Salt-Hydrate PCM Composition with Polymer-Mediated Phase Stability
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Solution Overview
Problem
Phase separation or segregation in salt-hydrate phase change materials (PCMs) leads to incongruent melting, reducing their heat storage capacity and efficiency, particularly at high salt concentrations, and conventional thickening methods impair heat transfer.
Innovation Solution
Incorporation of specific polymers with carboxylate and sulfonate groups, such as poly(4-styrenesulfonic acid-co-maleic acid) (P4SSA-co-MA), poly(methyl vinyl ether-alt-maleic acid) (PMVEMA), and polystyrene sulfonate (PSS), into salt-hydrate PCMs to prevent the formation of anhydrous precipitates and maintain thermodynamic stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If thickeners are added to increase viscosity to prevent segregation, then segregation is delayed, but heat transfer is hampered and enthalpy is lost
Solution Approach 1:
The invention changes the chemical composition parameters by introducing specific polymers with carboxylate and sulfonate groups that interact with salt-hydrate crystals through electrostatic and coordination interactions, preventing segregation without significantly altering the physical parameter of viscosity that would hamper heat transfer
Solution Approach 2:
The polymers act as intermediary substances that mediate between the salt-hydrate PCM and water, forming protective complexes around crystal surfaces that prevent anhydrous precipitate formation while maintaining the thermal properties of the base PCM composition
2Quantity of substance
If salt concentration is increased to enhance heat storage efficiency, then heat storage capacity is improved, but segregation occurs more readily
Solution Approach 1:
The polymers serve as intermediary agents that stabilize high-concentration salt-hydrate compositions by forming protective complexes around crystal surfaces, enabling the system to maintain homogeneity at salt concentrations that would otherwise cause severe segregation
Solution Approach 2:
The invention creates a composite material system combining salt-hydrate PCM with specific polymers having carboxylate and sulfonate groups, where the polymer component prevents segregation and enables stable operation at high salt concentrations for enhanced heat storage capacity
3Stability of the object's composition
If conventional polymers are used to prevent crystal formation, then nucleation is inhibited, but heat transfer efficiency is reduced due to thickening
Solution Approach 1:
The invention selects polymers with specific chemical parameters (carboxylate and sulfonate functional groups) that provide effective crystal surface interaction at low concentrations, achieving phase stability without the excessive viscosity increase that would reduce heat transfer power
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The polymers effectively inhibit segregation, ensuring homogeneous compositions with maintained heat storage capacity and efficient heat transfer, suitable for various applications by preventing the formation of unwanted phases and promoting controlled nucleation.
Implementation Method 1
The polymers effectively inhibit segregation, ensuring homogeneous compositions with maintained heat storage capacity and efficient heat transfer, suitable for various applications by preventing the formation of unwanted phases
Implementation Method 2
Incorporation of specific polymers with carboxylate and sulfonate groups, such as poly(4-styrenesulfonic acid-co-maleic acid) (P4SSA-co-MA), poly(methyl vinyl ether-alt-maleic acid) (PMVEMA), and polystyrene sulfonate (PSS), into salt-hydrate PCMs to prevent the formation of anhydrous precipitates
Implementation Method 3
Incorporation of specific polymers with carboxylate and sulfonate groups into salt-hydrate PCMs to prevent the formation of anhydrous precipitates and maintain thermodynamic stability
Implementation Method 4
Phase change materials (PCM) exhibit a high enthalpy of fusion, with the heat of fusion being generally considerably higher than the sensible heat. Due to their capacity store and release large amount of thermal energy as latent heat during their phase transition
Implementation Method 5
PCMs must have a transition temperature within the operational temperature range of the application and have a good thermal conductivity for efficient heat transfer
Data Source
Figure 1A
Figure 1B~2A
Figure 2B~2C
AI summary
The invention concerns a phase change material (PCM) composition, comprising an aqueous solution of a salt-hydrate phase change material component, one or more polymers, of which at least one polymer is a poly(4-styrenesulfonic acid-co-maleic acid), a poly(methyl vinyl ether-alt-maleic acid), or a polystyrene sulfonic acid, or a mixture of these polymers. The invention also concerns a method for producing a PCM composition comprising these polymers.