Light-force double-response polybutadiene film as well as preparation method and application thereof

Abstract

The invention discloses a light-force double-response polybutadiene film as well as a preparation method and application thereof, and belongs to the technical field of polymer functional materials and new energy. The method comprises the following steps: firstly, carrying out photosensitive functional modification on a polybutadiene main chain through molecular grafting; then constructing a soluble sacrificial layer on the surface of the matrix, and spin-coating a photosensitive polybutadiene solution to form a film; and annealing and cross-linking, and finally removing the sacrificial layer through selective solvent etching to prepare the independent light-force double-response polybutadiene film. By introducing the photosensitive group and utilizing the mechanical response characteristic of polybutadiene, the film material has light and force dual response functions. The dual-response characteristic can cooperatively regulate and control the ion selectivity and flux of the membrane, and effectively breaks through the performance bottleneck of the traditional membrane, so that the energy density and controllability of salinity gradient energy conversion are remarkably improved, and the membrane is further used for developing a high-performance salinity gradient energy power generation membrane material.

Description

Technical Field

[0001] This application belongs to the field of polymer functional materials and new energy technology, specifically, it relates to a photomechanical dual-response polybutadiene film, its preparation method and application. Background Technology

[0002] Salinity gradient energy, as a abundant, clean, and renewable energy source, is of great significance for alleviating the energy crisis through its efficient development and utilization. Currently, salinity gradient energy conversion technology mainly relies on membrane materials to achieve energy capture. However, traditional commercial ion exchange membranes face challenges such as high manufacturing costs, difficulty in synergistically optimizing ion selectivity and flux, and limitations in energy density and controllability, which restrict their large-scale application.

[0003] To improve energy density, existing research has prepared low-internal-resistance, high-selectivity membrane materials through molecular design and structural optimization. However, their performance is still limited by the inherent ion selectivity and flux balance of the membrane, resulting in insufficient tunability. Furthermore, by introducing single external stimulus response characteristics such as light, heat, force, and pH, membrane performance can be dynamically adjusted to overcome the above limitations. However, single-response membranes have limitations in response dimensions and functional integration, making it difficult to meet the higher demands for energy density and tunability in complex application scenarios.

[0004] Therefore, developing a membrane material with multiple response characteristics to synergistically improve the energy density and controllability of the salinity gradient energy conversion system has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] The purpose of this application is to provide a photomechanical dual-response polybutadiene membrane, its preparation method and application, which has dual photomechanical and mechanical response characteristics, can improve the energy density and controllability of ion exchange membranes, thereby promoting the application of ion channel membranes in salinity gradient power generation.

[0006] To achieve the above objectives, this application provides a method for preparing a photodynamic dual-response polybutadiene film, comprising the following steps: Photosensitive polybutadiene solution was obtained by photosensitive functionalization modification of the main chain of polybutadiene material through molecular grafting technology. A soluble sacrificial layer is constructed on the surface of the substrate to obtain a pretreated substrate; A photosensitive polydibutylene solution is applied to the surface of a pretreated substrate to form a film, thereby obtaining a substrate material containing a polymer film. An annealing and crosslinking treatment was performed on the matrix material containing the polymer film to obtain a photomechanical dual-response polybutadiene film composite material. A photosensitive polybutadiene film was prepared by removing the soluble sacrificial layer of the photosensitive polybutadiene film composite material using selective solvent etching.

[0007] Furthermore, molecular grafting technology is achieved through esterification or amidation reactions, in which... The amidation reaction includes the following steps: acyl chloride reaction of a carboxylic acid group with an acyl chloride reagent, and the resulting reaction product reacts with an amino group or a hydroxyl group. The acyl chloride reagent includes thionyl chloride, oxalyl chloride, phosphorus trichloride or phosphorus pentachloride.

[0008] Furthermore, the photosensitive molecules in the photosensitive polybutene solution are 5-(4-hydroxyphenyl)-10,15,20-(triphenyl)porphyrin, 5,15-bis(4-hydroxyphenyl)-10,20-diphenylporphyrin, 4-hydroxyazobenzene, 5-(4-aminophenyl)-10,15,20-(triphenyl)porphyrin, 5,15-bis(4-aminophenyl)-10,20-diphenylporphyrin, 4-aminoazobenzene, 1-(4-aminophenyl)-1,2,2-tristyrene, 5-(4-carboxyphenyl)-10,15,20-(triphenyl)porphyrin, 5,15-bis(4-carboxyphenyl)-10,20-diphenylporphyrin or azobenzene-4,4-dicarboxylic acid, 1-(4-carboxyphenyl)-1,2,2-tristyrene.

[0009] Furthermore, the polybutadiene material is carboxyl-terminated polybutadiene, amino-terminated polybutadiene, or hydroxyl-terminated polybutadiene, and the molecular weight of the polybutadiene material is 1000~15000.

[0010] Furthermore, the soluble sacrificial layer is made of polyvinyl alcohol or cellulose acetate, and its thickness is 100 nm to 500 nm.

[0011] Furthermore, the substrate is mica or silicon wafer, and the contact angle of the substrate surface is less than 90°.

[0012] Furthermore, the solvent of the photosensitive polybutene solution includes at least one of chloroform, toluene, dichloromethane and tetrahydrofuran, and the concentration of the photosensitive polybutene solution is 1wt% to 10wt%.

[0013] Furthermore, the annealing process can be carried out by thermal annealing, solvent annealing, or interface annealing.

[0014] Furthermore, the hot annealing environment is a vacuum, nitrogen, or inert gas environment, the annealing temperature is 50℃~100℃, and the annealing time is 4h~72h.

