CN115043969A

CN115043969A - Gel with surface patterning, preparation method and application

Info

Publication number: CN115043969A
Application number: CN202110252368.7A
Authority: CN
Inventors: 王树涛; 万茜子; 贾岚欣; 刘熹
Original assignee: Technical Institute of Physics and Chemistry of CAS
Current assignee: Technical Institute of Physics and Chemistry of CAS
Priority date: 2021-03-08
Filing date: 2021-03-08
Publication date: 2022-09-13
Anticipated expiration: 2041-03-08
Also published as: CN115043969B

Abstract

The invention relates to a preparation method of gel with surface patterning, which comprises the following steps: (1) providing a patterned substrate with hydrophilic regions and hydrophobic regions on the surface; (2) applying an emulsion comprising a hydrogel pre-polymerization liquid and an oleogel pre-polymerization liquid to the patterned substrate surface, the hydrogel monomers and the oleogel monomers in the pre-polymerization liquid self-assembling at the substrate surface; (3) after the emulsion polymerization was completed and peeled from the substrate, a gel with a pattern was obtained. The invention realizes the patterning of the gel surface by a simple infiltration transfer method, has simple and easy preparation process, does not need complex equipment, can simultaneously realize the preparation of gel patterns from 2D to 3D and from micro to macro, and has high definition and precision of the prepared patterns.

Description

Gel with surface patterning, preparation method and application

Technical Field

The invention belongs to the field of gel, and particularly relates to gel with a surface pattern, a preparation method and application thereof, a pattern transfer stamp containing the gel and an application method, and further relates to the gel with the surface pattern, the preparation method and application thereof, the pattern transfer stamp containing the gel and the application method, which are prepared by utilizing hydrophilic/hydrophobic interaction of a solid/liquid interface.

Background

The patterned gel can be used for detection, intelligent driving, biomolecule screening, cell differentiation induction and the like of DNA and fluorescent molecules, and has wide application prospects in actual life, so that the preparation method of the patterned gel is widely concerned. In the prior art, there are various methods for patterning gel, for example, a photo-degradable polyethylene glycol-based hydrogel is patterned by photolithography, and ultraviolet light can adjust the physicochemical properties of the gel in time and space and realize nano-scale patterning in bulk phase, but the method has high requirements for the type of gel and cannot realize surface patterning. The gel can be patterned by a 3D/4D printing method, but a complicated 3D/4D printing device is required, and the prepared pattern is a bulk phase pattern. The soft etching technology adopts a template reshaping method, gel prepolymerization liquid is poured on the surface with a specific structure, after photopolymerization, solidified gel is stripped from a substrate, and the structure with the specific pattern can be reshaped, but the method can only reshape a 3D pattern with a concave-convex structure, cannot obtain a 2D pattern, and has limited pattern precision. Computer-assisted ion ink jet printing technology is capable of printing large, very complex patterns directly on the surface of large-size hydrogel samples, but has limitations on the types of gels, with very low precision, only at the submicron level. Fine amino-containing oligo (ethylene glycol) methacrylate thermal response polymer patterns can be constructed on the silicon surface by an electron beam etching technology, but the method also has the problems of expensive equipment, long time consumption and high requirements on the types of gels.

Thus, the prior art techniques for preparing patterned gels generally suffer from the following problems: the gel type is greatly limited, the equipment is expensive, and the preparation is complex; often, only the body patterning of the gel can be realized, and the surface patterning of the gel is difficult to realize; and part of methods have low precision, and cannot realize 2D and 3D patterns and the like at the same time. Therefore, there is a need in the art to develop a method for preparing a surface patterned gel that can solve the above problems.

Disclosure of Invention

In view of the above problems in the prior art, the present invention provides a method for preparing a gel having a patterned surface, the method comprising the steps of:

(1) providing a patterned substrate with hydrophilic regions and hydrophobic regions on the surface;

(2) applying an emulsion containing hydrogel pre-polymerization liquid and oil gel pre-polymerization liquid to the surface of the patterned substrate, wherein hydrogel monomers and oil gel monomers in the pre-polymerization liquid are self-assembled at a solid-liquid interface;

(3) after the emulsion polymerization was completed and peeled from the substrate, a gel with a pattern was obtained.

After the emulsion is applied to a patterned substrate with hydrophilic areas and hydrophobic areas on the surface, the emulsion droplets can move directionally due to the induction effect of hydrophilic/hydrophobic interaction of a solid/liquid interface, the hydrophilic monomers can move to the hydrophilic areas of the substrate due to the hydrophilic interaction, and the hydrophobic monomers can move to the hydrophobic areas of the substrate due to the hydrophobic interaction, namely, the part of the emulsion contacting the hydrophilic areas becomes the surface area of the hydrophilic hydrogel after gelation, and the part contacting the hydrophobic areas becomes the surface area of the hydrophobic oleogel after gelation. Therefore, the pattern formed on the surface of the substrate due to the wettability difference can be perfectly transferred to the surface of the gel, and the gel with the patterned surface can be obtained.

The method selects the emulsion containing the hydrogel pre-polymerization liquid and the oleogel pre-polymerization liquid as the precursor of the patterned gel, utilizes the difference of the wettability of the substrate surface and the induction effect of hydrophilic/hydrophobic interaction to realize the directional migration of hydrophilic monomers and hydrophobic monomers in the emulsion, and obtains the gel with the patterned surface through polymerization molding. The size and the dimensionality of the gel pattern with the patterned surface are determined by a substrate, a two-dimensional substrate can be used for preparing two-dimensional gel, and a three-dimensional substrate can be used for preparing three-dimensional gel; the gel pattern size can range from microscopic (a few microns to hundreds of microns) to macroscopic (a few hundreds of microns to tens of centimeters). Therefore, through a simple preparation method, the preparation of gel patterns from 2D to 3D and from macro to micro can be realized at the same time, and the prepared patterns have high definition and precision.

Preferably, the emulsion comprises an oil-in-water emulsion or a water-in-oil emulsion; mixing the hydrogel prepolymer solution and the oil gel prepolymer solution, and emulsifying to obtain the emulsion; the hydrogel pre-polymerization solution comprises a hydrogel monomer, a hydrogel monomer initiator and a hydrogel cross-linking agent which are dispersed in water; the oil gel prepolymerization liquid comprises an oil gel monomer, an oil gel monomer initiator and an oil gel crosslinking agent.

The emulsion includes an oil-in-water emulsion or a water-in-oil emulsion, and a water-in-oil-in-water emulsion or a water-in-oil-in-water emulsion may also be used, as well as other emulsions comprising a hydrophilic monomer and a hydrophobic monomer, as long as a two-phase or multi-phase emulsion comprising a water phase and an oil phase can be formed. The emulsion is prepared by emulsifying a hydrogel pre-polymerization liquid and an oleogel pre-polymerization liquid after ultrasonic treatment to obtain a stable emulsion. The hydrogel monomer dispersed in water is subjected to crosslinking polymerization under the action of an initiator and a crosslinking agent to form hydrophilic hydrogel; and the oil gel monomer is subjected to cross-linking polymerization under the action of an initiator and a cross-linking agent to form hydrophobic oil gel. The hydrogel and the oleogel achieve intimate bonding through interfacial polymerization.

