Porous photothermal conversion material and preparation method thereof

Abstract

The invention relates to the field of photothermal conversion, and particularly discloses a porous photothermal conversion material and a preparation method thereof. The porous photothermal conversion material comprises a conjugated polymer grafted with at least one polymer shown in a formula I, a formula II and a formula III, the grafting amount of the # imgabs0 # polymer is greater than or equal to 0.01 wt% on the basis of the total weight of the conjugated polymer. The porous photo-thermal conversion material contains the conjugated polymer with a photo-thermal conversion effect, and the conjugated polymer is grafted with a specific type and specific content of polymer, so that the hydrophilicity of the photo-thermal conversion porous material can be improved, and the photo-thermal water evaporation rate of the photo-thermal conversion porous material is further remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of photothermal conversion, and in particular to a porous photothermal conversion material and a preparation method thereof. Background Art

[0002] Photothermal conversion materials are a type of material that can convert light energy into thermal energy. They have high energy conversion efficiency and simple processing and preparation processes. They have important application prospects in water treatment, photothermal therapy and other fields, and have received increasing attention in recent years. Especially in the field of water treatment, photothermal conversion materials can be used for photothermal seawater desalination. The specific process is to place the photothermal conversion material on the surface of seawater. Under the irradiation of sunlight, the temperature of the photothermal conversion material rises sharply, heating the seawater in contact with it, accelerating the evaporation of seawater, and condensing the evaporated water vapor to obtain fresh water. The surface properties of the photothermal conversion material will affect its efficiency in evaporating water, because the surface properties affect the mass transfer process of water. In addition, the structural characteristics of the photothermal seawater desalination material will also affect the efficiency of evaporating water, mainly affecting the mass transfer process of water vapor.

[0003] Photothermal conversion functional materials include metal and metal oxide nanomaterials, carbon nanomaterials, black phosphorus, organic conjugated polymers, etc. Among them, polymer photothermal conversion materials have the advantages of diverse synthesis methods, convenient preparation and processing, and a wide range of raw material sources. They are the most likely photothermal conversion functional materials to be applied on a large scale. Therefore, in order to apply polymer photothermal conversion materials to the field of photothermal seawater desalination, it is necessary to develop polymer photothermal conversion materials with suitable structures and surface properties to obtain a more efficient photothermal water evaporation rate. Summary of the invention

[0004] The purpose of the present invention is to overcome the problem that the photothermal water evaporation rate of photothermal conversion materials in the prior art cannot meet actual needs, and to provide a porous photothermal conversion material and a preparation method thereof. The porous photothermal conversion material contains a conjugated polymer with a photothermal conversion effect, and the conjugated polymer is grafted with a polymer of a specific type and a specific content, which can improve the hydrophilicity of the photothermal conversion porous material, thereby significantly improving the photothermal water evaporation rate of the photothermal conversion porous material.

[0005] In order to achieve the above-mentioned object, the first aspect of the present invention provides a porous photothermal conversion material, wherein the porous photothermal conversion material comprises a conjugated polymer grafted with a polymer represented by at least one of Formula I, Formula II and Formula III;

[0006]

[0007] Among them, R 1 is H or methyl; R 2 is H, methyl or ethyl; R 3 is H or methyl; R4 or R 5 Each independently represents H or methyl; R 6 is H or methyl; R 7 is H, Na or K; n, m and l are each independently an integer of 10-1000; based on the total weight of the conjugated polymer, the grafting amount of the polymer is greater than or equal to 0.01wt%.

[0008] A second aspect of the present invention provides a method for preparing a porous photothermal conversion material, wherein the method comprises:

[0009] (1) mixing a polyconjugated diene and a foaming agent, and foaming the mixture to obtain a porous material; wherein the amount of the foaming agent is 2-20 wt % based on the total weight of the polyconjugated diene and the foaming agent;

[0010] (2) contacting the porous material with an electron acceptor so that the polyconjugated diene in the porous material is converted into a conjugated polymer through reaction;

[0011] (3) contacting the product obtained in step (2) with a solution containing at least one polymer monomer represented by Formula 1, Formula 2 and Formula 3 to obtain the porous photothermal conversion material;

[0012]

[0013] Among them, R 1 ' is H or methyl; R 2 ' is H, methyl or ethyl; R 3 ' is H or methyl; R 4 ' or R 5 ' are each independently H or methyl; R 6 ' is H or methyl; R 7 ' is H, Na or K.

[0014] A third aspect of the present invention provides a porous photothermal conversion material prepared by the above preparation method.

[0015] Through the above technical solution, the porous photothermal conversion material and the preparation method thereof provided by the present invention achieve the following beneficial effects:

[0016] The porous photothermal conversion material provided by the present invention contains a conjugated polymer with a photothermal conversion effect, and the conjugated polymer is grafted with a polymer of a specific type and content, which can improve the hydrophilicity of the photothermal conversion porous material and thus significantly improve the photothermal water evaporation rate of the photothermal conversion porous material.

[0017] Furthermore, the porous photothermal conversion material has an open-pore structure with a porosity greater than or equal to 30%, so that the heated water vapor can be easily evaporated through the porous material. At the same time, after in-situ hydrophilic modification, water wets the entire porous photothermal conversion material through capillary action, thereby improving the water mass transfer process and significantly improving the photothermal water evaporation rate of the porous photothermal conversion material.

