A near-infrared light-driven hydrogel actuator and a preparation method and application thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GUANGDONG UNIV OF TECH
- Filing Date
- 2024-08-20
- Publication Date
- 2026-06-23
Smart Images
Figure HDA0005000463120000011 
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Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer materials technology, and in particular to a near-infrared light-driven hydrogel actuator, its preparation method, and its application. Background Technology
[0002] Optically driven flexible actuators have attracted much attention due to their advantages such as non-contact operation, fast response, programmability, and multifunctionality. Researchers have utilized the photothermal effects of photothermal conversion materials such as carbon nanomaterials, inorganic metal nanoparticles, metal oxide nanoparticles, and MXene to achieve remotely triggered photoinduced phase transitions in liquid crystals, polymers, and gels, thereby realizing optical actuation of flexible materials.
[0003] While photoresponse actuators offer significant advantages in speed, precision, and non-contact operation, they also have limitations in terms of the mechanical properties and stability of the materials used. Furthermore, optimizing the actuator's structural design to maximize its driving amplitude and photothermal conversion efficiency to expand its application needs requires further research. Summary of the Invention
[0004] The present invention aims to at least solve one of the aforementioned technical problems existing in the prior art. Therefore, one objective of the present invention is to provide a near-infrared light-driven hydrogel actuator; a second objective is to provide a method for preparing such a near-infrared light-driven hydrogel actuator; and a third objective is to provide applications of such a near-infrared light-driven hydrogel actuator.
[0005] The basic principles of this invention are explained as follows:
[0006] 1) This invention utilizes poly(N-isopropylacrylamide) (PNIPAM) and polyacrylamide (PAM) to construct an asymmetric bilayer hydrogel actuator. Due to the difference in thermal response of this bilayer structure, the two hydrogels expand and contract at different rates under the same thermal environment, thereby achieving bending deformation and causing the actuator to move in water.
[0007] 2) To achieve light-driven operation, carbon nanomaterials with efficient and rapid photo-thermal conversion capabilities are introduced into the PNIPAM layer, thereby converting the temperature response of the hydrogel actuator into near-infrared light response, enabling remote non-contact control of the hydrogel; and acrylic monomers are added during the preparation process to form a multi-network structure to improve the mechanical properties of the gel layer.
[0008] 3) Fluorescent dyes are doped into the PAM gel layer to give it fluorescence responsiveness, thereby enabling it to detect heavy metal pollutants.
[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0010] A first aspect of the present invention provides a near-infrared light-driven hydrogel actuator, comprising a first hydrogel layer and a second hydrogel layer;
[0011] The first hydrogel layer comprises the following raw materials: polyacrylamide precursor solution, poly(N-isopropylacrylamide) precursor solution, acrylic monomer and fluorescent staining agent;
[0012] The second hydrogel layer comprises the following raw materials: poly(N-isopropylacrylamide) precursor solution, acrylic monomer, and carbon nanomaterials.
[0013] Preferably, the fluorescent staining agent in the first hydrogel layer has a content of 100-500 μmol / L.
[0014] Preferably, the fluorescent staining agent includes one of Rhodamine B, acridine orange, malachite green, and crystal violet; more preferably, the fluorescent staining agent is Rhodamine B.
[0015] Preferably, the carbon nanomaterial content in the second hydrogel layer is 5-15 mg / L.
[0016] Preferably, the carbon nanomaterial includes one of carbon nanotubes, graphene, and carbon quantum dots; more preferably, the carbon nanomaterial is carbon nanotubes (CNTs).
[0017] Preferably, the near-infrared light-driven hydrogel actuator comprises the following raw materials: acrylamide monomer, N-isopropylacrylamide monomer, acrylic acid monomer, fluorescent dye, carbon nanomaterial, crosslinking agent, initiator, and solvent.
[0018] Preferably, the crosslinking agent includes at least one of N,N-methylenebisacrylamide, N-hydroxymethylacrylamide, diacetone acrylamide, ethylenedienebenzene, and ethylene glycol dimethacrylate; more preferably, the crosslinking agent is N,N-methylenebisacrylamide.
[0019] Preferably, the initiator is a photoinitiator; more preferably, the initiator includes at least one of 2,2-diethoxyacetophenone, 2-hydroxyalkylacetophenone, 2-aminealkylacetophenone, diphenylacetophenone, and 2,2-dimethoxy-2-phenylacetophenone; even more preferably, the initiator is 2,2-diethoxyacetophenone.
