US-20260125530-A1 - COMPOSITE AEROGEL, RECYCLABLE HEAT-STORAGE PHASE-CHANGE COMPOSITE MATERIAL WITH PHOTOTHERMAL CONVERSION FUNCTION, AND PREPARATION METHODS THEREFOR AND USE

US20260125530A1US 20260125530 A1US20260125530 A1US 20260125530A1US-20260125530-A1

Abstract

A composite aerogel, a recyclable heat-storage phase-change composite material with a photothermal conversion function are provided. The composite aerogel has a polymer and graphene. The polymer contains a maleic-anhydride-group-containing structural unit and a maleimide-group-containing structural unit. The composite aerogel can be used as a carrier to load a phase-change material, so as to obtain a recyclable heat-storage phase-change composite material, which has a photothermal conversion function and can also be recycled. The recyclable heat-storage phase-change composite material contains a composite aerogel and a phase-change material loaded in the composite aerogel.

Inventors

ZHAOYAN GUO
ZHENJIE LIU
Yi Gao
Jinmei Lai
Xiang Wang
Xiaohong Zhang
Binghai Li
WENLU LIU
Yue RU
Yuan Yao
Jinliang Qiao
Guicun Qi
Dehui KONG
Chenxi HU

Assignees

CHINA PETROLEUM & CHEMICAL CORPORATION
Sinopec (Beijing) Research Institute of Chemical Industry Co., Ltd.

Dates

Publication Date: 20260507
Application Date: 20230908
Priority Date: 20220909

Claims (17)