[0018] In the preparation method of the porous photothermal conversion material provided by the present invention, a polymer monomer with a hydrophilic structure is in situ introduced into the porous material containing a conjugated polymer, so that the polymer monomer undergoes an in situ polymerization reaction on the surface of the porous material. Compared with the preparation method of introducing a hydrophilic substance on the surface of the porous material by immersion or the like in the prior art, the hydrophilic group is firmly bonded to the surface of the porous photothermal conversion material, is not easy to fall off, and can be used for a long time. DETAILED DESCRIPTION

[0019] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0020] A first aspect of the present invention provides a porous photothermal conversion material, wherein the porous photothermal conversion material comprises a conjugated polymer grafted with a polymer represented by at least one of Formula I, Formula II and Formula III;

[0021]

[0022] Among them, R 1 is H or methyl; R 2 is H, methyl or ethyl; R 3 is H or methyl; R 4 or R 5 Each independently represents H or methyl; R 6 is H or methyl; R 7 is H, Na or K; n, m and l are each independently an integer of 10-1000; based on the total weight of the conjugated polymer, the grafting amount of the polymer is greater than or equal to 0.01wt%.

[0023] In the present invention, the porous photothermal conversion material contains a conjugated polymer with a photothermal conversion effect, and the conjugated polymer is grafted with a specific polymer, which can improve the hydrophilicity of the photothermal conversion porous material and thus significantly improve the photothermal water evaporation rate of the photothermal conversion porous material.

[0024] Specifically, in the present invention, grafting a polymer represented by at least one of Formula I, Formula II and Formula III onto a conjugated polymer can not only improve the hydrophilicity of the photothermal conversion porous material, but also improve the photothermal water evaporation rate of the photothermal conversion porous material.

[0025] In the present invention, when the grafting amount of the polymer is controlled to meet the above range, the surface of the porous material is changed from hydrophobic to hydrophilic, which has a capillary effect and can improve the mass transfer process of water during photothermal evaporation, thereby significantly improving the total photothermal water evaporation rate.

[0026] In the present invention, n, m and l refer to the degree of polymerization of the polymer.

[0027] In one embodiment of the present invention, in Formula I, R 1 is H or methyl, R 2 is H or methyl, preferably, in Formula I, R 1 is H or methyl, R 2 For H.

[0028] In one embodiment of the present invention, in Formula II, R 3 is H or methyl, R 4 and R 5 Each independently is H or methyl, preferably, R 3 is H or methyl, R 4 and R 5 Both are H.

[0029] In one embodiment of the present invention, in Formula III, R 6 is methyl, R 7 For that.

[0030] In a specific embodiment of the present invention, the polymer is selected from at least one of polyacrylic acid, polymethacrylic acid, polymethyl methacrylate, polyacrylamide, poly(N,N-dimethylacrylamide), polymethacrylamide and polysodium p-styrene sulfonate.

[0031] In a preferred embodiment of the present invention, the polymer is selected from at least one of polyacrylic acid, polymethacrylic acid, polyacrylamide, polymethacrylamide and sodium poly(p-styrene sulfonate).

[0032] In a particularly preferred embodiment of the present invention, the polymer is at least one selected from polyacrylic acid, polymethacrylic acid and polysodium p-styrene sulfonate.

[0033] Furthermore, based on the total weight of the conjugated polymer, the grafting amount of the polymer is 0.01 wt%-0.1 wt%, preferably, the grafting amount of the polymer is 0.05 wt%-0.1 wt%.

[0034] In a particularly preferred embodiment of the present invention, the polymer is selected from at least one of polyacrylic acid, polymethacrylic acid and polysodium p-styrene sulfonate, and when the grafting amount of the polymer is 0.05wt%-0.1wt% based on the total weight of the conjugated polymer, the porous photothermal conversion material has a particularly excellent photothermal water evaporation rate.

[0035] According to the present invention, the porous photothermal conversion material is an open-pore structure, and the porosity of the porous photothermal conversion material is greater than or equal to 30%.

[0036] In the present invention, the porous photothermal conversion material has an open-pore structure, and the porosity is greater than or equal to 30%, so that the heated water vapor can be easily evaporated through the porous material. At the same time, after in-situ hydrophilic modification, water wets the entire porous photothermal conversion material through capillary action, thereby improving the water mass transfer process, thereby significantly improving the photothermal water evaporation rate of the porous photothermal conversion material.

[0037] Furthermore, the porosity of the porous photothermal conversion material is 30%-80%.

[0038] According to the present invention, the conjugated polymer is prepared by reacting polyconjugated diene with an electron acceptor.

[0039] In the present invention, the polyconjugated diene refers to a polymer in which each structural unit comprises a double bond and is formed by addition polymerization of conjugated diene monomers. The structure of the polyconjugated diene can be represented by Formula IV:

[0040]

[0041] In Formula IV, R 8 and R 9 Typically each independently is hydrogen, halogen, C 1 -C 20 Preferably, R 8 and R 9 Each is independently selected from H, Cl, Br, I, methyl, ethyl, n-propyl or phenyl.

[0042] Specifically, the polyconjugated diene is further preferably at least one of trans-1,4-polyisoprene, cis-1,4-polyisoprene, trans-1,4-polybutadiene, cis-1,4-polybutadiene and 2,3-dimethyl-1,4-polybutadiene, and most preferably trans-1,4-polyisoprene.

