A high-toughness supramolecular hydrogel with adjustable interfacial hydration characteristics, and a preparation method and application thereof

Abstract

This invention relates to the field of supramolecular copolymer hydrogel technology, specifically to a high-strength and tough supramolecular hydrogel with tunable interfacial hydration properties, its preparation method, and its applications. This invention uses N-acryloylaminourea (NASC) monomer and a sulfonate-containing monomer (lubricating molecule) as raw materials, and adds a photoinitiator. A prepolymer solution of an organic solvent and water mixture is prepared using the dehydrogenation effect of an organic solvent. Crosslinking polymerization is carried out under ultraviolet light irradiation to obtain a supramolecular hydrogel. Then, water equilibrium is achieved to obtain a high-strength and tough supramolecular hydrogel with tunable interfacial hydration properties. The high-strength and tough supramolecular hydrogel prepared by this invention possesses high water content, excellent lubrication properties, mechanical properties, structural stability, and long-term service reliability, exhibiting excellent comprehensive performance and meeting the synergistic requirements of multi-dimensional material performance in complex engineering scenarios or biomedical fields.

Description

Technical Field

[0001] This invention relates to the field of supramolecular copolymer hydrogel technology, specifically to a high-strength and tough supramolecular hydrogel with adjustable interfacial hydration properties, its preparation method, and its applications. Background Technology

[0002] Hydrogen bonds are the most widespread and important form of molecular interaction in living organisms, maintaining the conformation of natural macromolecules such as proteins and DNA, enabling them to perform their corresponding biological functions. N-acryloylaminourea polymers (PNASC) exhibit excellent mechanical properties, demonstrating outstanding advantages in key mechanical indicators such as strength and modulus, meeting the requirements for material structural stability in various engineering applications. However, this polymer has a high coefficient of surface friction, leading to severe wear aggravation in conditions involving dynamic contact and relative motion. Therefore, it is urgent to optimize its lubrication performance through reasonable modification strategies to expand its application range in related fields. Currently, the core lubricating components of various developed biocompatible lubricating materials cover phospholipid molecules (such as phosphocholine compounds), anionic and cationic macromolecules (typically represented by betaine-type polymers), and natural hydrophilic lubricating macromolecules (including bio-derived materials such as chondroitin sulfate and gelatin). While these materials exhibit excellent lubrication performance due to their specific chemical structures and mechanisms of action, effectively reducing interfacial friction and improving sliding characteristics, they have significant shortcomings in key application indicators such as mechanical strength, structural stability, and long-term service reliability. Their overall performance fails to meet the synergistic requirements of complex engineering scenarios or the biomedical field for multi-dimensional material properties. Therefore, developing hydrogels that combine lubrication with mechanical strength, structural stability, and long-term service reliability is of great significance. Summary of the Invention

[0003] Therefore, the purpose of this invention is to provide a high-strength and tough supramolecular hydrogel with tunable interfacial hydration properties, its preparation method, and its applications. The high-strength and tough supramolecular hydrogel with tunable interfacial hydration properties prepared by this invention (hereinafter referred to as high-strength and tough supramolecular hydrogel) possesses both high water content and excellent lubrication properties, mechanical properties, structural stability, and long-term service reliability.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for preparing a high-strength, tough supramolecular hydrogel with tunable interfacial hydration properties, comprising the following steps: N-acryloylaminourea monomer, sulfonate-containing monomer, initiator, organic solvent, and water are mixed to obtain a precursor solution. The precursor solution is then subjected to a crosslinking polymerization reaction under ultraviolet light irradiation to obtain a supramolecular hydrogel. The sulfonate-containing monomer includes one or more of sulfonic acid monomers, sulfonate monomers, and sulfonic acid inner salt monomers. The molar amount of the sulfonate-containing monomer is 4-12% of the molar amount of the N-acryloylaminourea monomer. The organic solvent is a good solvent for N-acryloylaminourea monomer with dehydrogenation bonding function. The supramolecular hydrogel was subjected to water equilibrium to obtain a high-strength and tough supramolecular hydrogel with tunable interfacial hydration properties.

[0005] Preferably, the sulfonic acid monomer includes 2-acrylamide-2-methylpropanesulfonic acid; The sulfonate monomers include potassium 3-sulfopropyl acrylate; The sulfonic acid inner salt monomers include N-(3-sulfopropyl)-N-methacryloyloxyethyl-N,N-dimethylammonium betaine.

[0006] Preferably, the organic solvent includes dimethyl sulfoxide.

[0007] Preferably, the photoinitiator comprises lithium phenyl (2,4,6-trimethylbenzoyl) phosphate; The mass of the photoinitiator is 0.1 to 1% of the total mass of N-acryloylaminourea monomer and sulfonate group-containing monomer.

[0008] Preferably, the wavelength of the ultraviolet light is 405 nm, and the time of the crosslinking polymerization reaction is 10 to 30 seconds.

[0009] Preferably, the mass of the water used for water balance is 80 to 100 times the mass of the supramolecular hydrogel; The time required for water balance to be achieved is 7 to 10 days.

[0010] Preferably, the mixture includes: N-Acryloylaminourea was dissolved in an organic solvent to obtain an N-acryloylaminourea solution; The monomer containing the sulfonate group is dissolved in water to obtain a solution of the monomer containing the sulfonate group; The photoinitiator is dissolved in water to obtain a photoinitiator solution; The N-acryloylaminourea solution, the monomer solution containing sulfonate groups, and the photoinitiator solution are mixed.

[0011] Preferably, the mass concentration of the N-acryloylaminourea solution is 5-30%. The mass concentration of the monomer solution containing sulfonate groups is 5-40%; The initiator solution has a mass concentration of 0.05-5%; The mixing includes ultrasonic mixing, and the ultrasonic mixing time is 1 to 2 minutes.

[0012] The present invention also provides a high-strength and tough supramolecular hydrogel with adjustable interfacial hydration properties prepared by the preparation method described above.

