Texas A&M scientists have successfully demonstrated how 3D printed phase-change composites can be used to regulate inside building temperatures.
According to associate professor Emily Pentzer and her team, these phase-change material (PCM) composites can be added to building materials, like paint, or 3D printed as decorative home accents. They also offer huge energy savings when compared to conventional cooling and heating systems.
Phase-change materials change their physical state depending on the temperature in the environment. They convert from solid to liquid upon absorbing heat and vice-versa when they release heat.
The traditional approach to manufacturing PCM building materials requires forming a separate shell around each PCM particle and 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.
NASA Space Technology graduate research fellow Ciera Cipriani likens this to a pot with eggs and water.
“If each egg has to be placed in an individual container to be hard-boiled, fewer eggs will fit in the pot.”
“By removing the plastic containers, the veritable shell in our research, more eggs, or PCMs, can occupy a greater volume by packing closer together within the water/resin.”
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.
This ink composite enhances the production process for building materials containing PCMs and eliminates several steps, including encapsulation.
According to Pentzer, the resin/PCM mixture is soft, paste-like, and malleable, making it ideal for 3D printing but not for building structures.
To remedy this, the scientists used a light-sensitive resin that they cured with ultraviolet light to solidify the 3D printable paste, making it suitable for real-world applications.
Additionally, they found that the phase-changing wax embedded within the resin was not affected by the ultraviolet light and made up 70% of the printed structure.
Next, they tested the thermoregulation of their phase-changing composites by 3D printing a small-scale house-shaped model.
Results confirm that the model’s temperature differed by 40% compared to outside temperatures for both heating and cooling thermal cycles.
Image and content: Texas A&M University