Preferably, the hydraulicsThe rubber monomer has

The structure is shown in the specification, wherein R is a hydrophilic group, and the hydrophilic group comprises any one of an amide group, a carboxyl group, a hydroxyl group and an amino group or a combination of at least two of the amide group, the carboxyl group, the hydroxyl group and the amino group.

Preferably, the hydrogel monomer comprises any one of acrylamide, acrylic acid, hydroxyethyl acrylate or a combination of at least two thereof.

The hydrogel monomer has a hydrophilic group, and a proper hydrophilic group is selected, so that the hydrophilic monomer can generate hydrophilic interaction with modified molecules in a hydrophilic region on the surface of the substrate, and effective migration to the hydrophilic region of the substrate is realized, and the stronger the hydrophilic interaction is, the better the hydrophilic interaction is, and the clear and continuous boundaries and the integrity of patterns are ensured.

Preferably, the hydrogel prepolymer solution contains 1 to 6mol/L of hydrogel monomer, for example, 1.0mol/L, 1.5mol/L, 2.0mol/L, 2.5mol/L, 3.0mol/L, 3.5mol/L, 4.0mol/L, 4.5mol/L, 5.0mol/L, 5.5mol/L, 6.0mol/L, and the like, preferably 2.5 mol/L.

The hydrogel monomer content in the hydrogel prepolymerization solution is lower than 1mol/L, so that the mechanical strength of the hydrogel is poor, the amount of the monomer capable of moving to an interface is small, and the pattern integrity is reduced; the content of the hydrogel monomer is higher than 6mol/L, so that the hydrogel monomer is not easy to uniformly disperse, and the completeness of the pattern is also influenced.

Preferably, the hydrogel monomer initiator comprises benzophenones, benzoyl, preferably 2, 2-diethoxyacetophenone and/or 2-hydroxy-4' - (2-hydroxyethoxy) -2-methylpropiophenone; preferably, the hydrogel monomer initiator is present in the hydrogel prepolymer solution in an amount of 0.05mg/mL to 3mg/mL, for example, 0.05mg/mL, 0.1mg/mL, 0.5mg/mL, 1.0mg/mL, 1.5mg/mL, 2mg/mL, 2.5mg/mL, 3mg/mL, etc., preferably 0.5 mg/mL.

Initiators capable of initiating polymerization of the hydrogel monomers may be used, preferably 2, 2-diethoxyacetophenone and/or 2-hydroxy-4' - (2-hydroxyethoxy) -2-methylpropiophenone; when the content of the hydrogel monomer polymerization initiator in the hydrogel prepolymerization solution is lower than 0.05mg/mL, the photopolymerization is incomplete; when the content of the hydrogel monomer polymerization initiator is higher than 3mg/mL, implosion is easy to occur in the polymerization process, so that the polymerization is uneven, the mechanical strength is low, and the mechanical property of the prepared surface patterned gel is influenced.

Preferably, the hydrogel cross-linking agent comprises polyisocyanates, polyamines, polyols, glycidyl ethers, organic peroxides, silicones, metal organic compounds, inorganic substances, preferably inorganic nanoclay platelets and/or N, N-methylenebisacrylamide;

preferably, the hydrogel pre-polymerization solution contains 1 wt% to 16 wt% of the hydrogel crosslinking agent, such as 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, preferably the hydrogel crosslinking agent is an inorganic nanoclay platelet with a content of 8 wt%, or 0.05 wt% to 1 wt% of N, N-methylene bisacrylamide, such as 0.05 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, preferably 0.4 wt% of N, N-methylene bisacrylamide.

Any crosslinking agent capable of crosslinking the hydrogel monomer may be used, preferably inorganic nanoclay platelets and/or N, N-methylene bisacrylamide; when the content of the hydrogel crosslinking agent in the hydrogel prepolymerization solution is less than 1 wt%, the crosslinking degree of the prepolymerization solution is low, and adverse effects on gel formation are caused; when the content of the hydrogel crosslinking agent is more than 16% by weight, dispersion uniformity in water is poor, resulting in a decrease in mechanical strength of the gel.

Preferably, the oleogel monomer has

Structure (II) wherein R ₁ is-H, alkyl, R ₂ Is any one or the combination of at least two of alkyl, ester group, ether group and aromatic group, and the number of carbon chains is 4-18; preferably, the oleogel monomer comprises acrylates and/or methacrylates.

The oleogel monomer has a hydrophobic group, and a proper hydrophobic group is selected, so that the hydrophobic monomer can generate hydrophobic interaction with hydrophobic molecules modified on the surface of the substrate, and effective migration to a hydrophobic area of the substrate is realized, and thus clear and continuous boundaries of patterns and the integrity of the patterns are ensured.

When the number of carbon chains in the oleogel monomer is less than 4, the hydrophobic interaction between the oleogel monomer and the modified hydrophobic molecules is not strong enough, so that the defect of a pattern is easily caused; when the number of the carbon chains is more than 18, the oil gel monomer is solid at normal temperature, and is difficult to form stable emulsion with the hydrogel prepolymer.

Preferably, the molar ratio of oleogel monomer to hydrogel monomer is 5:1 to 1:5, e.g., 5:1, 4:1, 3:1, 2:1, 1:2, 1:3, 1:4, 1:5, preferably 2: 1;

the finally formed patterned gel has good performance by selecting a proper oil/hydrogel monomer ratio, the mechanical performance of the oil hydrogel can be improved by increasing the content of the oil gel, and when the oil/hydrogel monomer ratio is less than 1:5, a complete oil film is difficult to induce to form in a hydrophobic region, and the mechanical performance of the gel is poor; when the oil/hydrogel monomer ratio is greater than 5:1, the emulsion formed by the oil gel pre-polymerization solution and the hydrogel pre-polymerization solution is unstable and is prone to delamination before complete crosslinking.

Preferably, the oil gel monomer initiator comprises benzophenones, preferably 2, 2-diethoxyacetophenone; the oleogel monomer initiator is present in the oleogel pre-polymerization fluid in an amount of 0.02 wt% to 0.3 wt%, e.g., 0.02 wt%, 0.05 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, preferably 0.08 wt%;

initiators capable of initiating polymerization of the oleogel monomer may be used, preferably 2, 2-diethoxyacetophenone; when the content of the polymerization initiator of the oleogel monomer in the oleogel pre-polymerization liquid is lower than 0.02 wt%, the photopolymerization is incomplete, and when the content of the polymerization initiator of the oleogel monomer is higher than 0.3 wt%, implosion is easy to occur in the polymerization process, so that the polymerization is not uniform, the mechanical strength is low, and the mechanical performance of the prepared surface patterned gel is influenced.

Preferably, the oil gel cross-linking agent comprises polyisocyanates, polyamines, polyols, glycidyl ethers, organic peroxides, silicones, metal organic compounds, inorganic substances, preferably ethylene glycol dimethacrylate and/or polyethylene glycol dimethacrylate; preferably, the oil gel pre-polymerization liquid has an oil gel cross-linking agent content of 0.1 wt% to 8 wt%, such as 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 8 wt%, preferably 4 wt%.