[0020] Preferably, the solvent includes water or an organic solvent; the organic solvent includes dimethyl sulfoxide.
[0021] A second aspect of the present invention provides a method for preparing the near-infrared light-driven hydrogel actuator described in the first aspect of the present invention, comprising the following steps:
[0022] S1. Acrylamide monomer and N-isopropylacrylamide monomer are mixed with crosslinking agent, initiator and solvent respectively to obtain polyacrylamide precursor solution and poly(N-isopropylacrylamide) precursor solution;
[0023] S2. Take the polyacrylamide precursor solution and poly(N-isopropylacrylamide) precursor solution, add acrylic monomer and fluorescent dye, and solidify to form the first hydrogel layer;
[0024] S3. Take the poly(N-isopropylacrylamide) precursor solution, add acrylic monomer and carbon nanomaterials, and solidify it on the surface of the first hydrogel layer to form a second hydrogel layer, thereby obtaining the near-infrared light-driven hydrogel actuator.
[0025] Preferably, in the polyacrylamide precursor solution described in step S1, the mass ratio of acrylamide monomer, crosslinking agent, initiator and solvent is (2-7):(2-5):1:(800-850); more preferably, the mass ratio of acrylamide monomer, crosslinking agent, initiator and solvent is (4-6):(2-3):1:(830-840).
[0026] Preferably, in the polyacrylamide precursor solution described in step S1, the solvent is water.
[0027] Preferably, in the poly(N-isopropylacrylamide) precursor solution described in step S1, the ratio of N-isopropylacrylamide monomer, crosslinking agent, initiator, and solvent is (70-75) g: 1 g: (1-3) mL: (50-55) mL; more preferably, the ratio of N-isopropylacrylamide monomer, crosslinking agent, initiator, and solvent is (72-74) g: 1 g: (1-2) mL: (51-53) mL.
[0028] Preferably, in the poly(N-isopropylacrylamide) precursor solution described in step S2, the solvent is an organic solvent.
[0029] Preferably, in the first hydrogel layer described in step S2, the mass ratio of the acrylamide monomer to the N-isopropylacrylamide monomer is (8.5-13):1.
[0030] Preferably, in the first hydrogel layer described in step S2, the molar ratio of N-isopropylacrylamide monomer to acrylic acid monomer is (1-3):1.
[0031] Preferably, in the second hydrogel layer described in step S3, the molar ratio of N-isopropylacrylamide monomer to acrylic acid monomer is (1-3):1.
[0032] Preferably, in steps S2 and S3, the curing method is ultraviolet light curing.
[0033] Preferably, the curing time is 5-20 min; more preferably, the curing time is 5-15 min.
[0034] Preferably, the curing is carried out in a polytetrafluoroethylene mold.
[0035] Preferably, the curing is carried out under oxygen-free conditions.
[0036] Preferably, the volume ratio of the solution forming the first hydrogel layer to the second hydrogel layer is 1:(0.8-1.2).
[0037] The third aspect of the present invention provides the application of the near-infrared light-driven hydrogel actuator described in the first aspect of the present invention in the detection of heavy metal ions.
[0038] Preferably, the application specifically involves placing the near-infrared light-driven hydrogel actuator in a heavy metal ion solution and irradiating it with ultraviolet light to identify the heavy metal ions.
[0039] Preferably, the heavy metal ions include Hg. 2+ Cr 6+ At least one of them.
[0040] Preferably, the Hg 2+ The concentration is 1-50 mmol / L.
[0041] Preferably, the Cr 6+ The concentration is 1-10 mmol / L.
[0042] Preferably, the wavelength range of the ultraviolet light irradiation is 254-365nm.
[0043] Preferably, the amount of the near-infrared light-driven hydrogel actuator is 0.3-1g; more preferably, the amount of the near-infrared light-driven hydrogel actuator is 0.3-0.7g.
[0044] Compared with the prior art, the beneficial effects of the present invention are:
[0045] 1) The near-infrared light-driven hydrogel actuator provided by the present invention has an asymmetric bilayer structure constructed of poly(N-isopropylacrylamide) and polyacrylamide. The hydrogel can bend and deform under thermal conditions, driving the hydrogel to move in water. The first hydrogel layer contains a fluorescent dye, giving the hydrogel fluorescence responsiveness. The second hydrogel layer contains carbon nanomaterials, giving the hydrogel good near-infrared light responsiveness in both water and air media, realizing light-controlled driven deformation.