[0015] Furthermore, the solvent for solvent annealing includes at least one of chloroform, toluene, dichloromethane, acetone, tetrahydrofuran, ethanol, methanol, and water, with an annealing temperature of 0°C to 50°C and an annealing time of 1 day to 7 days.

[0016] Furthermore, the liquid phase material for interfacial annealing is at least one of deionized water, 0.1 mol / L to 2 mol / L dilute hydrochloric acid, 0.1 mol / L to 2 mol / L dilute sulfuric acid, acetonitrile, and ethanol, the annealing temperature is 0℃ to 50℃, and the annealing time is 0.5 h to 24 h.

[0017] Furthermore, the crosslinking treatment methods include chemical crosslinking, photocrosslinking, or thermal crosslinking.

[0018] Furthermore, the chemical crosslinking agent includes at least one of 1,12-dimercaptododecane, disulfur dichloride, sublimed sulfur, and iodine, with a crosslinking temperature of 0°C to 50°C and a crosslinking time of 1 min to 720 min.

[0019] Furthermore, the crosslinking agent for photocrosslinking is at least one of 2,2-dimethoxy-2-phenylacetophenone, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, and 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide. Photocrosslinking is performed by irradiation with an ultraviolet lamp with a wavelength of 254 nm to 365 nm, an ultraviolet light intensity of 0.1 mW / cm2 to 6 mW / cm2, and an irradiation time of 5 min to 60 min.

[0020] Furthermore, the temperature for thermal crosslinking is 10℃~50℃, and the crosslinking time is 4d~12d.

[0021] Furthermore, the solvent used in selective solvent etching includes at least one of water, ethanol, and chloroform, and the etching temperature is 10°C to 60°C.

[0022] Furthermore, the film-forming treatment method is spin coating, blade coating or drop coating, wherein the spin coating speed is 20 rpm to 4000 rpm.

[0023] This application also provides a photodynamic dual-response polybutadiene film with a thickness of 10 nm to 500 nm.

[0024] This application also provides an application of a photodynamic dual-response polybutadiene membrane in salinity gradient power generation, including the following steps: A photomechanically responsive polybutadiene membrane was used as a selective ion transport medium to separate chambers containing electrolyte solutions, with the electrolyte solution concentrations in the two separated chambers being inconsistent. Electricity can be generated by applying ultraviolet light and / or pressure to a photodynamic dual-response polybutadiene membrane.

[0025] Furthermore, applying pressure can be achieved by altering the liquid level difference in the electrolyte solution.

[0026] In summary, this application has the following advantages: This application utilizes molecular grafting technology to perform photosensitive functionalization modification on the polybutadiene backbone, enabling the construction of polymer films with controllable thickness. Subsequently, through annealing and crosslinking treatment, an independent photomechanical dual-response polybutadiene film is formed, which possesses excellent salt gradient power generation performance and photomechanical dual-response performance. Under the synergistic effect of light / mechanical / photomechanical, the energy density can be regulated.

[0027] Specifically, this application first uses molecular grafting technology to photosensitively functionalize the polybutadiene backbone to prepare a photomechanically responsive polybutadiene membrane. The functionalized polybutadiene has photosensitive molecules at both ends, connected to the polybutadiene via ester or amide bonds. Taking the photosensitive functionalization of carboxyl-terminated polybutadiene with 5-(4-aminophenyl)-10,15,20-(triphenyl)porphyrin as an example, the tetraphenylporphyrin structure can form ion transport channels during annealing. These channels can regulate transmembrane ion transport under ultraviolet light irradiation at wavelengths of 245 nm to 365 nm, exhibiting photoresponsiveness. Secondly, the polybutadiene structure can form a three-dimensional cross-linked network after cross-linking. This three-dimensional cross-linked network undergoes deformation under force, affecting the structure and distribution of the ion transport channels constructed by the tetraphenylporphyrin, thereby regulating transmembrane ion transport and achieving mechanical response. Therefore, the photomechanical dual-response polybutadiene film of this application can not only achieve high energy density, but also achieve regulation of energy density under the synergistic effect of light / mechanical / photomechanical. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the photomechanical dual-response polybutadiene film preparation process proposed in the embodiments of this application.

[0030] Figure 2 This is a test schematic diagram of salinity gradient power generation using a photodynamic dual-response polybutadiene membrane as proposed in Embodiment 1 of this application.

[0031] Figure 3 The performance test curves of salinity gradient power generation using a photodynamic dual-response polybutadiene membrane under different conditions, as proposed in Example 1 of this application, are shown.

[0032] Figure 4 This is a transmission electron microscope image of the photomechanical dual-response polybutadiene film proposed in Example 1 of this application. Detailed Implementation

[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] While traditional commercial ion exchange membranes have been applied in existing technologies, their inherent defects limit the further development of salinity gradient energy technology. Specifically, these membranes generally suffer from complex manufacturing processes and high costs, and their ion selectivity and flux are usually irreconcilable, resulting in low energy density. More importantly, the performance of these membranes is fixed once they are manufactured, lacking dynamic controllability and unable to adapt to changing operating conditions, exhibiting poor controllability.

[0035] Existing ion exchange membranes either suffer from performance stagnation due to a lack of dynamic response or limit their controllability due to a single response dimension, failing to achieve breakthrough improvements in controllability and energy density. Based on this, this application develops a photomechanical dual-response polybutadiene membrane that can respond individually or simultaneously to two external stimuli (i.e., light / mechanical or light and mechanical), thereby breaking through the bottleneck of single-performance limitations and significantly improving the energy density and controllability of salinity gradient energy conversion.

[0036] Specifically, in the first aspect, this application provides a method for preparing a photomechanically responsive polybutadiene film, such as... Figure 1 As shown, it includes the following steps: S1. Photosensitive polybutadiene solution was obtained by photosensitive functionalization modification of the main chain of polybutadiene material through molecular grafting technology.

