Ding-Shyue (Jerry) Yang and Postdoctoral Researcher Xing He Publish Findings in Nano Letters
In a new publication in the American Chemical Society鈥檚 , 葫芦影业 associate professor of chemistry Ding-Shyue (Jerry) Yang and postdoctoral researcher Xing He find a fundamental behavioral difference in the energy transport of solid-supported methanol thin films. Their findings could have implications in the behavior of both inorganic 2D materials and organic materials, such as solar panels and human cells.
Yang and He explain that understanding energy transport in different nanostructures is crucial to both a foundational understanding of, and practical applications for, heat management.
鈥淲e did not anticipate what we found,鈥� Yang said. 鈥淚n this study, we had a smooth, solid surface, a supporting solid surface, and we had methanol thin film samples grown on top. We wanted to understand how energy moves across this interface.鈥�
A Faster Energy Transport
Yang and He were curious to see the difference in the energy transport of methanol鈥檚 two structures. They used ultrafast electron diffraction to reach their conclusion, which Yang and his research group use frequently to study 2D materials. Yang鈥檚 laboratory is one of the few labs in the world that can conduct such experiments.
鈥淥ur experimental method prepares the methanol samples in two major structures,鈥� said Yang. 鈥淥ne is a 3D crystal structure. This means each sheet in the methanol thin film is a hydrogen-bonded layer, and neighboring sheets are also aligned,鈥� essentially docking into each other and connecting well.
鈥淲e can also prepare the methanol sample in a 2D layered structure,鈥� he adds. However, this structure does not allow the sheets of methanol to dock or fit together well. Instead, 鈥渢hey just kind of pile together.鈥�
Yang and He found thermal diffusion is the energy transport mechanism across methanol鈥檚 2D layered structure; whereas much faster, and more efficient ballistic energy transport is observed in the 3D crystal structure.
鈥淭heir structural difference seems subtle, but their dynamical responses to energy transport show a drastic difference,鈥� said Yang.
Similarities to Tungsten Diselenide
In their publication, Yang and He write that the contrast observed in methanol鈥檚 thin film structure may be similar to the large thermal conductivity difference seen in tungsten diselenide, which may provide further understanding about structural impacts on energy conduction in organic optoelectronic materials.
More broadly, the two explain it is also important to examine energy transport dynamics and structure-property relations in a variety of molecular systems.
鈥淲orking on this project was exciting because we found thermal conductivity changes drastically with just a slight change in the structural order of methanol molecular assemblies,鈥� said He, who has been working with Yang for almost eight years. 鈥淭his is a very important finding for various applications such as heat management in nanoscale electronics.鈥�
Applying Yang鈥檚 Experimental System Elsewhere
Seeing the impact that the structure of molecular thin film has on its properties, Yang said, leads his group to consider other molecular thin films, such as our cells.
鈥淥ur cell membrane is a molecular assembly. We need something that can transport across the cell membrane. A different structure could lead to different efficiency.鈥�
Because Yang and He have a system that allows them to draw a connection between a structure and a property, Yang said they will think about other systems that have this kind of molecular thin film with factors they could modify.
Yang thanks the National Science Foundation and the Welch Foundation for their continued funding of his research.
- Rebeca Trejo, College of Natural Sciences and Mathematics