[0043] In the present invention, the conjugated polymer is prepared by a doping reaction between the polyconjugated diene and an electron acceptor (i.e., a dopant). During the doping reaction, some single bonds on the main chain of the polyconjugated diene are gradually converted into double bonds, and segments containing conjugated double bonds are formed on the main chain, thereby obtaining the conjugated polymer, which has a structure similar to that of polyacetylene.

[0044] According to the present invention, the electron acceptor is selected from Cl 2 Br 2 ,I 2 、ICl、ICl 3 , IBr, IF 5 PF 5 , AsF 5 , SbF 5 , BF 5 , BCl 3 , BBr 3 、SO 3 ,NbF 5 、TaF 5 、MoF 5 、WF 5 , RuF 5 、PtCl 4 、TiCl 4 、AgClO 4 , AgBF 4 , HPtCl 6 HIrCl 6 ,TCNE,TCNQ,DDO,HF,HCl,HNO 3 , H 2 SO 4 HClO 4 、FSO 3 H, O 2 、XeOF 4 、XeF 4 、NOSbCl 6 and NOPF 6 At least one of, preferably Cl 2 Br 2 ,I 2 and AsF 5 At least one of, more preferably 1 2 .

[0045] In the present invention, there is no particular limitation on the degree of reaction of the polyconjugated diene, as long as the chemical bonds of the polyconjugated diene structural units are at least partially converted into conjugated double bonds. Usually, the electron acceptor is used in an excess dose, and the degree of reaction is controlled by controlling the reaction time, and the time of the doping treatment is generally not more than 72 hours.

[0046] In a specific embodiment of the present invention, the conjugated polymer is obtained by placing the polyconjugated diene in the steam containing the electron acceptor (e.g., the steam of the electron acceptor), and the higher the temperature of the steam, the shorter the reaction time. Preferably, the conjugated polymer is obtained by placing the polyconjugated diene in the steam of the electron acceptor (e.g., iodine steam) at 25-60°C for reaction (i.e., doping treatment) for 8-72 hours, in which case, the complete reaction of the polyconjugated diene can be achieved. More preferably, the conjugated polymer is obtained by placing the polyconjugated diene in the iodine steam at 30-60°C for reaction for 8-48 hours, preferably 24-48 hours.

[0047] In the present invention, the reaction between the polyconjugated diene and the electron acceptor can be carried out in the following manner: a porous material containing the polyconjugated diene is contacted with the electron acceptor to achieve doping treatment of the polyconjugated diene with the electron acceptor. The porous material is obtained by foaming the polyconjugated diene.

[0048] A second aspect of the present invention provides a method for preparing a porous photothermal conversion material, wherein the method comprises:

[0049] (1) mixing a polyconjugated diene and a foaming agent, and foaming the mixture to obtain a porous material; wherein the amount of the foaming agent is 2-20 wt % based on the total weight of the polyconjugated diene and the foaming agent;

[0050] (2) contacting the porous material with an electron acceptor so that the polyconjugated diene in the porous material is converted into a conjugated polymer through reaction;

[0051] (3) contacting the product obtained in step (2) with a solution containing at least one polymer monomer represented by Formula 1, Formula 2 and Formula 3 to obtain the porous photothermal conversion material;

[0052]

[0053] Among them, R 1 ' is H or methyl; R 2 ' is H, methyl or ethyl; R 3 ' is H or methyl; R 4 ' or R 5 ' are each independently H or methyl; R 6 ' is H or methyl; R 7 ' is H, Na or K.

[0054] In the method of the porous photothermal conversion material of the present invention, a polymer monomer with a hydrophilic structure is in situ introduced into a porous material comprising a conjugated polymer. Due to the residual free radicals in the conjugated polymer, the polymer monomer can undergo an in situ polymerization reaction on the surface of the porous material and be grafted onto the double bonds of the conjugated polymer. Compared with the preparation method of introducing a hydrophilic substance on the surface of a porous material by immersion or the like in the prior art, the hydrophilic group is firmly bonded to the surface of the porous photothermal conversion material, is not easy to fall off, and can be used for a long time.

[0055] Furthermore, when the amount of the foaming agent is controlled to meet the above range, it can ensure that the prepared porous material has an open-pore structure, which not only allows the heated water vapor to evaporate easily through the connected channels, but also allows the residual free radicals in the conjugated polymer to be exposed, thereby increasing the grafting amount of the hydrophilic polymer, so that the porous material thus prepared has a high polymer grafting amount, thereby improving the hydrophilicity of the porous photothermal conversion material and the rate of photothermal water evaporation.

[0056] In one specific embodiment of the present invention, in Formula 1, R 1 ' is H or methyl, R 2 ' is H or methyl, preferably, R 1 ' is H or methyl, R 2 'For H.

[0057] In one specific embodiment of the present invention, in Formula 2, R 3 ' is H or methyl, R 4 ' and R 5 ' are each independently H or methyl, preferably, R 3 ' is H or methyl, R 4 ' and R 5 'All are H.

[0058] In one specific embodiment of the present invention, in Formula 3, R 6 ' is methyl, R 7 'For that.

[0059] In a specific embodiment of the present invention, the polymer monomer is selected from at least one of acrylic acid, methacrylic acid, methyl methacrylate, acrylamide, N,N-dimethylacrylamide, methacrylamide and sodium p-styrene sulfonate.

[0060] In a preferred embodiment of the present invention, the polymer monomer is selected from at least one of acrylic acid, methacrylic acid, acrylamide, methacrylamide and sodium p-styrene sulfonate.