[0037] In a specific embodiment, molecular grafting technology is achieved through esterification or amidation reactions. The amidation reaction includes the following steps: acyl chloride reaction of a carboxylic acid group with an acyl chloride reagent, followed by reaction of the resulting product with an amino or hydroxyl group. The acyl chloride reagent includes thionyl chloride, oxalyl chloride, phosphorus trichloride, or phosphorus pentachloride. By attaching the photosensitive molecule to the main chain via amide or ester bonds, it is ensured that the photosensitive molecule will not detach during long-term use, repeated deformation, and light exposure, thus guaranteeing the long-term stability of the membrane performance.

[0038] Firstly, the photoresponse principle of this application lies in the covalent bonding of photosensitive molecules with photophysical / photochemical properties (such as porphyrins, azobenzenes, and tristyrene) to the polybutadiene backbone. Porphyrin molecules, under specific wavelengths of light, can act as photosensitizers, generating photogenerated electrons or excited-state energy, altering the local charge environment of the membrane or triggering subsequent reactions, thereby regulating ion transport. Azobenzene molecules undergo a reversible trans-cis isomerization transformation under ultraviolet / visible light irradiation. This molecular-scale configurational change causes the polymer chain to contract or expand, altering the membrane's pore size or hydrophilicity / hydrophobicity, thus enabling the switching or regulation of ion flux. Tristyrene molecules possess aggregation-induced emission properties; their molecular conformation and aggregation state are affected by light, and can be used to regulate the membrane's microstructure and optical signals, achieving monitoring and control of ion transport. Regardless of the chosen photosensitive molecule, the essence of the photoresponse lies in converting the light signal into changes in molecular-level structure or charge, ultimately manifesting as changes in macroscopic membrane performance. Secondly, the principle of the force response in this application lies in the selection of polybutadiene as the matrix material. Polybutadiene is a typical elastomer with highly flexible molecular chains. When the membrane is subjected to mechanical forces such as stretching or compression, its polymer chain network deforms. This deformation directly leads to the stretching or compression of ion channels within the membrane, changing the pore size; and the distance between polymer chains is altered, affecting the migration path and resistance of ions within the membrane. Therefore, the essence of the force response lies in directly converting mechanical force signals into changes in the membrane's microstructure, thereby dynamically adjusting its permeability and selectivity for ions. The principle of the light / force dual response in this application is that by first irradiating azobenzene molecules with light to convert them to the cis configuration (molecular chain contraction), a smaller tensile force can be applied, achieving a larger pore size change than simply applying tensile force, thus achieving the goal of low energy consumption and high controllability.

[0039] In a specific embodiment, the photosensitive molecules in the photosensitive polydibutylene solution are 5-(4-hydroxyphenyl)-10,15,20-(triphenyl)porphyrin, 5,15-bis(4-hydroxyphenyl)-10,20-diphenylporphyrin, 4-hydroxyazobenzene, 5-(4-aminophenyl)-10,15,20-(triphenyl)porphyrin, 5,15-bis(4-aminophenyl)-10,20-diphenylporphyrin, 4-aminoazobenzene, 1-(4-aminophenyl)-1,2,2-tristyrene, 5-(4-carboxyphenyl)-10,15,20-(triphenyl)porphyrin, 5,15-bis(4-carboxyphenyl)-10,20-diphenylporphyrin, or azobenzene-4,4-dicarboxylic acid, 1-(4-carboxyphenyl)-1,2,2-tristyrene. The photosensitive molecules in this application can be selected based on the wavelength of light required to respond and the response mode (configurational change, charge change).

[0040] In specific embodiments, the polybutene material is carboxyl-terminated polybutadiene, amino-terminated polybutadiene, or hydroxyl-terminated polybutadiene, and the molecular weight of the polybutene material is 1000~15000. The polybutene material of this application can be selected with different end groups and molecular weights to control the mechanical strength, flexibility, and grafting density of the membrane.

[0041] In a specific embodiment, the solvent of the photosensitive polybutene solution includes at least one of chloroform, toluene, dichloromethane and tetrahydrofuran, and the concentration of the photosensitive polybutene solution is 1wt%~10wt%.

[0042] S2. A soluble sacrificial layer is constructed on the substrate surface to obtain a pretreated substrate. The sacrificial layer allows for the fabrication of independent, uniformly thick films and minimizes the additional resistance introduced by the support, thus improving energy density.

[0043] In a specific embodiment, the soluble sacrificial layer is made of polyvinyl alcohol (PVA) or cellulose acetate (CA), and its thickness ranges from 100 nm to 500 nm. Both PVA and CA are readily film-forming polymers, capable of forming smooth, dense, and pinhole-free ultrathin films on substrates through spin coating. Furthermore, both PVA and CA are soluble in water, ethanol, and chloroform, making the sacrificial process gentle and non-corrosive, without causing any chemical damage to the upper polybutadiene target film. Most importantly, they exhibit sufficient adhesion to substrates such as mica and silicon wafers, ensuring they do not detach during film formation and annealing; while their adhesion to the hydrophobic polybutadiene film is relatively weak. When dissolved in water, they can easily separate from the polybutadiene film, achieving clean peeling.

[0044] In this specific embodiment, the substrate is mica or silicon wafer, and the contact angle of the substrate surface is less than 90°. The mica or silicon wafer is highly stable in the organic solvents used during film formation and at the subsequent annealing temperature, and will not react with the sacrificial layer or polymer film. Furthermore, the sacrificial layer material (PVA or CA) is coated in the form of an aqueous or alcoholic solution. This application controls the substrate surface to be hydrophilic (contact angle <90°) to ensure that the sacrificial layer solution can spread well on its surface, thereby forming a uniform liquid film. Only after drying can a smooth solid film be obtained.

