Magnetic nanoparticle-induced photo-crosslinking multi-response programmable gradient hydrogel as well as preparation method and application thereof
By combining magnetic field induction and photopolymerization technology, magnetic nanoparticle-induced photocross-linked multi-responsive programmable gradient hydrogels are prepared, which solves the time-consuming and energy-consuming problem of hydrogel preparation in the existing technology, and realizes a hydrogel actuator with multiple stimulus responses and programmable complex deformation. It has excellent tensile properties and reversible cyclability, and is suitable for bionic hydrogels and soft robots.
Patent Information
- Application Number
- CN202510968111.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-14
- Publication Date
- 2025-09-19
AI Technical Summary
Existing technologies make it difficult to manufacture hydrogel actuators with multiple stimulus responses and programmable complex deformations through simple and rapid methods, and the thermal polymerization process is time-consuming and energy-consuming.
Combining magnetic field induction and photopolymerization technology, the directional movement of magnetic nanoparticles under the action of an external magnetic field is utilized, and the characteristics of protonated spiropyran that closes under blue light and automatically opens after being shielded from light are combined to prepare magnetic nanoparticle-induced photocrosslinked multi-responsive programmable gradient hydrogels. Fast and efficient gradient hydrogel preparation is achieved through LED photopolymerization.
The prepared hydrogel has multiple stimulus responsiveness and programmability, excellent tensile properties, can be driven under thermal stimulation, blue light and near-infrared light, has reversible cyclability and programmed shape responsiveness, and is suitable for the field of bionic hydrogels and soft robots.
Smart Images
Figure CN120665234A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of flexible intelligent driving materials, and in particular to a magnetic nanoparticle-induced photocrosslinked multi-responsive programmable gradient hydrogel, and a preparation method and application thereof. Background Art
[0002] With the development of society and the advancement of science and technology, smart materials such as biomimetic soft materials and soft robots have attracted much attention. Programmable hydrogel actuators can exhibit complex movements under external stimuli and have potential application prospects in soft actuators, artificial muscles, and medical biology. However, how to create hydrogel actuators with multiple stimulus responses and programmable complex deformations through simple and rapid methods still faces huge challenges. Numerous studies have shown that magnetic nanoparticles can move rapidly and directionally under the action of an external magnetic field, which provides the possibility of using magnetic fields to assist in the rapid preparation of programmable gradient hydrogel actuators. Currently, there are reports on the preparation of pH-responsive programmable gradient hydrogels by combining magnetic field induction and thermal polymerization, but the thermal polymerization process is still time-consuming and energy-consuming. Photopolymerization is an advanced polymerization technology that is fast, efficient, energy-saving, and environmentally friendly. Therefore, combining magnetic field induction and photopolymerization technology will open up a new simple, efficient, and rapid approach to construct multiple stimulus-responsive programmable gradient hydrogel actuators.
[0003] Based on the above background, the present invention proposes a magnetic nanoparticle-induced photocrosslinked multi-responsive programmable gradient hydrogel and its preparation method and application. The gradient hydrogel programmatically adjusts the gradient structure and composition distribution of the hydrogel by controlling the direction of the magnetic field. By utilizing the characteristics of protonated spiropyran that closes the ring under blue light and automatically opens the ring after being shielded from light, the deformation and recovery of the hydrogel are synergistically promoted, and the hydrogel is endowed with blue light driving ability. In addition, the preparation method of the present invention is simple and efficient, and a gradient hydrogel can be prepared by one-step green LED photopolymerization. The gradient hydrogel has a gradient distribution of crosslinking degree and components from the top layer to the bottom layer. This multi-stimulus-responsive programmable gradient hydrogel and its preparation method provide new ideas and methods for the development of the field of smart materials, and have broad application prospects and potential. Summary of the Invention
[0004] The present invention proposes a magnetic nanoparticle-induced photocrosslinking multi-responsive programmable gradient hydrogel and its preparation method and application. The method is green and simple, and the prepared gradient hydrogel has excellent multi-stimulus responsiveness and programmability.
[0005] To achieve the above object, the present invention adopts the following technical solutions:
[0006] The first aspect of the present invention provides a magnetic nanoparticle-induced photocrosslinked multi-responsive programmable gradient hydrogel, wherein the precursor solution of the photocrosslinked stimulus-responsive gradient hydrogel consists of a carboxyl spiropyran monomer, a magnetic nanoparticle crosslinker, a thermosensitive monomer, a photoinitiator and a cosolvent.