1 . A composite aerogel, comprising a polymer and a graphene, wherein the polymer contains a maleic anhydride group-containing structural unit and a maleimide group-containing structural unit, wherein the maleic anhydride group refers to the maleimide group refers to
2 . The composite aerogel as claimed in claim 1 , characterized in that: an average value of ID/IG in a Raman spectrum on the surface of the composite aerogel is 1.2 or less, preferably 0.9 or less, and more preferably 0.85 or less; and/or, a mass ratio of the graphene to the polymer is (1:20)-(10:1), preferably (1:10)-(6:1), more preferably (1:5)-(1:1).
3 . The composite aerogel as claimed in claim 1 , characterized in that: the polymer in the composite aerogel is capable of being dissolved in aqueous ammonia at 0-150° C. to form a polymer aqueous solution; and/or, the graphene is obtained by reducing a graphene oxide, preferably, by first pre-reducing the graphene oxide using a reducing agent and then reducing under microwave; more preferably, the reducing agent is selected from at least one of ascorbic acid, gallic acid, sodium borohydride, amino acid.
4 . The composite aerogel as claimed in claim 1 , characterized in that: a mole proportion of the maleimide group-containing structural unit in the polymer is 5%-70%, preferably 10%-60%, more preferably 20%-50%, based on 100% of the total mole amount of the maleic anhydride group-containing structural unit and the maleimide group-containing structural unit.
5 . The composite aerogel as claimed in claim 1 , characterized in that: the polymer is derived from a polymer raw material containing one or more of maleic anhydride-, maleimide-, maleic acid and its ammonium salt-, maleamic acid and its ammonium salt-group-containing structural units; preferably, the polymer raw material is a copolymer of a polymerizable monomer including one or more of maleic anhydride, maleimide, maleic acid and its ammonium salt, maleamic acid and its ammonium salt with an olefin monomer; more preferably, the olefin monomer is at least one of α-methyl styrene, styrene, isobutylene.
6 . The composite aerogel as claimed in claim 1 , characterized in that: the composite aerogel is prepared by reacting a polymer raw material containing one or more of maleic anhydride-, maleimide-, maleic acid and its ammonium salt-, maleamic acid and its ammonium salt-group-containing structural units with aqueous ammonia under a closed condition, then mixing with a graphene oxide and a reducing agent, pre-freezing, freeze-drying, dehydrating and deaminating, and reducing.
7 . A preparation method of the composite aerogel as claimed in claim 1 , which comprises reacting a polymer raw material containing one or more of maleic anhydride-, maleimide-, maleic acid and its ammonium salt-, maleamic acid and its ammonium salt-group-containing structural units with aqueous ammonia under a closed condition, then mixing with a graphene oxide and a reducing agent, pre-freezing, freeze-drying, dehydrating and deaminating, and reducing to obtain the composite aerogel.
8 . The preparation method as claimed in claim 7 , characterized in that it comprises following steps: (1) reacting the polymer raw material with aqueous ammonia under a closed condition to obtain a polymer aqueous solution; (2) mixing the polymer aqueous solution obtained in step (1) with a graphene oxide and a reducing agent to obtain a mixed liquor, then pre-freezing and freeze-drying the mixed liquor, to obtain a composite polymer; (3) subjecting the composite polymer obtained in step (2) to heat treatment, and then to microwave irradiation, to obtain the composite aerogel.
9 . The preparation method as claimed in claim 8 , characterized in that: in step (1): based on 100% of the total mass of the reaction system, the mass fraction of the polymer raw material is 0.1%-30%, preferably 0.5%-10%, more preferably 1%-5%, and the mass fraction of ammonia by mass of ammonia in aqueous ammonia is 0.001%-30%, preferably 0.01%-10%, more preferably 0.1%-1%, the balance being water; and/or, the reaction conditions include that: the reaction temperature is 0-200° C., preferably 50-150° C., more preferably 80-100° C., and/or, the reaction time is 0.01-100 h, preferably 0.5-10 h, more preferably 1-5 h.
10 . The preparation method as claimed in claim 8 , characterized in that: in step (2): the graphene oxide is derived from a dispersion containing the graphene oxide, and the concentration of the graphene oxide in the dispersion is 1-100 mg/mL, preferably 3-30 mg/mL, more preferably 5-20 mg/mL; and/or, the reducing agent is selected from at least one of ascorbic acid, gallic acid, sodium borohydride, amino acid; and/or, a mass ratio of the reducing agent to the graphene oxide is 1:(0.1-20), preferably 1:(1-3); and/or, cold source temperatures in various directions of the mixed liquor during pre-freezing are the same or different, preferably, the cold source temperatures in various directions of the mixed liquor during pre-freezing are different; more preferably, the cold source temperatures in a single direction of the mixed liquor during pre-freezing are different; and/or, the freeze-drying conditions include that: the temperature is −10° C. or lower; and/or, the vacuum degree is 1000 Pa or lower.
11 . The preparation method as claimed in claim 8 , characterized in that: in step (3): the heat treatment conditions include that: a temperature is 100-300° C., preferably 120-220° C., more preferably 160-200° C.; a heat treatment time is 0.1-10 h, preferably 0.5-3 h, more preferably 1-2 h; and/or, the microwave irradiation power is 500-2000 W; the microwave irradiation time is 1-10 s, preferably 2-7 s, more preferably 3-5 s.
12 . The preparation method as claimed in claim 7 , characterized in that: the polymer raw material is capable of being reacted with aqueous ammonia to obtain a water-soluble polymer; and/or, the polymer raw material is a copolymer of a polymerizable monomer including one or more of maleic anhydride, maleimide, maleic acid and its ammonium salt, maleamic acid and its ammonium salt with an olefin monomer; more preferably, the olefin monomer comprises at least one of α-methyl styrene, styrene, isobutylene; preferably, the polymer raw material is at least one of styrene-maleic anhydride copolymer, maleic anhydride-isobutylene copolymer.
13 . A recyclable heat-storage phase-change composite material, comprising a composite aerogel and a phase-change material loaded in the composite aerogel; the composite aerogel is the composite aerogel as claimed in claim 1 .
14 . The recyclable heat-storage phase-change composite material as claimed in claim 13 , characterized in that: a mass ratio of the composite aerogel to the phase-change material is 1:(0.05-50); and/or, the phase-change material is an organic phase-change material, preferably a water-soluble phase-change materials and/or a non-water-soluble phase-change material, more preferably at least one of polyethylene glycol, lauric acid, stearyl alcohol, paraffin; and/or, a leakage of the phase-change material in the recyclable heat-storage phase-change composite material is less than 10 wt %, preferably less than 5 wt %, more preferably less than 2 wt % under the temperature conditions where the phase-change material is in a liquid state.
15 . A preparation method of the recyclable heat-storage phase-change composite material as claimed in claim 13 , comprising loading the phase-change material in the composite aerogel; preferably, the preparation method of the recyclable heat-storage phase-change composite material comprises: reacting a polymer raw material containing one or more of maleic anhydride-, maleimide-, maleic acid and its ammonium salt-, maleamic acid and its ammonium salt-group-containing structural units with aqueous ammonia under a closed condition, then mixing with a graphene oxide and a reducing agent, pre-freezing, freeze-drying, dehydrating and deaminating, and reducing to obtain the composite aerogel; and loading the phase-change material in the composite aerogel.
16 . A building energy conservation product, an air conditioning system, a waste heat utilization product or a solar energy storage product, comprising the recyclable heat-storage phase-change composite material as claimed in claim 13 .
17 . A preparation method of a recyclable heat-storage phase-change composite material, comprising loading the phase-change material in the composite aerogel; preferably, the preparation method of the recyclable heat-storage phase-change composite material comprises: obtaining a composite aerogel using the preparation method as claimed in claim 7 ; and loading the phase-change material in the composite aerogel, wherein the recyclable heat-storage phase-change composite material comprises a composite aerogel and a phase-change material loaded in the composite aerogel; the composite aerogel comprises a polymer and a graphene, wherein the polymer contains a maleic anhydride group-containing structural unit and a maleimide group-containing structural unit, wherein the maleic anhydride group refers to the maleimide group refers to