[0013] This invention also provides the application of the high-strength and tough supramolecular hydrogel with adjustable interfacial hydration properties described in the above technical solution in the preparation of materials in the biomedical field.

[0014] This invention uses N-acryloylaminourea (NASC) monomer and monomers containing sulfonate groups as raw materials, and adds a photoinitiator. A prepolymer solution of an organic solvent and water mixture is prepared by utilizing the dehydrogenation effect of an organic solvent. Crosslinking polymerization is then carried out under ultraviolet light irradiation to obtain a supramolecular hydrogel. After water equilibrium is achieved, a high-strength and tough supramolecular hydrogel with tunable interfacial hydration properties is obtained. The N-acryloylaminourea (NASC) monomer used in this invention has multiple hydrogen bonds and double bonds, enabling it to undergo free radical polymerization reactions to form a polymer network structure. Furthermore, the side groups of the NASC monomer contain urea functional groups, which can achieve hydrogen bond reconstruction through a solvent-induced phase inversion process, forming a hydrogen-bonded physical crosslinking network. This invention utilizes a supramolecular chemical solvent-induced phase transition hydrogen bond reconstruction strategy to introduce a functional lubricating component (a polymer containing monomers with sulfonate groups) into a PNASC polymer. During the phase transition, hydrogen bond reconstruction of the NNASC monomers and self-assembly of the lubricating molecules (monomers containing sulfonate groups) are induced, forming a high-strength and tough supramolecular hydrogel with a hydrogen bond network supporting phase and self-assembled hydration groups. This resolves the contradiction between high water content and high strength and toughness in current bio-lubricating hydrogels. Furthermore, the water content and number of hydrogen bonds in the high-strength and tough supramolecular hydrogel can be widely controlled by selecting different types of hydration groups (sulfonate monomers, sulfonate monomers, and sulfonate inner salt monomers) and adjusting their addition amounts, thus balancing the mechanical and tribological performance requirements. The high-strength and tough supramolecular hydrogel prepared by this invention possesses high water content, excellent lubrication performance, mechanical properties, structural stability, and long-term service reliability, exhibiting superior comprehensive performance and meeting the synergistic requirements of multi-dimensional material performance in complex engineering scenarios or biomedical fields.

[0015] As shown in the test results of the embodiments of the present invention, the high-strength and tough supramolecular hydrogel prepared by the present invention has an average water content of 39.1~86.9wt%; an average friction coefficient of 0.0485~0.146, which remains stable during 50,000 reciprocating friction cycles; an average tensile fracture strength of 1.99~6.58MPa; an average elastic modulus of 1.33~122MPa; and an average compressive strength of 1.48~9.78 and an average compressive modulus of 0.88~45.4MPa under 50% compression. This indicates that the high-strength and tough supramolecular hydrogel prepared by the present invention possesses high water content, excellent lubrication properties, mechanical properties, structural stability, and long-term service reliability, exhibiting excellent comprehensive performance.

[0016] This invention has found that, with the development of P(NASC / AMPS) X High-strength and tough supramolecular hydrogels and P(NASC / SAP) X The increase in the number of sulfonic acid and sulfonate groups in high-strength and tough supramolecular hydrogels leads to varying degrees of increase in water content and a decrease in mechanical properties. Under the combined effect of these two factors, the coefficient of friction initially decreases and then increases. Meanwhile, P(NASC / SBMA) X High-strength and tough supramolecular hydrogels are different; their water content and mechanical properties do not change with the increase of ionic groups, and their coefficient of friction shows a slow increasing trend. Attached Figure Description

[0017] Figure 1 A schematic diagram of the molecular design of a high-strength and tough supramolecular hydrogel; Figure 2 The images show (a), friction coefficient (b), tensile curve (c), and compression curve (d) of the PNASC polymer supramolecular hydrogel prepared in Comparative Example 1, where the inset in b is the contact angle. Figure 3 These are physical images of the high-strength and tough supramolecular hydrogels prepared in Examples 1-9, where a represents P(NASC / AMPS) with an AMPS addition amount of 4-12 mol% of NASC monomer. X (Image of actual product, b) shows SAP with an addition amount of 4-12 mol% of NASC monomer, P(NASC / SAP) X (Image showing physical product; c represents P(NASC / SBMA) with an SBMA addition amount of 4-12 mol% of the NASC monomer.) X (A physical display image, where x represents the molar percentage of sulfonic acid monomers in NASC;) Figure 4The diagram shows the water content and contact angle of the high-strength and tough supramolecular hydrogels prepared in Examples 1-9, where a represents P(NASC / AMPS) with an AMPS addition amount of 4-12 mol% of NASC monomer. X The moisture content and contact angle of ) are given, and b is the amount of SAP added at 4~12 mol% of NASC monomer, where P(NASC / SAP) is the concentration of NASC. X The moisture content and contact angle of ) are given, where c is the amount of SBMA added as 4-12 mol% of the NASC monomer, and P(NASC / SBMA) is used. X The moisture content and contact angle of the sample. Figure 5 The graph shows the friction coefficients of the high-strength and tough supramolecular hydrogels prepared in Examples 1-9, where a represents the coefficient of friction of P(NASC / AMPS) with an AMPS addition of 4-12 mol% of NASC monomer. X The friction coefficient of ), b is the amount of SAP added at 4~12 mol% of NASC monomer, P(NASC / SAP) X The friction coefficient of ) is c, where the amount of SBMA added is 4~12 mol% of the NASC monomer, and P(NASC / SBMA) is the coefficient of friction. X The coefficient of friction; Figure 6 The figures show the tensile properties of the high-strength and tough supramolecular hydrogels prepared in Examples 1-9, where a represents P(NASC / AMPS) with an AMPS addition of 4-12 mol% of NASC monomer. X The tensile stress-strain curves of P(NASC / SAP) are shown in Figure 1, where b represents the amount of SAP added at 4-12 mol% of NASC monomer. X The tensile stress-strain curves of P(NASC / SBMA) are shown, where c represents the amount of SBMA added at 4-12 mol% of the NASC monomer. X The tensile stress-strain curve of ). Figure 7 The graphs show the compression properties of the high-strength and tough supramolecular hydrogels prepared in Examples 1-9, where a represents P(NASC / AMPS) with an AMPS addition amount of 4-12 mol% of NASC monomer. X The compressive stress-strain curves of P(NASC / SAP) are shown in Figure 1. Figure 2 shows the compressive stress-strain curves of P(NASC / SAP) with an SAP addition amount of 4–12 mol% of NASC monomer. X The compressive stress-strain curves of P(NASC / SBMA) are shown, where c represents the amount of SBMA added at 4-12 mol% of the NASC monomer. X The compressive stress-strain curve; Figure 8 The diagram shows the ultra-long wear resistance of the high-strength and tough supramolecular hydrogels prepared in Examples 2, 5 and 7. Detailed Implementation

