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CN-121082884-B - Gradient self-heating material based on phase change-oxidation cooperative regulation and control as well as preparation method and application thereof

CN121082884BCN 121082884 BCN121082884 BCN 121082884BCN-121082884-B

Abstract

The invention relates to a gradient self-heating material based on phase change-oxidation cooperative regulation and control, and a preparation method and application thereof. The gradient self-heating material based on phase change-oxidation cooperative regulation comprises a core layer, a transition layer and a shell layer which are sequentially connected, wherein the core layer is a reduced iron powder-phenolic resin composite layer, the transition layer is a gradient transition structure of iron powder, CNT-graphite composite material and resin, the shell layer is a catalytic phase change material particle-resin composite layer, and the volume ratio of the shell layer, the transition layer and the core layer is 20% -30%, 20% -30% and 40% -60% respectively. The invention solves the problem that the interface between the oxidant and the phase change material is difficult to fail through chemical bonding reconstruction, adopts a gradient heat conduction structure design to break the heat accumulation bottleneck, realizes the cross-scale coordination of four large dimensions of exothermic reaction, heat storage phase change, heat conduction and dynamic regulation, and finally has the thermal response (the temperature is more than 50 ℃) time of <30 seconds.

Inventors

  • ZHU RUI
  • XU MING
  • JIA FEI
  • ZHANG FAN
  • CUI KAI
  • YIN PENG

Assignees

  • 中国建筑材料科学研究总院有限公司

Dates

Publication Date
20260505
Application Date
20250828

Claims (9)

  1. 1. A gradient self-heating material based on phase change-oxidation cooperative regulation is characterized by comprising a core layer, a transition layer and a shell layer which are sequentially connected, wherein, The core layer is a reduced iron powder-phenolic resin composite layer; the transition layer is a gradient transition structure of iron powder, CNT-graphite composite material and resin; the shell layer is a catalytic phase change material particle-resin composite layer; The volume ratio of the shell layer, the transition layer and the core layer is 20% -30%, 20% -30% and 40% -60% respectively; The core layer comprises 70 weight percent of reduced iron powder and 30 weight percent of phenolic resin, the transition layer comprises 50 weight percent of iron powder, 30 weight percent of CNT-graphite composite material and 20 weight percent of resin, and the shell layer comprises 60 weight percent of catalytic phase change material particles and 40 weight percent of resin.
  2. 2. The gradient self-heating material based on phase change-oxidation cooperative regulation and control according to claim 1, wherein the particle size of the reduced iron powder is less than or equal to 50 microns, and the particle size of the catalytic phase change material particles is 100-200 microns.
  3. 3. A method for preparing the gradient self-heating material based on phase change-oxidation cooperative regulation and control as claimed in claim 1 or 2, which comprises the following steps: a) Preparing a catalytic phase change precursor, namely constructing an eutectic system of ferric stearate and lauric acid, performing ultrasonic dispersion on graphene oxide, and performing directional crystallization molding; b) Constructing a grading framework, namely growing a vertical CNT array by using metal ion solution catalytic CVD and performing impregnation modification by using Fe < 3+ > solution; c) Centrifugal gradient molding, namely sequentially pouring a shell layer, a transition layer and a core layer at the rotating speed of 2000-3000rpm, wherein the volume ratio of the shell layer to the transition layer to the core layer is 20% -30%/20% -30%/40% -60%; d) And (3) performing three-stage gradient curing, namely performing program curing at 75-85 ℃ per 1-3h, 110-130 ℃ per 0.5-1.5h, and 180-220 ℃ per 0.4-0.6h to obtain the gradient self-heating material based on the phase change-oxidation synergistic regulation.
  4. 4. The method for preparing a gradient autothermal material based on synergistic phase change-oxidation regulation of claim 3, in which in step a) the preparation of the catalytic phase change precursor comprises: And melting eutectic of ferric stearate and lauric acid in a mass ratio of 3:7-4:6 in a nitrogen environment at 100-120 ℃, adding 0.5-1wt% of graphene oxide as a nucleating agent, and performing 40kHz/300W ultrasonic treatment for 20-30 minutes to realize crystal orientation control.
  5. 5. The method for preparing the gradient self-heating material based on phase change-oxidation cooperative regulation and control as set forth in claim 3, wherein in the step b), the graded skeleton construction is carried out such that the substrate adopts expanded graphite with the porosity of more than or equal to 85%, the CVD process parameters are that the volume ratio of acetylene to argon is 1 (4.5-5.5), the growth is carried out for 10-30 minutes at 600-800 ℃, The dipping concentration of the solution is 0.1-0.5mol/L, and the solution is dried at 70-90 ℃ to form A pre-load layer.
  6. 6. The method for preparing the gradient self-heating material based on phase change-oxidation cooperative regulation and control according to claim 3, wherein in the step b), the metal is Fe, co or a combination thereof, the metal ion solution is a metal ion coordination solution, and the vertical CNT array satisfies that the length-diameter ratio is more than or equal to 500 and the bonding strength with an expanded graphite matrix is more than or equal to 15MPa.
  7. 7. The method for preparing the gradient self-heating material based on the phase change-oxidation cooperative regulation and control as set forth in claim 3, wherein in the step c), the viscosity gradient of the slurry in the centrifugal gradient forming process is controlled to be 800cP of a shell layer, 1200cP of a transition layer and 1500cP of a core layer.
  8. 8. The method for preparing a gradient autothermal material based on synergistic phase change-oxidation control as claimed in claim 3, wherein in step d) the three-stage gradient curing comprises pre-curing at 75-85 ℃ for 1-3 h first, then heating to 110-130 ℃ for 0.5-1.5-h, and finally curing at 180-220 ℃ for 0.4-0.6h at a volume ratio of (70-80): 1-22): 4-6 Under the protection of mixed gas, the temperature is raised to 400-500 ℃ at 3-7 ℃ per min and kept for 2-3 hours, so as to form the interlocking interface of the phase change material crystal-carbonized resin-metal particles.
  9. 9. An industrial self-heating device is characterized in that the industrial self-heating device adopts the gradient self-heating material based on the phase change-oxidation cooperative regulation and control according to claim 1 or 2, wherein the thermal response time of the gradient self-heating material based on the phase change-oxidation cooperative regulation and control is less than or equal to 30 seconds, and the heat release density per unit mass is more than or equal to 450kJ/kg.