Description

TECHNICAL FIELD The present invention relates to a field of phase-change materials, and particularly relates to a composite aerogel, a recyclable heat-storage phase-change composite material with photothermal conversion function and a preparation method and an application thereof. BACKGROUND ART With the rapid increase in energy consumption and greenhouse gas emissions, the use of renewable energy sources such as solar energy and waste heat in an environmentally friendly manner is of great interest. As solar energy varies over time and space, the mismatch in energy supply and demand makes efficient storage of these energy sources an important issue. Latent heat-storage systems based on organic phase-change materials have large storage capacities, near constant phase-change temperatures and reversible storage and release of thermal energy. By means of phase-change materials, the huge gap between rapidly growing energy demand and limited fossil resource reserves can be closed. Therefore, phase-change materials are now widely used in air conditioning systems, building materials, solar energy storage, waste heat recycle and various electronic products. Organic phase-change materials, which have the advantages of stable performance, low supercooling degree, no phase separation and the like, are the most widely researched phase-change materials, mainly including paraffins, fatty acids, fatty alcohols and other organic compounds. However, organic phase-change materials are subject to the risk of leakage when used directly as energy storage materials, and it is essential that the phase-change materials are encapsulated to prevent leakage problems. In addition, it is also necessary to consider reprocess ability and recyclability of organic phase-change materials, so as to avoid environmental pollution and resource waste caused by them. Therefore, if a material with photothermal conversion performance is provided, combined with a phase-change material to obtain a recyclable cold-storage phase-change composite material with good photothermal conversion performance, low leakage of phase-change material and recyclability, it will achieve a major breakthrough in this field. Contents of the Invention In view of the technical problems existing in the prior art, an object of the present invention is to provide a composite aerogel, a recyclable heat-storage phase-change composite material with photothermal conversion function, a preparation method and an application thereof. The composite aerogel can be used as a carrier to load a phase-change material so as to obtain a recyclable heat-storage phase-change composite material with photothermal conversion function. At the same time, it can also be recovered in a simple and environmentally friendly manner. The recyclable heat-storage phase-change composite material with photothermal conversion function not only has photothermal conversion function, but also has low leakage and can be recycled at the same time, truly realizing the environmentally friendly utilization and effective storage of solar energy. The inventors of the present invention found that maleimide-based copolymers (polymers containing a maleic anhydride group and a maleimide group) can be prepared by low-cost copolymers and can be recovered by aqueous ammonia. In view of the prior art, the applicant of the present invention found in the research that a composite aerogel of a maleimide-based copolymer and a reduced graphene oxide can be prepared by mixing such copolymer with a graphene oxide and a reducing agent. Preferably, by reducing the aerogel rapidly and efficiently under microwave, a water-resistant maleimide-based copolymer-graphene composite aerogel can be obtained. The composite aerogel can be used, as a carrier of a phase-change material, to prevent leakage of the phase-change material, and can be recycled under the action of aqueous ammonia to obtain the graphene, the phase-change material and the polymer respectively. In summary, the present invention is intended to realize the leakage prevention and recycle of a phase-change material with photothermal conversion function, and to provide a composite aerogel suitable for use as a carrier of a phase-change material, and a recyclable heat-storage phase-change composite material with photothermal conversion function and a preparation method and an application thereof. A first aspect of the present invention is to provide a composite aerogel, comprising a polymer and a graphene, wherein the polymer contains a maleic anhydride group-containing structural unit and a maleimide group-containing structural unit. The composite aerogel can be used as a carrier to obtain, together with a phase-change material, a recyclable heat-storage phase-change composite material with photothermal conversion function, and at the same time, it can also be recycled in a simple and environmentally friendly manner. In a preferred embodiment of the present invention, an average va