue phase” state. Next, a polymer network was formed within the shell to stabilize the blue crystals without compromising their properties.
Creation of perfect crystals
The team then showed that the temperature of the blue phase crystals could be changed by 30 degrees without breaking. Not only that, this process formed crystals of a perfect, uniform blue phase, allowing researchers to better predict and control their behavior.
“Now that we understand and control these materials, we can take advantage of their unique optical properties,” says de Pablo. “The next step is to deploy them on the device and sensor To demonstrate their usefulness. “
Potential applications include display technology that can be turned on and off with very small changes in size, temperature, or exposure to light, or sensors that can detect radiation within a specific wavelength.
Monirosadat Sadati et al, Control of Chiral Nematic Monodomain Polymer Stabilized Cubic Nanocrystals by Confinement, ACS Nano (2021). DOI: 10.1021 / acsnano.1c04231
University of Chicago
Quote: Stabilized blue phase crystals are a new optical technology acquired from https://phys.org/news/2021-11-stabilized-blue-phase-crystals-optic.html on November 2, 2021 ( May 2nd, 2021)
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Stabilized blue phase crystals may lead to new optical technologies
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