Any cross-linking agent capable of cross-linking the oleogel monomer may be used, preferably ethylene glycol dimethacrylate and/or polyethylene glycol dimethacrylate; when the content of the oil gel crosslinking agent in the oil gel prepolymerization liquid is less than 0.1 wt%, the crosslinking degree of the prepolymerization liquid is low, and the gel formation is adversely affected; when the content of the oil gel crosslinking agent is more than 8 wt%, the polymerized gel is brittle, resulting in a decrease in mechanical strength of the patterned gel.

Preferably, the emulsion is obtained by emulsification with a power of 300W to 800W, such as 300W, 400W, 500W, 600W, 700W, 800W, preferably 585W, and an emulsification time of 0.5min to 3min, such as 0.5min, 1min, 1.5min, 2min, 2.5min, 3min, preferably 1 min;

the emulsion is uniformly mixed and stabilized through an ultrasonic emulsification process, if the emulsification power is lower than 300W or the emulsification time is lower than 0.5min, the uniform stability of the emulsion is poor, and if the emulsification power is higher than 800W or the emulsification time is higher than 3min, the temperature of the solution is increased due to high ultrasonic power and long time, so that the solution is easy to volatilize.

Preferably, the gelation method in step (3) is crosslinking polymerization, preferably illumination power is 200W-800W, such as 200W, 300W, 400W, 500W, 600W, 700W, 800W, preferably 500W, and polymerization time is 10 min-60 min, such as 10min, 20min, 30min, 40min, 50min, 60 min.

The emulsion containing the hydrogel pre-polymerization liquid and the oil gel pre-polymerization liquid is subjected to cross-linking polymerization by light irradiation to form a non-flowing gel, and the initiation power of the light is determined by the selected photoinitiator.

The size and dimension of the surface patterned gel are determined by the substrate, and the gel with different dimensions (two-dimensional, three-dimensional) and different sizes can be prepared by selecting different substrates; preferably, the three-dimensional structure comprises any one of a sphere, a cylinder, a prism, a pyramid or a frustum, or a combination of at least two thereof.

The dimension of the surface patterning gel is determined by the substrate, and when the patterned substrate is a plane, the prepared surface patterning gel is a sheet body with a two-dimensional structure; when the patterned substrate is a three-dimensional structure composed of one or more surfaces, the patterned gel is prepared as a three-dimensional structure after emulsion is applied to the three-dimensional structure and then cross-linked and polymerized, and taken out of the three-dimensional structure. The size of the surface patterned gel is determined by the substrate, and the gel size can range from microscopic (several micrometers to several hundred micrometers) to macroscopic (several hundred micrometers to several tens of centimeters).

The preparation method of the patterned substrate comprises the steps of carrying out hydrophilic treatment on the substrate to enable the surface of the substrate to be provided with hydrophilic areas, and carrying out hydrophobic treatment on the substrate to enable the surface of the substrate to be provided with hydrophobic areas.

Preferably, the hydrophilic treatment is an oxygen plasma treatment, preferably the oxygen plasma treatment time may be 4min to 15min, such as 4min, 5min, 6min, 7min, 8min, 9min, 10min, 11min, 12min, 13min, 14min, 15min, preferably 10 min.

And treating the cleaned substrate by oxygen plasma to modify hydroxyl groups on the surface of the substrate to be in a super-hydrophilic state. If the oxygen plasma treatment time is less than 4min, the number of hydroxyl groups for surface modification is small, the surface hydrophilicity is not enough, so that the hydrophilic interaction force of the substrate and the hydrogel is weak, and the pattern can generate defects; if the treatment time is longer than 15min, the adhesive tape, the photoresist and the like on the surface of the substrate are easily damaged, and the modification effect is influenced.

Preferably, the hydrophobic treatment is a treatment of the area with a hydrophobic material; preferably, the hydrophobic material comprises fluorosilane molecules or silane molecules; preferably, the treatment method of the hydrophobic treatment includes gas phase modification or liquid phase modification.

Modifying a hydrophobic material on the surface of the substrate through a gas phase or liquid phase condensation reaction to enable the surface of the substrate to be in a hydrophobic state, wherein the hydrophobic material comprises a fluorosilane molecule, a silane molecule or other molecules capable of enabling the surface to be modified in the hydrophobic state, and preferably the fluorosilane molecule comprises 1H,1H,2H, 2H-perfluorodecyltrimethoxy (triethoxy, trichloro) silane or 1H,1H,2H, 2H-perfluorooctyltrimethoxysilane (triethoxy, trichloro) silane; preferably, the silane molecule comprises any one of n-butyltrimethoxy (triethoxy, trichloro) silane, n-hexyltrimethoxy (triethoxy, trichloro) silane, n-octyltrimethoxy (triethoxy, trichloro) silane, dodecyltrimethoxy (triethoxy, trichloro) silane, hexadecyltrimethoxy (triethoxy, trichloro) silane or octadecyltrimethoxy (triethoxy, trichloro) silane.

Preferably, the time of the hydrophobic treatment is 3h to 10h, such as 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, more preferably 6 h.

The substrate surface is in a hydrophobic state by gas phase/liquid phase condensation reaction of fluorosilane or silane molecules. If the hydrophobic modification time is less than 3h, the number of hydrophobic molecules for surface modification is small, the surface hydrophobicity is not enough, the hydrophobic interaction is weak, and the patterned gel has defects; the treatment time is more than 10h, and the hydrophobicity of the surface of the substrate is not further improved.

Preferably, the preparation method of the patterned substrate comprises a mask method and/or a step processing method;

as an optional technical solution, when the patterned substrate is a plane, a mask method is used to prepare the patterned substrate, and the mask method includes the following steps:

(a) carrying out hydrophilic treatment on the surface of the substrate, and then carrying out hydrophobic treatment;

(b) placing a mask on the surface of the substrate according to a preset pattern, and only exposing a preset hydrophilic region;

(c) carrying out hydrophilic treatment on the exposed preset hydrophilic area;

(d) and removing the mask to form a patterned substrate with hydrophilic regions and hydrophobic regions.

As another optional technical solution, when the patterned substrate is a plane, the patterned substrate is prepared by using a mask method, and the mask method may further include the following steps:

(a') subjecting the surface of the substrate to a hydrophilic treatment;

(b') placing a mask on the surface of the substrate according to a preset pattern, and only exposing a preset hydrophobic region;

(c') performing a hydrophobic treatment on the exposed predetermined hydrophobic region;

(d') removing the mask to form a patterned substrate having hydrophilic and hydrophobic regions.

Preferably, the masking material comprises tape, photoresist or other material that can form an exposed patterned region on the surface of the substrate, preferably using photoresist as the masking material to obtain a more precise pattern on the substrate.

Preferably, the mask may be prepared by: uniformly and lightly sticking a layer of adhesive tape (without air bubbles) on the surface of the substrate or spin-coating a layer of photoresist, drawing a specific pattern by using drawing software, punching the pattern on the adhesive tape or the photoresist by using a laser marker or a photomask plate, exposing the pattern, tearing off the residual adhesive tape or washing off the residual photoresist after the hydrophilic/hydrophobic area of the surface is constructed, and thus forming the substrate with the preset pattern.

