Cellulosic fibers having enhanced reversible thermal properties and methods of forming thereof

1. A lyocell-type cellulosic fiber having enhanced reversible thermal properties, comprising:

a fiber body formed of one or more elongated members, at least one elongated member including a cellulosic material and a temperature regulating material including a phase change material contained by a containment structure, the temperature regulating material being dispersed substantially uniformly within the cellulosic material and the phase change material having a transition temperature in the range of 22° C. to 40° C.

2. The cellulosic fiber of claim 1 , wherein the phase change material includes a paraffinic hydrocarbon having 16 to 22 carbon atoms.

3. The cellulosic fiber of claim 1 , wherein the phase change material includes a polyhydric alcohol.

4. The cellulosic fiber of claim 1 , wherein the phase change material includes one of a polymeric phase change material, a polyethylene glycol, a polyethylene oxide, a polytetramethylene glycol, and a polyester.

5. The cellulosic fiber of claim 1 , wherein the elongated member includes from about 5 percent to about 70 percent by weight of the temperature regulating material.

6. The cellulosic fiber of claim 1 , wherein the plurality of elongated members are arranged in one of an island-in-sea configuration, a segmented-pie configuration, a core-sheath configuration, a slde-by-slde configuration, and a striped configuration.

7. The cellulosic fiber of claim 1 , wherein the fiber body is between 0.1 and 100 denier.

8. A lyocell-type cellulosic fiber having enhanced reversible thermal properties, comprising:

a plurality of island members, at least one Island member of the plurality of Island members including

a phase change material contained In a containment structure, the phase change material having a transition temperature in the range of 16° C. to 45° C.; and

a sea member surrounding each of the plurality of Island members and forming an exterior of the cellulosic fiber, the sea member including a sea cellulosic material.

9. A cellulosic fiber comprising:

a fiber body including a cellulosic material and a plurality of microcapsules dispersed in the cellulosic material, the plurality of microcapsules containing a phase change material having a latent heat of at least 40 J/g and a transition temperature in the range of 0° C. to 100° C., the phase change material providing thermal regulation based on at least one of absorption and release of the latent heat at the transition temperature, wherein the cellulosic fiber has a cross-section that is generally X-shaped, generally Y-shaped, generally T-shaped or generally H-shaped, wherein the cellulosic material includes one of cellulose and cellulose acetate.

10. The cellulosic fiber of claim 9 , wherein the plurality of microcapsules have sizes in the range of 0.1 to 20 microns.

11. The cellulosic fiber of claim 9 , wherein the plurality of microcapsules are monodisperse with respect to sizes of the plurality of microcapsules.

12. The cellulosic fiber of claim 9 , wherein the latent heat of the phase change material is in the range of 60 J/g to 400 J/g.

13. The cellulosic fiber of claim 9 , wherein the transition temperature of the phase change material is in the range of 0° C. to 50° C.

14. The cellulosic fiber of claim 9 , wherein the phase change material includes a paraffinic hydrocarbon.

15. The cellulosic fiber of claim 9 , wherein the phase change material includes a polyhydric alcohol.

16. The cellulosic fiber of claim 9 , wherein the phase change material includes one of a polyethylene glycol, a polyethylene oxide, a polytetramethylene glycol, and a polyester.

17. The cellulosic fiber of claim 9 , wherein the cellulosic fiber includes from 5 percent to 40 percent by weight of the plurality of microcapsules containing the phase change material.