Liquid-liquid phase transition compositions and processes
The present application pertains to liquid-liquid phase transition compositions and processes. In one embodiment a liquid-liquid phase transition process comprises first forming a composition comprising a glycol polymer and water and then phase transitioning the composition at or above the composition's cloud point temperature to form at least two liquid phases. The enthalpy of liquid-liquid phase transition may be greater than 5 kJ per kg as measured by a calorimeter and each liquid phase may have unique and advantageous properties. In another embodiment the application pertains to compositions suitable for liquid-liquid phase transition compositions.
1. A liquid-liquid phase transition process comprising:
forming a composition comprising a glycol polymer, water, and a glycol ether, wherein the composition has a cloud point temperature; and
phase transitioning the composition at or above the composition's cloud point temperature to form at least two liquid phases;
wherein a first liquid phase of said at least two liquid phases comprises greater than 50 wt % water;
wherein a second liquid phase of said at least two liquid phases comprises the glycol polymer and the glycol ether; and
wherein the second liquid phase comprising the glycol polymer has a density less than the density of the liquid phase comprising greater than 50 wt % water when non-contiguously separate from other liquid phases and at a temperature of 10° C. according to ASTM D1122; and
enthalpy of liquid-liquid phase transition is greater than 5 kJ per kg as measured by a mixing calorimeter;
wherein said glycol ether is selected from an alkylene glycol alkyl ether, a dialkylene glycol alkyl ether, a trialkylene glycol alkyl ether, an alkylene glycol dialkyl ether, or any combination thereof wherein alkyl is a C1-C6 alkyl;
wherein the cloud point comprises a combined cloud point; and
wherein the process is employed in an HVAC system.
2. The process of claim 1 wherein the glycol polymer comprises a polypropylene glycol.
3. The process of claim 1 wherein the glycol polymer comprises a polyethylene glycol.
4. The process of claim 1 wherein the glycol polymer comprises a block co-polymer.
5. The process of claim 4 wherein the block co-polymer is selected from PEG-Ran-PG, or PPG-PEG-PPG, or PEG-PPG-PEG, or any combination thereof.
6. The process of claim 1 wherein the glycol polymer has an average molecular number greater than or equal to 1,000 and less than or equal to 3,000.
7. The process of claim 1 wherein the glycol ether is diethylene glycol monohexyl ether.
8. A liquid-liquid phase transition process comprising:
forming a composition comprising a glycol polymer with an average molecular number greater than or equal to 1000, water, and a glycol ether; and
phase transitioning the composition into at least two liquid phases;
wherein a first liquid phase of said at least two liquid phases comprises greater than 50 wt % water;
wherein a second liquid phase of said at least two liquid phases comprises the glycol polymer with an average molecular number greater than or equal to 1000 and the glycol ether;
wherein the second liquid phase comprising the glycol polymer has a viscosity less than 100 cP at 25° C. wherein viscosity is measured on the second liquid phase as a non-contiguous separate phase with a viscometer; and
wherein the enthalpy of liquid-liquid phase transition is greater than 5 kJ per kg of composition as measured by a mixing calorimeter; and
wherein said glycol ether is selected from an alkylene glycol alkyl ether, a dialkylene glycol alkyl ether, a trialkylene glycol alkyl ether, an alkylene glycol dialkyl ether, or any combination thereof wherein alkyl is a C1-C6 alkyl; and
wherein the process is employed in an HVAC system.
9. The process of claim 8 wherein the second liquid phase further comprises a density reducing reagent.
10. The process of claim 8 wherein the second liquid phase further comprises a density enhancing reagent.
11. The process of claim 8 wherein the second liquid phase further comprises a viscosity reducing reagent.
12. The process of claim 8 wherein the glycol ether and the glycol polymer have a combined cloud point.
13. The process of claim 8 wherein the glycol polymer comprises at least 50 wt. % of the second liquid phase based on the total weight of the second phase.
14. The process of claim 8 wherein the glycol polymer comprises at least 80 wt. % of the second liquid phase based on the total weight of the second phase.
15. The process of claim 8 wherein the second liquid phase comprises less than 20 wt. % water based on the total weight of the second phase.
16. The process of claim 8 wherein the composition comprises a cloud point temperature of greater than 25° C.
17. The process of claim 8 wherein the composition comprises a cloud point temperature of less than 25° C.
18. The process of claim 8 wherein the glycol ether is diethylene glycol monohexyl ether.