[0018] This invention provides a method for preparing a high-strength, tough supramolecular hydrogel with tunable interfacial hydration properties, comprising the following steps: N-acryloylaminourea monomer, sulfonate-containing monomer, initiator, organic solvent, and water are mixed to obtain a precursor solution. The precursor solution is then subjected to a crosslinking polymerization reaction under ultraviolet light irradiation to obtain a supramolecular hydrogel. The sulfonate-containing monomer includes one or more of sulfonic acid monomers, sulfonate monomers, and sulfonic acid inner salt monomers. The molar amount of the sulfonate-containing monomer is 4-12% of the molar amount of the N-acryloylaminourea monomer. The organic solvent is a good solvent for N-acryloylaminourea monomer with dehydrogenation bonding function. The supramolecular hydrogel was subjected to water equilibrium to obtain a high-strength and tough supramolecular hydrogel with tunable interfacial hydration properties.

[0019] Unless otherwise specified, the materials and equipment used in this invention are all commercially available products in the field.

[0020] This invention involves mixing N-acryloylaminourea monomer, a sulfonate-containing monomer, an initiator, an organic solvent, and water to obtain a precursor solution. The precursor solution is then subjected to a crosslinking polymerization reaction under ultraviolet light irradiation to obtain a supramolecular hydrogel. The sulfonate-containing monomer includes one or more of sulfonic acid monomers, sulfonate monomers, and sulfonic acid inner salt monomers. The molar amount of the sulfonate-containing monomer is 4-12% of the molar amount of the N-acryloylaminourea monomer. The organic solvent is a good solvent for N-acryloylaminourea monomer with dehydrogenation bonding capabilities.

[0021] In this invention, the NASC monomer can be a commercially available product or be prepared in-house. This invention does not impose any special limitations on the preparation method of the NASC monomer, and adopts a preparation method of NASC monomer that is well known to those skilled in the art.

[0022] In this invention, the sulfonic acid monomer includes one or more of sulfonic acid monomers, sulfonate monomers, and sulfonic acid inner salt monomers, and may also be sulfonic acid monomers, sulfonate monomers, or sulfonic acid inner salt monomers; the sulfonic acid monomer may include 2-acrylamido-2-methylpropanesulfonic acid (AMPS); the sulfonate monomer may include potassium 3-sulfopropylacrylate (SAP); the sulfonic acid inner salt monomer may include N-(3-sulfopropyl)-N-methacryloyloxyethyl-N,N-dimethylammonium betaine (SBMA). In this invention, the molar amount of the monomer containing the sulfonate group is 4-12% of the molar amount of the N-acryloylaminourea monomer, and may also be 5-10%, specifically 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, or 12%. This invention uses sulfonic acid monomers as lubricating molecules. The lubricating phase can be controlled over a wide range of water content and hydrogen bond number of high-strength and tough supramolecular hydrogels by selecting different types of hydration groups (sulfonic acid monomers, sulfonate monomers and sulfonic acid inner salt monomers) and adjusting their addition amount, thus balancing the mechanical and tribological properties of high-strength and tough supramolecular hydrogels.

[0023] In this invention, the photoinitiator may include lithium phenyl (2,4,6-trimethylbenzoyl)phosphate. In this invention, the mass of the photoinitiator may be 0.1-1% of the total mass of N-acryloylaminourea monomer and sulfonate-containing monomer, or 0.2-0.4%, specifically 0.1%, 0.2%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.3%, 0.31%, 0.35%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1%.

[0024] In this invention, the organic solvent may include DMSO.

[0025] In this invention, the water may include ultrapure water; the resistivity of the ultrapure water may be 18.2 MΩ·cm. In this invention, the mass ratio of the organic solvent to water may be 1.5~4:1, or 2~3.5:1, specifically 3:1.

[0026] In this invention, the mixing may include: dissolving N-acryloylaminourea in an organic solvent to obtain an N-acryloylaminourea solution; dissolving a monomer containing a sulfonate group in water to obtain a monomer solution containing a sulfonate group; dissolving a photoinitiator in water to obtain a photoinitiator solution; and mixing the N-acryloylaminourea solution, the monomer solution containing a sulfonate group, and the photoinitiator solution.

[0027] This invention involves dissolving N-acryloylaminourea in an organic solvent to obtain an N-acryloylaminourea solution. In this invention, the mass concentration of the N-acryloylaminourea solution can be 5-50%, or 20-40%, specifically 5%, 10%, 15%, 20%, 25%, 30%, 35%, 38%, 40%, 45%, or 50%. In this invention, the dissolution temperature can be 80-95℃, specifically 90℃; during the dissolution process, the solution is shaken once every 3-10 minutes (specifically 3, 5, 7, 9, or 10 minutes); the dissolution time can be 30-40 minutes, or 30-35 minutes.

