Thermostatic packaging

Abstract

Arrangements and methods for thermostatic packaging are provided herein. In some embodiments, in response to a change in temperature, an endothermic or exothermic reaction can be initiated to counteract the change in temperature.

1 . A cooling system comprising:
 a first reactant;   a second reactant, wherein the first reactant can endothermically react with the second reactant to absorb heat; and   a temperature-responsive divider positioned between at least some of the first reactant and at least some of the second reactant,
 wherein at a first temperature, the temperature-responsive divider is impermeable to the first reactant, the second reactant, or the first reactant and the second reactant, and 
 wherein at a second temperature, the temperature-responsive divider is permeable to the first reactant, the second reactant, or the first reactant and the second reactant. 
   
     
     
         2 . The cooling system of  claim 1 , wherein the first reactant contacts a first side of the temperature-responsive divider, wherein the second reactant contacts a second side of the temperature-responsive divider, and wherein the first side is opposite to the second side of the temperature-responsive divider. 
     
     
         3 . The cooling system of  claim 1 , wherein the temperature-responsive divider comprises an expandable sheet comprising at least a perforation, wherein the perforation is impermeable to the first reactant and the second reactant when the expandable sheet is in a first conformation, and wherein the perforation is permeable to the first reactant, the second reactant, or the first reactant and the second reactant when the expandable sheet is in a second conformation. 
     
     
         4 . The cooling system of  claim 3 , wherein the expandable sheet comprises at least one of a rubber, a metal, or an elastomer material. 
     
     
         5 . The cooling system of  claim 3 , wherein the temperature-responsive divider further comprises at least one temperature-responsive actuator in tensile communication with the expandable sheet, wherein the at least one temperature-responsive actuator is configured to position the sheet in the first conformation at the first temperature, and wherein the at least one temperature-responsive actuator is configured to position the sheet in the second conformation at the second temperature, wherein the second temperature is greater than the first temperature. 
     
     
         6 . The cooling system of  claim 5 , wherein the at least one temperature-responsive actuator comprises at least one of a bimetal, a shape-memory metal alloy, or a shape memory polymer. 
     
     
         7 . The cooling system of  claim 1 , wherein the temperature-responsive divider comprises a polymer membrane, wherein at least a portion of a surface of the polymer membrane is hydrophilic at a first temperature, and wherein the portion of the surface of the polymer membrane is hydrophobic at a second temperature, wherein the second temperature is greater than the first temperature. 
     
     
         8 . The cooling system of  claim 7 , wherein the polymer membrane comprises N-isopropyl acryl amide. 
     
     
         9 . The cooling system of  claim 1 , wherein the first reactant and the second reactant comprise a first/second reactant pairing comprising at least one of: H 2 O/NH 4 NO 3 , H 2 O/NH 4 Cl, NH 4 NO 3 /Urea, H 2 O/Urea, H 2 O/Ba(NO 3 ) 2 , citric acid/sodium bicarbonate, H 2 O/Xylitol, and H 2 O/Erythritol. 
     
     
         10 . The cooling system of  claim 1 , wherein at least one of the first reactant and the second reactant comprises a liquid, a gel, or a liquid and a gel. 
     
     
         11 . The cooling system of  claim 1 , further comprising:
 a first compartment configured to contain the first reactant; and   a second compartment configured to contain the second reactant, wherein at least a portion of the first compartment is defined by a first surface of the temperature-responsive divider, and wherein at least a portion of the second compartment is defined by a second surface of the temperature-responsive divider.   
     
     
         12 . The cooling system of  claim 1 , further comprising a storage compartment disposed adjacent to the first reactant, the second reactant, or the first and second reactant. 
     
     
         13 . The cooling system of  claim 1 , wherein the temperature-responsive divider can change to a configuration that is impermeable to the first reactant, the second reactant, or the first and second reactant upon a return of the temperature-responsive divider to the first temperature. 
     
     
         14 . The cooling system of  claim 1 , wherein the second temperature is higher than the first temperature. 
     
     
         15 . A method of regulating a temperature, the method comprising:
 providing a cooling system comprising:
 a first reactant; 
 a second reactant, wherein the first reactant can react endothermically with the second reactant; and 
 a temperature-responsive divider positioned between at least a part of the first reactant from at least a part of the second reactant; and 
 changing a first conformation of the temperature-responsive divider to a second conformation of the temperature-responsive divider upon an increase in temperature, wherein the second conformation permits the first reactant, the second reactant, or the first and the second reactant to pass through the temperature-responsive divider such that an endothermic reaction occurs. 
   
     
     
         16 . The method of  claim 15 , wherein the first conformation effectively separates the first reactant from the second reactant at the first temperature, thereby preventing the first reactant from reacting with the second reactant. 
     
     
         17 . The method of  claim 15 , the method further comprising changing the second conformation of the temperature-responsive divider to the first conformation upon a decrease in the temperature. 
     
     
         18 . The method of  claim 15 , wherein the temperature-responsive divider comprises an expandable sheet that comprises at least one perforation, and wherein changing the first conformation of the temperature-responsive divider to the second conformation of the temperature-responsive divider comprises straining the expandable sheet such that the at least one perforation opens. 
     
     
         19 . The method of  claim 15 , wherein the temperature-responsive divider comprises a bimetal, and wherein changing the first conformation of the temperature-responsive divider to the second conformation of the temperature-responsive divider comprises bending the bimetal. 
     
     
         20 . The method of  claim 15 , wherein the temperature-responsive divider comprises at least one of a shape-memory alloy or a shape memory polymer, and wherein changing the first conformation of the temperature-responsive divider to the second conformation of the temperature-responsive divider comprises changing a shape of the shape-memory alloy or the shape memory polymer. 
     
     
         21 . The method of  claim 15 , wherein the temperature-responsive divider comprises a surface of a polymer, and wherein changing the first conformation of the temperature-responsive divider to the second conformation of the temperature-responsive divider comprises changing at least a portion of the surface of the polymer from a hydrophilic state to a hydrophobic state. 
     
     
         22 . The method of  claim 15 , wherein the increase in local temperature comprises an increase of at least about 5° C. 
     
     
         23 . The method of  claim 15 , wherein the first reactant and the second reactant comprise a first/second reactant pairing comprising at least one of: H 2 O/NH 4 NO 3 , H 2 O/NH 4 Cl, NH 4 NO 3 /Urea, H 2 O/Urea, H 2 O/Ba(NO 3 ) 2 , citric acid/sodium bicarbonate, H 2 O/Xylitol, and H 2 O/Erythritol. 
     
     
         24 . A packaging comprising:
 a first reactant;   a second reactant, wherein the first reactant can endothermically react with the second reactant to absorb heat; and   a temperature-responsive divider positioned between at least some of the first reactant and at least some of the second reactant,
 wherein at a first temperature, the temperature-responsive divider is impermeable to the first reactant, the second reactant, or the first reactant and the second reactant, and 
 wherein at a second temperature, the temperature-responsive divider is permeable to the first reactant, the second reactant, or the first reactant and the second reactant. 
   
     
     
         25 . A method of preparing a cooling system, the method comprising:
 providing a first reactant;   providing a second reactant, wherein the first reactant can endothermically react with the second reactant to absorb heat; and   providing a temperature-responsive divider positioned between at least some of the first reactant and at least some of the second reactant,
 wherein at a first temperature, the temperature-responsive divider is impermeable to the first reactant, the second reactant, or the first reactant and the second reactant, and 
 wherein at a second temperature, the temperature-responsive divider is permeable to the first reactant, the second reactant, or the first reactant and the second reactant. 
   
     
     
         26 - 29 . (canceled)