[0061] In a particularly preferred embodiment of the present invention, the polymer monomer is selected from at least one of acrylic acid, methacrylic acid and sodium p-styrene sulfonate.

[0062] Furthermore, based on the total weight of the polyconjugated diene and the foaming agent, the amount of the foaming agent is 10-20 wt%.

[0063] According to the present invention, the blowing agent is selected from physical blowing agents and / or chemical blowing agents.

[0064] In the present invention, there is no particular limitation on the type of physical foaming agent, and conventional physical foaming agents in the art, such as nitrogen and / or carbon dioxide, may be used.

[0065] In the present invention, there is no particular limitation on the type of chemical foaming agent, and conventional chemical foaming agents in the art may be used, such as AC foaming agent and / or OBSH foaming agent.

[0066] According to the present invention, the foaming conditions include: a foaming temperature of 130-180° C., a foaming pressure of 1-10 MPa, and a foaming time of 0.5-3 h.

[0067] In the present invention, the structure of the polyconjugated diene can be represented by Formula IV:

[0068]

[0069] In Formula IV, R 8 and R 9 Typically each independently is hydrogen, halogen, C 1 -C 20 Preferably, R 8 and R 9 Each is independently selected from H, Cl, Br, I, methyl, ethyl, n-propyl or phenyl.

[0070] Specifically, the polyconjugated diene is further preferably at least one of trans-1,4-polyisoprene, cis-1,4-polyisoprene, trans-1,4-polybutadiene, cis-1,4-polybutadiene and 2,3-dimethyl-1,4-polybutadiene, and most preferably trans-1,4-polyisoprene.

[0071] According to the present invention, the electron acceptor is selected from Cl 2 Br 2 ,I 2 、ICl、ICl 3 , IBr, IF 5 PF 5 , AsF 5 , SbF 5 , BF 5 , BCl 3 , BBr 3 、SO3 ,NbF 5 、TaF 5 、MoF 5 、WF 5 , RuF 5 , PtCl 4 、TiCl 4 、AgClO 4 , AgBF 4 , HPtCl 6 HIrCl 6 ,TCNE,TCNQ,DDO,HF,HCl,HNO 3 , H 2 SO 4 HClO 4 、FSO 3 H, O 2 、XeOF 4 、XeF 4 、NOSbCl 6 and NOPF 6 At least one of, preferably Cl 2 Br 2 ,I 2 and AsF 5 At least one of, more preferably 1 2 .

[0072] In the present invention, in step (2), the polyconjugated diene in the porous material can be partially or completely converted into a conjugated polymer after contacting with the electron acceptor, and the reaction time (ie, contact time) is usually not more than 72 hours.

[0073] In a specific embodiment of the present invention, the contacting is performed by placing the porous material in the steam containing the electron acceptor. Preferably, step (2) comprises: placing the porous material in the steam of the electron acceptor at 25-60° C. for reaction for 8-72 hours. More preferably, step (2) comprises: placing the porous material in the iodine steam at 30-60° C. for reaction for 8-48 hours, preferably 24-48 hours.

[0074] According to the present invention, in step (3), the temperature of the contact reaction can be adjusted according to the type of polymer monomer, for example, the temperature of the contact reaction is 25-50°C; the time of the contact reaction is greater than or equal to 2 hours, preferably greater than or equal to 8 hours, and more preferably greater than or equal to 12 hours.

[0075] In the present invention, preferably, the contact reaction is carried out in the presence of a protective atmosphere. The type of the protective atmosphere is not particularly limited, and may be nitrogen, for example.

[0076] In the present invention, in step (3), an excess amount of polymer monomer solution is added to ensure that the grafting amount of the polymer in the prepared porous photothermal conversion material is greater than or equal to 0.01wt%, preferably 0.01wt%-0.1wt%, based on the total weight of the conjugated polymer.

[0077] In the present invention, the preparation method further comprises washing and drying the product after the contact reaction in step (3).

[0078] In the present invention, unless otherwise specified, room temperature is 25°C.

[0079] A third aspect of the present invention provides a porous photothermal conversion material prepared by the above preparation method.

[0080] The present invention will be described in detail below by way of examples. In the following examples,

[0081] Test method for the evaporation rate of porous materials by photothermal water: Take a sample with a diameter of 3 cm and a thickness of 2 mm, place it on the surface of a beaker of pure water, immerse the sample in water to a thickness of 1 mm, and then place the sample under a light intensity of 100 mW / cm 2 The mass of the beaker and the sample is tested under a white light source, and the mass of the evaporated water is obtained by decreasing with the illumination time. The mass of the evaporated water is converted into the evaporation rate of the sample per unit area under illumination, and the unit is kg / (m 2 h), the experimental environment temperature was 25°C and the humidity was 50%.

[0082] The porosity of porous photothermal conversion materials is measured by density method.

[0083] The grafting amount of the polymer in the porous photothermal conversion material is measured by weighing method.

[0084] The raw materials used in the examples and comparative examples are all commercially available.

[0085] Example 1

[0086] (1) 900 g of trans-1,4-polyisoprene was mixed with 100 g of blowing agent OBSH, and pelletized using a single-screw extruder. 15 g of the pellets were placed in a mold and pressed into a sample with a diameter of 10 cm and a thickness of 2 mm. The sample was placed in an autoclave for foaming at a temperature of 160° C. and a pressure of 2 MPa for 1 h to obtain a porous material.