[0045] S3. The photosensitive polybutene solution is applied to the surface of the pretreated substrate to form a film, thereby obtaining a substrate material containing a polymer film.

[0046] In a specific embodiment, the film-forming treatment method is spin coating, blade coating or drop coating, wherein the spin coating speed is 20 rpm to 4000 rpm.

[0047] S4. Annealing and crosslinking treatments are performed on the matrix material containing the polymer film to obtain a photomechanically responsive polybutadiene membrane composite material. Annealing eliminates internal stress and makes the molecular chains more regularly arranged; that is, annealing eliminates microscopic pores and defects within the membrane, making the membrane denser, reducing non-selective leakage current, and thus improving ion selectivity. Furthermore, membranes with regular structures and fewer defects have clearer ion transport paths and lower internal resistance, which is more conducive to improving energy density. Crosslinking constructs a stable three-dimensional network structure, ensuring the membrane is insoluble in solvents and maintains structural integrity after multiple deformations and light exposures, improving the membrane's durability. Moreover, the crosslinked network structure is fundamental to the membrane's excellent mechanical strength; it effectively resists tensile and compressive forces, preventing plastic deformation or rupture during force response, ensuring the membrane's cycle life.

[0048] In specific embodiments, the annealing process is carried out by thermal annealing, solvent annealing, or interface annealing.

[0049] Preferably, the thermal annealing environment is a vacuum, nitrogen, or inert gas environment, the annealing temperature is 50℃~100℃, and the annealing time is 4h~72h. Thermal annealing refers to heating near the glass transition temperature (50℃~100℃ is a suitable range for polybutadiene), allowing the polymer chain segments to gain sufficient kinetic energy to move and slide. This releases the internal stress generated by solvent evaporation during film formation, and the molecular chains adjust from a disordered, coiled state to a more ordered, extended state.

[0050] Preferably, the solvent for solvent annealing includes at least one of chloroform, toluene, dichloromethane, acetone, tetrahydrofuran, ethanol, methanol, and water. The annealing temperature is 0℃~50℃, and the annealing time is 1d~7d. Solvent annealing involves placing the membrane in a solvent vapor environment. The solvent molecules swell the polymer film, essentially plasticizing the polymer chains, allowing them to move and rearrange at lower temperatures. After annealing, the solvent evaporates, leaving the optimized structure.

[0051] Preferably, the liquid material for interfacial annealing is at least one selected from deionized water, 0.1 mol / L to 2 mol / L dilute hydrochloric acid, 0.1 mol / L to 2 mol / L dilute sulfuric acid, acetonitrile, and ethanol. The annealing temperature is 0℃ to 50℃, and the annealing time is 0.5 h to 24 h. Interfacial annealing involves contacting the membrane with a specific liquid material. The liquid interface can induce specific rearrangement or phase separation of the polymer chains on the membrane surface, thereby optimizing the surface properties.

[0052] In specific embodiments, the crosslinking treatment method is chemical crosslinking, photocrosslinking, or thermal crosslinking.

[0053] Preferably, the chemical crosslinking agent includes at least one selected from 1,12-dimercaptododecane, disulfide, sublimed sulfur, and iodine, with a crosslinking temperature of 0°C to 50°C and a crosslinking time of 1 min to 720 min. Specifically, chemical crosslinking involves adding a crosslinking agent containing bifunctional or polyfunctional groups (such as dimercapto compounds or disulfides) as a bridge to react with the double bonds or functional groups on the polybutadiene backbone, thereby connecting different chains.

[0054] Preferably, the crosslinking agent for photocrosslinking is at least one selected from 2,2-dimethoxy-2-phenylacetophenone, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, and 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide. Photocrosslinking is performed using ultraviolet (UV) lamp irradiation with a wavelength of 254 nm to 365 nm, a UV light intensity of 0.1 mW / cm² to 6 mW / cm², and an irradiation time of 5 min to 60 min. Specifically, photocrosslinking is achieved by adding a photoinitiator (such as DMPA). Under UV irradiation, the photoinitiator decomposes to generate free radicals or cations, which can further attack the double bonds on the polybutadiene backbone, thereby initiating a free radical polymerization reaction between chains and forming a crosslinked network.

[0055] Preferably, the temperature for thermal crosslinking is 10℃~50℃, and the crosslinking time is 4d~12d. Thermal crosslinking utilizes the thermal reactivity of the unsaturated double bonds on the polybutadiene backbone. Under relatively long time (4d~12d) and a certain temperature (10℃~50℃), the double bonds can directly undergo an addition reaction, thereby forming crosslinks.

[0056] S5. A photosensitive polybutadiene film is prepared by removing the soluble sacrificial layer of the photosensitive polybutadiene film composite material through selective solvent etching.

[0057] In a specific embodiment, the solvent used in the selective solvent etching method includes at least one of water, ethanol, and chloroform, and the etching temperature is 10°C to 60°C.

[0058] Secondly, based on a general inventive concept, this application also provides a photomechanically responsive polybutadiene film with a thickness of 10 nm to 500 nm.

[0059] Thirdly, based on a general inventive concept, this application also provides an application of a photodynamic dual-response polybutadiene membrane in salinity gradient power generation, comprising the following steps: a. A photomechanically responsive polybutadiene membrane is used as a selective ion transport medium to separate chambers containing electrolyte solutions, with the electrolyte solution concentrations in the two separated chambers being inconsistent. b. Power generation can be achieved by applying ultraviolet light and / or pressure to a photodynamic dual-response polybutadiene membrane.

[0060] In a specific implementation, the pressure is applied by changing the liquid level difference of the electrolyte solution.

