KR102324171B1 - Double-hydrophobic-coating through quenching for hydrogels and its manufacturing method - Google Patents

Abstract

The present invention relates to a double hydrophobic coating hydrogel and a method for producing a double hydrophobic coating hydrogel, and more particularly, a double hydrophobic coating in which a hydrophobic polymer layer is formed on the surface of the hydrogel, and oil is adsorbed to the hydrophobic polymer layer It relates to a method for producing a double hydrophobic coating hydrogel and a double hydrophobic coating hydrogel having a structure that is excellent in both anti-drying properties and anti-swelling properties.

Description

Double-hydrophobic-coating hydrogel and its manufacturing method {Double-hydrophobic-coating through quenching for hydrogels and its manufacturing method}

The present invention relates to a double hydrophobic coating hydrogel and a method for producing a double hydrophobic coating hydrogel, and more particularly, a double hydrophobic coating in which a hydrophobic polymer layer is formed on the surface of the hydrogel, and oil is adsorbed to the hydrophobic polymer layer It relates to a method for producing a double hydrophobic coating hydrogel and a double hydrophobic coating hydrogel having a structure that is excellent in both anti-drying properties and anti-swelling properties.

Hydrogel is one of the compositions attracting attention in that it has a high water content and can be applied to various fields by controlling chemical or physical properties.

In particular, the hydrogel can be used for bone, cartilage, skin regeneration, drug delivery, and wound treatment of the human body, and thus the demand for tissue regeneration and cell therapy is increasing day by day.

Accordingly, hydrogels with excellent mechanical, structural, biological and electrical properties have been developed over the past 10 years.

However, since the conventional hydrogel contains a large amount of water, it is inevitably dried in air, thereby reducing flexibility and functionality.

For example, in the case of calcium-alginate hydrogel, when exposed to air, it dries within 5 hours.

In addition, most hydrogels swell significantly when immersed in water due to the hydrophilicity of the polymer, which causes the mechanical properties to be dramatically reduced.

For example, when polyacrylamide (PAAm) hydrogel is immersed in water, it swells to 4 times its original volume in 4 hours.

That is, since drying and swelling are one of the intrinsic properties of a hydrogel, it is necessary to develop a hydrogel having strong resistance to drying and swelling.

The present invention has been devised to solve these problems, and an object of the present invention is to provide a double hydrophobic coating hydrogel and a method for preparing a double hydrophobic coating hydrogel excellent in both anti-drying and anti-swelling properties.

Objects of the present invention are not limited to the objects mentioned above, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention provides a hydrogel; a hydrophobic polymer layer formed on the outer surface of the hydrogel; and an oil quenched and contained in the hydrophobic polymer layer; provides a double hydrophobic coating hydrogel comprising.

In a preferred embodiment, the hydrogel is a polyacrylamide (PAAm) hydrogel or a calcium-alginate polyacrylamide (Ca-alginate/PAAm) hydrogel.

In a preferred embodiment, the hydrophobic polymer layer is an octyl acrylate polymer, a dodecyl acrylate polymer or a stearyl acrylate polymer.

In a preferred embodiment, the hydrophobic polymer layer is a copolymer in which dodecyl acrylate and stearyl acrylate are polymerized in a volume ratio of 1:1.

In a preferred embodiment, the hydrophobic polymer layer has a thickness of 200 μm to 350 μm.

In a preferred embodiment, the oil is silicone oil or castor oil.

In a preferred embodiment, the viscosity of the oil is 1000 cSt to 2000 cSt at room temperature.

In a preferred embodiment, the contact angle of the double hydrophobic coating hardgel is 90° or more.

In addition, the present invention is the double hydrophobic coating hydrogel; and a drug supported on the hydrogel; further provides a drug delivery system comprising.

In addition, the present invention further provides a hydrogel lens comprising the double hydrophobic coating hydrogel.

In addition, the present invention further provides a hydrogel film comprising the double hydrophobic coating hydrogel.

In addition, the present invention is a hydrogel preparation step of preparing a hydrogel; a radical initiator forming step of immersing the prepared hydrogel in a radical initiator solution to form a radical initiator on the surface of the hydrogel; forming a hydrophobic polymer by immersing the hydrogel in which the radical initiator is formed in a hydrophobic monomer solution, whereby the radical initiator formed on the surface of the hydrogel is polymerized to form a hydrophobic polymer layer; an oil adsorption step of immersing the hydrogel on which the hydrophobic polymer layer is formed in an oil solution at a first temperature to adsorb the oil to the hydrophobic polymer layer; and a quenching step of immersing the hydrogel to which the oil is adsorbed in an oil solution of a second temperature lower than the first temperature, and quenching so that the oil is confined in the hydrophobic polymer layer; Double hydrophobic coating comprising a It further provides a method for producing a hydrogel.