[0087] (2) The porous material is doped in saturated iodine vapor at room temperature for 24 hours.

[0088] (3) After taking out, immediately add 20 wt% acrylic acid (in Formula 1, R 1 ' is H; R 2' is H) in an aqueous solution (volume of the solution is 2L), stirred and nitrogen is introduced for protection, reacted at 25°C for 8 hours, taken out, washed with ethanol and dried to obtain a porous photothermal conversion material A1. The weight of the product obtained in step (2) and the weight of the porous photothermal conversion material A1 are respectively weighed, and it is calculated that the grafting amount of polyacrylic acid is 0.05wt% based on the total weight of the conjugated polymer in the porous photothermal conversion material A1, and in formula I, n is 200. The porosity of the porous photothermal conversion A1 and the light-heated water evaporation rate are tested, and the results are shown in Table 1.

[0089] Example 2

[0090] (1) 900 g of trans-1,4-polyisoprene was mixed with 100 g of blowing agent OBSH, and pelletized using a single-screw extruder. 15 g of the pellets were placed in a mold and pressed into a sample with a diameter of 10 cm and a thickness of 2 mm. The sample was placed in an autoclave for foaming at a temperature of 160° C. and a pressure of 2 MPa for 1 h to obtain a porous material.

[0091] (2) The porous material is doped in saturated iodine vapor at room temperature for 24 hours.

[0092] (3) After taking out, immediately add 20 wt% methacrylic acid (in Formula 1, R 1 'For CH 3 ; R 2 'H) in an aqueous solution (volume of the solution is 2L), stirred and nitrogen was introduced at the same time, reacted at 25°C for 8 hours, taken out, washed with ethanol and dried to obtain a porous photothermal conversion material A2, the weight of the product obtained in step (2) and the weight of the porous photothermal conversion material A2 were weighed respectively, and it was calculated that the grafting amount of polymethacrylic acid in the porous photothermal conversion material A2 was 0.06wt% based on the total weight of the conjugated polymer in the porous photothermal conversion material A2, and in formula I, n was 250. The porosity and photothermal water evaporation rate of the porous photothermal conversion material A2 were tested, and the results are shown in Table 1.

[0093] Example 3

[0094] (1) 900 g of trans-1,4-polyisoprene was mixed with 100 g of blowing agent OBSH, and pelletized using a single-screw extruder. 15 g of the pellets were placed in a mold and pressed into a sample with a diameter of 10 cm and a thickness of 2 mm. The sample was placed in an autoclave for foaming at a temperature of 160° C. and a pressure of 2 MPa for 1 h to obtain a porous material.

[0095] (2) The porous material is doped in saturated iodine vapor at room temperature for 24 hours.

[0096] (3) After taking out, 20 wt% methyl methacrylate (in Formula 1, R 1 'For CH 3 ; R 2 'For CH 3 ) in an aqueous solution (volume of the solution is 2 L), stirred and nitrogen was introduced at the same time, reacted at 25° C. for 8 hours, then taken out, washed with ethanol and dried to obtain a porous photothermal conversion material A3. The weight of the product obtained in step (2) and the weight of the porous photothermal conversion material A2 were weighed respectively. It was calculated that the grafting amount of polymethyl methacrylate was 0.08wt% based on the total weight of the conjugated polymer in the porous photothermal conversion material A3, and in formula I, n was 300. The porosity of the porous photothermal conversion material A3 and the evaporation rate of the light-heated water were tested, and the results are shown in Table 1.

[0097] Example 4

[0098] (1) 900 g of trans-1,4-polyisoprene was mixed with 100 g of blowing agent OBSH, and pelletized using a single-screw extruder. 15 g of the pellets were placed in a mold and pressed into a sample with a diameter of 10 cm and a thickness of 2 mm. The sample was placed in an autoclave for foaming at a temperature of 160° C. and a pressure of 2 MPa for 1 h to obtain a porous material.

[0099] (2) The porous material is doped in saturated iodine vapor at room temperature for 24 hours.

[0100] (3) After taking out, immediately add 20 wt% acrylamide (in Formula 2, R 3 ' is H; R 4 ' and R 5 ' are all H) in an aqueous solution (the volume of the solution is 2L), stirred and nitrogen is introduced at the same time, reacted at 25°C for 8 hours, taken out, washed with ethanol and dried to obtain a porous photothermal conversion material A4. Based on the total weight of the conjugated polymer in the porous photothermal conversion material A4, the weight of the product obtained in step (2) and the weight of the porous photothermal conversion material A4 are respectively weighed. It is calculated that the grafting amount of polyacrylamide is 0.02wt%, and in formula II, m is 100. The porosity of the porous photothermal conversion material A4 and the evaporation rate of the light-heated water are tested, and the results are shown in Table 1.

[0101] Example 5

[0102] (1) 900 g of trans-1,4-polyisoprene was mixed with 100 g of blowing agent OBSH, and pelletized using a single-screw extruder. 15 g of the pellets were placed in a mold and pressed into a sample with a diameter of 10 cm and a thickness of 2 mm. The sample was placed in an autoclave for foaming at a temperature of 160° C. and a pressure of 2 MPa for 1 h to obtain a porous material.

[0103] (2) The porous material is doped in saturated iodine vapor at room temperature for 24 hours.