[0028] This invention involves dissolving a monomer containing a sulfonate group in water to obtain a monomer solution containing a sulfonate group. In this invention, the mass concentration of the monomer solution containing the sulfonate group can be 5-40%, or 10-35%, specifically 5%, 10%, 10.7%, 11.9%, 14.0%, 15%, 19.4%, 20%, 21.3%, 24.5%, 25%, 28.8%, 30%, 32.7%, 35%, 38%, or 40%. In this invention, the monomer solution containing sulfonate groups may include a sulfonic acid monomer solution, a sulfonate monomer solution, or a sulfonic acid inner salt monomer solution; the mass concentration of the sulfonic acid monomer solution may be 10.7% to 26.5%, specifically 10.7%, 19.4%, or 26.5%; the mass concentration of the sulfonate monomer solution may be 11.9% to 28.8%, specifically 11.9%, 21.3%, or 28.8%; and the concentration of the sulfonic acid inner salt monomer solution may be 14.0% to 32.7%, specifically 14.0%, 24.5%, or 32.7%. In this invention, the dissolution temperature may be room temperature (18-25°C).

[0029] This invention involves dissolving a photoinitiator in water to obtain a photoinitiator solution. In this invention, the mass concentration of the initiator solution is 0.05-5%, and can also be 0.1-0.3%, specifically 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, or 0.5%. In this invention, the dissolution can be carried out at room temperature (18-25°C).

[0030] This invention involves mixing the N-acryloylaminourea solution, the monomer solution containing sulfonate groups, and the photoinitiator solution. In this invention, the mixing may include ultrasonic mixing, the ultrasonic mixing time of which may be 1-2 minutes or 1-1.5 minutes; the mixing temperature may be at room temperature (18-25°C).

[0031] In this invention, the wavelength of the ultraviolet light is 405 nm; the time of the crosslinking polymerization reaction can be 10-30 seconds, or 10-20 seconds, specifically 10 seconds, 15 seconds, 20 seconds, 25 seconds or 30 seconds; the crosslinking polymerization reaction is carried out at room temperature.

[0032] After obtaining the supramolecular hydrogel, the present invention performs water equilibration on the supramolecular hydrogel to obtain a high-strength and tough supramolecular hydrogel with adjustable interfacial hydration properties.

[0033] In this invention, the mass of the water used for water equilibration is 80-100 times, or even 90-100 times, the mass of the supramolecular hydrogel; the water can be ultrapure water with a resistivity of 18.2 MΩ·cm. The water equilibration time can be 7-10 days, or even 7-8 days, specifically 7, 7.5, 8, 8.5, 9, 9.5, or 10 days; the water equilibration can be carried out at room temperature (18-25°C). During the water equilibration process, this invention utilizes a supramolecular chemical solvent-induced phase transition hydrogen bond reconstruction strategy and introduced lubricating components to induce hydrogen bond reconstruction and lubricating molecule self-assembly during the phase transition, forming a hydrogel-supporting phase with a hydrogen bond network and a lubricating phase with self-assembled hydrated groups, thus resolving the contradiction between high water content and high strength and toughness in current biological lubricating hydrogels.

[0034] Figure 1 This is a schematic diagram of the molecular design of a high-strength and tough supramolecular hydrogel. Specifically, urea groups are introduced on the left to construct a multiple hydrogen bond network, thereby significantly improving the strength of the hydrogel. Strong hydration groups, such as sulfonic acid groups, including acids, salts, and internal salts, are introduced on the right. These groups can form a dense hydrated layer on the material surface, significantly reducing the interfacial friction coefficient and improving the material's lubrication performance through strong hydration. The unsaturated double bonds at the ends of the molecular chains are used for polymerization cross-linking to form a stable three-dimensional network structure.

[0035] The present invention also provides a high-strength and tough supramolecular hydrogel with adjustable interfacial hydration properties prepared by the preparation method described above.

[0036] In this invention, the water content of the high-strength and tough supramolecular hydrogel with adjustable interfacial hydration properties can be 30-90%, or 39.1-86.9%, specifically 39.1%, 39.2%, 40.1%, 44.3%, 49.2%, 64.3%, 66.8%, 78.7%, or 86.9%. When the monomer containing sulfonate groups is AMPS, the water content can be 49.2-86.9%; when the monomer containing sulfonate groups is SAP, the water content can be 44.3-78.7%; and when the monomer containing sulfonate groups is SBMA, the water content can be 39.1-40.1%.

[0037] In this invention, the friction coefficient of the high-strength and tough supramolecular hydrogel with adjustable interfacial hydration properties can be 0.04~0.15, or 0.0485~0.146, specifically 0.0485, 0.0546, 0.0633, 0.0759, 0.0796, 0.0871, 0.106, 0.126, or 0.146; when the monomer containing sulfonate groups is AMPS, the friction coefficient can be 0.0546~0.106; when the monomer containing sulfonate groups is SAP, the friction coefficient can be 0.0485~0.0796; when the monomer containing sulfonate groups is SBMA, the friction coefficient can be 0.0871~0.146.

[0038] In this invention, the tensile fracture strength of the high-strength and tough supramolecular hydrogel with adjustable interfacial hydration properties can be 1.5~7 MPa, or 1.99~6.58 MPa, specifically 1.99 MPa, 3.99 MPa, 4.07 MPa, 4.27 MPa, 4.41 MPa, 5.81 MPa, 6.18 MPa, or 6.58 MPa; when the monomer containing the sulfonate group is AMPS, the tensile fracture strength can be 1.99~6.18 MPa; when the monomer containing the sulfonate group is SAP, the tensile fracture strength can be 4.27~6.58 MPa; when the monomer containing the sulfonate group is SBMA, the tensile fracture strength can be 4.07~6.18 MPa.

[0039] In this invention, the elastic modulus of the high-strength and tough supramolecular hydrogel with adjustable interfacial hydration properties can be 1~130 MPa, or 1.33~122 MPa, specifically 1.33 MPa, 2.11 MPa, 2.79 MPa, 7.72 MPa, 50.5 MPa, 92.9 MPa, 112 MPa, 119 MPa, or 122 MPa; when the monomer containing the sulfonate group is AMPS, the elastic modulus can be 1.33~50.5 MPa; when the monomer containing the sulfonate group is SAP, the elastic modulus can be 2.79~92.9 MPa; when the monomer containing the sulfonate group is SBMA, the elastic modulus can be 112~122 MPa.