In a preferred embodiment, the hydrogel is a polyacrylamide (PAAm) hydrogel or a calcium-alginate polyacrylamide (Ca-alginate/PAAm) hydrogel.

In a preferred embodiment, 2,2-azobisisobutyronitrile (AIBN) is used as the radical initiator.

In a preferred embodiment, the radical initiator solution contains 2,2-azobisisobutyronitrile (AIBN) and an organic solvent.

In a preferred embodiment, after the radical initiator forming step, the hydrogel heating step of heat-treating the hydrogel to remove the organic solvent; further comprises.

In a preferred embodiment, the hydrophobic monomer is an acrylate-based monomer.

In a preferred embodiment, the acrylate-based monomer is octyl acrylate, dodecyl acrylate or stearyl acrylate.

In a preferred embodiment, the acrylate-based monomer is a mixture of dodecyl acrylate and stearyl acrylate in a volume ratio of 1:1.

In a preferred embodiment, the hydrophobic polymer forming step is reacted at 120° C. for 30 minutes to 45 minutes.

In a preferred embodiment, the temperature of the oil solution in the oil adsorption step is 80 °C to 120 °C.

In a preferred embodiment, the temperature of the oil solution in the quenching step is room temperature.

In a preferred embodiment, the oil is silicone oil (silicone oil) or castor oil (caster oil) is used.

In a preferred embodiment, the viscosity of the oil is 1000 cSt to 2000 cSt at room temperature.

The present invention has the following excellent effects.

On the other hand, the conventional hydrogel has swelling resistance by changing the internal chemical structure, but according to the manufacturing method of the double hydrophobic coating hydrogel and the double hydrophobic coating hydrogel of the present invention, without changing the chemical structure of the hydrogel, the surface of the hydrogel By providing a double hydrophobic coating structure consisting of a hydrophobic polymer layer and an oil quenched and adsorbed on the hydrophobic polymer layer, it has excellent anti-drying properties and anti-swelling properties with a mechanism similar to that of mammalian skin.

According to the manufacturing method of the double hydrophobic coating hydrogel and the double hydrophobic coating hydrogel of the present invention, it has excellent stability in various aquatic environments such as water, seawater, saline, etc., has excellent adhesion, and there is no restriction of applied oil. There is an effect that can be used in various fields such as a bio-based drug delivery system, a hydrogel lens, and a hydrogel film.

1 is a view for explaining a double hydrophobic coating hydrogel according to the present invention.
2 is a schematic diagram for explaining a method of manufacturing a double hydrophobic coating hydrogel according to the present invention.
3 is a step diagram for explaining a method of manufacturing a double hydrophobic coating hydrogel according to the present invention.
4 is a photograph confirming the weight change over time in the condition that the double hydrophobic coating hydrogel according to the present invention is exposed to air.
5 is a graph confirming the drying characteristics of the double hydrophobic coating hydrogel according to the present invention under the conditions of exposure to air.
6 is a result confirming the air drying characteristics of the hydrogel according to the chain length of the hydrophobic polymer.
7 is a result of confirming the air drying characteristics of the hydrogel according to the oil viscosity.
8 is a graph confirming the drying characteristics of the double hydrophobic coating hydrogel according to the quenching temperature.
9 is a result confirming the tensile properties of the double hydrophobic coating hydrogel according to the present invention.
10 is a result confirming the compression characteristics of the double hydrophobic coating hydrogel according to the present invention.
11 is a result confirming the air drying characteristics before and after 10 consecutive loading/unloading cycles at a compression strain of 0.5 using the double hydrophobic coating hydrogel according to the present invention.
12 is a result of confirming 10 consecutive loading/unloading cycles at a compressive strain of 0.5 using a double hydrophobic coating hydrogel according to the present invention.
13 is a graph confirming the swelling characteristics under the condition that the double hydrophobic coating hydrogel according to the present invention is immersed in various water.
14 is a photograph confirming the change with time in the condition that the double hydrophobic coating hydrogel according to the present invention is immersed in water.
15 is a surface SEM image of Comparative Example 1.
16 is a surface SEM image of Example 1. FIG.
17 is a cross-sectional SEM image of Example 1. FIG.
18 is a cross-sectional SEM image of the double hydrophobic coating hydrogel according to the polymerization time of the hydrophobic polymer formation step.
19 is a result confirming the air drying characteristics of the double hydrophobic coating hydrogel according to the polymerization time of the hydrophobic polymer formation step.
20 is an image confirming the contact angle between the water droplet and the surface of Comparative Example 1.
21 is an image confirming the contact angle between the water droplet and the surface of Comparative Example 3.
22 is an image confirming the contact angle between the water droplet and the surface of Example 1.
23 is a schematic diagram showing a method for evaluating the surface adhesion force of Example 1.
24 is a graph showing the evaluation result of the surface adhesion force of Example 1.
25 is a graph confirming the drying characteristics of Example 5 under the conditions of exposure to air.
26 is a graph confirming the swelling characteristics under the condition that Example 5 is immersed in water.
27 is a result of confirming the tensile properties using Example 5.
28 is a result of confirming the tensile properties using Example 5, (a) shows the young's module and tensile strength, (b) shows the work of extension.
29 is a result of confirming the compressive characteristics using Example 5, (a) is a compressive stress-strain curve, (b) shows the young's module and compressive strength (compressive strain 0.9).
30 is a graph confirming drying characteristics under conditions of exposure to air using Example 6.