[0046] 2) The near-infrared light-driven hydrogel actuator provided by the present invention has a simple preparation method. During the preparation process, adding acrylic monomer to the first hydrogel layer is beneficial to improving the toughness of the gel layer. Adding poly(N-isopropylacrylamide) precursor solution can make the two layers more tightly bonded. Adding acrylic monomer to the second hydrogel layer can promote the dispersion of carbon nanomaterials.
[0047] 3) The near-infrared light-driven hydrogel actuator provided by this invention has fluorescence responsiveness and can be used to detect Hg. 2+ Cr 6+ The presence of heavy metal ions expands the applications of actuators. Attached Figure Description
[0048] Figure 1 FESEM images of the near-infrared light-driven hydrogel actuators in Example 1(a) and Comparative Example 1(b);
[0049] Figure 2 The image shows a comparison of the near-infrared light-driven hydrogel actuator in Example 1 before (a) and after (b) thermal response in water at 50°C.
[0050] Figure 3 The deformation of the near-infrared light-driven hydrogel actuator in Example 1 under near-infrared light irradiation in air;
[0051] Figure 4 The deformation of the near-infrared light-driven hydrogel actuator in Example 1 under near-infrared light irradiation in water is shown.
[0052] Figure 5 This is a photograph of the object captured by the gripper in Example 1.
[0053] Figure 6 The fluorescence color of the hydrogel at a wavelength of 254 nm in different solutions is shown in Example 2.
[0054] Figure 7 The fluorescence color of the hydrogel at a wavelength of 365 nm in different solutions is shown in Application Example 2.
[0055] Figure 8 For example 3, different concentrations of Hg 2+ Fluorescence curve of hydrogel in solution;
[0056] Figure 9 To illustrate the application of hydrogels at a wavelength of 365 nm with different concentrations of Hg in Example 3 2+ Fluorescence color in solution;
[0057] Figure 10 For example 3, different concentrations of Cr 6+ Fluorescence curve of hydrogel in solution;
[0058] Figure 11 To illustrate the application of hydrogels at a wavelength of 365 nm with different concentrations of Cr in Example 3 6+ Fluorescent color in the solution. Detailed Implementation
[0059] The present invention will be further described in detail below through specific embodiments. Unless otherwise specified, the raw materials, reagents, or apparatus used in the embodiments and comparative examples are all available from conventional commercial sources or can be obtained by existing technical methods. Unless otherwise specified, the test or experimental methods are conventional methods in the art.
[0060] Example 1
[0061] This embodiment provides a near-infrared light-driven hydrogel actuator, which is prepared by the following steps:
[0062] S1. Dissolve 575 mg N-isopropylacrylamide monomer and 7.83 mg N,N-methylenebisacrylamide in 406 μL of dimethyl sulfoxide solution, add 11.025 μL of 2,2-diethoxyacetophenone, and sonicate at room temperature to obtain PNIPAM precursor solution;
[0063] S2. Dissolve 0.6g of acrylamide monomer and 0.03g of N,N-methylenebisacrylamide in 10mL of water, add 0.012g of 2,2-diethoxyacetophenone, and sonicate at room temperature to obtain a PAM precursor solution.
[0064] S3. Take 200 μL of PNIPAM precursor solution and 200 μL of PAM precursor solution, add 20 μL of acrylic monomer and 10 μL of 0.01 mol / L Rhodamine B aqueous solution, stir thoroughly to form the first hydrogel layer prepolymer solution;
[0065] S4. Take 300 μL of PNIPAM precursor solution and 70 μL of acrylic monomer, add 3.7 mg of CNT, stir thoroughly to form the second hydrogel prepolymer solution;
[0066] S5. Add 200 μL of the first hydrogel layer prepolymer solution to the polytetrafluoroethylene mold, cover with a glass slide to isolate oxygen, and irradiate with ultraviolet light for 10 min to form the first hydrogel layer. Then add 200 μL of the second hydrogel layer prepolymer solution and irradiate with ultraviolet light for 10 min to form the second hydrogel layer that is tightly bonded to the first hydrogel layer, thus obtaining the near-infrared light driven hydrogel actuator CNT&PNIPAM / PAM-1.