[0040] In this invention, the compressive strength of the high-strength and tough supramolecular hydrogel with adjustable interfacial hydration properties can be 1~10 MPa under a compression of 50%, or it can be 1.48~9.78 MPa, specifically 1.48 MPa, 1.57 MPa, 2.21 MPa, 2.88 MPa, 6.39 MPa, 6.46 MPa, 9.57 MPa, 9.66 MPa, or 9.78 MPa; when the monomer containing the sulfonate group is AMPS, the compressive strength can be 1.48~6.39 MPa; when the monomer containing the sulfonate group is SAP, the compressive strength can be 1.57~6.46 MPa; when the monomer containing the sulfonate group is SBMA, the compressive strength can be 9.57~9.78 MPa.

[0041] In this invention, the compressive modulus of the high-strength and tough supramolecular hydrogel with adjustable interfacial hydration properties is 0.5~50 MPa, and can also be 0.88~45.4 MPa, specifically 0.88 MPa, 1.61 MPa, 2.20 MPa, 3.62 MPa, 14.1 MPa, 25.7 MPa, 41.5 MPa, 43.3 MPa, or 45.4 MPa; when the monomer containing the sulfonate group is AMPS, the compressive modulus can be 0.88~14.1 MPa; when the monomer containing the sulfonate group is SAP, the compressive modulus can be 1.61~25.7 MPa; when the monomer containing the sulfonate group is SBMA, the compressive modulus can be 41.5~45.4 MPa.

[0042] This invention also provides the application of the high-strength and tough supramolecular hydrogel with tunable interfacial hydration properties described in the above-mentioned technical solution in the preparation of materials in the biomedical field. In this invention, the biomedical materials may include biomedical repair materials or biomedical replacement materials. The high-strength and tough supramolecular hydrogel prepared by this invention possesses high water content, excellent lubrication properties, mechanical properties, structural stability, and long-term service reliability, exhibiting excellent comprehensive performance and capable of meeting the synergistic requirements of multi-dimensional material performance in complex engineering scenarios or the biomedical field.

[0043] To further illustrate the present invention, the following detailed description, in conjunction with embodiments, of the high-strength and tough supramolecular hydrogel with adjustable interfacial hydration properties provided by the present invention, its preparation method, and its application, should not be construed as limiting the scope of protection of the present invention.

[0044] In the various examples and comparative examples, NASC is N-acryloylaminourea, DMSO is dimethyl sulfoxide, AMPS is 2-acrylamido-2-methylpropanesulfonic acid, SAP is potassium 3-sulfopropyl acrylate, SBMA is N-(3-sulfopropyl)-N-methacryloyloxyethyl-N,N-dimethylammonium betaine, and LAP is lithium phenyl(2,4,6-trimethylbenzoyl)phosphate. The resistivity of ultrapure water is 18.2 MΩ·cm. Unless otherwise specified, the ambient temperature is room temperature (18~25°C).

[0045] The mechanical properties of the hydrogel were tested using an EZ-Test (SHIMADZU, Japan) universal testing machine equipped with a 500N sensor. Four standard tensile test strips (total length 35 mm, effective length 12 mm, width 2 mm) with thicknesses of 0.6–0.7 mm were cut from the hydrogel sheet. The tensile rate was 100 mm / min. Young's modulus (E, MPa) was determined by the slope between 10% and 20% strain on the stress-strain curve. The tensile strength (MPa) and elongation at break (%) of the hydrogel were obtained from the fracture point of the stress-strain curve. The height and diameter of the cylindrical hydrogel samples were 6 mm and 8 mm, respectively. The compression test rate was 3 m / min. The compressive stress was calculated using F / A0, where F is the applied force and A0 is the initial contact area; the compressive strain was calculated using h / h0, where h and h0 represent the height after deformation and the original height, respectively. The compressive modulus (E, MPa) was determined by the slope between 5% and 10% strain on the stress-strain curve. Friction tests were conducted on a ball-disc reciprocating friction testing machine (CSM, Anton Paar, Switzerland). Al₂O₃ balls with a diameter of 6 mm were used as the contact pair, and a hydrogel substrate with a diameter of 30 mm and a height of 5 mm was used as the test substrate. The sample surface had to be kept flat. The applied load and sliding frequency were set to 5 N and 1 Hz, respectively. One complete reciprocating linear motion was defined as one cycle, with a distance of 10 mm per sliding cycle. Stable friction curves were obtained after 600 or 50,000 cycles. The hydrogel was completely immersed in a water bath during the friction test. The test temperature was room temperature. The test results for each index are the average values ​​of five samples.

[0046] Comparative Example 1 Place NASC monomer (3g, 0.02324mol) and DMSO (4.9g) in a centrifuge tube, shake well initially, and then place in a 90℃ oven. Shake once every 5 minutes until the NASC monomer is completely dissolved in DMSO, which takes about 30 minutes, to obtain the NASC solution.

[0047] Place LAP (0.01 g) and ultrapure water (2.1 g) in a centrifuge tube and shake at room temperature to dissolve, thus obtaining a LAP solution.

[0048] After mixing the NASC solution and LAP solution, wrap the mixture in aluminum foil (to protect it from light) and sonicate for 1 minute to obtain a precursor solution. Pour 4 / 5 of the precursor solution into a 100mm×100mm acrylic mold and irradiate it with a 405nm ultraviolet light source for 10 seconds to obtain a pure PNASC polymer sheet with a thickness of 0.6~0.7mm.

[0049] The remaining precursor solution was transferred in 300 μL to a mold with a diameter of 8 mm using a pipette. This process was repeated until all the precursor solution was used. The mold was then irradiated with a 405 nm ultraviolet light source for 10 seconds to obtain multiple pure PNASC polymer cylinders with a diameter of 8 mm and a height of 6 mm.