As for the terms used in the present invention, general terms that are currently widely used as possible have been selected, but in certain cases, there are also terms arbitrarily selected by the applicant. So the meaning should be understood.

Hereinafter, the technical configuration of the present invention will be described in detail with reference to preferred embodiments shown in the accompanying drawings.

However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Like reference numerals refer to like elements throughout.

1 is a view for explaining a double hydrophobic coating hydrogel according to the present invention.

1, the double hydrophobic coating hydrogel 100 according to an embodiment of the present invention is a hydrogel excellent in both anti-drying and anti-swelling properties, hydrogel 110, hydrophobic polymer layer 120 and oil ( 130) is included.

The hydrogel 110 may be a bulk type hydrogel, polyacrylamide (PAAm) hydrogel or calcium-alginate polyacrylamide (Ca-alginate/PAAm) hydrogel may be used.

The hydrophobic polymer layer 120 is formed on the outer surface of the hydrogel 110 .

In addition, the hydrophobic polymer layer 120 may be an octyl acrylate polymer, a dodecyl acrylate polymer, or a stearyl acrylate polymer.

In addition, the hydrophobic polymer layer 120 may be a copolymer in which dodecyl acrylate and stearyl acrylate are polymerized in a volume ratio of 1:1.

In addition, the thickness of the hydrophobic polymer layer 120 is preferably 200㎛ to 350㎛.

The reason is that when exposed to air, the anti-drying performance is excellent and a uniform coating layer is formed.

The oil 130 is quenched and contained in the hydrophobic polymer layer 120 .

In other words, the oil 130 is adsorbed to the hydrophobic polymer layer 120 , and is quantified so as to be confined in the hydrophobic polymer layer 120 .

In addition, various types of oil may be used as the oil 130 , and for example, silicone oil or caster oil may be used as the oil 130 .

In addition, the viscosity of the oil 130 is preferably 1000cSt to 2000cSt at room temperature.

This is because when 1000 cSt to 2000 cSt high viscosity oil is used, the polymer chain length is longer and molecular weight is higher than when 100 cSt low viscosity oil is used, and it is formed into a stable entangled structure with a hydrophobic polymer, drying resistance, swelling resistance This is because it can have an increased advantage.

In addition, the contact angle of the double hydrophobic coating hydrogel according to the present invention is formed to be 90 ° or more.

In other words, the contact angle between the water droplet and the double hydrophobic coating hydrogel 100 surface is formed to be 90° or more.

In addition, the double hydrophobic coating hydrogel 100 may be provided as a hydrogel lens or a hydrogel film, and may be provided as a drug carrier together with the drug carried on the hydrogel 110 .

In addition, the present invention further provides a method for producing a double hydrophobic coating hydrogel, and below will be described in detail for a method for producing a double hydrophobic coating hydrogel according to the present invention.

Figure 2 is a step diagram for explaining the method of manufacturing a double hydrophobic coating hydrogel according to the present invention, Figure 3 is a schematic diagram for explaining the main process of the manufacturing method of the double hydrophobic coating hydrogel according to the present invention.

2 and 3, the method for producing a double hydrophobic coating hydrogel according to the present invention is a double hydrophobic coating structure comprising a hydrophobic polymer layer on the surface of the hydrogel and an oil quenched and adsorbed to the source polymer layer. As a manufacturing method for preparing a double hydrophobic hydrogel having excellent both anti-drying properties and anti-swelling properties, a step of preparing the hydrogel 110 is first performed (S100).

Here, the hydrogel 110 may be a bulk-type hydrogel, polyacrylamide (PAAm) hydrogel or calcium-alginate polyacrylamide (Ca-alginate/PAAm) hydrogel may be used.

