Fish mucus-methacrylated gelatin hydrogel with lubricating and drag-reducing performance and preparation method of fish mucus-methacrylated gelatin hydrogel

Abstract

The invention discloses fish mucus-methacrylated gelatin hydrogel with lubrication and resistance reduction performance and a preparation method of the fish mucus-methacrylated gelatin hydrogel. The preparation process of the hydrogel comprises the following steps: firstly, preparing a methacrylated gelatin hydrogel (GelMA) precursor by utilizing an amidation reaction of methacrylic anhydride (MA) and gelatin (Gel), and then realizing gelation by utilizing hydrogen bond interaction of a fish mucus freeze-dried product (MC) and GelMA and photo-crosslinking of the GelMA precursor and polyethylene glycol diacrylate (PEGDA) under ultraviolet light of 365nm. The mucus-methylacryloylated gelatin hydrogel (MC-GelMA) is obtained after the mucus-methylacryloylated gelatin hydrogel is prepared. The hydrogel prepared by the preparation method disclosed by the invention has excellent swelling resistance and mechanical strength. Meanwhile, the hydrogel also has good lubrication and drag reduction performance, and can be used as a ship drag reduction material.

Description

Technical Field

[0001] The invention relates to a fish mucus-methacrylylated gelatin hydrogel with lubrication and drag reduction performance and a preparation method thereof Background Art

[0002] When solids and fluids move relative to each other, various resistances will be generated. The oil delivery rate of oil pipelines affects our production and life to a certain extent. If the oil delivery volume does not meet the daily production needs, it may cause serious economic losses. Increasing the oil delivery rate of oil pipelines can reduce the friction between pipelines and crude oil and condensate oil, thereby greatly increasing the oil delivery volume and improving the service life of oil pipelines. When ships travel on the water, they will be subject to the friction resistance of water. According to the survey, if the resistance is reduced by 10%, the ship's sailing speed and sailing distance will increase by 3.57% at the same time, which improves the ability of long-distance navigation and reduces energy consumption. Therefore, it is necessary to find a drag reduction material with excellent performance.

[0003] At present, many methods for fluid drag reduction have been proposed, including superhydrophobic drag reduction, soft wall method, bubble method, high polymer additive method, gully method, etc. Superhydrophobic wall surface is easy to lose superhydrophobic properties and drag reduction effect in practical applications. The bubble method also requires additional energy consumption when generating bubbles. High polymer additives are difficult to use in drag reduction of long-distance ships. The gully method is more difficult to prepare gully structures of specific shapes. Flexible wall surface can effectively absorb turbulent kinetic energy through elastic deformation, and then release energy through deformation rebound, which suppresses the pressure pulse of fluid, slows down the transition of boundary layer from laminar flow to turbulent flow, improves the stability of boundary layer, and achieves the purpose of drag reduction. Polyurea elastomer is often used in flexible wall drag reduction, but its preparation process requires high temperature and high pressure; hydrogel flexible wall surface can be used as drag reduction material in medical devices, artificial cartilage, coating and other fields. Methacrylic gelatin hydrogel can be prepared in a short time by photocrosslinking, and the operation is simple, but the mechanical properties of methacrylic gelatin are weak and the swelling rate in water is large.

[0004] Therefore, it is of great significance to prepare a suitable hydrogel flexible wall drag reduction material. Summary of the invention

[0005] The object of the present invention is to provide a fish mucus-methacrylated gelatin hydrogel with lubricating and drag reducing properties and a preparation method thereof. The fish mucus-methacrylated gelatin hydrogel with lubricating and drag reducing properties of the present invention has good anti-swelling properties, mechanical strength and drag reducing properties. The present invention can improve the mechanical properties and anti-swelling ability of the methacrylated gelatin hydrogel by adding fish mucus to the methacrylated gelatin hydrogel.

[0006] The fish mucus-methacrylated gelatin hydrogel with lubricating and drag-reducing properties of the present invention is prepared by utilizing the hydrogen bonding interaction between the fish mucus freeze-dried product (MC) and the methacrylated gelatin hydrogel GelMA precursor and the photocuring cross-linking effect between the GelMA precursor and polyethylene glycol diacrylate (PEGDA). The fish mucus can be firmly combined in the three-dimensional network of the hydrogel without being lost, which is beneficial to long-term drag reduction.

