Organic-inorganic hybrid reversible phase change material as well as preparation method and application thereof

Abstract

The invention discloses an organic-inorganic hybrid reversible phase change material as well as a preparation method and application thereof, and belongs to the field of functional materials. According to the organic-inorganic hybrid reversible phase change material, N, N, N-trimethyl isopropylamine and a halogen substituted derivative thereof are used as organic cations, an iron halide anion [FeX] (X = Cl, Br) with a tetrahedral configuration is used as an inorganic anion, and a molecular crystal is prepared through a solution evaporation method. The material is subjected to reversible solid-solid phase change in a mild temperature range (about 330-356 K) close to the working temperature of a device, and is obviously changed along with the dielectric constant in a phase change temperature region. The phase change temperature and the dielectric response behavior can be adjusted by cooperatively regulating and controlling the structure of the organic cation and the type of the inorganic halogen complex anion. The material is mild in preparation method, is suitable for amplification and film processing, and can be used for a dielectric regulation and control structure, a reconfigurable dielectric unit and a packaging layer dielectric function module.

Description

Technical Field

[0001] This invention relates to the field of functional materials technology, and in particular to an organic-inorganic hybrid reversible phase change material, its preparation method, and its application. Background Technology

[0002] Solid-state phase change materials (SCTs) are substances whose crystal structure undergoes a reversible transformation during heating or cooling, resulting in significant changes in their dielectric, electrical, thermal, or mechanical properties. Existing SCTs primarily focus on inorganic oxide and chalcogenide systems, such as VO2 and Ge–Sb–Te materials. While these materials have a foundation for development in areas such as phase change storage, infrared modulation, and thermistors, they suffer from limitations including limited controllability, high fabrication temperatures, high crystal stress, and limited processing methods, making it difficult to meet the demands of flexible applications, low-temperature processing, or reconfigurable dielectric control devices.

[0003] In recent years, organic-inorganic hybrid materials have attracted attention due to their low-energy-consumption crystal phase transitions, solution-processable properties, and structural designability. However, most existing research focuses on ferroelectric materials and molecular switch materials, and a functional material system that can simultaneously possess reversible solid-state phase transitions, dielectric response, structural tunability, and solution-processable properties has not yet been formed.

[0004] Therefore, it is necessary to develop a novel hybrid phase change material whose structure, phase transition temperature, and dielectric behavior are all tunable, to provide a new material basis for dielectric modulation and reconfigurable devices. Summary of the Invention

[0005] The purpose of this invention is to provide an organic-inorganic hybrid reversible phase change material, its preparation method, and its application, so as to solve the problems in the background art.

[0006] To address the aforementioned technical problems, this invention provides an organic-inorganic hybrid reversible phase change material comprising a hybrid crystal structure formed by organic cations and inorganic anions, wherein: The organic cation is N,N,N-trimethylisopropylamine or its haloalkyl derivative; The inorganic anion is a tetrahedral iron halide anion, FeX4. − X is Cl or Br; the organic-inorganic hybrid reversible phase change material undergoes a reversible solid-state phase transition in a mild temperature range close to the device operating temperature, and its dielectric constant undergoes a reversible change during the phase transition, so that the dielectric properties of the material can be reconstructed between different phase states.

[0007] In one embodiment, the organic-inorganic hybrid reversible phase change material is [C6NH]. 16 FeCl4 or [C6NH 15 Cl]FeBr4.

[0008] In one embodiment, the organic cation is [C6NH4+]. 16 ] + or [C6NH 15 Cl] + .

[0009] In one embodiment, the dielectric constant of the organic-inorganic hybrid reversible phase change material undergoes a sudden change or a step change within the phase change temperature range.

[0010] In one embodiment, the phase transition temperature and dielectric response amplitude are adjusted by synergistically controlling the haloalkyl structure and the type of iron halide anion in the organic cation.

[0011] In one embodiment, the phase transition of the organic-inorganic hybrid reversible phase change material is a reversible solid-solid phase transition that does not involve a melting process.

[0012] In one embodiment, the organic-inorganic hybrid reversible phase change material is prepared in Xingtai in the form of single crystal, microcrystalline powder, or thin film.