[0104] (3) After taking out, immediately add 20 wt% N,N-dimethylacrylamide (in Formula 2, R 3 ' is H; R 4 ' and R 5 'All CH 3 ) in an aqueous solution (volume of the solution is 2 L), stirred and nitrogen was introduced for protection, reacted at 25° C. for 8 hours, taken out, washed with ethanol and dried to obtain a porous photothermal conversion material A5. The weight of the product obtained in step (2) and the weight of the porous photothermal conversion material A5 were weighed based on the total weight of the conjugated polymer in the porous photothermal conversion material A5. The grafting amount of poly(N,N-dimethylacrylamide) was 0.03wt%, and in formula II, m was 200. The porosity of the porous photothermal conversion material A5 and the evaporation rate of the light-heated water were tested, and the results are shown in Table 1.

[0105] Example 6

[0106] (1) 900 g of trans-1,4-polyisoprene was mixed with 100 g of blowing agent OBSH, and pelletized using a single-screw extruder. 15 g of the pellets were placed in a mold and pressed into a sample with a diameter of 10 cm and a thickness of 2 mm. The sample was placed in an autoclave for foaming at a temperature of 160° C. and a pressure of 2 MPa for 1 h to obtain a porous material.

[0107] (2) The porous material is doped in saturated iodine vapor at room temperature for 24 hours.

[0108] (3) After taking out, add 20 wt% methacrylamide (R 3 'For CH 3 ; R 4 ' and R 5 ' are all H) in an aqueous solution (volume of the solution is 2L), stirred and nitrogen is introduced for protection, reacted at 25°C for 8 hours, taken out, washed with ethanol and dried to obtain a porous photothermal conversion material A6, the weight of the product obtained in step (2) and the weight of the porous photothermal conversion material A6 are weighed respectively, and it is calculated that the grafting amount of polymethyl acrylamide is 0.04wt% based on the total weight of the conjugated polymer in the porous photothermal conversion material A6, and in formula II, m is 230. The porosity of the porous photothermal conversion material A6 and the evaporation rate of the light-heated water are tested, and the results are shown in Table 1.

[0109] Example 7

[0110] (1) 900 g of trans-1,4-polyisoprene was mixed with 100 g of blowing agent OBSH, and pelletized using a single-screw extruder. 15 g of the pellets were placed in a mold and pressed into a sample with a diameter of 10 cm and a thickness of 2 mm. The sample was placed in an autoclave for foaming at a temperature of 160° C. and a pressure of 2 MPa for 1 h to obtain a porous material.

[0111] (2) The porous material is doped in saturated iodine vapor at room temperature for 24 hours.

[0112] (3) After taking out, immediately add 20 wt% sodium p-styrene sulfonate (in Formula 3, R 6 ' is H; R 7 ' is Na) aqueous solution (solution volume is 2L), stirring and nitrogen protection, reacting at 25°C for 8 hours, then taking out, washing with ethanol and drying to obtain porous photothermal conversion material A7. Based on the total weight of the conjugated polymer in the porous photothermal conversion material A7, the weight of the product obtained in step (2) and the weight of the porous photothermal conversion material A7 are respectively weighed. It is calculated that the grafting amount of polymethyl acrylamide is 0.1wt%, and in formula III, l is 800. The porosity of the porous photothermal conversion material A7 and the evaporation rate of light-heated water are tested, and the results are shown in Table 1.

[0113] Example 8

[0114] (1) 900 g of trans-1,4-polyisoprene was mixed with 100 g of blowing agent OBSH, and pelletized using a single-screw extruder. 15 g of the pellets were placed in a mold and pressed into a sample with a diameter of 10 cm and a thickness of 2 mm. The sample was placed in an autoclave for foaming at a temperature of 160° C. and a pressure of 2 MPa for 1 h to obtain a porous material.

[0115] (2) The porous material is doped in saturated iodine vapor at room temperature for 24 hours.

[0116] (3) After taking out, immediately add 20 wt% acrylic acid (in Formula 1, R 1 ' is H; R 2 'H) in an aqueous solution (volume of the solution is 2L), stirred and nitrogen was introduced at the same time, reacted at 25°C for 24 hours, taken out, washed with ethanol and dried to obtain a porous photothermal conversion material A8. The weight of the product obtained in step (2) and the weight of the porous photothermal conversion material A8 were weighed based on the total weight of the conjugated polymer in the porous photothermal conversion material A8. It was calculated that the grafting amount of polyacrylic acid was 0.08wt%, and in formula I, n was 400. The porosity of the porous photothermal conversion material A8 and the evaporation rate of the light-heated water were tested, and the results are shown in Table 1.

[0117] Example 9

[0118] (1) 800 g of trans-1,4-polyisoprene was mixed with 200 g of blowing agent OBSH, and granulated using a single-screw extruder. 15 g of the granules were placed in a mold and pressed into a sample with a diameter of 10 cm and a thickness of 2 mm. The sample was placed in an autoclave for foaming at a temperature of 160° C., a pressure of 2 MPa, and a time of 1 h to obtain a porous material.

[0119] (2) The porous material is doped in saturated iodine vapor at room temperature for 24 hours.