[0007] The preparation method is as follows: extract the mucus of fish (such as loach), centrifuge, freeze-dry, and obtain MC. Dissolve gelatin (Gel) in PBS buffer, heat and stir to dissolve, add DMF, add methacrylic anhydride (MA) dropwise, stir at 40°C for 4h, add ethanol to precipitate the product, dialyze for 3d after centrifugation, and freeze-dry to obtain a GelMA precursor freeze-dried product, dissolve the GelMA precursor freeze-dried product in deionized water, stir at 40°C until dissolved, add PEGDA, MC, (2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone) I2959 photoinitiator, and photocrosslink under ultraviolet light at 365nm to obtain mucus-methacrylylated gelatin hydrogel (MC-GelMA).

[0008] Specific:

[0009] 1) The collected fish mucus was centrifuged at 3000 r / min for 5 min, and the upper bubbles and lower sediment were removed after centrifugation. The intermediate clear liquid was freeze-dried to obtain MC;

[0010] 2) Dissolve Gel in 1×PBS, heat to 40°C and stir to dissolve until it is uniform and transparent, add DMF, add MA dropwise, heat to 40°C and continue stirring for 4h, add ethanol to precipitate the product, put the precipitated product into a centrifuge at 5000r / min, centrifuge for 10min, collect the precipitate and dissolve it in deionized water, dialyze at 40°C for 3d, and then freeze-dry to obtain a lyophilized product of GelMA precursor;

[0011] 3) The lyophilized product of GelMA precursor was dissolved in deionized water, heated to 40°C and stirred until dissolved, PEGDA, a certain amount of MC, and I2959 photoinitiator were added, the solution was introduced into a PTFE mold, and photocrosslinking was performed under ultraviolet light at 365 nm to obtain MC-GelMA hydrogel.

[0012] In the above scheme, further, in the step 2), the amount of Gel relative to MA is 1.25 g Gel / ml MA, at which point theoretically all free amino groups in Gel are replaced by the amidation reaction of MA; the dropping speed of MA in the step 2 is 1 ml / min; the concentration of GelMA in the step 3) is 0.1 g / ml; the mass ratio of GelMA to PEGDA in the step 3) is 1:1; the concentrations of MC and I2959 photoinitiators in the step 3) are 0.5-1 mg / ml and 2.5 mg / ml, respectively.

[0013] The beneficial effects of the present invention are:

[0014] 1. The present invention adopts 1.25g Gel / ml MA, and uses MA to modify Gel, so that the amino group of Gel can be completely grafted with MA to introduce double bonds. The dropping speed of MA is 1ml / min, so that Gel and MA have sufficient time to react, and can be cross-linked into a covalent network under ultraviolet light conditions. The introduction of small molecular weight PEGDA can form an interpenetrating network with GelMA to enhance the strength and mechanical properties of the hydrogel. The introduction of MC can produce hydrogen bond interaction with GelMA to enhance the mechanical properties and lubrication and drag reduction capabilities.

[0015] 2. In the present invention, GelMA, MC and PEGDA are prepared by a one-pot method. The preparation method is simple, but attention should be paid to the ratio of various raw materials. If the ratio is not appropriate, the mechanical properties and drag reduction ability will be reduced.

[0016] 3. The MC-GelMA prepared by the present invention has excellent drag reduction performance on epoxy resin, aluminum alloy and glass. At the same time, the hydrogel has good mechanical strength and anti-swelling performance. It can be used as a ship drag reduction material. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 (a) is a schematic diagram of the preparation mechanism of GelMA, and (b) is a schematic diagram of the preparation mechanism of the fish mucus-methacrylylated gelatin hydrogel with lubrication and drag reduction performance of the present invention;

[0018] Figure 2 is the H NMR spectrum of MA, Gel, and GelMA;

[0019] Figure 3 is the infrared spectra of MC-GelMA3, MC, and GelMA;

[0020] Figure 4(a) shows the dissolution of loach mucus in different solutions for 10 min, (b) shows the dissolution of loach mucus in different solutions for 30 min, (c) shows the dissolution of loach mucus in different solutions for 1 h, and (d) shows the dissolution of loach mucus in different solutions for 3 h.

