4results about How to "High phase change enthalpy" patented technology

The invention discloses a low-thermal-conductivity phase change aerogel material as well as a preparation method and application thereof. The phase change enthalpy value of the material is 50J / g to 110J / g; the phase change temperature is 0-60 DEG C; and the heat conductivity coefficient is 0.08 W / (m.K)-0.1 W / (m.K). The novel low-thermal-conductivity phase-change material is generated by curing polydimethylsiloxane (PDMS) and the phase-change microcapsules. The phase change aerogel material is simple in synthesis process, relatively high in phase change enthalpy value and good in phase change cycle stability. The method has important application prospects in the two aspects of heat energy collection and heat insulation temperature control.

This invention relates to a method for preparing a core-shell structured Al-Zn@Al2O3 composite phase change thermal storage material, belonging to the technical field of medium- and high-temperature phase change thermal storage materials. This invention involves adding an aluminum powder suspension to an HCl solution and stirring at 45–65°C for 5–10 minutes. Gelatin is then added, and the mixture is reacted at 45–65°C with stirring for 10–20 minutes to obtain solution A. NH4F solution is slowly added to solution A at 40–60°C with stirring, and the reaction continues for 30–60 minutes. A mixture of zinc sulfate solution and ethylenediaminetetraacetic acid is then added, and the mixture is reacted for 3–5 hours. After standing, the solid and liquid are separated. The solid is washed 3–5 times alternately with anhydrous ethanol-water-anhydrous ethanol and dried to obtain solid B. Under a protective atmosphere, solid B is uniformly heated to 600–660°C and calcined at high temperature for 2–4 hours to obtain aluminum-zinc alloy powder. Under an air atmosphere, the aluminum-zinc alloy powder is uniformly heated to ~800°C and calcined at high temperature for 1–4 hours to obtain a core-shell structured Al-Zn@Al2O3 high-temperature phase change heat storage material.

The application relates to a preparation method of a graphene composite phase change thermal interface material. An oxidized graphene dispersion liquid is provided, a centrifugal roller coating and a layer-by-layer drying process are adopted to form a multilayer oxidized graphene unit layer on a substrate, and an oxidized graphene film is obtained; the oxidized graphene film is placed in a limited space, gradient heat reduction treatment is carried out, the film is controllably expanded in the out-of-plane direction, and a reduced graphene oxide film with a micro-nano cavity structure is formed; the reduced graphene oxide film is subjected to graphitization treatment, and a graphene micro-nano cavity film is obtained; through a vacuum impregnation method, a molten phase change material is filled into the micro-nano cavity structure of the graphene micro-nano cavity film. The thermal interface material has high phase change enthalpy (196.2 J / g), excellent thermal performance (in-plane thermal conductivity 65.5 W.m ‑1 ·K ‑1 , out-of-plane 21.9 W.m ‑1 ·K ‑1 , and low interface thermal resistance (0.575 K.cm 2 ·W ‑1 ).

This invention discloses a phase change material, its preparation method, and its applications, relating to the field of phase change energy storage materials technology. The preparation method of the phase change material of this invention includes the following steps: S1. Adding a crosslinking agent, an initiator, h-MWCNTs, and water to polyethylene glycol to obtain a mixed liquid; S2. Performing a crosslinking reaction on the mixed liquid and drying it to obtain the phase change material. This invention incorporates h-MWCNTs (hydroxylated carbon nanotubes) while simultaneously causing crosslinking of the polyethylene glycol molecular chains. h-MWCNTs can induce uniform orientation of the polyethylene glycol molecular chains, thus increasing the phase change enthalpy and thermal conductivity of the phase change material.