[0050] All pure PNASC polymer samples were placed in 1L of ultrapure water for 7 days to equilibrate and obtain PNASC polymer hydrogels. The mechanical and tribological properties of the PNASC polymer hydrogels were then tested.

[0051] Figure 2 The figures (a), friction coefficient (b), tensile curve (c), and compression curve (d) of the PNASCC polymer supramolecular hydrogel are shown. In figure (b), the inset is the contact angle. It can be seen that the friction coefficient of the PNASCC polymer supramolecular hydrogel prepared in this comparative example is 0.415; the tensile breaking strength is 6.86 MPa; the elastic modulus is 152 MPa; the compressive strength is 9.72 MPa and the compressive modulus is 51.2 MPa under 50% compression.

[0052] Example 1 Place NASC monomer (3g, 0.02324mol) and DMSO (4.9g) in a centrifuge tube, shake well initially, and then place in a 90℃ oven. Shake once every 5 minutes until the NASC monomer is completely dissolved in DMSO, which takes about 30 minutes, to obtain the NASC solution.

[0053] AMPS monomer (0.1926 g, molar amount of 4 mol% of NASC monomer) and ultrapure water (1.6 g) were placed in a centrifuge tube and dissolved by shaking at room temperature to obtain AMPS solution.

[0054] Place LAP (0.01 g) and ultrapure water (0.5 g) in a centrifuge tube and shake at room temperature to dissolve, thus obtaining a LAP solution.

[0055] Mix the NASC solution, AMPS solution and LAP solution, wrap the mixture in aluminum foil (to protect from light), and sonicate for 1 minute to obtain the precursor solution.

[0056] 4 / 5 of the precursor solution was poured into a 100mm×100mm acrylic mold and irradiated with a 405nm ultraviolet light source for 10 seconds to obtain a P(NASC / AMPS4) supramolecular hydrogel sheet with a thickness of 0.6~0.7mm.

[0057] The remaining precursor solution was transferred in 300 μL increments to an 8 mm diameter mold using a pipette until all the precursor solution was used. The mold was then irradiated with a 405 nm UV light source for 10 seconds to obtain multiple P(NASC / AMPS4) supramolecular hydrogel cylinders with a diameter of 8 mm and a height of 6 mm, which were used for compression performance testing. All supramolecular hydrogel samples were equilibrated in 1 L of ultrapure water for 7 days to obtain high-strength and tough P(NASC / AMPS4) supramolecular hydrogels. The mechanical and tribological properties of the high-strength and tough supramolecular hydrogels with tunable interfacial hydration characteristics were then tested.

[0058] The water content and contact angle diagrams of the high-strength and tough supramolecular hydrogel prepared in this embodiment are shown below. Figure 4 In section a, the friction coefficient diagram is shown below. Figure 5 See diagram for tensile properties (a). Figure 6 See diagram for compression performance in section a. Figure 7 In the middle, a, by Figures 4-7 It can be seen that the P(NASC / AMPS4) high-strength and tough supramolecular hydrogel prepared in this embodiment has a water content of 49.2%, a friction coefficient of 0.106, a tensile fracture strength of 6.18 MPa, an elastic modulus of 50.5 MPa, a compressive strength of 6.39 MPa and a compressive modulus of 14.1 MPa under a compression of 50%.

[0059] Example 2 The only difference from Example 1 is that the amount of AMPS monomer used is 8 mol% of the amount of NACS monomer, respectively, to obtain P(NASC / AMPS8) supramolecular hydrogel sheets and P(NASC / AMPS8) supramolecular hydrogel cylinders, and after water equilibration, P(NASC / AMPS8) high-strength and tough supramolecular hydrogel is obtained.

[0060] The water content and contact angle diagrams of the high-strength and tough supramolecular hydrogel prepared in this embodiment are shown below. Figure 4 In section a, the friction coefficient diagram is shown below. Figure 5 See diagram for tensile properties (a). Figure 6 See diagram for compression performance in section a. Figure 7 For example, the ultra-long wear resistance performance diagram is shown in Figure a. Figure 8 In the middle, a, by Figures 4-8 It can be seen that the P(NASC / AMPS8) high-strength and tough supramolecular hydrogel prepared in this embodiment has a water content of 66.8%; a friction coefficient of 0.0546, and maintains a low friction coefficient of 0.033 during 50,000 reciprocating friction cycles, indicating excellent structural stability and long-term service reliability; a tensile fracture strength of 3.99 MPa and an elastic modulus of 2.11 MPa; a compressive strength of 2.21 MPa and a compressive modulus of 2.20 MPa under 50% compression.

[0061] Example 3 The only difference from Example 1 is that the amount of AMPS monomer used is 12 mol% of the NASC monomer, resulting in P(NASC / AMPS) 12 supramolecular hydrogel sheets and P(NASC / AMPS) 12 supramolecular hydrogel cylinders, after water equilibrium, yield P(NASC / AMPS) 12 High-strength and tough supramolecular hydrogel.

[0062] The water content and contact angle diagrams of the high-strength and tough supramolecular hydrogel prepared in this embodiment are shown below. Figure 4 In section a, the friction coefficient diagram is shown below. Figure 5 See diagram for tensile properties (a). Figure 6 See diagram for compression performance in section a. Figure 7 In the middle, a, by Figures 4-7 It can be seen that the P(NASC / AMPS) prepared in this embodiment... 12 The high-strength and tough supramolecular hydrogel has a water content of 86.9%, a friction coefficient of 0.0759, a tensile fracture strength of 1.99 MPa, an elastic modulus of 1.33 MPa, a compressive strength of 1.48 MPa and a compressive modulus of 0.88 MPa under a compression of 50%.

[0063] By comparing Comparative Example 1 and Examples 1-3, as the amount of AMPS monomer added increased, the water content of the supramolecular hydrogel increased from 49% to 87%, and the tensile and compressive properties decreased sharply, with a performance loss of 68-77%; the combined effect of these two factors led to a decrease in the coefficient of friction followed by an increase.

