阅读说明：本技术 一种粘附水凝胶及其制备方法 (Adhesive hydrogel and preparation method thereof ) 是由 陈莉 邓泽鹏 何洋 江鹏 王彦杰 于 2019-10-09 设计创作，主要内容包括：本发明提出一种粘附水凝胶及其制备方法,涉及高分子材料领域。该方法包括下述步骤：(1)将阳离子单体、光引发剂、阴离子组分和水混合,得前驱体溶液；(2)将上述前驱体溶液脱泡；(3)采用紫外光照射步骤(2)所得前驱体溶液,引发阳离子单体聚合,产生的阳离子单体聚合物与阴离子组分作用形成粘附水凝胶；其中,所述步骤(1)中,所述阴离子组分包括糖胺聚糖及其衍生物。本发明所述粘附水凝胶质地柔软,可用于粘附各种表面,粘附强度高,且具有自愈性能,提高了凝胶的实用性。(The invention provides an adhesive hydrogel and a preparation method thereof, and relates to the field of high polymer materials. The method comprises the following steps: (1) mixing a cationic monomer, a photoinitiator, an anionic component and water to obtain a precursor solution; (2) defoaming the precursor solution; (3) irradiating the precursor solution obtained in the step (2) by using ultraviolet light to initiate the polymerization of a cationic monomer, and reacting the generated cationic monomer polymer with an anionic component to form an adhesive hydrogel; wherein, in the step (1), the anionic component comprises glycosaminoglycan and derivatives thereof. The adhesive hydrogel disclosed by the invention is soft in texture, can be used for adhering various surfaces, is high in adhesive strength, has self-healing performance, and improves the practicability of the gel.)

1. A method for preparing an adherent hydrogel, comprising the steps of:

(1) mixing a cationic monomer, a photoinitiator, an anionic component and water to obtain a precursor solution;

(2) defoaming the precursor solution;

(3) irradiating the precursor solution obtained in the step (2) by using ultraviolet light to initiate the polymerization of a cationic monomer, and reacting the generated cationic monomer polymer with an anionic component to form the hydrogel;

wherein the anionic component comprises a glycosaminoglycan and derivatives thereof.

2. The method of claim 1,

the anion component comprises one or more of chondroitin sulfate, keratan sulfate, dermatan sulfate and heparan sulfate.

3. The method of claim 1,

in the step (1), the cationic monomer is a quaternary ammonium salt type cationic monomer;

preferably, the quaternary ammonium salt type cationic monomer includes one of acryloyloxyethyltrimethyl ammonium chloride, [3- (methacrylamido) propyl ] trimethylammonium chloride, and (3-acrylamidopropyl) trimethylammonium chloride.

4. The method of claim 1,

in the step (1), the molar ratio of the charged cationic monomer to the charged anionic component is 1: (0.05-1.25);

preferably, the molar ratio of the charged charges of the cationic monomer and the anionic component is 1: (0.1-0.5).

5. The method of claim 1,

in the step (1), the molar ratio of the cationic monomer to the photoinitiator is 1: (0.1% -0.5%);

the photoinitiator is ketoglutaric acid.

6. The method of claim 1,

in the step (1), the concentration of the charges carried by the precursor solution is 1.5-3.5 mol/L; preferably, the concentration of the charges carried by the precursor solution is 2-3 mol/L; more preferably, the concentration of the charge carried by the precursor solution is 2.5 mol/L.

7. The method of claim 1,

the step (2) is specifically as follows: and (2) carrying out ultrasonic treatment on the precursor solution obtained in the step (1) to remove large bubbles, then carrying out vacuum treatment, and standing to remove micro bubbles.

8. The method of claim 7,

in the step (2), the ultrasonic treatment time is 0.5-3 h; the pressure of the vacuum treatment is-0.1 MPa, and the time is 0.5-1.5 h.

9. The method of claim 1,

in the step (3), the light source wavelength of the ultraviolet light is 365nm, the power is 300W, and the illumination time is 9-13 h.

10. An adhesive hydrogel prepared by the method of any one of claims 1-9.

Technical Field

The invention relates to the field of high polymer materials, in particular to adhesive hydrogel and a preparation method thereof.