[0067] Example 2
[0068] This embodiment provides a near-infrared light-driven hydrogel actuator, which is prepared by the following steps:
[0069] S1. Dissolve 575 mg N-isopropylacrylamide monomer and 7.83 mg N,N-methylenebisacrylamide in 406 μL of dimethyl sulfoxide solution, add 11.025 μL of 2,2-diethoxyacetophenone, and sonicate at room temperature to obtain PNIPAM precursor solution;
[0070] S2. Dissolve 0.6g of acrylamide monomer and 0.03g of N,N-methylenebisacrylamide in 10mL of water, add 0.012g of 2,2-diethoxyacetophenone, and sonicate at room temperature to obtain a PAM precursor solution.
[0071] S3. Take 300 μL of PNIPAM precursor solution and 200 μL of PAM precursor solution, add 20 μL of acrylic monomer and 10 μL of 0.01 mol / L Rhodamine B aqueous solution, stir thoroughly to form the first hydrogel layer prepolymer solution;
[0072] S4. Take 300 μL of PNIPAM precursor solution and 70 μL of acrylic monomer, add 3.7 mg of CNT, stir thoroughly to form the second hydrogel prepolymer solution;
[0073] S5. Add 200 μL of the first hydrogel layer prepolymer solution to the polytetrafluoroethylene mold, cover with a glass slide to isolate oxygen, and irradiate with ultraviolet light for 10 min to form the first hydrogel layer. Then add 200 μL of the second hydrogel layer prepolymer solution and irradiate with ultraviolet light for 10 min to form the second hydrogel layer that is tightly bonded to the first hydrogel layer, thus obtaining the near-infrared light driven hydrogel actuator CNT&PNIPAM / PAM-2.
[0074] Example 3
[0075] This embodiment provides a near-infrared light-driven hydrogel actuator, which is prepared by the following steps:
[0076] S1. Dissolve 575 mg N-isopropylacrylamide monomer and 7.83 mg N,N-methylenebisacrylamide in 406 μL of dimethyl sulfoxide solution, add 11.025 μL of 2,2-diethoxyacetophenone, and sonicate at room temperature to obtain PNIPAM precursor solution;
[0077] S2. Dissolve 0.6g of acrylamide monomer and 0.03g of N,N-methylenebisacrylamide in 10mL of water, add 0.012g of 2,2-diethoxyacetophenone, and sonicate at room temperature to obtain a PAM precursor solution.
[0078] S3. Take 200 μL of PNIPAM precursor solution and 300 μL of PAM precursor solution, add 20 μL of acrylic monomer and 10 μL of 0.01 mol / L Rhodamine B aqueous solution, stir thoroughly to form the first hydrogel layer prepolymer solution;
[0079] S4. Take 300 μL of PNIPAM precursor solution and 70 μL of acrylic monomer, add 3.7 mg of CNT, stir thoroughly to form the second hydrogel prepolymer solution;
[0080] S5. Add 200 μL of the first hydrogel layer prepolymer solution to the polytetrafluoroethylene mold, cover it with a glass slide to isolate oxygen, and irradiate with ultraviolet light for 10 min to form the first hydrogel layer. Then add 200 μL of the second hydrogel layer prepolymer solution and irradiate with ultraviolet light for 10 min to form the second hydrogel layer that is tightly bonded to the first hydrogel layer, thus obtaining the near-infrared light driven hydrogel actuator CNT&PNIPAM / PAM-3.
[0081] Comparative Example 1
[0082] This comparative example provides a near-infrared light-driven hydrogel actuator, which differs from Example 1 in that it does not contain carbon nanotubes. The preparation steps are as follows:
[0083] S1. Dissolve 575 mg N-isopropylacrylamide monomer and 7.83 mg N,N-methylenebisacrylamide in 406 μL of dimethyl sulfoxide solution, add 11.025 μL of 2,2-diethoxyacetophenone, and sonicate at room temperature to obtain PNIPAM precursor solution;
[0084] S2. Dissolve 0.6g of acrylamide monomer and 0.03g of N,N-methylenebisacrylamide in 10mL of water, add 0.012g of 2,2-diethoxyacetophenone, and sonicate at room temperature to obtain a PAM precursor solution.
