Event

Abstract:

Phase transitions of materials between solid and liquid are widely utilized for waste heat storage, via endothermic melting and exothermic crystallization processes that solely depend on the changing temperature of the environment. Phase transitions that can be induced by different stimuli, orthogonal to temperature change, will allow for the active control over the energy storage time and energy release process, overcoming the limitations of the conventional phase change materials.

In this talk, design principles of optically-controllable phase change materials that incorporate organic photoswitches, ranging from azobenzenes to hydrazones, will be presented. Various photochromic core structures and functional groups have been explored to understand the structure-property relationship of the stimuli-responsive material systems. The application of photo-controlled phase transition in solar photon and thermal energy storage as well as sustainable catalysis will be discussed.

Research Interest 

Research in our group focuses on developing a wide range of versatile and unique optically controlled molecular switches for energy conversion/storage and optoelectronic applications. Photo-switchable molecular systems are triggered by absorbing light and rapidly respond via structural change that provides control over a broad array of properties in diverse organic and inorganic systems. These reversible switches allow for the repeatable operation of energy harvesting schemes on a large scale as well as the discrete on/off modulation of nanoscale devices via their structural and electrical changes at the molecular level. The organic switches provide such opportunities across different length scales due to the ease of the molecular level design and prediction of collective properties in the bulk.

In our group, we will investigate the integration of the structural design of tailored photo-switches with the fabrication of solid-state devices ranging from large-scale thermal batteries and de-icing films to nanoscale electronic devices. We predict that novel photo-switches will have transformative impact in thermal energy storage, solar energy conversion, and molecular electronics and optoelectronics.

https://sites.google.com/brandeis.edu/hangroup

Host: Dr. Mallouk