[0021] Figure 5 (a) is the swelling ratio of Gel, GelMA, MC-GelMA1, MC-GelMA2, and MC-GelMA3 in deionized water for 7 days, (b) is the swelling ratio of Gel, GelMA, MC-GelMA1, MC-GelMA2, and MC-GelMA3 in artificial seawater for 7 days; MC-GelMA1, MC-GelMA2, and MC-GelMA3 represent that the concentration of MC in step 3) is 0.5 mg / ml, 0.75 mg / ml, and 1 mg / ml, respectively;

[0022] Figure 6 are the compression curves of Gel, GelMA, and MC-GelMA3;

[0023] Figure 7 (a) is the amplitude scanning diagram of Gel, GelMA, and MC-GelMA, (b) is the frequency scanning diagram of Gel, GelMA, and MC-GelMA;

[0024] Figure 8 It is the friction coefficient between plastic wrap, plastic wrap + MC, MC-GelMA and epoxy resin, aluminum alloy and glass. DETAILED DESCRIPTION

[0025] The present invention is further described below with reference to the accompanying drawings and specific examples.

[0026] The schematic diagram of the preparation mechanism of the fish mucus-methacrylated gelatin hydrogel with lubrication and drag reduction performance of the present invention is as follows Figure 1 As shown. MA reacts with the free amino groups in Gel through an amidation reaction to prepare the GelMA precursor, and then the GelMA precursor is cross-linked with PEGDA and MC under ultraviolet light at 365nm to initiate double bonds for photocuring, wherein PEGDA is used as a cross-linking agent for photocuring, and MC reacts with its inherent amino groups and hydroxyls and the residual amino groups and hydroxyls of GelMA to produce hydrogen bonds. The above multiple effects synergistically endow the hydrogel with excellent properties. Fish mucus can be firmly bound to the three-dimensional network of the hydrogel without being lost, which is beneficial to long-term drag reduction. MA, Gel, and GelMA 1 H NMR spectra Figure 2 As shown, 1 appeared on GelMA ’ 2 ’The two characteristic peaks are generated by the successful grafting of MA onto Gel and the introduction of hydrogen on the double bond. ’ It is the characteristic peak produced by the unreacted amino group in gelatin. Figure 3 Shown at 3350-3300cm -1 The peak at 1650cm is the stretching vibration peak of the intermolecular hydrogen bond. The absorption peak of MC-GelMA3 is enhanced relative to that of GelMA because MC forms a hydrogen bond with GelMA. -1 The peak at 1100 cm is the characteristic peak of the amide group. The absorption intensity of the MC-GelMA3 sample is greater than that of GelMA. This result shows that the protein in the mucus is successfully grafted and cross-linked to GelMA. -1 The absorption peak is generated by the stretching vibration of CO. The stretching vibration intensity of MC-GelMA3 sample is greater than that of GelMA. This result shows that the fat in the mucus is successfully grafted and cross-linked to GelMA. The above shows that the fish mucus is successfully grafted and cross-linked to GelMA. The dissolution state of MC in various solutions is as follows Figure 4 As shown in the figure, MC becomes transparent and completely soluble in deionized water after 1 hour. MC is white and turbid in acetone, dilute acid, and ethyl acetate, and is clumpy in 70% ethanol, with no obvious dissolution. Figure 5 As shown in the figure, the swelling rate of Gel in deionized water and artificial seawater is greater than 100% and then begins to degrade. The swelling rates of GelMA, MC-GelMA1, MC-GelMA2, and MC-GelMA3 in deionized water and artificial seawater are all less than 25% within 7 days. Figure 6 As shown in Figure 2, photocuring crosslinking and the addition of MC can enhance the compression resistance of hydrogels. Figure 7 As shown in the figure, the strain scan shows that the linear viscoelastic region of the three hydrogels is between 0.01 and 0.4. The strain of 0.01 is selected for frequency scan, and it is found that the elastic modulus (G') is greater than the storage modulus (G"), and they are all gel-like within the frequency range. Drag reduction test Figure 8 As shown in the figure, both MC and GelMA can reduce the static friction coefficient, and MC-GelMA3 modified by MC has better drag reduction effect.