[0085] S3. Take 200 μL of PNIPAM precursor solution and 200 μL of PAM precursor solution, add 20 μL of acrylic monomer and 10 μL of 0.01 mol / L Rhodamine B aqueous solution, stir thoroughly to form the first hydrogel layer prepolymer solution;
[0086] S4. Take 300 μL of PNIPAM precursor solution and 70 μL of acrylic monomer, stir thoroughly to form the second hydrogel layer prepolymer solution;
[0087] S5. Add 200 μL of the first hydrogel layer prepolymer solution to the polytetrafluoroethylene mold, cover with a glass slide to isolate oxygen, and irradiate with ultraviolet light for 10 min to form the first hydrogel layer. Then add 200 μL of the second hydrogel layer prepolymer solution and irradiate with ultraviolet light for 10 min to form the second hydrogel layer that is tightly bonded to the first hydrogel layer, thus obtaining the near-infrared light-driven hydrogel actuator PNIPAM / PAM-1.
[0088] Comparative Example 2
[0089] This comparative example provides a near-infrared light-driven hydrogel actuator, which differs from Example 1 in that it does not contain Rhodamine B. The preparation steps are as follows:
[0090] S1. Dissolve 575 mg N-isopropylacrylamide monomer and 7.83 mg N,N-methylenebisacrylamide in 406 μL of dimethyl sulfoxide solution, add 11.025 μL of 2,2-diethoxyacetophenone, and sonicate at room temperature to obtain PNIPAM precursor solution;
[0091] S2. Dissolve 0.6g of acrylamide monomer and 0.03g of N,N-methylenebisacrylamide in 10mL of water, add 0.012g of 2,2-diethoxyacetophenone, and sonicate at room temperature to obtain a PAM precursor solution.
[0092] S3. Take 200 μL of PNIPAM precursor solution and 200 μL of PAM precursor solution, add 20 μL of acrylic monomer, stir thoroughly to form the first hydrogel layer prepolymer solution;
[0093] S4. Take 300 μL of PNPIPAM precursor solution and 70 μL of acrylic monomer, add 3.7 mg of CNT, stir thoroughly to form the second hydrogel layer prepolymer solution;
[0094] S5. Add 200 μL of the first hydrogel layer prepolymer solution to the polytetrafluoroethylene mold, cover it with a glass slide to isolate oxygen, and irradiate with ultraviolet light for 10 min to form the first hydrogel layer. Then add 200 μL of the second hydrogel layer prepolymer solution and irradiate with ultraviolet light for 10 min to form the second hydrogel layer that is tightly bonded to the first hydrogel layer, thus obtaining the near-infrared light driven hydrogel actuator CNT&PNIPAM / PAM-4.
[0095] Characterization and performance testing
[0096] 1. The near-infrared light-driven hydrogel actuators CNT&PNIPAM / PAM-1 and PNIPAM / PAM-1 prepared in Example 1 and Comparative Example 1 were swollen in pure water for 2-3 days to remove unreacted monomers and other impurities, freeze-dried, and their morphology was observed using a field emission scanning electron microscope:
[0097] Figure 1 The following are FESEM images of the near-infrared light-driven hydrogel actuators in Example 1(a) and Comparative Example 1(b), generated by... Figure 1 It can be seen that, compared with the hydrogel without carbon nanotubes in Comparative Example 1, the surface particles of the hydrogel in Example 1 increased, and the carbon nanotube particles were successfully attached.
[0098] 2. The near-infrared light-driven hydrogel actuator CNT&PNIPAM / PAM-1 prepared in Example 1 was swollen in pure water for 2-3 days. After removing unreacted monomers and other impurities, its volume change was observed by placing it in water at 50°C.
[0099] Figure 2 This is a comparison image of the near-infrared light-driven hydrogel actuator in Example 1 before (a) and after (b) thermal response in water at 50°C. Figure 2 It can be seen that the near-infrared light-driven hydrogel actuator in Example 1 can undergo a significant volume change in water at 50°C, indicating that it has good temperature-sensitive properties. This volume phase change can generate driving force to drive the hydrogel to move in water.
[0100] 3. Deformation test of the near-infrared light driven hydrogel actuator CNT&PNIPAM / PAM-1 in Example 1 under near-infrared light irradiation in air:
[0101] Figure 3 The image shows the deformation of the near-infrared light-driven hydrogel actuator in Example 1 under near-infrared light irradiation in air. From left to right, the images show the deformation after irradiation with near-infrared light (808nm) for 0s, 10s, 15s, 20s, and 30s. Figure 3 It is known that, due to the photothermal effect of carbon nanotubes, hydrogels can undergo significant volume changes in air, achieving light-controlled driven deformation.