Description

Gradient self-heating material based on phase change-oxidation cooperative regulation and control as well as preparation method and application thereof Technical Field The invention relates to a gradient self-heating material based on phase change-oxidation cooperative regulation and control and a preparation method and application thereof, belonging to the technical field of self-heating materials, functional materials and energy conversion. Background With the wide application of self-heating materials in the fields of special packaging, polar equipment and the like, the prior art exposes the core contradiction of insufficient heating control precision and unbalanced thermal inertia management. When the traditional self-heating system is used for coping with sudden low-temperature impact or dynamic thermal environment, technical bottlenecks such as delayed hot start, unstable continuous heat supply (fluctuation amplitude > +/-8 ℃) and disordered thermal gradient distribution exist commonly. Especially in the scenes of self-heating, self-heat preservation and the like of individual field foods, the existing materials are difficult to cooperatively realize the dual requirements of rapid thermal activation and thermal inertia compensation. In recent years, research on self-heating material systems has been mainly conducted around a coupling mechanism of metal oxidation heat release and phase change heat storage. The technical path realizes basic thermal regulation and control by physically mixing the oxidant and the phase change material, and optimizes the thermal management performance by aid of auxiliary components such as a catalyst, a high heat conduction material and the like. However, existing solutions still face significant challenges in terms of thermal response efficiency, dynamic regulatory capability, long-term stability, and the like. The prior improvement scheme such as a multilayer packaging structure and a microencapsulation technology still has the essential limitations that the heat conduction efficiency is reduced by 55% -70% due to a physical isolation layer, while the packaging rate of a phase change material is improved to 85% due to the latter, the heat transfer efficiency is severely restricted by the contact thermal resistance (more than or equal to 10 < -3 m2 >. K/W) of a shell material (silicon dioxide and the like) and an oxidation heat generator. More importantly, the prior art fails to construct a dynamic matching mechanism of heat release intensity and heat storage capacity, and when an environment suffering from minus 30 ℃ is suddenly changed into a 5 ℃ wet and warm environment, the failure probability of the thermal inertia compensation of the system is as high as 78%. Therefore, development of an intelligent self-heating material system with controllable oxidation heat release, self-adaptive phase change heat storage and gradient heat conduction is needed. Disclosure of Invention In view of the above, the main purpose of the invention is to provide a gradient self-heating material based on phase change-oxidation cooperative regulation with high efficiency energy release, accurate temperature control, quick response and stable circulation, and a preparation method and application thereof, and the problem to be solved is to solve the problem that the interface failure problem of an oxidant and a phase change material is solved by chemical bonding reconstruction, and the gradient heat conduction structure is adopted to break the heat accumulation bottleneck, so as to realize the cross-scale cooperation of four dimensions of exothermic reaction, heat storage phase change, heat conduction and dynamic regulation. The aim and the technical problems of the invention are realized by adopting the following technical proposal. The invention provides a gradient self-heating material based on phase change-oxidation cooperative regulation, which comprises a core layer, a transition layer and a shell layer which are sequentially connected, wherein, The core layer is a reduced iron powder-phenolic resin composite layer; the transition layer is a gradient transition structure of iron powder, CNT-graphite composite material and resin; the shell layer is a catalytic phase change material particle-resin composite layer; The volume ratio of the shell layer, the transition layer and the core layer is 20% -30%, 20% -30% and 40% -60% respectively. The aim and the technical problems of the invention can be further realized by adopting the following technical measures. Preferably, the gradient self-heating material based on the phase change-oxidation synergistic regulation comprises 70wt% of reduced iron powder and 30wt% of phenolic resin in percentage by mass, the transition layer comprises 50wt% of iron powder, 30wt% of CNT-graphite composite material and 20wt% of resin in percentage by mass, and the shell layer comprises 60wt% of catalytic phase change material particles and 40wt% of resin in perc