Hydrogel-web composites for thermal energy transfer applications and methods of making the same
View Patent ↗The present disclosure is generally directed to hydrogel-fibrous web composites that can be used various heat transfer applications. For instance, the thermally conductive hydrogel-fibrous web composite can be used as a skin-contacting layer in a thermal energy transfer pad used to control patient body temperature. The hydrogel polymer is integral to the fibers of the web. Thus, the hydrogel-fibrous web composite provides good thermal conductivity and skin adhesion properties. The present disclosure is also generally directed to methods of preparing the hydrogel-fibrous web composites.
1. A thermally conductive fibrous material comprising
a web of fibers; and
a hydrogel integrated within said fibers of said web, wherein the hydrogel has a three-dimensional crosslinked structure that is intertwined with the fibers of the web, the hydrogel comprising a monomer, an initiator, a cross-linking agent, and a solubilizer selected from the group consisting of cyclo-dextrin, cyclodextrin derivatives, and hydrotropes.
2. A thermally conductive fibrous material as in claim 1 , wherein said monomer is selected from the group consisting of N-vinyl pyrrolidone, hydroxyethyl methacrylate, methacrylic acid or its salt, styrene sulfonic acid or its salt, potassium sulfopropyl acrylate, dimethyl acrylamide, dimethyl amino ethyl methacrylate or its quaternary salt derivative, and acrylamido methyl propane sulfonic acid or its salt.
3. A thermally conductive fibrous material as in claim 1 , wherein said initiator is a photo-initiator and wherein polymerization of the hydrogel monomer is initiated by UV light.
4. A thermally conductive fibrous material as in claim 1 , wherein said crosslinker is selected from the group consisting of methylene-bis-acrylamide, diethylene glycol diacrylate, poly(ethylene glycol) diacrylate, triethylene glycol-bis-methacrylate, ethylene glycol-bis-methacrylate, ethylene glycol-dimethacrylate, bisacrylamide, triethyleneglycol-bis-acrylate, 3,3′-ethylidene-bis(N-vinyl-2-pyrrolidone), trimethylolpropate trimethacrylate, glycerol trimethacrylate, polyethylene glycol dimethacrylate, and polymethacrylate crosslinkers.
5. A thermally conductive fibrous material as in claim 1 , wherein the basis weight of the web of fibers is from about 8 gsm to about 40 gsm.
6. A thermally conductive fibrous material as in claim 1 , wherein the basis weight of the hydrogel is from about 10 gsm to about 1000 gsm.
7. A thermal energy transfer pad comprising the thermally conductive fibrous material as in claim 1 .
8. A thermally conductive fibrous material as in claim 1 , wherein said web of fibers comprises a nonwoven web.
9. A thermally conductive fibrous material as in claim 8 , wherein said nonwoven web comprises a spunbond web.
10. A thermally conductive fibrous material as in claim 1 , wherein the hydrogel-fibrous web composite has a water content of from about 20% by weight to about 80% by weight.
11. A thermally conductive fibrous material as in claim 1 , wherein the hydrogel has a water content greater than about 20% by weight.