Temperature control inside buildings

In a new study, researchers at Texas A&M University have created novel 3D printable phase-change material (PCM) composites that can regulate ambient temperatures inside buildings using a simpler and cost-effective manufacturing process. Furthermore, these composites can be added to building materials, like paint, or 3D printed as decorative home accents to seamlessly integrate into different indoor environments. “The ability to integrate phase-change materials into building materials using a scalable method opens opportunities to produce more passive temperature regulation in both new builds and already existing structures,” said Emily Pentzer, associate professor in the Department of Materials Science and Engineering and the Department of Chemistry.  This study was published in the June issue of the journal Matter.  One of the materials that has gained a lot of interest for temperature regulation is phase-change materials. As the name suggests, these compounds change their physical state depending on the temperature in the environment. So, when phase-change materials store heat, they convert from solid to liquid upon absorbing heat and vice versa when they release heat. Thus, unlike HVAC systems that rely solely on external power to heat and cool, these materials are passive components, requiring no external electricity to regulate temperature. 

The traditional approach to manufacturing PCM building materials requires forming a separate shell around each PCM particle, like a cup to hold water, then adding these newly encased PCMs to building materials. However, finding building materials compatible with both the PCM and its shell has been a challenge. In addition, this conventional method also decreases the number of PCM particles that can be incorporated into building materials. To overcome these challenges, past studies have shown that when using phase-changing paraffin wax mixed with liquid resin, the resin acts as both the shell and building material. This method locks the PCM particles inside their individual pockets, allowing them to safely undergo a phase change and manage thermal energy without leakage.

Similarly, Pentzer and her team first combined light-sensitive liquid resins with a phase-changing paraffin wax powder to create a new 3D printable ink composite, enhancing the production process for building materials containing PCMs and eliminating several steps, including encapsulation.  The resin/PCM mixture is soft, paste-like, and malleable, making it ideal for 3D printing but not for building structures. By using a light-sensitive resin, they cured it with an ultraviolet light to solidify the 3D printable paste, making it suitable for real-world applications. 

Source: Texas A&M University news release