[0061] The technical solutions described above in this application will be explained in detail below with reference to specific embodiments.

[0062] The following embodiments in this application all use polybutadiene photosensitive functionalized by molecular grafting technology, and the specific preparation methods include: (1) Acyl chloride of carboxyl-terminated polybutadiene Weigh 1.2g of carboxyl-terminated polybutadiene (molecular weight 4000~5000) and dissolve it in 30mL of dichloromethane. Add 53μL of oxaloyl chloride and 2 drops of N,N-dimethylformamide. React at room temperature under nitrogen for 2.5 hours until no more bubbles are generated.

[0063] (2) Grafting of 5-(4-aminophenyl)-10,15,20-(triphenyl)porphyrin Weigh 1g of 5-(4-aminophenyl)-10.15.20-(triphenyl)porphyrin and dissolve it in 30mL of dichloromethane. Add 171μL of triethylamine and add the acyl-chlorinated terminal carboxyl polybutadiene from (1) dropwise at 0℃. After stirring for 12 hours, a dichloromethane solution of photofunctionalized polybutadiene is obtained.

[0064] (3) Purification of photofunctionalized polybutadiene The solution in (2) was concentrated to 5 mL at 40 °C and -0.08 MPa in a rotary evaporator. The concentrated solution was then added dropwise to 300 mL of methanol and stirred. The precipitated photofunctionalized polybutadiene was collected and washed three times with 100 mL of methanol and 100 mL of n-hexane to obtain purified photofunctionalized polybutadiene.

[0065] Example 1 This embodiment provides a photodynamic dual-response polybutadiene film, which is prepared by the following method: (1) A 5wt% polyvinyl alcohol-1788 aqueous solution was spin-coated onto the surface of a mica substrate at 4000 rpm and dried in an argon atmosphere for 1 h to obtain a soluble polyvinyl alcohol sacrificial layer with a thickness of 500 nm on the surface of the mica substrate.

[0066] (2) The functionalized polybutadiene was prepared into a chloroform film-forming solution with a concentration of 1wt%, and was spin-coated onto the soluble polyvinyl alcohol sacrificial layer on the surface of mica at a speed of 4000rpm. After drying at -0.1MPa and 35℃ for 30min, it was heat-annealed at 120℃ for 12h to obtain a polybutadiene film.

[0067] After annealing, the polybutadiene membrane was placed in a vacuum dryer and 1 drop of disulfide was added. Sulfur crosslinking was carried out at -0.08 MPa for 3 minutes. After completion, it was rinsed with carbon disulfide until the unreacted sulfur crosslinking agent and sulfur were completely washed away, thus obtaining the photodynamic dual-response polybutadiene membrane composite material.

[0068] (3) The soluble polyvinyl alcohol sacrificial layer of the photoresponsive polybutadiene film composite material was removed by etching with an aqueous solution (the photoresponsive polybutadiene film composite material was wiped along the edge of the mica with deionized water, and then slowly immersed in the deionized water from one side. As the immersion process proceeded, the soluble polybutadiene gradually dissolved, and the photoresponsive polybutadiene film continuously detached from the mica substrate. When fully immersed, the photoresponsive polybutadiene film completely detached from the mica substrate and floated on the water surface), resulting in an independent photoresponsive polybutadiene film with a thickness of 120 nm (its transmission electron microscope image is shown in Figure 1). Figure 4 As shown in the figure, it can be used as a salinity gradient electrostatic membrane.

[0069] Experimental Example 1 The photodynamic dual-response polybutadiene membrane obtained in Example 1 was subjected to salinity gradient power generation performance testing, including the following steps: 1) Concentration gradient-driven energy conversion device is constructed in the electrochemical testing system, using a photomechanical dual-response polybutadiene membrane as a selective ion transport medium to separate two electrolyte chambers (where the electrolyte in the high-concentration region is 0.5 mol / L KCl, and the electrolyte in the low-concentration region is 0.01 mol / L KCl), such as... Figure 2 As shown.

[0070] 2) When the system is in a non-equilibrium state, cations undergo transmembrane directional migration driven by chemical potential difference, forming an electrochemical potential.

[0071] Current-time tests were conducted using an electrochemical workstation, and the current values ​​were recorded under different resistances using a variable resistance box. The power generation can be calculated using P=I²×RL (where P represents power in W; I represents current in A; and RL represents applied resistance in Ω). The experimentally measured power generation density reached 10.52 W / m² under gradients of 0.01 mol / L and 0.5 mol / L KCl.

[0072] Experimental Example 2 The photodynamic biresponsive polybutadiene film obtained in Example 1 was subjected to a photodynamic biresponsiveness test, and the energy conversion device in Example 1 was used again, including the following steps: 3) Apply 365nm ultraviolet light to the photomechanically responsive polybutadiene film using a laser pointer, such as... Figure 3As shown, the experimentally measured power generation density reached 12.83 W / m2 under a gradient of 0.01 mol / L and 0.5 mol / L KCl and an illumination of 100 mW·cm-2.

[0073] 4) By changing the liquid level difference of the electrolyte solution to apply pressure to the photodynamic dual-response polybutadiene membrane, the power generation density was experimentally measured to reach 13.51 W / m2 under a pressure difference of 4 mbar at gradients of 0.01 mol / L and 0.5 mol / L KCl.

[0074] 5) Under the synergistic effect of light and power, the experimentally measured power generation density reached 16.56 W / m2 under gradients of 0.01 mol / L and 0.5 mol / L KCl, 100 mW·cm-2 illumination, and 4 mbar pressure difference.