[0027] Embodiment 1:

[0028] 1) Put the clean and intact loach into a ziplock bag, rub it to make it secrete mucus, collect the mucus in a centrifuge at 3000r / min for 5min, remove the upper bubbles and the lower sediment after centrifugation, take the middle clear liquid for freeze-drying, and obtain MC;

[0029] 2) Dissolve 10g of Gel in 200ml of 1×PBS, heat to 40°C and stir to dissolve until uniform and transparent, add 330ml of DMF, add 8ml of MA to the above solution at a rate of 1ml / min, heat to 40°C and continue stirring for 4h, add ethanol to precipitate the product, put the precipitated product into a centrifuge at 5000r / min, centrifuge for 10min, collect the precipitate and dissolve it in deionized water, dialyze at 40°C for 3d, and then freeze-dry to obtain a lyophilized product of GelMA precursor;

[0030] 3) Dissolve 1 g of GelMA precursor freeze-dried product in 10 ml of deionized water, heat to 40°C and stir until dissolved, add 1 g of PEGDA, 0.005 g of MC, and 0.025 g of I2959 photoinitiator, introduce the solution into a polyfluoroethylene mold, and perform photocrosslinking under ultraviolet light at 365 nm to obtain MC-GelMA1 hydrogel.

[0031] The maximum swelling rate of the MC-GelMA1 hydrogel prepared in this example in deionized water within 7 days is 23.36%, and the maximum swelling rate in artificial seawater within 7 days is 17.26%. The hydrogel has certain compression resistance and drag reduction performance.

[0032] Embodiment 2:

[0033] 1) Put the clean and intact loach into a ziplock bag, rub it to make it secrete mucus, collect the mucus in a centrifuge at 3000r / min for 5min, remove the upper bubbles and the lower sediment after centrifugation, take the middle clear liquid for freeze-drying, and obtain MC;

[0034] 2) Dissolve 10g of Gel in 200ml of 1×PBS, heat to 40°C and stir to dissolve until uniform and transparent, add 330ml of DMF, add 8ml of MA to the above solution at a rate of 1ml / min, heat to 40°C and continue stirring for 4h, add ethanol to precipitate the product, put the precipitated product into a centrifuge at 5000r / min, centrifuge for 10min, collect the precipitate and dissolve it in deionized water, dialyze at 40°C for 3d, and then freeze-dry to obtain a lyophilized product of GelMA precursor;

[0035] 3) Dissolve 1 g of GelMA precursor freeze-dried product in 10 ml of deionized water, heat to 40°C and stir until dissolved, add 1 g of PEGDA, 0.0075 g of MC, and 0.025 g of I2959 photoinitiator, introduce the solution into a polyfluoroethylene mold, and perform photocrosslinking under ultraviolet light at 365 nm to obtain MC-GelMA2 hydrogel.

[0036] The maximum swelling rate of the MC-GelMA hydrogel prepared in this example in deionized water within 7 days is 23.26%, and the maximum swelling rate in artificial seawater within 7 days is 24.30%. The hydrogel has certain compression resistance and drag reduction performance.

