Thermally conductive nanomaterial coatings on flexible foam or fabrics
A flexible cellular foam or fabric product is coated with a coating including highly thermally conductive nanomaterials. The highly thermally conductive nanomaterials may be carbon nanomaterials, metallic, or non-metallic solids. The carbon nanomaterials may include, but are not necessarily limited to, carbon nanotubes and graphene nanoplatelets. The highly thermally conductive nanomaterials may include but are not limited to nano-sized solids that may include graphite flakes, for example. When coated on a surface of flexible foam, the presence of nanomaterials may impart greater thermal effusivity, greater thermal conductivity, and/or a combination of these improvements. The flexible foam product may be polyurethane foam, latex foam, polyether polyurethane foam, viscoelastic foam, high resilient foam, polyester polyurethane foam, foamed polyethylene, foamed polypropylene, expanded polystyrene, foamed silicone, melamine foam, among others.
1. A flexible cellular foam product comprising:
a flexible open-celled polyether polyurethane foam substrate having at least one surface; and
a coating layer comprising a highly thermally conductive nanomaterial comprising a graphene nanoplatelet, and a binder comprising a styrene-acrylic emulsion polymer on the at least one surface of the flexible foam substrate, the binder binding the highly thermally conductive nanomaterial of the coating layer to the at least one surface of the flexible foam substrate,
the highly thermally conductive nanomaterial being present on the at least one surface of the flexible open-celled polyether polyurethane foam substrate, and not interposed within the flexible open-celled polyether polyurethane foam substrate, and the coating layer further comprises a microencapsulated phase change material comprising n-octadecane.
2. The flexible cellular foam product of claim 1 , wherein the coating layer comprises between 0.0001 wt % and 50 wt % highly thermally conductive nanomaterials.
3. The flexible cellular foam product of claim 1 , wherein the highly thermally conductive nanomaterials have a thermal conductivity of greater than 5 W/(m-K).
4. The flexible cellular foam product of claim 1 , wherein the coating layer is present on the surface of the flexible open-celled polyether polyurethane foam substrate in a thickness of between 10 g/m 2 and 25,000 g/m 2 , inclusively.
5. The flexible cellular foam product of claim 1 , wherein the highly thermally conductive nanomaterial has a length in at least one dimension of between about 1 nm independently and 1,000 nm.
6. The flexible cellular foam product of claim 1 , wherein the coating layer further comprises an extender comprising talc.
7. The flexible cellular foam product of claim 1 , wherein the coating layer further comprises a stabilizer in an amount up to about 5 wt %.
8. The flexible cellular foam product of claim 1 , wherein the coating layer further comprises:
a surfactant in an amount between about 0.01 wt % independently and about 5 wt %; and
an extender comprising talc.