[0064] Example 4 The only difference from Example 1 is that the AMPS monomer was replaced with SAP monomer (0.2159 g, which is 4 mol% of the NASC monomer), and P(NASC / SAP4) supramolecular hydrogel sheets and P(NASC / SAP4) supramolecular hydrogel cylinders were obtained. After water equilibration, P(NASC / SAP4) high-strength and tough supramolecular hydrogel was obtained.

[0065] The water content and contact angle diagrams of the high-strength and tough supramolecular hydrogel prepared in this embodiment are shown below. Figure 4 For example, see the friction coefficient diagram in section b. Figure 5 For example, see diagram b for tensile properties. Figure 6 For the compression performance diagram in section b, see [image]. Figure 7 b, by Figures 4-7 It can be seen that the P(NASC / SAP4) high-strength and tough supramolecular hydrogel prepared in this embodiment has a water content of 44.3%; a friction coefficient of 0.0796; a tensile fracture strength of 6.58 MPa; an elastic modulus of 92.9 MPa; a compressive strength of 6.46 MPa and a compressive modulus of 25.7 MPa under a compression of 50%.

[0066] Example 5 The only difference from Example 4 is that the amount of SAP monomer used is 8 mol% of NASC monomer, respectively to obtain P(NASC / SAP8) supramolecular hydrogel sheets and P(NASC / SAP8) supramolecular hydrogel cylinders, and after water equilibration, P(NASC / SAP8) high-strength and tough supramolecular hydrogel is obtained.

[0067] The water content and contact angle diagrams of the high-strength and tough supramolecular hydrogel prepared in this embodiment are shown below. Figure 4 For example, see the friction coefficient diagram in section b. Figure 5 For example, see diagram b for tensile properties. Figure 6 For the compression performance diagram in section b, see [image]. Figure 7 For medium b, see the diagram of ultra-long wear resistance. Figure 8 b, by Figures 4-8 It can be seen that the P(NASC / SAP8) high-strength and tough supramolecular hydrogel prepared in this embodiment has a water content of 64.3%; a friction coefficient of 0.0485, and maintains a low friction coefficient of 0.057 during 50,000 reciprocating friction cycles, indicating excellent structural stability and long-term service reliability; a tensile fracture strength of 5.81 MPa and an elastic modulus of 7.72 MPa; a compressive strength of 2.88 MPa and a compressive modulus of 3.62 MPa under a compression of 50%.

[0068] Example 6 The only difference from Example 4 is that the amount of SAP monomer used is 12 mol% of the NASC monomer, resulting in P(NASC / SAP) 12 supramolecular hydrogel sheets and P(NASC / SAP) 12 supramolecular hydrogel cylinders, after water equilibrium, yield P(NASC / SAP) 12 High-strength and tough supramolecular hydrogel.

[0069] The water content and contact angle diagrams of the high-strength and tough supramolecular hydrogel prepared in this embodiment are shown below. Figure 4 For example, see the friction coefficient diagram in section b. Figure 5 For example, see diagram b for tensile properties. Figure 6 For the compression performance diagram in section b, see [image]. Figure 7 b, by Figures 4-7 It can be seen that the P(NASC / SAP) prepared in this embodiment... 12 The supramolecular hydrogel has a water content of 78.7%, a friction coefficient of 0.0633, a tensile breaking strength of 4.27 MPa, an elastic modulus of 2.79 MPa, a compressive strength of 1.57 MPa and a compressive modulus of 1.61 MPa under a compression of 50%.

[0070] Comparing Examples 4-6, it can be seen that as the amount of SAP monomer added increases, the water content of the high-strength and tough supramolecular hydrogel increases from 44% to 79%, and the tensile and compressive properties also decrease sharply, with a performance loss of 35-76%; the combined effect of these two factors leads to a decrease in the coefficient of friction followed by an increase.

[0071] Compared with supramolecular hydrogels containing AMPS, supramolecular hydrogels containing SAP monomers exhibit better mechanical and tribological properties.

[0072] Example 7 The only difference from Example 1 is that the AMPS monomer was replaced with SBMA monomer (0.2596g, which is 4mol% of the NASC monomer), and P(NASC / SBMA4) supramolecular hydrogel sheets and P(NASC / SBMA4) supramolecular hydrogel cylinders were obtained. After water equilibration, P(NASC / SBMA4) high-strength and tough supramolecular hydrogel was obtained.

[0073] The water content and contact angle diagrams of the high-strength and tough supramolecular hydrogel prepared in this embodiment are shown below. Figure 4 In the middle c, the friction coefficient diagram is shown below. Figure 5 For example, see the tensile property diagram for C. Figure 6 For the compression performance graph in section c, see [image]. Figure 7 For medium C, see the diagram for ultra-long wear resistance. Figure 8 c in the middle, by Figures 4-8 It can be seen that the P(NASC / SBMA4) high-strength and tough supramolecular hydrogel prepared in this embodiment has a water content of 39.2%; a friction coefficient of 0.0871, which gradually increases during 50,000 reciprocating friction cycles, with a final friction coefficient of 0.236, indicating excellent structural stability and long-term service reliability; a tensile fracture strength of 6.18 MPa and an elastic modulus of 119 MPa; a compressive strength of 9.78 MPa and a compressive modulus of 45.4 MPa under a compression of 50%.

[0074] Example 8 The only difference from Example 7 is that the amount of SBMA monomer used is 8 mol% of the amount of NASC monomer, respectively, to obtain P(NASC / SBMA8) supramolecular hydrogel sheets and P(NASC / SBMA8) supramolecular hydrogel cylinders, and after water equilibrium, P(NASC / SBMA8) high-strength and tough supramolecular hydrogel is obtained.