[0007] Preferably, the carboxyl spiropyran monomer has the structural formula:
[0008]
[0009] R is independently selected from: -COOH,
[0010] Preferably, the magnetic nanoparticle crosslinking agent is composed of up-conversion nanoparticles, ferrosoferric oxide and γ-methacryloxypropyltrimethoxysilane, and the structural formula of the up-conversion nanoparticles is LiYF4:Yb 3+ ,Tm 3+ @LiYF4.
[0011] Preferably, the temperature-sensitive monomer is one or a combination of two or more of N-isopropylacrylamide, N,N-dimethylacrylamide, dimethylaminoethyl methacrylate, and N-vinylcaprolactam; preferably, the temperature-sensitive monomer is N-isopropylacrylamide.
[0012] Preferably, the photoinitiator is one or a combination of two or more of (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, 1-hydroxycycloethylphenylacetone, and 1-hydroxy-1-methylethylphenyl ketone; preferably, the photoinitiator is (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide.
[0013] Preferably, the cosolvent is one or a combination of two or more of 1,4-dioxane, tetrahydrofuran, methanol, and ethanol.
[0014] Preferably, the carboxyl spiropyran monomer accounts for 0.4 mol% of the total molar mass of the thermosensitive monomer; the magnetic nanoparticle crosslinker accounts for 0-8 wt% of the total mass of the thermosensitive monomer and the carboxyl spiropyran monomer; the photoinitiator accounts for 1 mol% of the total molar mass of the thermosensitive monomer and the carboxyl spiropyran monomer; and the co-solvent content is 1 mL.
[0015] A second aspect of the present invention provides a method for preparing a magnetic nanoparticle-induced photocrosslinked multi-responsive programmable gradient hydrogel, comprising the following steps:
[0016] Different solutions of a magnetic nanoparticle crosslinker, a thermosensitive monomer, a carboxyspiropyran monomer, a photoinitiator, and a cosolvent were injected into a polytetrafluoroethylene mold and allowed to stand for 0.5-2 hours. Subsequently, polymerization was initiated under LED light, and the cosolvent was removed by deionized water treatment to produce a gradient hydrogel.
[0017] Preferably, the LED light wavelengths are 365nm, 385nm, 395nm and 405nm, and the light intensity is 100mW / cm 2 , the irradiation time is 5-60min.
[0018] The third aspect of the present invention provides an application of magnetic nanoparticle-induced photocrosslinking multi-responsive programmable gradient hydrogel in light driving, wherein the magnetic nanoparticle-induced photocrosslinking multi-responsive programmable gradient hydrogel is applied to intelligent bionic materials, soft robots, light actuators, and microfluidic valves.
[0019] The above technical solution has the following beneficial effects:
[0020] 1. The method of preparing magnetic nanoparticle-induced photocrosslinking multi-stimulus responsive and programmable gradient hydrogels is green and simple, and the prepared hydrogels have excellent tensile properties.
[0021] 2. The magnetic nanoparticle-induced photocrosslinking multi-stimulus response and programmable gradient hydrogel prepared by the present invention can be driven under thermal stimulation, blue light irradiation and near-infrared light irradiation, and has good reversible cyclicity.
[0022] 3. By adjusting the direction of the applied magnetic field, the present invention can programmatically design the gradient hydrogel's response shape to thermal or near-infrared light stimulation. This gradient hydrogel has potential applications in fields such as biomimetic hydrogels and soft robotics. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 Schematic diagram of the preparation process of gradient hydrogel;
[0024] Figure 2 The atomic percentages of the top and bottom layers of the gradient hydrogel prepared in Example 1;
[0025] Figure 3 This is the SEM image of the gradient hydrogel prepared in Example 1;
[0026] Figure 4 Temperature changes of the gradient hydrogel prepared in Example 2 under irradiation with 980nm near-infrared light of different powers;
[0027] Figure 5 Stress-strain curves of gradient hydrogels prepared in Examples 1, 3, 4, and 5;
[0028] Figure 6 This is a photograph of the deformation of the gradient hydrogel prepared in Example 6 under blue light stimulation;
[0029] Figure 7 These are the deformation images of the gradient hydrogel prepared in Example 7 in 60°C water and 20°C water;
[0030] Figure 8 This is the reversible cycling curve of the gradient hydrogel prepared in Example 8 under near-infrared light driving;
[0031] Figure 9 These are pictures of the gradient hydrogels prepared in Examples 9-12 being driven in 60°C-20°C water and under near-infrared light. DETAILED DESCRIPTION
[0032] The present invention will be further described in detail below with reference to specific embodiments and test examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.