[0013] In one embodiment, the thin film morphology is prepared by solution spin coating, inkjet printing, drop coating, or low-temperature evaporation.

[0014] The present invention also provides a dielectric control structure comprising the above-mentioned organic-inorganic hybrid reversible phase change material, and utilizes the reversible change of the dielectric constant of the material during the phase transition process to achieve dielectric property regulation.

[0015] In one embodiment, the dielectric modulation structure is used as an adjustable capacitor unit, a reconfigurable dielectric layer, or a signal coupling modulation structure in the encapsulation layer.

[0016] The present invention also provides a reconfigurable functional unit, characterized in that it comprises the above-mentioned organic-inorganic hybrid reversible phase change material, and the dielectric properties of the unit are reversibly changed by applying thermal stimulation, electric field or photothermal effect to the material to trigger a solid phase transition.

[0017] The present invention also provides the use of the above-mentioned organic-inorganic hybrid reversible phase change material in constructing dielectric control structures, temperature-responsive dielectric elements, or reconfigurable packaging functional units.

[0018] This invention provides an organic-inorganic hybrid reversible phase change material, its preparation method, and its application, which have the following beneficial effects: (1) The material of the present invention can undergo a reversible solid-phase phase transition in a mild temperature range close to the operating temperature of the device, with mild triggering conditions, which is suitable for engineering applications; (2) The dielectric constant changes significantly during the phase transition, enabling reconfigurable dielectric properties; (3) Solid-solid phase transition avoids structural damage caused by melting and improves cycle stability; (4) The preparation method is simple and suitable for scale-up and thin film processing; (5) Achieving designability of material properties through organic-inorganic synergistic regulation; (6) Applicable to dielectric control structures and reconfigurable packaged functional modules. Attached Figure Description

[0019] Figure 1 The organic-inorganic hybrid phase change material [C6NH] of this invention 16 Schematic diagram of the crystal morphology of FeCl4; Figure 2 The organic-inorganic hybrid phase change material [C6NH] of this invention 15 Schematic diagram of the crystal morphology of Cl]FeBr4; Figure 3 This is a schematic diagram of the preparation process of the hybrid material of the present invention; Figure 4 [C6NH] 16 FeCl4 and [C6NH 15 Schematic diagram of Cl]FeBr4 heated and cooled using DSC; Figure 5 A schematic diagram illustrating the response mechanism of a phase transition leading to a reversible change in dielectric properties; Figure 6 A schematic diagram illustrating the response mechanism of reversible changes in dielectric properties at different frequencies; Figure 7 This is a schematic diagram of a dielectric control unit constructed based on the material of this invention; Figure 8 This is a schematic diagram of the material applied to the dielectric modulation structure of the encapsulation layer. Detailed Implementation

[0020] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a further detailed explanation of the organic-inorganic hybrid reversible phase change material, its preparation method, and its applications. The advantages and features of the present invention will become clearer from the following description. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0021] This invention provides an organic-inorganic hybrid reversible phase change material with the general chemical formula: [C6NH 16 FeCl4, [C6NH 15 Cl]FeBr4, where: [C6NH 16 [⁺] is an organic cation composed of N,N,N-trimethylisopropylamine; [FeCl4] - [FeBr4] -It is a tetrachloroferric acid anion. This material undergoes a reversible solid-state phase transition during heating or cooling, exhibiting a significant dielectric anomaly in the phase transition temperature range. Furthermore, the organic cation can be [C6NH4+]. 16 ] + [C6NH] 15 Cl] + The organic-inorganic hybrid phase change material is [C6NH 16 FeCl4 or [C6NH 15 Cl]FeBr4.

[0022] Example 1: Material Preparation [C6NH 16 FeCl4: Add 1 mmol of [C6NH4+] 16 I was dissolved in deionized water, 0.5 mmol of Ag₂CO₃ was added and the mixture was stirred for 3 hours; after filtration, hydrochloric acid was added dropwise to completely eliminate CO₃²⁻, followed by slow addition of FeCl₃ aqueous solution and continued stirring for 1 hour; the resulting solution was allowed to stand and evaporate for about a week to obtain square yellow crystals [C₆NH₃]. 16 FeCl4.