[0075] The water content and contact angle diagrams of the high-strength and tough supramolecular hydrogel prepared in this embodiment are shown below. Figure 4 In the middle c, the friction coefficient diagram is shown below. Figure 5 For example, see the tensile property diagram for C. Figure 6 For the compression performance graph in section c, see [image]. Figure 7 c in the middle, by Figures 4-7It can be seen that the P(NASC / SBMA8) high-strength and tough supramolecular hydrogel prepared in this embodiment has a water content of 39.1%; a friction coefficient of 0.126; a tensile fracture strength of 4.41 MPa; an elastic modulus of 122 MPa; a compressive strength of 9.66 MPa and a compressive modulus of 43.3 MPa under a compression of 50%.

[0076] Example 9 The only difference from Example 7 is that the amount of SBMA monomer used is 12 mol% of the NASC monomer, resulting in P(NASC / SBMA) 12 supramolecular hydrogel sheets and P(NASC / SBMA) 12 supramolecular hydrogel cylinders, after water equilibrium, yield P(NASC / SBMA) 12 High-strength and tough supramolecular hydrogel.

[0077] The water content and contact angle diagrams of the high-strength and tough supramolecular hydrogel prepared in this embodiment are shown below. Figure 4 In the middle c, the friction coefficient diagram is shown below. Figure 5 For example, see the tensile property diagram for C. Figure 6 For the compression performance graph in section c, see [image]. Figure 7 c in the middle, by Figures 4-7 It can be seen that the P(NASC / SBMA) prepared in this embodiment... 12 The high-strength and tough supramolecular hydrogel has a water content of 40.1%, a friction coefficient of 0.146, a tensile breaking strength of 4.07 MPa, an elastic modulus of 112 MPa, a compressive strength of 9.57 MPa and a compressive modulus of 41.5 MPa under a compression of 50%.

[0078] Comparative examples 7-9 show that as the amount of SBMA monomer added increases, the water content and compressibility of the high-strength and tough supramolecular hydrogel remain basically unchanged, while the tensile properties decrease (34%); the coefficient of friction shows a slow increasing trend.

[0079] Figure 3 These are physical images of the high-strength and tough supramolecular hydrogels prepared in Examples 1-9, where a represents P(NASC / AMPS) with an AMPS addition amount of 4-12 mol% of NASC monomer. X (Image of actual product, b) shows SAP with an addition amount of 4-12 mol% of NASC monomer, P(NASC / SAP) X (Image showing physical product; c represents P(NASC / SBMA) with an SBMA addition amount of 4-12 mol% of the NASC monomer.) XThe physical image shows that x represents the molar percentage of sulfonate group monomers in NASC. It can be seen that different sulfonate group monomers have significant differences in the swelling behavior of P(NASC) hydrogel: AMPS and SAP can effectively promote the water absorption and swelling of hydrogel, and the degree of swelling increases with the increase of their molar fraction; while SBMA has no significant effect on the swelling behavior of hydrogel.

[0080] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a high-strength, tough supramolecular hydrogel with tunable interfacial hydration properties, characterized in that, Includes the following steps: N-acryloylaminourea monomer, sulfonate-containing monomer, initiator, organic solvent, and water are mixed to obtain a precursor solution. The precursor solution is then subjected to a crosslinking polymerization reaction under ultraviolet light irradiation to obtain a supramolecular hydrogel. The sulfonate-containing monomer includes one or more of sulfonic acid monomers, sulfonate monomers, and sulfonic acid inner salt monomers. The molar amount of the sulfonate-containing monomer is 4-12% of the molar amount of the N-acryloylaminourea monomer. The organic solvent is a good solvent for N-acryloylaminourea monomer with dehydrogenation bonding function. The supramolecular hydrogel was subjected to water equilibrium to obtain a high-strength and tough supramolecular hydrogel with tunable interfacial hydration properties.

2. The preparation method according to claim 1, characterized in that, The sulfonic acid monomers include 2-acrylamide-2-methylpropanesulfonic acid; The sulfonate monomers include potassium 3-sulfopropyl acrylate; The sulfonic acid inner salt monomers include N-(3-sulfopropyl)-N-methacryloyloxyethyl-N,N-dimethylammonium betaine.

3. The preparation method according to claim 1, characterized in that, The organic solvent includes dimethyl sulfoxide.

4. The preparation method according to claim 1, characterized in that, The photoinitiator includes lithium phenyl (2,4,6-trimethylbenzoyl) phosphate; The mass of the photoinitiator is 0.1 to 1% of the total mass of N-acryloylaminourea monomer and sulfonate group-containing monomer.

5. The preparation method according to claim 1, characterized in that, The wavelength of the ultraviolet light is 405 nm, and the cross-linking polymerization reaction takes 10 to 30 seconds.

6. The preparation method according to claim 1, characterized in that, The mass of the water used for water balance is 80 to 100 times the mass of the supramolecular hydrogel; The time required for water balance to be achieved is 7 to 10 days.

7. The preparation method according to any one of claims 1 to 4, characterized in that, The mixture includes: N-Acryloylaminourea was dissolved in an organic solvent to obtain an N-acryloylaminourea solution; The monomer containing the sulfonate group is dissolved in water to obtain a solution of the monomer containing the sulfonate group; The photoinitiator is dissolved in water to obtain a photoinitiator solution; The N-acryloylaminourea solution, the monomer solution containing sulfonate groups, and the photoinitiator solution are mixed.

8. The preparation method according to claim 7, characterized in that, The N-acryloylaminourea solution has a mass concentration of 5-30%. The mass concentration of the monomer solution containing sulfonate groups is 5-40%; The initiator solution has a mass concentration of 0.05-5%; The mixing includes ultrasonic mixing, and the ultrasonic mixing time is 1 to 2 minutes.

9. A high-strength, high-toughness supramolecular hydrogel with adjustable interfacial hydration properties prepared by the preparation method according to any one of claims 1 to 8.

10. The application of the high-strength and tough supramolecular hydrogel with adjustable interfacial hydration properties as described in claim 9 in the preparation of materials in the biomedical field.

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