[0033] The raw materials used in the following examples are as follows:
[0034] Carboxyl spiropyran monomer:
[0035] SP2C is preferred.
[0036] Magnetic nanoparticle crosslinker: composed of upconversion nanoparticles, ferroferric oxide and γ-methacryloxypropyltrimethoxysilane. The upconversion nanoparticle structure is LiYF4:Yb 3+ ,Tm 3+ @LiYF4.
[0037] Temperature-sensitive monomer: N-isopropylacrylamide, N,N-dimethylacrylamide, dimethylaminoethyl methacrylate, N-vinylcaprolactam; preferably N-isopropylacrylamide.
[0038] Photoinitiator: (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, 1-hydroxycycloethylphenylacetone, 1-hydroxy-1-methylethylphenylketone.
[0039] Cosolvents: 1,4-dioxane, tetrahydrofuran, methanol, ethanol.
[0040] [Example 1]
[0041] Preparation of gradient hydrogel 1.
[0042] 5 mmol of N-isopropylacrylamide (NIPAAM), 0.4 mol% of carboxyl spiropyran (SP2C), 6 wt% of magnetic nanoparticle crosslinker (MFeUC), 1 mol% of (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide (TPO), 800 μL of 1,4-dioxane, and 200 μL of H2O were mixed and dissolved by ultrasonication. The solution was then injected into a glass mold with a size of 15 mm × 2 mm × 0.5 mm. Then, as shown in FIG. Figure 1 As shown, under the action of magnetic field at 405nm (100mW / cm 2 ) LED light source for 5 min, and then soaked in deionized water for 10 min to prepare gradient hydrogel 1.
[0043] [Example 2]
[0044] Preparation of gradient hydrogel 2.
[0045] 5 mmol of NIPAAM, 0.4 mol% of SP1C, 6 wt% of MFeUC, 1 mol% of TPO, 800 μL of 1,4-dioxane, and 200 μL of H2O were mixed and dissolved by ultrasonication. The solution was then injected into a glass mold with a size of 15 mm × 2 mm × 0.5 mm. Then, the solution was stirred at 405 nm (100 mW / cm2) under the action of a magnetic field. 2 ) LED light source for 5 min, and then soaked in deionized water for 10 min to prepare gradient hydrogel 2.
[0046] [Examples 3-5]
[0047] Prepare gradient hydrogels 3-5.
[0048] The steps of Example 1 were repeated, except that the amount of MFeUC added was different. The amount added and the hydrogel number are shown in Table 1.
[0049] Table 1. Addition amount of MFeUC used in Examples 3-5
[0050] Formula and number Example 3 Example 4 Example 5 MFeUC addition amount (wt%) 2 4 8 Hydrogel No. 3 4 5
[0051] [Examples 6-8]
[0052] Prepare gradient hydrogels 6-8.
[0053] The steps of Example 1 were repeated, except that the temperature-sensitive monomers were different. The hydrogel numbers are shown in Table 2.
[0054] Table 2. Thermosensitive monomers used in Examples 6-8
[0055]
[0056] [Examples 9-12]
[0057] Preparation of gradient hydrogels 9-12.
[0058] The steps of Example 1 were repeated, except that the direction of the magnetic field was different. The hydrogel numbers are shown in Table 3.
[0059] Table 3. Magnetic fields applied at different locations on programmable hydrogels
[0060]
[0061] Test Example 1
[0062] The purpose of this test example is to illustrate that the magnetic nanoparticles in the gradient hydrogel 1 prepared in Example 1 induce the hydrogel composition to be distributed in a gradient from the top layer to the bottom layer under the action of a magnetic field.
[0063] The present invention uses energy dispersive spectroscopy (EDS) technology to characterize the element gradient distribution in the gradient hydrogel 1. Figure 2 As shown in the figure, the atomic percentages of Si, Fe, and Y elements gradually increase from the top to the bottom of the hydrogel. MFeUC is the sole source of Si, Fe, and Y elements in the hydrogel, indicating that the magnetic properties of MFeUC lead to its directional migration under the action of the magnetic field, resulting in a gradient distribution in the hydrogel.
[0064] Test Example 2
[0065] The purpose of this test example is to further illustrate that the cross-linking degree of the hydrogel in the gradient hydrogel 1 prepared in Example 1 changes gradually from the top layer to the bottom layer.