Preferably, the hydrophilic region and the hydrophobic region are located on the same surface of the substrate; placing a second substrate in opposition to the hydrophilic and hydrophobic regions of the patterned substrate and adding a spacer between the two substrates to maintain a gap between the two substrates prior to applying the emulsion to the substrate surface in step (2); dropwise adding the emulsion into the gap until the whole gap is filled; and then carrying out cross-linking polymerization on the emulsion to obtain the gel with the patterned surface.

Preferably, the thickness of the gasket is 200 μm to 3mm, preferably 1 mm.

As a preferred embodiment, when the patterned substrate is a three-dimensional structure composed of one or more surfaces, the patterned substrate is prepared using a step-by-step process, which includes the steps of:

and splitting the substrate according to a preset pattern, then respectively carrying out hydrophilic treatment and/or hydrophobic treatment, and then assembling the split substrate according to the preset pattern. Preferably, the substrate is a three-dimensional structure with an internal space, preferably a mold with an internal surface, the mold is split into at least two parts, the internal surface of each part is subjected to hydrophilic treatment and/or hydrophobic treatment, then the split molds are combined to form the mold with the internal space, the internal surface of which is patterned by the hydrophilic region and the hydrophobic region, the gel emulsion is poured into the mold to be polymerized, and then the gel emulsion is taken out, so that the three-dimensional structure of the patterned gel can be obtained.

Another object of the invention is to provide a surface patterned gel having a first surface region and a second surface region of different wettability;

preferably, the surface patterned gel is prepared by the preparation method according to object one;

preferably, the contact angle of the first surface region is from 65 ° to 120 °, and the contact angle of the second surface region is from 5 ° to 45 °;

preferably, the first surface region is enriched with lipophilic groups and the second surface region is enriched with hydrophilic groups;

preferably, the lipophilic group comprises any one of alkyl, ester, ether and aromatic groups or the combination of at least two of the alkyl, ester, ether and aromatic groups;

preferably, the hydrophilic group includes any one of an amide group, a carboxyl group, a hydroxyl group, an amino group, or a combination of at least two thereof.

The first surface region of the surface-patterned gel is an oleogel region, is enriched with oleophilic groups, and corresponds to a hydrophobic region of the patterned substrate, because hydrophobic monomers in the emulsion directionally move to the hydrophobic region of the substrate due to hydrophobic interaction; the second surface region is a hydrogel region enriched with hydrophilic groups corresponding to the hydrophilic region of the patterned substrate due to the directional movement of hydrophilic monomers in the emulsion to the hydrophilic region of the substrate via hydrophilic interactions.

Preferably, the depth of the first surface region and the second surface region are each independently selected from 4 μm

～20μm。

Because the hydrophilic/hydrophobic induction effect exists only at the solid/liquid interface, the directional movement of the hydrophilic monomer and the hydrophobic monomer can not occur in the emulsion phase, therefore, after the emulsion is gelled, the hydrophilic and hydrophobic patterns exist only on the surface of the gel, and the depths of the patterns are respectively and independently selected from 4 mu m to 20 mu m. While the thickness of the gel has no effect on the surface patterning, no matter how thick the gel is, the patterning of the gel only occurs at the surface.

It is a further object of the present invention to provide a use of the surface patterning gel according to the second object, wherein the surface patterning gel is used for any one or a combination of at least two of pattern transfer, detection of DNA molecules and/or fluorescent molecules, and anisotropic adhesion.

Applying water-soluble dye or oil-soluble dye on the surface of the surface-patterned gel, wherein the water-soluble dye or oil-soluble dye can be used for pattern transfer; dripping a solution with DNA molecules and/or fluorescent molecules into the hydrophilic region of the surface patterned gel, wherein the solution can be used for detecting the DNA molecules and/or the fluorescent molecules; by having at least one region of the surface-patterned gel as a hydrogel and at least one region as an oleogel, an anisotropic adhesive material can be prepared due to the difference in viscosity between the oleogel and the hydrogel.

The fourth object of the present invention is to provide a pattern transfer stamp, comprising the surface-patterned gel according to the second object, wherein the first surface region and the second surface region of the surface-patterned gel are on the same surface;

preferably, in the pattern transfer stamp, the second surface region of the surface patterned gel absorbs a water-soluble dye, and/or the first surface region of the surface patterned gel absorbs an oil-soluble dye.

In the pattern transfer stamp, the first surface region of the surface patterning gel is a hydrophobic region and thus can be dyed only by oil-soluble dyes, and the second surface region is a hydrophilic region and thus can be dyed only by water-soluble dyes, and by applying water-soluble dyes and/or oil-soluble dyes of different colors, the gel surface can present a predetermined pattern and can be used for pattern transfer.

The fifth object of the present invention is to provide a method for using the pattern transfer stamp according to the fourth object, the method comprising the steps of:

covering hydrogel pre-polymerization liquid on the surface of the pattern transfer seal, polymerizing the hydrogel pre-polymerization liquid through ultraviolet irradiation, and stripping polymerized gel from the transfer seal after polymerization to realize pattern transfer.

Preferably, the hydrogel pre-polymerization solution comprises a hydrogel monomer, a hydrogel monomer initiator and a hydrogel cross-linking agent dispersed in water.

And applying hydrogel pre-polymerization liquid on the surface of the pattern transfer seal, wherein in the process of polymerizing the hydrogel pre-polymerization liquid by ultraviolet irradiation, water-soluble dye on the surface of the seal is diffused into the inner surface of the corresponding area of the hydrogel, and the polymerized hydrogel is stripped from the transfer seal to realize pattern transfer.

Compared with the prior art, the invention has the following beneficial effects:

(1) according to the invention, the emulsion containing the hydrogel pre-polymerized liquid and the oleogel pre-polymerized liquid is selected as the precursor of the patterned gel, the directional migration of the hydrogel monomer and the oleogel monomer in the emulsion is realized by utilizing the difference of the wettability of the substrate surface and the induction effect of hydrophilic/hydrophobic interaction of the interface, the patterning of the gel surface can be directly realized by an infiltration transfer method, the preparation process is simple and feasible, and complex equipment is not required.

(2) In a preferred technical scheme, the invention selects proper hydrogel monomers and oil gel monomers, and the compositions and the proportions of the hydrogel pre-polymerization liquid and the oil gel pre-polymerization liquid to ensure that the directional induction and the transfer of an interface are complete, so that the pattern boundary of the prepared patterned gel is clear and the precision is high.

(3) In a preferable technical scheme, the invention can ensure that the prepared surface-patterned gel has excellent mechanical properties, swelling resistance, stretchability and other properties by selecting proper emulsion composition and proportion and controlling emulsification and polymerization conditions, so that the application of the surface-patterned gel in a plurality of scenes becomes possible.

(4) Because the hydrophilic/hydrophobic interaction induction effect exists only at the solid/liquid interface, the invention can prepare the gel with patterned surface, the gel phase is not patterned, and the whole thickness of the gel has no influence on the surface patterning, and the gel patterning only occurs on the surface no matter the thickness of the gel. That is, the gel phase of the patterned gel prepared by the present invention is not changed except for the patterned surface, the overall performance of the gel is not affected by the patterning process, and the non-patterned surface is not affected when used for other purposes.