Background

In recent years, with the development of the fields of tissue engineering, biomedicine, wearable flexible equipment and the like, the hydrogel has good application prospects in the aspects of tissue adhesives, human-computer interfaces and the like by virtue of the advantages of softness, wetting, strong deformation capability and good biocompatibility.

The surface of the traditional hydrogel is smooth, no adhesive force exists between the traditional hydrogel and the surface of inorganic and organic substances, and the hydrogel is adhered to a matrix by using an adhesive in order to be applied to the surface of human tissues or electronic devices, but most of the traditional adhesives are toxic and are not suitable for being used by contacting with the skin, and the traditional adhesives have no elasticity and cannot deform along with the movement of an adhered object, so that the application of the hydrogel is limited. Therefore, researchers explore different preparation methods to enable the hydrogel to have the adhesive capacity, so that the adhesion between the hydrogel and a matrix is realized, and the application range of the hydrogel is widened.

Zhao et al (Yuk H, Zhang T et al nature Materials, 2015; 15:190.) developed an adherent hydrogel with strong adhesion resulting from covalent anchoring between the hydrogel and the surface-modified matrix, which can adhere to the surface of glass, ceramic, etc. Materials by covalent bonding to the polymer network of the surface to be adhered. The method requires that the surface of the adhered substance must be modified by using a proper anchoring chemical modifier, and the treatment process is complicated.

Pang et al (Baik S, Kim D W et al Nature, 2017; 546(7658):396-400.) inspired by octopus, developed an artificial bionic octopus sucker microstructure adhesive patch that can be reversibly used in a wet/dry adhesive system. The adhesive patch shows strong, reversible and highly repeatable adsorption effect on silicon wafers and glass no matter what environment. However, this type of adhesion is only suitable for relatively flat surfaces and does not adhere well to irregular surfaces, greatly limiting its application.

Polyion complex (PIC) gel is hydrogel formed by polymers with opposite charges through electrostatic interaction, and due to the characteristics of excellent mechanical properties and physical crosslinking, the PIC gel attracts wide attention in the fields of high-strength gel and intelligent response gel.

However, the polyion complex gel in the prior art is usually prepared by a two-step method (sequential and separate polymerization of cationic monomer and anionic monomer), and the process is complicated; and the resulting gel was relatively hard in texture, which was not conducive to firm adhesion to irregular solid surfaces.

Disclosure of Invention

The invention provides the adhesive hydrogel and the preparation method thereof, the needed adhesive hydrogel can be prepared in one step, the process is simple, the reaction condition is mild, and the obtained hydrogel has good adhesive property and can be firmly adhered to irregular solid surfaces.

The invention provides a preparation method of adhesive hydrogel, which is characterized in that a cationic monomer is initiated by a photoinitiator to carry out homopolymerization, and then the homopolymerization is carried out with an anionic component to form the hydrogel with an interpenetrating network structure.

The invention provides a preparation method of adhesive hydrogel, which comprises the following steps:

(1) mixing a cationic monomer, a photoinitiator, an anionic component and water to obtain a precursor solution;

(2) defoaming the precursor solution;

(3) irradiating the precursor solution obtained in the step (2) by using ultraviolet light to initiate the polymerization of a cationic monomer, and reacting the generated cationic monomer polymer with an anionic component to form an adhesive hydrogel;

wherein, in the step (1), the anionic component comprises glycosaminoglycan and derivatives thereof.

Further, the anion component comprises one or more of chondroitin sulfate, keratan sulfate, dermatan sulfate and heparan sulfate.

Further, in the step (1), the cationic monomer is a quaternary ammonium salt type cationic monomer;

preferably, the quaternary ammonium salt type cationic monomer includes one of acryloyloxyethyltrimethyl ammonium chloride, [3- (methacrylamido) propyl ] trimethylammonium chloride, and (3-acrylamidopropyl) trimethylammonium chloride.

Further, in the step (1), the molar ratio of the charged cationic monomer to the charged anionic component is 1: (0.05-1.25);

preferably, the molar ratio of the charges of the cationic monomer and the anionic component is 1: (0.1-0.5).