[0120] (3) After taking out, immediately add 20 wt% acrylic acid (in Formula 1, R 1 ' is H; R 2 'H) in an aqueous solution (volume of the solution is 2L), stirred and nitrogen was introduced at the same time, reacted at 25°C for 8 hours, taken out, washed with ethanol and dried to obtain a porous photothermal conversion material A9, the weight of the product obtained in step (2) and the weight of the porous photothermal conversion material A9 were weighed respectively, and it was calculated that the grafting amount of polyacrylic acid in the porous photothermal conversion material A9 was 0.06wt% based on the total weight of the conjugated polymer in the porous photothermal conversion material A9, and in formula I, n is 200. The porosity of the porous photothermal conversion material A9 and the evaporation rate of the light-heated water were tested, and the results are shown in Table 1.

[0121] Comparative Example 1

[0122] 15 g of trans-1,4-polyisoprene pellets were placed in a mold and pressed into a sample with a diameter of 10 cm and a thickness of 2 mm. The sample was then doped in saturated iodine vapor at room temperature for 24 h. After being taken out, it was washed with ethanol and dried to obtain photothermal conversion material D1. The porosity of the photothermal conversion material and the evaporation rate of the photothermal water were tested. The results are shown in Table 1.

[0123] Comparative Example 2

[0124] (1) 900 g of trans-1,4-polyisoprene was mixed with 100 g of blowing agent OBSH, and pelletized using a single-screw extruder. 15 g of the pellets were placed in a mold and pressed into a sample with a diameter of 10 cm and a thickness of 2 mm. The sample was placed in an autoclave for foaming at a temperature of 160° C. and a pressure of 2 MPa for 1 h to obtain a porous material.

[0125] (2) The above-mentioned porous material was doped in saturated iodine vapor at room temperature for 24 hours. After being taken out, it was washed with ethanol and dried to obtain a photothermal conversion material D2. The porosity and photothermal water evaporation rate of the photothermal conversion material D2 were tested. The results are shown in Table 1.

[0126] Comparative Example 3

[0127] (1) 900 g of trans-1,4-polyisoprene was mixed with 100 g of blowing agent OBSH, and pelletized using a single-screw extruder. 15 g of the pellets were placed in a mold and pressed into a sample with a diameter of 10 cm and a thickness of 2 mm. The sample was placed in an autoclave for foaming at a temperature of 160° C. and a pressure of 2 MPa for 1 h to obtain a porous material.

[0128] (2) The above-mentioned porous material was doped in saturated iodine vapor at room temperature for 24 hours. After being taken out, it was washed with ethanol and dried. Then, the porous material was immersed in a 10wt% sodium dodecylsulfonate aqueous solution (solution volume was 1L) for 24 hours to obtain a photothermal conversion material D3, wherein the content of sodium dodecylbenzenesulfonate in the photothermal conversion material D3 was 0.003wt%. The porosity of the photothermal conversion material D3 and the evaporation rate of the photothermal water were tested. The results are shown in Table 1.

[0129] Comparative Example 4

[0130] 15g of trans-1,4-polyisoprene pellets were placed in a mold and pressed into a sample with a diameter of 10cm and a thickness of 2mm. The sample was then doped in saturated iodine vapor at room temperature for 24h. After being taken out, it was immediately placed in a 20wt% acrylic acid aqueous solution (solution volume was 2L), stirred and nitrogen was introduced for protection, reacted at 25°C for 8 hours, taken out, washed with ethanol and dried to obtain a photothermal conversion material D4. The weight of the product obtained in step (2) and the weight of the porous photothermal conversion material A2 were weighed respectively. It was calculated that the grafting amount of polyacrylic acid in the porous photothermal conversion material D4 was 0.005wt% based on the total weight of the conjugated polymer, and in formula I, n was 200. The porosity of the porous photothermal conversion material D4 and the photothermal water evaporation rate were tested, and the results are shown in Table 1.

[0131] Comparative Example 5

[0132] (1) 990 g of trans-1,4-polyisoprene was mixed with 10 g of blowing agent OBSH, and pelletized using a single-screw extruder. 15 g of the pellets were placed in a mold and pressed into a sample with a diameter of 10 cm and a thickness of 2 mm. The sample was placed in an autoclave for foaming at a temperature of 160° C. and a pressure of 2 MPa for 1 h to obtain a porous material.

[0133] (2) The porous material is doped in saturated iodine vapor at room temperature for 24 hours.

[0134] (3) After taking out, immediately put it into a 20wt% acrylic acid aqueous solution (solution volume is 2L), stir and pass nitrogen protection at the same time, react at 25°C for 8 hours, take it out, wash it with ethanol and dry it to obtain the photothermal conversion material D5, weigh the weight of the product obtained in step (2) and the weight of the porous photothermal conversion material A2 respectively, and calculate that the grafting amount of polyacrylic acid in the porous photothermal conversion material D5 is 0.008wt%, based on the total weight of the conjugated polymer in the porous photothermal conversion material D5, and in formula I, n is 200. The porosity of the porous photothermal conversion material D5 and the light-heat water evaporation rate were tested, and the results are shown in Table 1.

[0135] Table 1

[0136]

[0137]

[0138] It can be seen from the results in Table 1 that by grafting a specific type and content of hydrophilic polymers into the porous photothermal conversion materials provided by Examples 1-9 of the present invention, the photothermal water evaporation rate of the porous photothermal conversion materials can be significantly improved.

[0139] Furthermore, the light-heated water evaporation rate of Examples 1, 2, and 7-9 in which polyacrylic acid, polymethyl methacrylate or polysodium p-styrene sulfonate is grafted and the grafting amount of the polymer is controlled to be 0.05wt%-1wt% is further improved.