(5) The size and the dimensionality of the surface patterning gel prepared by the invention are adjustable and controllable, and the two-dimensional structural gel with any pattern or shape and the three-dimensional gel with any shape can be prepared by changing the shape or the structure of the substrate. The gel pattern size can range from microscopic (a few microns to hundreds of microns) to macroscopic (a few hundreds of microns to tens of centimeters).

(6) The preparation method of the patterned gel is applicable to various gels and has wide application range.

(7) The surface patterning gel prepared by the invention is suitable for various application scenes, can be used as a transfer seal for pattern transfer, can be used as a detection platform for detecting the strength of DNA molecules and fluorescent molecules, can also be used for anisotropic adhesion, and has very wide application prospect.

(8) After the surface patterning gel prepared by the invention is stretched, the conditions such as pattern fracture and the like can not occur, the integrity and the continuity of the pattern can still be maintained, and the stretched pattern can be obtained on the surface of the hydrogel after the transfer printing process.

Drawings

FIG. 1 is a comparison of the sharpness of surface patterned gel patterns prepared from different monomers of the present application;

FIG. 2 is a graph showing the wettability of the oil/hydrogel regions on the surface of the patterned gel of the present application;

FIG. 3 is a graph of the effect of thickness on surface patterning of a surface patterned gel sample of the present application;

FIG. 4 is a graph of the swelling resistance of a surface patterned gel prepared according to the present application;

FIG. 5 is a graph of the stretchability of a surface patterned gel prepared according to the present application;

FIG. 6 is a transferability of a surface patterned gel pattern prepared herein;

FIG. 7 is a stretched pattern transferred from a surface patterned gel made in accordance with the present application after stretching;

FIG. 8 is a graph of the performance of the surface patterned gel patterns prepared in the present application for the detection of fluorescent molecules;

fig. 9 is a macroscopic 3D hydrogel pattern prepared by the present application;

FIG. 10 is a macroscopic hydrogel pattern (a) and an oleogel pattern (b) prepared herein;

FIG. 11 is a microscopic hydrogel pattern (a) and oleogel pattern (b) prepared in accordance with the present application;

fig. 12 is a composite pattern of macroscopic hydrogels and oleogels made herein.

Detailed Description

The technical solution of the present application is further explained by the following embodiments.

It should be understood by those skilled in the art that the examples are only for the understanding of the present application and should not be construed as a specific limitation of the present application.

Example 1

A method of preparing a gel having a surface pattern, the method comprising the steps of:

(1) providing a patterned substrate having hydrophilic regions and hydrophobic regions on a surface thereof, the patterned substrate being prepared by:

(1-1) treating the cleaned glass sheet by using oxygen plasma, wherein the oxygen plasma treatment time is 10min, and the power is 160W, so that the surface of the glass sheet is modified with hydroxyl groups and is in a super-hydrophilic state; then modifying fluorosilane on the surface of the glass sheet through gas phase or liquid phase condensation reaction, wherein the fluorosilane is 1H,1H,2H, 2H-perfluorodecyl trimethoxy silane and is in a hydrophobic state;

(1-2) uniformly and lightly sticking a layer of adhesive tape on the hydrophobic surface of the glass sheet;

(1-3) drawing a specific pattern by using drawing software, and punching the pattern on the adhesive tape by using a laser marker to tear off the adhesive tape at the position with the pattern; then, oxygen plasma treatment is carried out for 10min, the power is 160W, the place without the adhesive tape (torn off) is in a super-hydrophilic state, and the place covered by the adhesive tape is still in a hydrophobic state;

(1-4) tearing off the residual adhesive tape to obtain a patterned substrate with a hydrophilic area and a hydrophobic area on the surface;

(2) applying an emulsion comprising a hydrogel pre-polymerization liquid and an oleogel pre-polymerization liquid to a patterned substrate surface, wherein hydrophilic monomers and hydrophobic monomers in the pre-polymerization liquid self-assemble on the substrate surface; preparing a hydrogel prepolymer solution: adding 0.15mol of hydrogel monomer acrylamide, 4.8g of cross-linking agent nanoclay and 30mg of photoinitiator 2, 2-diethoxyacetophenone into 60mL of water, and dispersing to obtain a hydrogel pre-polymerization solution;

preparing an oil gel pre-polymerization liquid: mixing 0.3mol of an oleogel monomer lauryl methacrylate, 3g of a cross-linking agent ethylene glycol dimethacrylate and 60mg of a photoinitiator 2, 2-diethoxyacetophenone;

mixing the hydrogel pre-polymerized liquid and the oil gel pre-polymerized liquid according to the mol ratio of the oil gel monomer to the hydrogel monomer of 2:1, and emulsifying for 1min under the power of 585W to obtain stable emulsion;

dropwise adding the obtained emulsion between a patterned glass sheet and another common glass sheet, wherein the glass sheets are separated by a gasket, and the hydrogel monomer and the oleogel monomer in the pre-polymerization solution are self-assembled on the surface of the substrate of the patterned glass sheet;

(3) after gelling and peeling the emulsion from the substrate, obtaining a gel with patterning;

and carrying out ultraviolet irradiation polymerization on the oil-water gel emulsion, wherein the ultraviolet irradiation polymerization power is 500W, the photopolymerization time is 30min, and stripping the gel subjected to crosslinking polymerization from the substrate to obtain the patterned gel.

Examples 2 to 7

The only difference from example 1 is the choice of hydrogel monomer or oleogel monomer.

The hydrogel monomer in example 2 was 0.15mol hydroxyethyl acrylate.

The hydrogel pre-polymerization solution in example 3 was composed of 0.15mol of acrylic acid, 21.3mL of water, 31.5mL of a 4 wt% polyvinyl alcohol solution, 121.3mg of N, N-methylenebisacrylamide, and 126mg of 2-hydroxy-4' - (2-hydroxyethoxy) -2-methylpropiophenone. This is because the negatively charged acrylic acid cannot be cross-linked by the nanoclay platelets in example 1, thus requiring the exchange of cross-linking agents, where a 4 wt% solution of polyvinyl alcohol can act as an emulsion stabilizer while increasing the mechanical strength of the hydrogel.

The hydrogel monomer in example 4 was 0.15mol of N, N-dimethylacrylamide.

The oleogel monomer in example 5 was 42.7g butyl methacrylate.

The oleogel monomer in example 6 was 51.1g hexyl methacrylate.

The oleogel monomer in example 7 was 59.5g of isooctyl methacrylate.

Examples 8 to 15

The difference from example 1 is only the monomer content, the initiator type and content, and the crosslinker type and content in the hydrogel prepolymer solution.

The content of the monomer in the hydrogel prepolymerization solution in example 8 was 0.06 mol.

The content of the monomer in the hydrogel prepolymerization solution in example 9 was 0.36 mol.

The content of the photoinitiator in the hydrogel prepolymerized liquid in example 10 was 3 mg.

The content of the photoinitiator in the hydrogel precursory in example 11 was 180 mg.

The kind of the photoinitiator in the hydrogel prepolymerized liquid in example 12 was 2-hydroxy-4' - (2-hydroxyethoxy) -2-methylpropiophenone, and the content was 60 mg.

The content of the crosslinking agent in the hydrogel prepolymerized liquid in example 13 was 0.6 g.

