In a significant stride towards energy conservation in the construction sector, researchers have unveiled promising advancements in cholesteric liquid crystal materials. This innovative approach addresses the pressing energy crisis, particularly in buildings where energy consumption is alarmingly high. Mei-na Yu, a lead researcher from the Institute for Advanced Materials and Technology at the University of Science and Technology Beijing, emphasizes the urgency of the situation. “The majority of energy loss in buildings stems from windows, which have a different heat transfer coefficient compared to other building materials. Our research aims to mitigate this issue through smart window technologies,” she stated.
Cholesteric liquid crystals possess unique bistable properties, allowing them to exist in two stable states: a transparent planar state and an opaque focal conic state. The ability to switch between these states without requiring an external electric field could revolutionize energy usage in buildings. This is particularly crucial as windows traditionally account for significant energy loss due to heat transfer. By integrating cholesteric liquid crystals into window designs, buildings could effectively regulate heat and light, leading to substantial energy savings.
The research highlights the role of bent molecular materials in controlling defects within the cholesteric liquid crystals. These defects, particularly oily streaks, can compromise the performance of the liquid crystals. “By introducing the bent molecule CB7CB, we were able to reduce these defects and stabilize the focal conic state,” Yu explained. This advancement not only enhances the functionality of the liquid crystals but also opens the door to new applications, such as bistable displays and electronic labels.
The electro-optical tests conducted in the study revealed that the composite containing CB7CB successfully achieved bistable states, paving the way for the development of colorless and colorful bistable light shutters. These shutters can maintain both transparent and opaque states without any external power, offering a more energy-efficient alternative to existing solutions based on polymer-dispersed liquid crystals. The implications for commercial building applications are profound; smart windows utilizing this technology could significantly reduce energy consumption while enhancing occupant comfort.
Furthermore, factors such as anchoring strength and cell thickness were examined, revealing that strong anchoring and thicker cells are not conducive to achieving the desired focal conic state. This nuanced understanding of material properties is essential for optimizing future designs of smart windows.
As the construction industry seeks innovative solutions to reduce energy use and improve sustainability, the findings of this research could lead to widespread adoption of cholesteric liquid crystal technologies in building designs. Yu’s work, published in the journal Engineering Science, underscores the potential of these materials to transform how we think about energy efficiency in our built environment. For more information on this research, visit the Institute for Advanced Materials and Technology at the University of Science and Technology Beijing.