[0075] Example 2 This embodiment provides a photodynamic dual-response polybutadiene film, which is prepared by the following method: (1) A 5wt% polyvinyl alcohol-1788 aqueous solution was spin-coated onto the surface of a mica substrate at 4000 rpm and dried in an argon atmosphere for 1 h to obtain a soluble polyvinyl alcohol sacrificial layer with a thickness of 500 nm on the surface of the mica substrate.

[0076] (2) The functionalized polybutadiene was prepared into a chloroform film-forming solution with a concentration of 1 wt%, and spin-coated onto a soluble polyvinyl alcohol sacrificial layer on the surface of mica at 4000 rpm. After drying at -0.1 MPa and 35°C for 30 min, solvent annealing was performed to obtain a polybutadiene film. The method of solvent annealing after vacuum drying was as follows: the spin-coated material was placed in a vacuum desiccator, and 20 mL of acetone was added to form an acetone environment. The material was then placed at room temperature (25°C) for 7 days.

[0077] After annealing, the polybutadiene membrane was placed in a vacuum dryer, and 1 drop of disulfide dichloride was added. Sulfur crosslinking was carried out at -0.08 MPa for 3 minutes. After completion, it was rinsed with carbon disulfide until the unreacted sulfur crosslinking agent and sulfur were completely washed away, thus obtaining the photodynamic dual-response polybutadiene membrane composite material.

[0078] (3) The soluble polyvinyl alcohol sacrificial layer of the photodynamic dual-response polybutadiene film composite material is removed by etching with aqueous solution (wipe the photodynamic dual-response polybutadiene film composite material along the edge of the mica with deionized water, and then slowly immerse the photodynamic dual-response polybutadiene film composite material into the deionized water from one side. As the immersion process proceeds, the soluble polybutadiene gradually dissolves and the photodynamic dual-response polybutadiene film continuously detaches from the mica substrate. When fully immersed, the photodynamic dual-response polybutadiene film completely detaches from the mica substrate and floats on the water surface), resulting in an independent photodynamic dual-response polybutadiene film with a thickness of 120 nm, which can be used as a salinity gradient power generation film.

[0079] The photomechanically responsive polybutadiene film obtained in Example 2 was tested using the methods of Example 1 and Example 2, and the results are as follows: 1) The experiment showed that the power generation density reached 11.23 W / m2 under the gradients of 0.01 mol / L and 0.5 mol / L KCl.

[0080] 2) The experiment showed that the power generation density reached 12.45 W / m2 under a gradient of 0.01 mol / L and 0.5 mol / L KCl and 100 mW·cm-2 illumination.

[0081] 3) The experiment showed that the power generation density reached 13.70 W / m2 under the gradient of 0.01 mol / L and 0.5 mol / L KCl and a pressure difference of 4 mbar.

[0082] 4) The experiment showed that the power generation density reached 16.02 W / m2 under the gradients of 0.01 mol / L and 0.5 mol / L KCl, 100 mW·cm-2 illumination, and 4 mbar pressure difference.

[0083] Example 3 This embodiment provides a photodynamic dual-response polybutadiene film, which is prepared by the following method: (1) A 5wt% polyvinyl alcohol-1788 aqueous solution was spin-coated onto the surface of a mica substrate at 4000 rpm and dried in an argon atmosphere for 1 h to obtain a soluble polyvinyl alcohol sacrificial layer with a thickness of 500 nm on the surface of the mica substrate.

[0084] (2) The functionalized polybutadiene was prepared into a chloroform film-forming solution with a concentration of 1 wt%. At the same time, 3% of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide was added as a crosslinking agent for photocrosslinking. The solution was spin-coated onto a soluble polyvinyl alcohol sacrificial layer on the surface of mica at 4000 rpm. After drying at -0.1 MPa and 35°C for 30 min, the solution was heat-annealed at 120°C for 12 h to obtain a polybutadiene film.

[0085] After annealing, the polybutadiene film was placed under 365nm ultraviolet light (50W power) for 20 minutes to obtain a photomechanical dual-response polybutadiene film composite material.

[0086] (3) The soluble polyvinyl alcohol sacrificial layer of the photodynamic dual-response polybutadiene film composite material was removed by etching with an aqueous solution (the photodynamic dual-response polybutadiene film composite material was wiped along the edge of the mica with deionized water, and then the photodynamic dual-response polybutadiene film composite material was slowly immersed into the deionized water from one side. As the immersion process proceeded, the soluble polybutadiene gradually dissolved, and the photodynamic dual-response polybutadiene film was continuously separated from the mica substrate. When it was fully immersed, the photodynamic dual-response polybutadiene film was completely separated from the mica substrate and floated on the water surface), resulting in an independent photodynamic dual-response polybutadiene film with a thickness of 120 nm, which can be used as a salinity gradient power generation film.

[0087] The photomechanically responsive polybutadiene film obtained in Example 3 was tested using the methods of Example 1 and Example 2, and the results are as follows: 1) The experiment showed that the power generation density reached 12.03 W / m2 under the gradients of 0.01 mol / L and 0.5 mol / L KCl.

[0088] 2) The experiment showed that the power generation density reached 13.78 W / m2 under a gradient of 0.01 mol / L and 0.5 mol / L KCl and 100 mW·cm-2 illumination.

[0089] 3) The experiment showed that the power generation density reached 12.95 W / m2 under the gradient of 0.01 mol / L and 0.5 mol / L KCl and a pressure difference of 4 mbar.

[0090] 4) The experiment showed that the power generation density reached 15.70 W / m2 under gradients of 0.01 mol / L and 0.5 mol / L KCl, 100 mW·cm-2 illumination, and 4 mbar pressure difference.