The content of the crosslinking agent in the hydrogel prepolymerized liquid in example 14 was 9.6 g.

The type of the crosslinking agent in the hydrogel precursory in example 15 was N, N-methylenebisacrylamide, and the content was 240 mg.

Examples 16 to 22

The differences from example 1 are only in the monomer content, the type and content of the initiator, and the type and content of the crosslinking agent in the oil gel prepolymer solution.

The molar ratio of oleogel monomer to hydrogel monomer in example 16 was 5: 1.

The molar ratio of oleogel monomer to hydrogel monomer in example 17 was 1: 5.

The content of photoinitiator in the oil gel prepolymer in example 18 was 0.02 wt%.

The photoinitiator content of the oleogel prepolymer liquid in example 19 was 0.3 wt%.

The content of the crosslinking agent in the oil gel prepolymer liquid in example 20 was 0.1% by weight.

The content of the crosslinking agent in the oil gel pre-polymerization liquid in example 21 was 8 wt%.

The kind of the cross-linking agent in the oil gel pre-polymerization solution in example 22 was polyethylene glycol dimethacrylate, and the content was 4 wt%.

Examples 23 to 28

The only difference from example 1 is the selection of the substrate processing conditions including oxygen plasma treatment time, hydrophobic molecule selection, hydrophobic treatment time, patterned substrate.

The oxygen plasma treatment time in example 23 was 4 min.

The treatment time of oxygen plasma in example 24 was 15 min.

The molecule used for hydrophobic modification in example 25 was n-octyltrimethoxysilane.

The molecule used for the hydrophobic modification in example 26 was hexadecyltrimethoxysilane.

The time for hydrophobic modification of the substrate surface in example 27 was 2 h.

The time for hydrophobic modification of the substrate surface in example 28 was 12 h.

Examples 29 to 30

The only difference from example 1 is the choice of the photopolymerisation conditions.

In example 29, the UV power was 200W and the polymerization time was 60 min.

In example 30, the power of the ultraviolet light was 800W and the polymerization time was 10 min.

Example 31

Three-dimensional gels were prepared using three-dimensional molds, spheres and cylinders.

Comparative example 1

The only difference from example 1 is that the patterned gel cannot be formed using a solution of aqueous gel monomer and oil gel monomer, rather than an emulsion.

Comparative example 2

The only difference from example 1 is that a surface-patterned gel could not be obtained using only a hydrogel.

Application example one

The gels obtained in example and comparative example 1 were prepared into a pattern transfer stamp. Comparative example 1 failed to form a surface-patterned gel, and thus no application example experiment was performed.

Application example two

The surface-patterned gel obtained in example 1 was used to prepare a pattern transfer stamp, which was stretched and then subjected to pattern transfer.

Application example three

The surface patterned gel obtained in the embodiment 1 is used for detecting fluorescent molecules, DNA molecules to be detected with different concentrations are combined with a probe through base complementary pairing to realize fluorescent signal amplification, the solution is dripped into a surface hydrogel area of the patterned gel, and the fluorescence intensity of reaction solutions containing the DNA with different concentrations to be detected is detected by using a fluorescence confocal microscope under the same detection condition.

And (3) performance testing:

(1) contact angle: measuring the contact angle of the first surface region and the contact angle of the second surface region of the surface-patterned gel obtained in example, and the contact angle of the hydrogel surface of comparative example 2;

the test method comprises the following steps: all samples were tested for contact angle of the surfaces (first and second surface) after polymerization was complete using a german Dataphysics OCA20 instrument at room temperature with a drop volume controlled to 2 uL.

(2) Pattern definition: and (3) dripping a water-soluble dye on the surface of the patterned gel obtained in the embodiment to dye, calculating the percentage of the sum of the area of the redundant part and the area of the missing part of the first region in the preset area of the first region as A, and when A is less than 5%, marking the pattern definition as excellent, and when A is 5% -10%, marking the pattern definition as good.

(3) Mechanical properties (tensile properties): the surface-patterned gels obtained in examples and comparative example 2 were tested for mechanical properties.

The test method comprises the following steps: the gel sample was cut into strips (length 6cm, width 1cm, thickness 2mm) for tensile testing. All experiments were tested using a Mark-10 ESM301 motorized test rig, with one end of the strip clamped with a clamp during the test, stretched upward at a speed of 20mm/min, the stress and strain data recorded during the stretching, and the ratio of stress to strain calculated at 10% strain.

(4) Swelling resistance: the surface-patterned gels obtained in examples and comparative examples were tested for swelling resistance.

The test method comprises the following steps: the surface-patterned gel was cut into a size of 1cm × 1cm, and a pentagonal hydrogel pattern (initial length of 0.6cm) was formed in the middle of the surface of each piece of gel. And (3) dyeing the hydrogel pattern area into blue by using methylene blue, soaking the hydrogel pattern area into different solvents for 5 hours, taking out the hydrogel pattern area, taking a picture by using a camera, and measuring the length change of the front and rear pentagons. The algorithm for the swelling ratio is: q is L/L ₀ X is 100%; wherein L is the length of the five-pointed star after swelling, L ₀ Is the initial length of the five-pointed star.

(5) Transferability: the surface-patterned gels obtained in examples and comparative examples were tested for transferability.

The test method comprises the following steps: and applying hydrogel pre-polymerization liquid on the surface of the patterned gel which locally absorbs dye molecules, irradiating the surface of the patterned gel for 5-10 min by ultraviolet light to polymerize the hydrogel pre-polymerization liquid, allowing the dye molecules on the surface of the transfer print to have enough time to transfer at a solid/liquid interface, and finally stripping the polymerized gel from the transfer print. Transferability if the pattern of the patterned gel surface is completely transferred to the hydrogel surface; otherwise, there is no transferability.

(6) Fluorescence molecule detection sensitivity: the surface patterned gel obtained in example 1 was tested for fluorescent molecule detection concentration.

The test method comprises the following steps: combining the DNA molecules to be detected with different concentrations with the probe through base complementary pairing and realizing fluorescence signal amplification, dripping the solution into the surface hydrogel area of the patterned gel, detecting the fluorescence intensity of the reaction solution containing the DNA with different concentrations to be detected by using a fluorescence confocal microscope under the same detection condition, calculating a fitted standard curve, and obtaining a correlation coefficient.

The test results are shown in table 1:

TABLE 1

As can be seen from table 1, according to the method for preparing a gel with surface patterning of the present application, an emulsion containing a hydrogel pre-polymerization liquid and an oleogel pre-polymerization liquid is applied to a patterned substrate surface with hydrophilic regions and hydrophobic regions, and a hydrogel monomer and an oleogel monomer in the pre-polymerization liquid are self-assembled on the substrate surface, so that a gel with surface patterning can be obtained. By adjusting the content and the type of the hydrogel monomer, the oleogel monomer, the initiator and the cross-linking agent, and adjusting the substrate processing time, the hydrophobic material and the emulsion polymerization conditions, the expected and desired corresponding product can be obtained.