[0102] 4. Deformation test of the near-infrared light driven hydrogel actuator CNT&PNIPAM / PAM-1 in Example 1 under near-infrared light irradiation in water:
[0103] Figure 4 The figure shows the deformation of the near-infrared light-driven hydrogel actuator in Example 1 under near-infrared light irradiation in water. Figure 4 (a) Before near-infrared light irradiation Figure 4 (b) After 30 seconds of near-infrared light irradiation, by Figure 4 It is known that after 30 seconds of near-infrared light (808nm) irradiation, the hydrogel in water can also undergo significant volume changes, and it also exhibits light-controlled driven deformation.
[0104] Application Example 1
[0105] The near-infrared light-driven hydrogel actuator CNT&PNIPAM / PAM-1 in Example 1 was designed as a petal-shaped gripper and used to grasp objects in water. Figure 5 To capture a photograph of an object using the gripper in Example 1, by... Figure 5 It can be seen that the driving force of the volume phase change of the near-infrared light-driven hydrogel actuator in Example 1 can drive the hydrogel to move in water well, and can successfully grasp objects in the water, thus expanding the application of hydrogel actuators.
[0106] Application Example 2
[0107] The near-infrared light-driven hydrogel actuators CNT&PNIPAM / PAM-1 and CNT&PNIPAM / PAM-4 from Example 1 and Comparative Example 2 were applied to the detection of heavy metal ions in pure water at a concentration of 5 mmol / L Hg. 2+ Solution, 5 mmol / L Cr 3+ Solution, 5 mmol / L Cr 6+ 0.5g of CNT&PNIPAM / PAM-1 and 0.5g of CNT&PNIPAM / PAM-4 were added to the solution, and their fluorescence color changes were observed under ultraviolet light at 254nm and 365nm, respectively.
[0108] Figure 6 To illustrate the fluorescence color of the hydrogel at a wavelength of 254 nm in different solutions in Example 2, Figure 7 The fluorescence color of the hydrogel at a wavelength of 365 nm in different solutions is shown in Example 2. Figure 6 and Figure 7 It can be seen that at wavelengths of 254 nm and 365 nm, the near-infrared light-driven hydrogel actuator with added Rhodamine B in Example 1 exhibits orange fluorescence in water; at Hg 2+ In solution, the gel fluorescence changes from orange to bright yellow; in Cr 6+ In solution, the gel fluorescence faded slightly; in Cr 3+ In solution, the fluorescence color of the gel remains essentially unchanged; however, in Comparative Example 2, due to the absence of a fluorescent dye, the near-infrared light-driven hydrogel actuator lacks fluorescence responsiveness. Therefore, the near-infrared light-driven hydrogel actuator provided by this invention can be used for Hg based on changes in fluorescence color within a specific ultraviolet wavelength range. 2+ and Cr 6+ The detection.
[0109] Application Example 3
[0110] The near-infrared light-driven hydrogel actuator CNT&PNIPAM / PAM-1 from Example 1 was used to treat different concentrations of Hg. 2+ The test was conducted in pure water at a concentration of 1 mmol / L Hg. 2+Solution, 5 mmol / L Hg 2+ Solution, 10 mmol / L Hg 2+ Solution and 50 mmol / L Hg 2+ 0.5g of CNT&PNIPAM / PAM-1 was added to the solution, and its fluorescence curve in the wavelength range of 520-700nm and its fluorescence change under 365nm ultraviolet light were detected.
[0111] Figure 8 For example 3, different concentrations of Hg 2+ Fluorescence curve of hydrogel in solution; Figure 9 To illustrate the application of hydrogels at a wavelength of 365 nm with different concentrations of Hg in Example 3 2+ The fluorescent color in the solution. (From...) Figure 8 It can be seen that, within the range of 1-50 mmol / L, the fluorescence intensity of the near-infrared light-driven hydrogel actuator CNT&PNIPAM / PAM-1 increases with Hg. 2+ The concentration of ions increases and then decreases; due to Figure 9 It can be seen that at 365nm, different Hg 2+ The fluorescence color of the gel varies depending on the ion concentration.
[0112] Application Example 4
[0113] The near-infrared light-driven hydrogel actuator CNT&PNIPAM / PAM-1 from Example 1 was used for different concentrations of Cr 6+ The test was conducted in pure water at a concentration of 1 mmol / L Cr. 6+ Solution, 5 mmol / L Cr 6+ Solution and 10 mmol / L Cr 6+ 0.5g of CNT & PNIPAM / PAM-1 were added to the solution, and their fluorescence curves in the wavelength range of 520-700nm and their fluorescence changes under 365nm ultraviolet light were detected.