[0037] Embodiment 3:

[0038] 1) Put the clean and intact loach into a ziplock bag, rub it to make it secrete mucus, collect the mucus in a centrifuge at 3000r / min for 5min, remove the upper bubbles and the lower sediment after centrifugation, take the middle clear liquid for freeze-drying, and obtain MC;

[0039] 2) Dissolve 10g of Gel in 200ml of 1×PBS, heat to 40°C and stir to dissolve until uniform and transparent, add 330ml of DMF, add 8ml of MA to the above solution at a rate of 1ml / min, heat to 40°C and continue stirring for 4h, add ethanol to precipitate the product, put the precipitated product into a centrifuge at 5000r / min, centrifuge for 10min, collect the precipitate and dissolve it in deionized water, dialyze at 40°C for 3d, and then freeze-dry to obtain a lyophilized product of GelMA precursor;

[0040] 3) Dissolve 1 g of GelMA precursor freeze-dried product in 10 ml of deionized water, heat to 40°C and stir until dissolved, add 1 g of PEGDA, 0.01 g of MC, and 0.025 g of I2959 photoinitiator, introduce the solution into a polyfluoroethylene mold, and perform photocrosslinking under ultraviolet light at 365 nm to obtain MC-GelMA3 hydrogel.

[0041] The maximum swelling rate of the MC-GelMA hydrogel prepared in this example in deionized water within 7 days is 19.92%, and the maximum swelling rate in artificial seawater within 7 days is 18.58%. The hydrogel has certain compression resistance and drag reduction performance.

Claims

1. A fish mucus-methacrylated gelatin hydrogel with lubricating and drag reducing properties, characterized in that: The hydrogel realizes gelation by hydrogen bond interaction between MC and GelMA precursor and photocuring crosslinking between GelMA precursor and PEGDA; the preparation method of the hydrogel comprises the following steps: extracting fish mucus, centrifuging and freeze-drying to obtain MC, dissolving Gel in PBS buffer, heating and stirring to dissolve, adding DMF, adding MA dropwise, stirring at 40°C for 4h, adding ethanol to precipitate the product, dialyzing for 3d after centrifugation, freeze-drying to obtain a GelMA precursor freeze-dried product, dissolving the GelMA precursor freeze-dried product in deionized water, stirring at 40°C until dissolved, adding PEGDA, MC and I2959 photoinitiator, and photocrosslinking under ultraviolet light to obtain MC-GelMA.

2. The method for preparing a fish mucus-methacrylated gelatin hydrogel having lubricating and drag reducing properties as claimed in claim 1, characterized in that: The specific preparation steps include: 1) The collected fish mucus was centrifuged at 3000 r / min for 5 min, and the upper bubbles and lower sediment were removed after centrifugation. The intermediate clear liquid was freeze-dried to obtain MC; 2) Dissolve Gel in 1×PBS, heat to 40°C and stir to dissolve until it is uniform and transparent, add DMF, add MA dropwise, heat to 40°C and continue stirring for 4h, add ethanol to precipitate the product, put the precipitated product into a centrifuge at 5000r / min, centrifuge for 10min, collect the precipitate and dissolve it in deionized water, dialyze at 40°C for 3d, and then freeze-dry to obtain a lyophilized product of GelMA precursor; 3) Dissolve the lyophilized GelMA precursor in deionized water, heat to 40°C and stir until dissolved, add PEGDA, MC, and I2959 photoinitiator, and photocrosslink the solution under ultraviolet light at 365 nm.

3. The method for preparing the fish mucus-methacrylated gelatin hydrogel with lubrication and drag reduction performance as claimed in claim 2, characterized in that: In the step 2), the amount of Gel relative to MA is 1.25 g Gel / ml MA.

4. The method for preparing the fish mucus-methacrylated gelatin hydrogel with lubrication and drag reduction performance according to claim 2, characterized in that: The dropping speed of MA in the step 2) is 1 ml / min.

5. The method for preparing the fish mucus-methacrylated gelatin hydrogel with lubrication and drag reduction performance as claimed in claim 2, characterized in that: The concentration of GelMA in step 3) is 0.1 g / ml.

6. The method for preparing the fish mucus-methacrylated gelatin hydrogel with lubrication and drag reduction performance according to claim 2, characterized in that: In the step 3), the mass ratio of GelMA to PEGDA is 1:

1.

7. The method for preparing the fish mucus-methacrylated gelatin hydrogel with lubrication and drag reduction performance as claimed in claim 2, characterized in that: In the step 3), the concentrations of MC and I2959 photoinitiators are 0.5-1 mg / ml and 2.5 mg / ml respectively.

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