1. It can be known from comparative examples 1 to 4 that the stronger the hydrophilic interaction between the hydrogel monomer and the hydrophilic group of the hydrophilic region on the substrate surface, the better the definition of the obtained pattern, for example, fig. 1(a) is the patterned gel obtained in example 1, fig. 1(b), fig. 1(c) and fig. 1(d) are the patterned gels obtained in examples 2, 3 and 4, respectively, the better the definition of the pattern generated by the hydrogel monomers Acrylamide (AM), hydroxyethyl acrylate (HEA) and Acrylic Acid (AA), and the better the hydrophilicity of the hydrogel monomer N, N-Dimethylacrylamide (DMA) monomer is not stronger than the three hydrogel monomers, and the interface induction is weak, so that the pattern can generate defects and the pattern definition is good.

2. It is known from comparative examples 5 to 7 that the larger the number of carbon chains of the oleogel monomer is in the range of 4 to 18, the better the pattern definition is, for example, fig. 1(e), 1(f), and 1(g) are the patterned gels obtained in examples 5, 6, and 7, respectively, the pattern definition generated by the oleogel monomers Hexyl Methacrylate (HMA) and 2-methyl hexyl methacrylate (EMA) is excellent, the hydrophobic carbon chains of the oleogel monomer n-Butyl Methacrylate (BMA) are not as long as the two oleogel monomers, the hydrophobic interaction is weak, the interface induction is not strong, and thus the pattern may have defects, and the pattern definition is good.

3. From comparative examples 8 to 15, it is known that, when the contents of the hydrogel monomer, the initiator and the crosslinking agent in the hydrogel prepolymerization solution are selected within the range of the present invention, a uniform and stable emulsion can be prepared, and the definition of the surface-patterned gel pattern prepared by the method of the present invention is excellent.

4. It can be known from comparative examples 16-22 that the contents of the oleogel monomer, the initiator and the cross-linking agent in the oleogel pre-polymerization solution are selected within the range of the present invention, so that a uniform and stable emulsion can be prepared, and the pattern definition of the surface-patterned gel prepared by the method of the present invention is excellent.

5. It is known from comparative examples 23 to 28 that the substrate has better hydrophilicity/hydrophobicity by selecting suitable substrate treatment conditions, the substrate and the oil hydrogel can generate a hydrophilicity/hydrophobicity inducing effect, and in comparative example 23, the oxygen plasma treatment time is short, the surface modified hydroxyl groups are few, the hydrophilic interaction force is weak, so that the pattern can generate defects, and the pattern definition is good. In comparative example 27, the time for hydrophobic modification was short, the amount of hydrophobic molecules for surface modification was small, and the hydrophobic interaction force was weak, so that the pattern was defective and the pattern definition was good.

6. It is known from comparative examples 29 to 30 that selecting the illumination power and the polymerization time according to the photoinitiator within the range of the present invention can crosslink and polymerize the emulsion to form a gel having a certain mechanical strength, and the pattern definition of the surface-patterned gel prepared by the method of the present invention is excellent.

7. As is apparent from comparative example 31, three-dimensional patterned gels prepared by the method of the present invention using a three-dimensional mold were spherical and cylindrical, wherein dark portions were areas of the hydrogel after dyeing and light portions were areas of the oleogel without dyeing, as shown in fig. 9.

8. The surface-patterned gels obtained in examples 1 to 31 of the present application form hydrophilic regions and hydrophobic regions, the contact angles between the first surface region and the second surface region are shown in table 1, fig. 2 shows the wettability characterization of example 1, the upper graph in the figure is the contact angle of the first surface region (hydrophobic region) of the patterned gel, and the lower graph is the contact angle of the second surface region (hydrophilic region).

9. The thickness of the surface-patterned gel sample obtained in the present application has no influence on the surface patterning, no matter how thick the sample is, the gel is patterned only on the surface of the gel, and fig. 3 shows the surface-patterned gel obtained in example 1, wherein the gel thicknesses are 1mm, 2mm and 2.5mm from top to bottom in sequence.

10. The maximum swelling ratios of the patterned gels obtained in examples 1 and 23-31 in different solvents are less than or equal to 110%, the maximum swelling ratios of the patterned gels obtained in examples 2-22 in different solvents are less than or equal to 120%, and the patterned gels have excellent swelling resistance, and fig. 4 shows the swelling resistance performance characterization of example 1, wherein the ordinate direction in the figure is the swelling ratio of the surface patterned gel in different solvents, and the upper pentacle pattern is the hydrogel region of the corresponding surface patterned gel.

11. The mechanical properties of the surface-patterned gels obtained in examples 1 to 31 of the present application are shown in table 1, and the surface-patterned gels have certain stretchability, and do not break or fracture when the strain is 10%, so that the surface-patterned gels can be used for transferring stamps or other purposes; the patterned gels obtained in examples 1, 4, 8, 9, 12, 16, 17 and 22-30 have repeatable stretchability, good gel elasticity and can bear larger deformation continuously; figure 5 shows the reciprocating tensile properties characterization of example 1.

12. The pattern transfer stamps prepared by the application examples of examples 1 to 30 of the present application all had pattern transferability, fig. 6(a) - (c) show the transfer performance characterization of the application example of example 1, fig. 6(a) shows the prepared surface-patterned gel, (b) shows the surface-patterned hydrogel obtained by using hydrogel as a receiving medium, the pattern can be completely transferred to the hydrogel surface according to the ratio of 1:1, and (c) shows that the pattern does not have any defect after water impact for 60s, and the transferred pattern is very stable.

13. The pattern transfer stamp manufactured according to the application example of example 1 of the present application can still realize pattern transfer after stretching to obtain a stretched pattern, fig. 7(a) - (d) show the stretch transfer performance characterization of the application example of example 1, fig. 7(a) shows the prepared surface patterned gel, (b) shows the surface patterned gel obtained after stretching the surface patterned gel, (c) shows the surface patterned hydrogel obtained by using the hydrogel as a receiving medium, the stretched pattern can be completely transferred to the surface of the hydrogel according to the ratio of 1:1, and (d) shows that after 60s of water impact, the pattern has no defects and is very stable.

14. The surface patterned gel obtained in the example 1 is used for detecting the concentration of fluorescent molecules, the detection sensitivity is high, and R is ² 0.99554, FIG. 8 shows the characterization of the surface patterned gel of example 1 for the detection of fluorescent molecule concentration, the left panel from left to right showing the fluorescence enrichment process with time (0s-150 s).

15. Macroscopic and microscopic surface patterned gels can be prepared using the methods of the present application, and fig. 10 is a macroscopic hydrogel pattern and an oleogel pattern prepared in example 1, where in fig. 10(a) the dark portions are the stained hydrogel areas and the white portions are the unstained oleogel areas; in FIG. 10(b), the dark portion is a stained oleogel region and the white portion is an unstained hydrogel region. FIG. 11 is a microscopic hydrogel pattern and oleogel pattern, with the patterned portions being fluorescence-stained hydrogel regions and the unpatterned portions being unstained oleogel regions in FIG. 11 (a); in FIG. 11(b), the structural portion is a region of the fluorescently stained oleogel, and the remaining portion is a region of the unstained hydrogel. It can be seen that the method of the present application can yield surface patterned gels with high pattern definition at both the macroscopic and microscopic dimensions.

