Tuning the Temperature-Dependent Thermal Conductivity via Complex Colloidal Superstructures*

The ability to precisely tune the temperature dependence of the thermal conductivity possess a vital challenge to develop and conceive future heat management devices. In this contribution, we demonstrate the vast potential of polymer colloidal crystals to address and master these challenges. We achieve this goal based on the constriction-controlled thermal transport through well-defined colloidal crystal superstructures. These colloidal superstructures are specifically built by tailor-made latex particles with distinct glass transition temperatures. We exploit their multiresponsive film formation at various temperatures to demonstrate unprecedented control over thermal conductivity at temperatures between 25 °C and 200 °C. Based on the film formation process, we can irreversibly increase the thermal conductivity by a factor of about three. We show how to control:
i) the temperature, where the increase in thermal conductivity happens
ii) the sharpness of the thermal conductivity increase
iii) the height of the increase in thermal conductivity
iv) the incorporation of a multistep increase in thermal conductivity