[0066] The cross section of the freeze-dried hydrogel 1 was observed using a JSM-5610LV scanning electron microscope (SEM). Figure 3 It can be seen that the pore size of the cross-linked network structure from the top layer to the bottom layer is distributed in a gradient, which indicates that the cross-linking degree of the hydrogel is distributed in a gradient from the top layer to the bottom layer.
[0067] Test Example 3
[0068] The purpose of this test example is to illustrate that the gradient hydrogel 2 prepared in Example 2 has a good photothermal conversion effect.
[0069] Under irradiation of 980nm near-infrared light of different powers, the temperature change of the gradient hydrogel 2 was monitored using a thermocouple. Figure 4 It can be seen that as the near-infrared light intensity increases, the temperature change (ΔT) of the gradient hydrogel 2 also increases. When the near-infrared light intensity increases to 1.5 W / cm 2When exposed to near-infrared light for 60 seconds, the ΔT value of gradient hydrogel 2 reached 63.5°C. While keeping other experimental conditions unchanged, the intensity of the near-infrared light showed a strong positive correlation with the temperature change of the hydrogel. This result indicates that by adjusting the power of the near-infrared light, the temperature of the gradient hydrogel after photothermal conversion can be effectively controlled.
[0070] Test Example 4
[0071] The purpose of this test example is to illustrate that the addition of MFeUC can improve the tensile properties of the gradient hydrogels 1 and 3-5 prepared in Examples 1 and 3-5.
[0072] Gradient hydrogels 1 and 3-5 were prepared into dumbbell-shaped hydrogel strips of 35 mm × 2 mm × 2 mm. The tensile stress and strain of gradient hydrogels 1 and 3-5 were tested at 25°C using an Instron electronic universal testing machine at a tensile speed of 10 mm / min. Figure 5 As can be seen, as the MFeUC content increases from 2wt% to 8wt%, the fracture stress of the gradient hydrogel gradually increases, from 14kPa to 199kPa, a more than 10-fold increase, while the strain increases from 54% to over 118%, indicating that gradient hydrogels 1, 3-5 have excellent tensile properties.
[0073] Test Example 5
[0074] The purpose of this test example is to illustrate that the gradient hydrogel 6 prepared in Example 6 has fast driving capability.
[0075] The wavelength is 455nm and the intensity is 100mW / cm 2 The blue light was irradiated at a distance of 3 cm from the spline and the blue light driving process of the hydrogel was recorded using a camera. Figure 6 It can be seen that gradient hydrogel 1 can bend 95° within 40 seconds, which indicates that gradient hydrogel 6 has fast actuation capability under blue light.
[0076] Test Example 6
[0077] The purpose of this test example is to illustrate that the gradient hydrogel 7 prepared in Example 7 has good thermal response deformation properties.
[0078] Figure 7 It shows that the gradient hydrogel 7 prepared in Example 7 deformed 630° in 20 seconds in 60°C water. When the hydrogel was placed in 20°C water, the hydrogel gradually recovered, which shows that the prepared gradient hydrogel 7 has excellent temperature-responsive reversible deformation ability.
[0079] Test Example 7
[0080] The purpose of this test example is to illustrate that the gradient hydrogel prepared in Example 8 has fast driving ability and reusability under near-infrared light.
[0081] Figure 8 It is shown that the gradient hydrogel 8 prepared in Example 8 exhibits significant deformation after irradiation with 980nm near-infrared light for 30s, but can quickly recover to its initial state after standing in a dark environment for 2min, and still has good reversible cycling characteristics in 10 consecutive deformation-recovery cycles, indicating that the gradient hydrogel 8 has good reusability.
[0082] Test Example 8
[0083] The purpose of this test example is to illustrate that the gradient hydrogel 9-12 prepared in Examples 9-12 has multiple stimulus responses and programmability in water at 60°C-20°C and under near-infrared light on-off.
[0084] By applying a magnetic field at different positions of the photosensitive precursor solution and fixing the gradient structure by photopolymerization, a series of programmable gradient hydrogel strips were quickly prepared. Figure 9 As shown in (a) and (b), after the gradient hydrogels 9 and 10 are immersed in 60℃ water, they quickly show the shape of "microphone" and "6", respectively, and gradually recover after being placed in 20℃ water. Similarly, under near-infrared light irradiation, the programmed gradient hydrogels 11 and 12 can show the "δ" type and "fishhook" type, with remote control complex response characteristics (such as Figure 9 (c) and (d) show that the hydrogel gradually returns to its original shape after standing in the dark. In summary, a programmable complex shape gradient hydrogel actuator with thermal and near-infrared light response was successfully fabricated by adjusting the magnetic field direction.