16. By adopting the method, the gel with the complex pattern on the surface can be accurately dyed in different areas by adopting a gradual dyeing process and dyes with different colors and properties, fig. 12 is a macroscopic hydrogel and oleogel composite pattern prepared by the embodiment 1, wherein the dark part is a hydrogel area, the light part is an oleogel area, and the white part is an oleogel area. It can be seen that the definition of the surface patterned gel pattern is high, and the lines of the pattern are complete and clear.

The staining process of the surface patterned gel was:

staining process of the first surface region: spraying a water film on the surface of the gel after polymerization is finished to protect the second surface region, and then dripping oil-soluble dye on the surface of the gel, wherein only the first surface region can absorb dye molecules and be dyed; after 5min, the residual liquid on the gel surface was removed, and the first surface region of the patterned gel was successfully stained.

Staining process of the second surface region: placing the gel sample after polymerization under oil (n-decane) to protect the first surface region, dripping water-soluble dye on the gel surface, and only the second surface region can absorb dye molecules and be dyed; after 5min, the gel was removed from under the oil and the surface residual liquid was removed, i.e. the second surface region of the patterned gel was successfully stained.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of preparing a gel having a surface pattern, the method comprising the steps of:

(1) providing a patterned substrate with a surface having hydrophilic regions and hydrophobic regions;

(2) applying an emulsion comprising a hydrogel pre-polymerization liquid and an oleogel pre-polymerization liquid to the patterned substrate surface, the hydrogel monomers and the oleogel monomers in the pre-polymerization liquid self-assembling at the substrate surface;

2. The method of claim 1, wherein the emulsion comprises an oil-in-water emulsion or a water-in-oil emulsion;

preferably, the hydrogel prepolymer solution and the oil gel prepolymer solution are mixed and emulsified to obtain the emulsion;

preferably, the hydrogel pre-polymerization solution comprises a hydrogel monomer, a hydrogel monomer initiator and a hydrogel cross-linking agent dispersed in water; the oil gel prepolymerization liquid comprises an oil gel monomer, an oil gel monomer initiator and an oil gel crosslinking agent.

3. The method according to any one of claims 1 to 2, wherein the hydrogel monomer has

A structure, wherein R is a hydrophilic group comprising any one of an amide group, a carboxyl group, a hydroxyl group, an amino group, or a combination of at least two thereof;

preferably, the hydrogel monomer comprises any one of acrylamide, acrylic acid and hydroxyethyl acrylate or a combination of at least two of the acrylamide, the acrylic acid and the hydroxyethyl acrylate;

preferably, in the hydrogel pre-polymerization liquid, the content of the hydrogel monomer is 1 mol/L-6 mol/L, preferably 2.5 mol/L;

preferably, the hydrogel monomer initiator comprises benzophenones, benzoyl, preferably 2, 2-diethoxyacetophenone and/or 2-hydroxy-4' - (2-hydroxyethoxy) -2-methylpropiophenone;

preferably, in the hydrogel pre-polymerization solution, the content of the hydrogel monomer initiator is 0.05 mg/mL-3 mg/mL, preferably 0.5 mg/mL.

preferably, in the hydrogel pre-polymerization solution, the content of the hydrogel cross-linking agent is 1 wt% to 16 wt%, preferably the hydrogel cross-linking agent is an inorganic nanoclay sheet with a content of 8 wt%, or 0.05 wt% to 1 wt% of N, N-methylene bisacrylamide, preferably 0.4 wt% of N, N-methylene bisacrylamide.

4. The method according to any one of claims 1 to 3, wherein the oil gel monomer has

Structure (II) wherein R ₁ is-H, alkyl, R ₂ Is any one or the combination of at least two of alkyl, ester group, ether group and aromatic group, and the number of carbon chains is 4-18;

preferably, the oil gel monomer comprises acrylates and/or methacrylates.

Preferably, the molar ratio of oleogel monomer to hydrogel monomer is from 5:1 to 1:5, preferably 2: 1;

preferably, the oil gel monomer initiator comprises benzophenones, preferably 2, 2-diethoxyacetophenone;

preferably, in the oil gel pre-polymerization liquid, the content of the oil gel monomer initiator is 0.02 wt% to 0.3 wt%, preferably 0.08 wt%;

preferably, the oil gel cross-linking agent comprises polyisocyanates, polyamines, polyols, glycidyl ethers, organic peroxides, silicones, metal organic compounds, inorganic substances, preferably ethylene glycol dimethacrylate and/or polyethylene glycol dimethacrylate;

preferably, the content of the oil gel cross-linking agent in the oil gel pre-polymerization liquid is 0.1 wt% to 8 wt%, preferably 4 wt%.

5. The process according to any one of claims 1 to 4, wherein the emulsion is obtained by emulsification, the power of emulsification being 300W to 800W, the time of emulsification being 0.5min to 3 min;

preferably, the gelation method in the step (3) is crosslinking polymerization, preferably illumination polymerization, preferably the illumination power is 200W-800W, and the polymerization time is 10 min-60 min.

6. A method according to any one of claims 1 to 5, wherein the patterned substrate is a planar or three-dimensional structure consisting of one or more surfaces;

preferably, the three-dimensional structure comprises any one of a sphere, a cylinder, a prism, a pyramid or a frustum, or a combination of at least two thereof.

7. The production method according to any one of claims 1 to 6, wherein the patterned substrate is produced by subjecting the substrate to a hydrophilic treatment to impart hydrophilic regions to the surface of the substrate and a hydrophobic treatment to impart hydrophobic regions to the surface of the substrate;

preferably, the preparation method comprises a mask method and/or a step-by-step treatment method;

preferably, the step-processing method is a method of splitting the substrate according to a predetermined pattern, then respectively performing hydrophilic treatment and/or hydrophobic treatment, and then assembling the split substrate according to a predetermined pattern;

preferably, the hydrophilic treatment is oxygen plasma treatment, preferably the oxygen plasma treatment time can be 4min to 15min, preferably 10 min;

preferably, the hydrophobic treatment is a treatment of the area with a hydrophobic material;

preferably, the hydrophobic material comprises fluorosilane molecules or silane molecules;

preferably, the treatment method of the hydrophobic treatment comprises gas phase modification or liquid phase modification;

preferably, the time of the hydrophobic treatment is 3 to 10 hours, and more preferably 6 hours.

8. A surface patterned gel having a first surface region and a second surface region of different wettability;

preferably, the surface patterned gel is prepared by the preparation method of any one of claims 1 to 7;

preferably, the first surface region is enriched with lipophilic groups; the second surface region is enriched with hydrophilic groups;

Preferably, the depth of the first surface region and the second surface region are each independently selected from 4 μm to 20 μm.

9. Use of the surface patterning gel of claim 8 for any one or a combination of at least two of pattern transfer, detection of DNA molecules and/or fluorescent molecules, anisotropic adhesion.

10. A pattern transfer stamp, comprising the surface patterned gel of claim 8, the first and second surface regions of the surface patterned gel being on the same surface;

11. A method of using the pattern transfer stamp of claim 10, the method comprising the steps of:

covering hydrogel pre-polymerization liquid on the surface of the pattern transfer printing stamp, polymerizing the hydrogel pre-polymerization liquid through ultraviolet irradiation, and stripping the polymerized hydrogel from the transfer printing stamp after polymerization to realize pattern transfer printing.