[0140] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A porous photothermal conversion material, characterized in that: The porous light-to-heat conversion material comprises a conjugated polymer grafted with a polymer of at least one of Formula I, Formula II and Formula III; Wherein, R1 is H or methyl; R2 is H, methyl or ethyl; R3 is H or methyl; R4 or R5 is H or methyl respectively; R6 is H or methyl; R7 is H, Na or K; n, m and l are each independently an integer of 10-1000, and the grafting amount of the polymer is greater than or equal to 0.01wt% based on the total weight of the conjugated polymer.

2. The porous photothermal conversion material according to claim 1, wherein: Based on the total weight of the conjugated polymer, the grafting amount of the polymer is 0.01wt%-0.1wt%.

3. The porous photothermal conversion material according to claim 1 or 2, wherein: The porous photothermal conversion material has an open-pore structure, and the porosity of the porous photothermal conversion material is greater than or equal to 30%, preferably 30%-80%.

4. The porous photothermal conversion material according to any one of claims 1 to 3, wherein: The conjugated polymer is prepared by reacting polyconjugated diene with an electron acceptor.

5. The porous photothermal conversion material according to claim 4, wherein: The polyconjugated diene is at least one selected from trans-1,4-polyisoprene, cis-1,4-polyisoprene, trans-1,4-polybutadiene, cis-1,4-polybutadiene and 2,3-dimethyl-1,4-polybutadiene, preferably trans-1,4-polyisoprene.

6. The porous photothermal conversion material according to claim 4 or 5, wherein: The electron acceptor is selected from at least one of Cl2, Br2, I2, ICl, ICl3, IBr, IF5, PF5, AsF5, SbF5, BF5, BCl3, BBr3, SO3, NbF5, TaF5, MoF5, WF5, RuF5, PtCl4, TiCl4, AgClO4, AgBF4, HPtCl6, HIrCl6, TCNE, TCNQ, DDO, HF, HCl, HNO3, H2SO4, HClO4, FSO3H, O2, XeOF4, XeF4, NOSbCl6 and NOPF6, preferably at least one of Cl2, Br2, I2 and AsF5, and more preferably I2.

7. The porous photothermal conversion material according to any one of claims 1 to 6, wherein: The conjugated polymer is obtained by placing the polyconjugated diene in the steam containing the electron acceptor for reaction; preferably, the conjugated polymer is obtained by placing the polyconjugated diene in the steam of the electron acceptor at 25-60° C. for reaction for 8-72 hours.

8. A method for preparing a porous photothermal conversion material, characterized in that: The method comprises: (1) mixing a polyconjugated diene and a foaming agent, and foaming the mixture to obtain a porous material; wherein the amount of the foaming agent is 2-20 wt % based on the total weight of the polyconjugated diene and the foaming agent; (2) contacting the porous material with an electron acceptor so that the polyconjugated diene in the porous material is converted into a conjugated polymer through reaction; (3) contacting the product obtained in step (2) with a solution containing at least one polymer monomer represented by Formula 1, Formula 2 and Formula 3 to obtain the porous photothermal conversion material; wherein R1' is H or methyl; R2' is H, methyl or ethyl; R3' is H or methyl; R4' or R5' are each independently H or methyl; R6' is H or methyl; and R7' is H, Na or K.

9. The method according to claim 8, wherein: Based on the total weight of the polyconjugated diene and the foaming agent, the amount of the foaming agent is 10-20wt%; Preferably, the blowing agent is selected from a physical blowing agent and / or a chemical blowing agent; Preferably, the foaming conditions include: a foaming temperature of 130-180° C., a foaming pressure of 1-10 MPa, and a foaming time of 0.5-3 h.

10. The method according to claim 8 or 9, wherein: The polyconjugated diene is at least one selected from trans-1,4-polyisoprene, cis-1,4-polyisoprene, trans-1,4-polybutadiene, cis-1,4-polybutadiene and 2,3-dimethyl-1,4-polybutadiene, preferably trans-1,4-polyisoprene; Preferably, the electron acceptor is selected from at least one of Cl2, Br2, I2, ICl, ICl3, IBr, IF5, PF5, AsF5, SbF5, BF5, BCl3, BBr3, SO3, NbF5, TaF5, MoF5, WF5, RuF5, PtCl4, TiCl4, AgClO4, AgBF4, HPtCl6, HIrCl6, TCNE, TCNQ, DDO, HF, HCl, HNO3, H2SO4, HClO4, FSO3H, O2, XeOF4, XeF4, NOSbCl6 and NOPF6, preferably at least one of Cl2, Br2, I2 and AsF5, more preferably I2.

11. The method according to any one of claims 8 to 10, wherein: In step (3), the conditions of the contact reaction include: a polymerization temperature of 25-50° C. and a polymerization time of greater than or equal to 2 hours; Preferably, in step (2), the contact is carried out by placing the porous material in the steam containing the electron acceptor; preferably, step (2) comprises: placing the porous material in the steam of the electron acceptor at 25-60° C. for reaction for 8-72 hours.

12. The method according to any one of claims 8 to 11, wherein: In step (3), the amount of the product obtained in step (2) and the polymer monomer solution is such that, in the porous photothermal conversion material, the grafting amount of the polymer is greater than or equal to 0.01wt%, preferably 0.01wt%-0.1wt%, based on the total weight of the conjugated polymer.

13. A porous light-to-heat conversion material prepared by the method according to any one of claims 8 to 12.

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