[0085] In addition, other hydrogels of the present invention can be synthesized according to the methods in the examples, which will not be described in detail here.
[0086] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.
[0087] The above results indicate that the magnetic nanoparticle-induced photocrosslinked multi-responsive programmable gradient hydrogel provided by the present invention has excellent reusability, multi-stimulus response and programmability.
Claims
1. A magnetic nanoparticle-induced photocrosslinked multi-responsive programmable gradient hydrogel, characterized in that: The precursor solution of the magnetic nanoparticle-induced photocrosslinked multi-responsive programmable gradient hydrogel consists of a carboxyl spiropyran monomer, a magnetic nanoparticle crosslinking agent, a thermosensitive monomer, a photoinitiator and a cosolvent.
2. The magnetic nanoparticle-induced photocrosslinked multi-responsive programmable gradient hydrogel according to claim 1, characterized in that: The carboxyl spiropyran monomer structural formula is: R is independently selected from: -COOH, 3. The magnetic nanoparticle-induced photocrosslinked multi-responsive programmable gradient hydrogel according to claim 1, characterized in that: The magnetic nanoparticle crosslinking agent is composed of up-conversion nanoparticles, ferroferric oxide and γ-methacryloxypropyltrimethoxysilane. The structural formula of the up-conversion nanoparticles is LiYF4:Yb 3+ ,Tm 3+ @LiYF4.
4. The magnetic nanoparticle-induced photocrosslinked multi-responsive programmable gradient hydrogel according to claim 1, characterized in that: The temperature-sensitive monomer is one or a combination of two or more of N-isopropylacrylamide, N,N-dimethylacrylamide, dimethylaminoethyl methacrylate, and N-vinylcaprolactam; preferably, the temperature-sensitive monomer is N-isopropylacrylamide.
5. The magnetic nanoparticle-induced photocrosslinked multi-responsive programmable gradient hydrogel according to claim 1, characterized in that: The photoinitiator is one or a combination of two or more of (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, 1-hydroxycycloethylphenylacetone, and 1-hydroxy-1-methylethylphenyl ketone; preferably, the photoinitiator is (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide.
6. The magnetic nanoparticle-induced photocrosslinking multi-responsive programmable gradient hydrogel according to claim 1, characterized in that: The cosolvent is one or a combination of two or more of 1,4-dioxane, tetrahydrofuran, methanol and ethanol.
7. The magnetic nanoparticle-induced photocrosslinked multi-responsive programmable gradient hydrogel according to claim 1, characterized in that: The carboxyl spiropyran monomer accounts for 0.4 mol% of the total molar mass of the thermosensitive monomer; the magnetic nanoparticle crosslinker accounts for 0-8 wt% of the total mass of the thermosensitive monomer and the carboxyl spiropyran monomer; the photoinitiator accounts for 1 mol% of the total molar mass of the thermosensitive monomer and the carboxyl spiropyran monomer; and the cosolvent content is 1 mL.
8. The method for preparing a magnetic nanoparticle-induced photocrosslinked multi-responsive programmable gradient hydrogel according to any one of claims 1 to 7, characterized in that: The steps include: Different solutions of a magnetic nanoparticle crosslinker, a thermosensitive monomer, a carboxyspiropyran monomer, a photoinitiator, and a cosolvent were injected into a polytetrafluoroethylene mold and allowed to stand for 0.5-2 hours. Subsequently, polymerization was initiated under LED light, and the cosolvent was removed by deionized water treatment to produce a gradient hydrogel.
9. The method for preparing magnetic nanoparticle-induced photocrosslinked multi-responsive programmable gradient hydrogel according to claim 8, characterized in that: The LED light wavelengths are 365nm, 385nm, 395nm and 405nm, and the light intensity is 100mW / cm 2 , the irradiation time is 5-60min.
10. A use of the magnetic nanoparticle-induced photocrosslinking multi-response programmable gradient according to any one of claims 1 to 7, characterized in that: The magnetic nanoparticle-induced photocrosslinking multi-response programmable gradient is applied to intelligent bionic materials, soft robots, optical actuators, and microfluidic valves.