[0091] Example 4 This embodiment provides a photodynamic dual-response polybutadiene film, which is prepared by the following method: (1) A 5wt% polyvinyl alcohol-1788 aqueous solution was spin-coated onto the surface of a mica substrate at 4000 rpm and dried in an argon atmosphere for 1 h to obtain a soluble polyvinyl alcohol sacrificial layer with a thickness of 500 nm on the surface of the mica substrate.

[0092] (2) The functionalized polybutadiene was prepared into a chloroform film-forming solution with a concentration of 2wt%, and spin-coated onto the soluble polyvinyl alcohol sacrificial layer on the surface of mica at a speed of 2000rpm. After drying at -0.1MPa and 35℃ for 30min, it was heat-annealed at 120℃ for 12h to obtain a polybutadiene film.

[0093] After annealing, the polybutadiene membrane was placed in a vacuum dryer, and 1 drop of disulfide dichloride was added. Sulfur crosslinking was carried out at -0.08 MPa for 3 minutes. After completion, it was rinsed with carbon disulfide until the unreacted sulfur crosslinking agent and sulfur were completely washed away, thus obtaining the photodynamic dual-response polybutadiene membrane composite material.

[0094] (3) The soluble polyvinyl alcohol sacrificial layer of the photodynamic dual-response polybutadiene film composite material was removed by etching with an aqueous solution (the photodynamic dual-response polybutadiene film composite material was wiped along the edge of the mica with deionized water, and then the photodynamic dual-response polybutadiene film composite material was slowly immersed into the deionized water from one side. As the immersion process proceeded, the soluble polybutadiene gradually dissolved, and the photodynamic dual-response polybutadiene film was continuously separated from the mica substrate. When it was fully immersed, the photodynamic dual-response polybutadiene film was completely separated from the mica substrate and floated on the water surface), resulting in an independent photodynamic dual-response polybutadiene film with a thickness of 200 nm, which can be used as a salinity gradient power generation film.

[0095] The photomechanically responsive polybutadiene film obtained in Example 4 was tested using the methods of Example 1 and Example 2, and the results are as follows: 1) The experiment showed that the power generation density reached 9.26 W / m2 under the gradients of 0.01 mol / L and 0.5 mol / L KCl.

[0096] 2) The experiment showed that the power generation density reached 11.96 W / m2 under a gradient of 0.01 mol / L and 0.5 mol / L KCl and an illumination of 100 mW·cm-2.

[0097] 3) The experiment showed that the power generation density reached 12.07 W / m2 under the gradient of 0.01 mol / L and 0.5 mol / L KCl and a pressure difference of 4 mbar.

[0098] 4) The experiment showed that the power generation density reached 14.24 W / m2 under the gradients of 0.01 mol / L and 0.5 mol / L KCl, 100 mW·cm-2 illumination, and 4 mbar pressure difference.

[0099] Example 5 This embodiment provides a photodynamic dual-response polybutadiene film, which is prepared by the following method: (1) A 5 wt% aqueous solution of polyvinyl alcohol-1788 was spin-coated onto the surface of a mica substrate at 4000 rpm and dried in an argon atmosphere for 1 h to obtain a 100 nm thick soluble polyvinyl alcohol sacrificial layer on the surface of the mica substrate.

[0100] (2) The functionalized polybutadiene was prepared into a toluene film-forming solution with a concentration of 1wt%, and was spin-coated onto the soluble polyvinyl alcohol sacrificial layer on the surface of mica at a speed of 4000rpm. After drying at -0.1MPa and 35℃ for 30min, it was heat-annealed at 120℃ for 12h to obtain a polybutadiene film.

[0101] After annealing, the polybutadiene membrane was placed in a vacuum dryer, and 1 drop of disulfide dichloride was added. Sulfur crosslinking was carried out at -0.08 MPa for 3 minutes. After completion, it was rinsed with carbon disulfide until the unreacted sulfur crosslinking agent and sulfur were completely washed away, thus obtaining the photodynamic dual-response polybutadiene membrane composite material.

[0102] (3) The soluble polyvinyl alcohol sacrificial layer of the photodynamic dual-response polybutadiene film composite material was removed by etching with an aqueous solution (the photodynamic dual-response polybutadiene film composite material was wiped along the edge of the mica with deionized water, and then the photodynamic dual-response polybutadiene film composite material was slowly immersed into the deionized water from one side. As the immersion process proceeded, the soluble polybutadiene gradually dissolved, and the photodynamic dual-response polybutadiene film was continuously separated from the mica substrate. When it was fully immersed, the photodynamic dual-response polybutadiene film was completely separated from the mica substrate and floated on the water surface), and an independent photodynamic dual-response polybutadiene film with a thickness of 80 nm was obtained, which can be used as a salinity gradient power generation film.

[0103] The photomechanically responsive polybutadiene film obtained in Example 5 was tested using the methods of Example 1 and Example 2, and the results are as follows: 1) The experiment showed that the power generation density reached 9.25 W / m2 under the gradients of 0.01 mol / L and 0.5 mol / L KCl.

[0104] 2) The experiment showed that the power generation density reached 11.38 W / m2 under a gradient of 0.01 mol / L and 0.5 mol / L KCl and an illumination of 100 mW·cm-2.

[0105] 3) The experiment showed that the power generation density reached 11.15 W / m2 under the gradient of 0.01 mol / L and 0.5 mol / L KCl and a pressure difference of 4 mbar.

[0106] 4) The experiment showed that the power generation density reached 12.55 W / m2 under the gradients of 0.01 mol / L and 0.5 mol / L KCl, 100 mW·cm-2 illumination, and 4 mbar pressure difference.

[0107] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0108] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0109] Finally, it should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes the element.