Further, in the step (1), the molar ratio of the cationic monomer to the photoinitiator is 1: (0.1% -0.5%);

preferably, the photoinitiator is ketoglutaric acid.

Further, in the step (1), the concentration of the charges carried by the precursor solution is 1.5-3.5 mol/L; preferably, the concentration of the charges carried by the precursor solution is 2-3 mol/L; more preferably, the concentration of the charge carried by the precursor solution is 2.5 mol/L.

Further, the step (2) is specifically as follows: and (2) carrying out ultrasonic treatment on the precursor solution prepared in the step (1) to remove large bubbles, then carrying out vacuum treatment, and standing to remove micro bubbles.

Further, in the step (2), the time of ultrasonic treatment is 0.5-3 h; the pressure of vacuum treatment is-0.1 MPa, and the time is 0.5-1.5 h.

Further, in the step (3), the light source wavelength of the ultraviolet light is 365nm, the power is 300W, and the illumination time is 9-13 h.

The invention also provides the adhesive hydrogel prepared by the method.

The invention has the following beneficial effects:

according to the invention, a cationic monomer, a photoinitiator thereof and an anionic component are added, under the initiation of ultraviolet light, the cationic monomer is polymerized to form a long-chain cationic polymer, and a short-chain anionic component can be inserted into gaps of the long-chain polymers intertwined with each other, so that the regulation and control of the gel viscoelasticity are realized, and the gel is soft in texture to adapt to various complex solid surfaces; the formed network structure can maintain the shape of the gel and improve the adhesive strength of the gel; the reversibility of electrostatic interaction between the anionic polymer and the cationic polymer ensures that the adhesive gel has self-healing property, and improves the practicability of the gel.

The preparation method of the hydrogel is simple in process, does not need special equipment, and is mild in condition. Meanwhile, the raw materials are safe and nontoxic, no cross-linking agent is required to be added, a gel system is simplified, and the gel toxicity caused by the fact that the unreacted cross-linking agent remains in the gel is avoided.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is gel rheological data of different anion and cation ratios, wherein FIG. 1(A) is a strain scanning data graph and FIG. 1(B) is a frequency scanning data graph; g 'represents storage modulus, G' represents loss modulus;

FIG. 2 is a schematic view of a lap shear strength test;

FIG. 3 is a schematic diagram of the adhesive strength of an adhesive hydrogel to different substances, wherein FIG. 3(A) is the adhesive strength of the adhesive hydrogel to different inorganic substances according to different charge ratios of anions and cations, and FIG. 3(B) is the adhesive strength of the adhesive hydrogel to different organic substances according to different charge ratios of anions and cations;

FIG. 4 is a digital photograph of a demonstration of the self-healing performance of an adhesive hydrogel;

fig. 5 is a rheological recovery characterization diagram of the self-healing performance of the adhesive hydrogel, wherein fig. 5(a) is a rheological characterization diagram of the self-healing performance of the gel when the charge ratio of anions and cations is 0.1, fig. 5(B) is a rheological characterization diagram of the self-healing performance of the gel when the charge ratio of anions and cations is 0.25, and fig. 5(C) is a rheological characterization diagram of the self-healing performance of the gel when the charge ratio of anions and cations is 0.5;

FIG. 6 is an SEM representation of hydrogels obtained according to different anion-cation charge ratios of the examples;

fig. 7 is a graph showing the effect of different concentrations on hydrogel adhesion performance of examples, wherein fig. 7(a) is a gel forming condition of different concentration systems, and fig. 7(B) is an SEM characterization graph showing surface fitting condition of hydrogel matrix obtained by different concentration systems.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The embodiment of the invention provides a preparation method of adhesive hydrogel, which comprises the following steps:

(1) mixing a cationic monomer, a photoinitiator, an anionic component and water to obtain a precursor solution;

(2) defoaming the precursor solution;

(3) irradiating the precursor solution obtained in the step (2) by using ultraviolet light to initiate the polymerization of cationic monomers, and reacting the generated cationic polymers with anionic components to form adhesive hydrogel;

wherein the anionic component comprises a glycosaminoglycan and derivatives thereof.