[0114] Figure 10 For example 4, different concentrations of Cr 6+ Fluorescence curve of hydrogel in solution; Figure 11 To illustrate the application of hydrogels at a wavelength of 365 nm with different concentrations of Cr in Example 4 6+ The fluorescent color in the solution. (From...) Figure 10 It can be seen that, within the range of 1-10 mmol / L, the fluorescence intensity of the near-infrared light-driven hydrogel actuator CNT&PNIPAM / PAM-1 increases with Cr. 6+ The concentration of ions increases and then decreases; due to Figure 11 It can be seen that at 365nm, different Cr 6+ The fluorescence color of the gel varies depending on the ion concentration.
[0115] The near-infrared light-driven hydrogel actuator provided by this invention exhibits good temperature sensitivity. The driving force generated by the volume phase change can propel the hydrogel in water. Under near-infrared light irradiation, it undergoes significant volume changes in both water and air media. This volume phase change can be utilized to expand its applications to include grippers, etc. Within the wavelength range of 520-700 nm, the fluorescence intensity of the gel decreases with increasing heavy metal ion concentration. At a wavelength of 365 nm, the fluorescence color of the gel differs for different ion concentrations, making it well-suited for applications involving Hg. 2+ and Cr 6+ Detection of heavy metal ions.
Claims
1. A near-infrared light-driven hydrogel actuator, characterized in that, It includes a first hydrogel layer and a second hydrogel layer; The raw materials for preparing the first hydrogel layer are: polyacrylamide precursor solution, poly(N-isopropylacrylamide) precursor solution, acrylic monomer and fluorescent staining agent; The raw materials for preparing the second hydrogel layer are: poly(N-isopropylacrylamide) precursor solution, acrylic monomer and carbon nanomaterials; The polyacrylamide precursor solution comprises acrylamide monomer, crosslinking agent, initiator, and water in a mass ratio of (2-7): (2-5): 1: (800-850); the poly(N-isopropylacrylamide) precursor solution comprises N-isopropylacrylamide monomer, crosslinking agent, initiator, and organic solvent in a ratio of (70-75) g: 1 g: (1-3) mL: (50-55) mL. In the first hydrogel layer, the mass ratio of acrylamide monomer to N-isopropylacrylamide monomer is (8.5-13):1; the molar ratio of N-isopropylacrylamide monomer to acrylic acid monomer is (1-3):1; and the content of the fluorescent dye is 100-500 μmol / L. In the second hydrogel layer, the molar ratio of N-isopropylacrylamide monomer to acrylic acid monomer is (1-3):1; the content of carbon nanomaterial is 5-15 mg / L.
2. The near-infrared light-driven hydrogel actuator according to claim 1, characterized in that, The fluorescent staining agent includes one of Rhodamine B, acridine orange, malachite green, and crystal violet.
3. The near-infrared light-driven hydrogel actuator according to claim 1, characterized in that, The carbon nanomaterials include one of carbon nanotubes, graphene, and carbon quantum dots.
4. The method for preparing the near-infrared light-driven hydrogel actuator according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Mix acrylamide monomer, crosslinking agent, initiator and water to obtain a polyacrylamide precursor solution; mix N-isopropylacrylamide monomer, crosslinking agent, initiator and organic solvent to obtain a poly(N-isopropylacrylamide) precursor solution; S2. Take the polyacrylamide precursor solution and poly(N-isopropylacrylamide) precursor solution, add acrylic monomer and fluorescent dye, and solidify to form the first hydrogel layer; S3. Take the poly(N-isopropylacrylamide) precursor solution, add acrylic monomer and carbon nanomaterials, and solidify it on the surface of the first hydrogel layer to form a second hydrogel layer, thereby obtaining the near-infrared light-driven hydrogel actuator.
5. The preparation method according to claim 4, characterized in that, The volume ratio of the solution forming the first hydrogel layer to the second hydrogel layer is 1:(0.8-1.2).
6. The application of the near-infrared light-driven hydrogel actuator according to any one of claims 1-3 in the detection of heavy metal ions.
7. The application according to claim 6, characterized in that, The heavy metal ions include Hg 2+ Cr 6+ At least one of them.