[0110] This application uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for preparing a photodynamic dual-response polybutadiene film, characterized in that, Includes the following steps: Photosensitive polybutadiene solution was obtained by photosensitive functionalization modification of the main chain of polybutadiene material through molecular grafting technology. A soluble sacrificial layer is constructed on the surface of the substrate to obtain a pretreated substrate; The photosensitive polybutene solution is used to form a film on the surface of the pretreated substrate to obtain a substrate material containing a polymer film. The matrix material containing the polymer film is annealed and crosslinked to obtain a photomechanical dual-response polybutadiene film composite material. The photoresponsive polybutadiene film was prepared by removing the soluble sacrificial layer of the photoresponsive polybutadiene film composite material using selective solvent etching.

2. The preparation method according to claim 1, characterized in that, The molecular grafting technique is achieved through esterification or amidation reactions, wherein... The amidation reaction includes the following steps: acyl chloride reaction of a carboxylic acid group with an acyl chloride reagent, and the resulting reaction product reacts with an amino group or a hydroxyl group, wherein the acyl chloride reagent includes thionyl chloride, oxalyl chloride, phosphorus trichloride or phosphorus pentachloride.

3. The preparation method according to claim 1 or 2, characterized in that, The photosensitive molecules in the photosensitive polydibutylene solution are 5-(4-hydroxyphenyl)-10,15,20-(triphenyl)porphyrin, 5,15-bis(4-hydroxyphenyl)-10,20-diphenylporphyrin, 4-hydroxyazobenzene, 5-(4-aminophenyl)-10,15,20-(triphenyl)porphyrin, 5,15-bis(4-aminophenyl)-10,20-diphenylporphyrin, 4-aminoazobenzene, 1-(4-aminophenyl)-1,2,2-tristyrene, 5-(4-carboxyphenyl)-10,15,20-(triphenyl)porphyrin, 5,15-bis(4-carboxyphenyl)-10,20-diphenylporphyrin, or azobenzene-4,4-dicarboxylic acid, 1-(4-carboxyphenyl)-1,2,2-tristyrene.

4. The preparation method according to claim 1, characterized in that, The polybutadiene material is carboxyl-terminated polybutadiene, amino-terminated polybutadiene, or hydroxyl-terminated polybutadiene, and the molecular weight of the polybutadiene material is 1000~15000.

5. The preparation method according to claim 1, characterized in that, The soluble sacrificial layer is made of polyvinyl alcohol or cellulose acetate, and its thickness is 100 nm to 500 nm.

6. The preparation method according to claim 1, characterized in that, The substrate is mica or silicon wafer, and the contact angle of the substrate surface is less than 90°.

7. The preparation method according to claim 1, characterized in that, The solvent of the photosensitive polybutene solution includes at least one of chloroform, toluene, dichloromethane and tetrahydrofuran, and the concentration of the photosensitive polybutene solution is 1wt% to 10wt%.

8. The preparation method according to claim 1, characterized in that, The annealing process is performed by thermal annealing, solvent annealing, or interface annealing.

9. The preparation method according to claim 8, characterized in that, The heat annealing environment is a vacuum, nitrogen, or inert gas environment, the annealing temperature is 50℃~100℃, and the annealing time is 4h~72h.

10. The preparation method according to claim 8, characterized in that, The solvent used for solvent annealing includes at least one of chloroform, toluene, dichloromethane, acetone, tetrahydrofuran, ethanol, methanol, and water. The annealing temperature is 0℃ to 50℃, and the annealing time is 1 day to 7 days.

11. The preparation method according to claim 8, characterized in that, The liquid phase material for the interface annealing is at least one of deionized water, 0.1 mol / L to 2 mol / L dilute hydrochloric acid, 0.1 mol / L to 2 mol / L dilute sulfuric acid, acetonitrile, and ethanol. The annealing temperature is 0℃ to 50℃, and the annealing time is 0.5 h to 24 h.

12. The preparation method according to claim 1, characterized in that, The crosslinking treatment method is chemical crosslinking, photocrosslinking, or thermal crosslinking.

13. The preparation method according to claim 12, characterized in that, The chemical crosslinking agent includes at least one of 1,12-dimercaptododecane, disulfur dichloride, sublimed sulfur, and iodine. The crosslinking temperature is 0℃~50℃ and the crosslinking time is 1min~720min.

14. The preparation method according to claim 12, characterized in that, The photocrosslinking agent is at least one selected from 2,2-dimethoxy-2-phenylacetophenone, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, and 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide. The photocrosslinking is performed by irradiation with an ultraviolet lamp with a wavelength of 254 nm to 365 nm, an ultraviolet light intensity of 0.1 mW / cm² to 6 mW / cm², and an irradiation time of 5 min to 60 min.

15. The preparation method according to claim 12, characterized in that, The temperature for thermal crosslinking is 10℃~50℃, and the crosslinking time is 4d~12d.

16. The preparation method according to claim 1, characterized in that, The solvent used in the selective solvent etching method includes at least one of water, ethanol, and chloroform, and the etching temperature is 10℃~60℃.

17. The preparation method according to claim 1, characterized in that, The film-forming process is performed by spin coating, blade coating, or drop coating, wherein the spin coating speed is 20 rpm to 4000 rpm.

18. A photodynamic dual-response polybutadiene film, characterized in that, The preparation method according to any one of claims 1-17 is obtained.

19. The application of the photodynamic dual-response polybutadiene membrane according to claim 18 in salinity gradient power generation, characterized in that, Includes the following steps: The photomechanically responsive polybutadiene membrane is used as a selective ion transport medium to separate the chambers of the electrolyte solution, and the electrolyte solution concentrations of the two separated chambers are inconsistent. Electricity can be generated by applying ultraviolet light and / or pressure to the photomechanical dual-response polybutadiene membrane.

20. The application according to claim 19, characterized in that, The method of applying pressure is to change the liquid level difference of the electrolyte solution.

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