[0023] [C6NH 15 Cl]FeBr4: Add 1 mmol [C6NH 15 [Cl]I was dissolved in deionized water, 0.5 mmol of Ag2CO3 was added and the mixture was stirred for 3 hours; after filtration, hydrochloric acid was added dropwise to completely eliminate CO3²⁻, followed by slow dropwise addition of FeBr3 aqueous solution and continued stirring for 1 hour; the resulting solution was allowed to stand and evaporate for about a week to obtain square yellow crystals [C6NH] 15 Cl]FeBr4.

[0024] Example 2: Phase Change Performance Test The dielectric constant of the two materials mentioned above was measured as a function of temperature in a temperature-controlled testing device. Figure 4 As shown, the results indicate that significant dielectric anomalies occur near 330 K and 356 K, proving that the solid-state phase transition is consistent with the dielectric response.

[0025] Example 3: Construction example of dielectric modulation structure (application example) The material is made into a thin film and sandwiched between the upper and lower electrodes. External heating triggers a phase transition and causes a change in the dielectric constant, thereby achieving reversible adjustment of the dielectric properties of the unit structure.

[0026] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. An organic-inorganic hybrid reversible phase change material, characterized in that, It contains a hybrid crystal structure formed by organic cations and inorganic anions, wherein: The organic cation is N,N,N-trimethylisopropylamine or its haloalkyl derivative; The inorganic anion is a tetrahedral iron halide anion, FeX4. − X is Cl or Br; the organic-inorganic hybrid reversible phase change material undergoes a reversible solid-state phase transition in a mild temperature range close to the device operating temperature, and its dielectric constant undergoes a reversible change during the phase transition, so that the dielectric properties of the material can be reconstructed between different phase states.

2. The organic-inorganic hybrid reversible phase change material as described in claim 1, characterized in that, The organic-inorganic hybrid reversible phase change material is [C6NH 16 FeCl4 or [C6NH 15 Cl]FeBr4.

3. The organic-inorganic hybrid reversible phase change material as described in claim 1, characterized in that, The organic cation is [C6NH4+]. 16 ] + or [C6NH 15 Cl] + .

4. The organic-inorganic hybrid reversible phase change material as described in claim 1, characterized in that, The organic-inorganic hybrid reversible phase change material exhibits abrupt or step-like changes in dielectric constant within the phase change temperature range.

5. The organic-inorganic hybrid reversible phase change material as described in claim 1, characterized in that, The phase transition temperature and dielectric response amplitude can be adjusted by synergistically regulating the haloalkyl structure and the type of iron halide anion in organic cations.

6. The organic-inorganic hybrid reversible phase change material as described in claim 1, characterized in that, The phase transition of the organic-inorganic hybrid reversible phase change material is a reversible solid-solid phase transition, which does not involve a melting process.

7. The organic-inorganic hybrid reversible phase change material as described in claim 1, characterized in that, The organic-inorganic hybrid reversible phase change material is prepared in Xingtai in the form of single crystals, microcrystalline powders, or thin films.

8. The organic-inorganic hybrid reversible phase change material as described in claim 7, characterized in that, The thin film morphology is prepared by solution spin coating, inkjet printing, drop coating or low-temperature evaporation.

9. A dielectric modulation structure, characterized in that, The invention comprises the organic-inorganic hybrid reversible phase change material according to any one of claims 1–8, and utilizes the reversible change of the dielectric constant of the material during the phase change process to achieve dielectric property regulation.

10. The dielectric modulation structure as described in claim 9, characterized in that, The dielectric control structure is used as an adjustable capacitor unit, a reconfigurable dielectric layer, or a signal coupling control structure in the packaging layer.

11. A reconfigurable functional unit, characterized in that, The organic-inorganic hybrid reversible phase change material comprising any one of claims 1–8, wherein a solid-state phase change is triggered by applying thermal stimulation, an electric field or photothermal effect to the material, thereby causing a reversible change in the dielectric properties of the unit cells.

12. Use of the organic-inorganic hybrid reversible phase change material according to any one of claims 1-8 in constructing dielectric control structures, temperature-responsive dielectric elements, or reconfigurable packaging functional units.

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