The embodiment of the invention adopts a one-step method (cationic monomer homopolymerization and electrostatic combination with short-chain anionic components) to prepare the polyion composite hydrogel, which is different from the situation that the high-charge-concentration precursor solution in the preparation process of the polyion composite gel in the prior art often causes the prepared hydrogel to be hard in texture.

According to the embodiment of the invention, a cationic monomer, a photoinitiator thereof and an anionic component are added, under the initiation of ultraviolet light, the cationic monomer polymerizes to form a long-chain cationic polymer, while the anionic component does not change, then, the generated positive cationic polymer long chains are intertwined with each other and combined with the negative anionic component through electrostatic interaction to form an interpenetrating three-dimensional network structure.

In the three-dimensional network structure, short-chain anionic components (glycosaminoglycan and derivatives thereof) can be inserted into the gaps of the long-chain polymer, so that the regulation and control of the gel viscoelasticity are realized, and the gel is soft in texture to adapt to various complex solid surfaces; the formed network structure can maintain the shape of the gel and improve the adhesive strength of the gel; the reversibility of electrostatic interaction between the anionic polymer and the cationic polymer ensures that the adhesive gel has self-healing performance, and improves the practicability of the gel.

In addition, the preparation method of the adhesive hydrogel is simple in process, does not need special equipment, and is mild in condition. Meanwhile, the raw materials are safe and nontoxic, no cross-linking agent is required to be added, a gel system is simplified, and the gel toxicity caused by the fact that the unreacted cross-linking agent remains in the gel is avoided.

The glycosaminoglycan and the derivatives thereof selected by the embodiment of the invention are short-chain polymers, and the short-chain polymers can be inserted into the gaps of the cationic long-chain polymers, so that the modulus of the gel can be reduced under the condition of not reducing the concentration of the gel liquid; meanwhile, the glycosaminoglycan has viscosity, which is beneficial to improving the adhesive capacity of the gel; and the glycosaminoglycan is taken from animal cartilage, is non-toxic and harmless, and can improve the biocompatibility of the gel.

In an embodiment of the present invention, the anionic component comprises glycosaminoglycans and derivatives thereof.

Preferably, the glycosaminoglycan comprises one or more of chondroitin sulfate, keratan sulfate, dermatan sulfate, and heparin.

Specifically, the derivative corresponding to the glycosaminoglycan may be a salt corresponding to the glycosaminoglycan, such as a salt of chondroitin sulfate, a salt of keratan sulfate, a salt of dermatan sulfate, a salt of heparin, and more specifically, may be chondroitin sulfate or a calcium salt of chondroitin sulfate, keratan sulfate or a sodium salt of keratan sulfate, and the like.

In one embodiment of the present invention, the suitable cationic monomer is a quaternary ammonium salt type cationic monomer. Preferably, the quaternary ammonium salt type cationic monomer includes one of acryloyloxyethyltrimethyl ammonium chloride, [3- (methacrylamido) propyl ] trimethylammonium chloride, and (3-acrylamidopropyl) trimethylammonium chloride. The cationic monomer selected by the embodiment of the invention can perform homopolymerization reaction under the action of a photoinitiator to generate cationic polymer long chains with positive charge, which are mutually entangled, and can form ionic bonds with polysaccharide short chains of glycosaminoglycan through electrostatic interaction, thereby forming an interpenetrating three-dimensional network structure.

In one embodiment of the present invention, the molar ratio of the charged cationic monomer to the charged anionic component is 1: (0.05-1.25). Specifically, the ratio of 1: 0.1, 1: 0.25, 1: 0.5, 1: 0.75, 1: 1.0, 1: 1.25, etc. In the embodiment of the invention, each repeating disaccharide unit structure in the anion component such as chondroitin sulfate has at least one negative charge, and in the high-concentration system, each mole of repeating disaccharide unit structure in the anion component has one mole of negative charges, so that the error caused by the fact that the charge of each individual disaccharide unit structure is more than one is negligible.

Thus, the molar ratio of cationic monomer to anionic component is 1: (0.05-1.25). By the number of moles of the charge of the anionic component, the number of moles of the disaccharide unit structure in the anionic component can be obtained, and thus the mass of the disaccharide unit structure, that is, the mass of the anionic component can be calculated. And 1mol of the cationic monomer has 1mol of charge.