Phase change material core thermoplastic shell filament
The present disclosure relates to encapsulation of a phase change material (PCM) enabled by extrusion of a thermoplastic polymer shell and a PCM core, which can be additively manufactured to form a variety of designs for use in a variety of settings, including for use as thermal energy storage devices in building heating ventilation and air conditioning (HVAC) systems. The thermoplastic polymer shell surrounding a PCM core may be used as a filament in three-dimensional (3D) printing or may be extruded during the additive manufacturing process.
1 . A thermal energy storage filament device for additive manufacturing, the device comprising:
a shell comprising an extruded thermoplastic polymer; and
a filled core comprising a phase change material; wherein:
the phase change material comprises a salt hydrate, a hydrogel, and a nucleating agent,
the salt hydrate comprises tetrabutylammonium bromide (TBAB) hydrate,
the hydrogel comprises poly (acrylamide-co-acrylic acid),
the nucleating agent comprises sodium phosphate dibasic dodecahydrate,
the shell comprises a length and an interior,
the filled core is positioned within the interior of the shell and extends through the length of the shell; and
the extruded thermoplastic polymer comprises a base polymer and a high thermal conductivity filler.
2 . The device of claim 1 , wherein the base polymer comprises polycaprolactone (PCL), thermoplastic polyurethane (TPU), polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), polyvinyl alcohol (PVA), polyethylene terephthalate (PET), and/or polycarbonate (PC).
3 . The device of claim 1 , wherein the extruded thermoplastic polymer has a thermal conductivity greater than about 1 W/m·K.
4 . The device of claim 1 , wherein the salt hydrate comprises sodium sulfate decahydrate, calcium chloride hexahydrate, disodium hydrogen phosphate dodecahydrate, and/or sodium acetate trihydrate.
5 . The device of claim 1 , wherein the nucleating agent comprises borax or silver iodide (AgI).
6 . The device of claim 1 , wherein the phase change material comprises about 1-10 wt % hydrogel, 1-5 wt % nucleating agent, and 85-99 wt % salt hydrate.
7 . The device of claim 1 , wherein the high thermal conductivity filler comprises hexagonal boron nitride and carbon black.