Next, by immersing the prepared hydrogel 110 in a radical initiator solution, a radical initiator forming step (S200) of forming a radical initiator on the surface of the hydrogel is performed.

Here, 2,2-azobisisobutyronitrile (AIBN) is used as the radical initiator, and in order to form the AIBN on the surface of the hydrogel 110, the radical initiator solution is 2,2-azobisisobutyronitrile (AIBN) and A solution containing an organic solvent is used.

For example, the organic solvent may be benzene.

Next, after separating the hydrogel 110 from the radical initiator solution, a hydrogel heating step of heat-treating the hydrogel 110 so that benzene remaining on the surface of the hydrogel 110 is evaporated (S300) is performed

At this time, the heating step (S300) may be performed for 2 minutes at a temperature condition of 120 ℃.

That is, in the heating step ( S300 ), only the AIBN is formed on the surface of the hydrogel 110 by evaporating and removing the benzene.

Next, by immersing the hydrogel 110 in which the radical initiator is formed in the hydrophobic monomer solution 10, the radical initiator formed on the surface of the hydrogel is polymerized to form a hydrophobic polymer layer 120 . A forming step (S400) is performed.

Here, the hydrophobic monomer may be an acrylate-based monomer.

For example, the acrylate-based monomer may be octyl acrylate, dodecyl acrylate, or stearyl acrylate.

Here, the octyl acrylate (OA) is a short-chain monomer, the dodecyl acrylate (DA) is a medium-length chain monomer, and the stearyl acrylate (SA) is a long-chain monomer.

In addition, as the acrylate-based monomer, a mixture of dodecyl acrylate (DA) and stearyl acrylate (SA) in a volume ratio of 1:1 may be used.

In addition, the hydrophobic polymer forming step (S400) is preferably reacted for 30 minutes to 45 minutes at 120 ℃.

Next, an oil adsorption step ( S500) is performed.

In the oil adsorption step (S500), the first temperature of the oil solution is preferably 80 ℃ to 120 ℃.

In addition, in the oil adsorption step (S500), unreacted in the hydrophobic polymer forming step (S400), unreacted monomers remaining on the surface of the hydrogel 110 may be washed.

Next, the hydrogel 110 to which the oil is adsorbed is immersed in the oil solution 30 at a second temperature lower than the first temperature, and quenched so that the oil 130 is confined in the hydrophobic polymer layer 120 . A quenching step (S600) of (quenching) is performed.

In the quenching step (S600), the second temperature of the oil solution is preferably room temperature.

In addition, various types of oils may be used as the oil 130 used in the oil adsorption step (S500) and the quenching step (S600), for example, the oil 130 is silicone oil. Alternatively, castor oil may be used.

In addition, the viscosity of the oil 130 is preferably 1000cSt to 2000cSt at room temperature.

Comparative Example 1 (Preparation of polyacrylamide hydrogel)

A precursor solution of 3M AAm monomer, 0.1 mol% MBAA (based on monomer concentration), and 0.1 mol% APS (based on monomer concentration) were prepared in deionized water, and then dissolved oxygen was removed.

Thereafter, 2 μL/mL TMED was added, transferred to a glass mold, and reacted at room temperature for 12 hours to obtain a molded polyacrylamide hydrogel by separating it from the mold.

Comparative Example 2 (Preparation of oil single coating polyacrylamide hydrogel, S100)

Using the polyacrylamide hydrogel of Comparative Example 1, it was immersed in a silicone oil solution at 120° C. for 15 minutes.

Then, the oil-adsorbed hydrogel was quenched by immersion in a silicone oil solution at room temperature for 15 minutes, and the hydrogel was taken out of the oil solution, and then excess oil was wiped off.

Comparative Example 3 (Preparation of hydrophobic polymer layer single coating polyacrylamide hydrogel)

Using the polyacrylamide hydrogel of Comparative Example 1, it was immersed in a 4 wt% AIBN/benzene solution at room temperature for 4 hours and at 120° C. for 20 minutes.

Thereafter, the hydrogel was dried at 120° C. for 2 minutes to allow benzene to evaporate and only AIBN to be formed on the surface of the hydrogel.

Next, the hydrogel was immersed in a hydrophobic monomer solution at 120° C. in which dodecyl acrylate (DA) and stearyl acrylate (SA) were mixed at a volume ratio of 1:1 for 30 minutes to be polymerized by AIBN to form a hydrophobic polymer layer. .

Comparative Example 4 (Calcium-alginate polyacrylamide hydrogel preparation)

A precursor solution of 1.56 wt % sodium-alginate and 1.75 M AAm monomer, 0.03 mol % MBAA (based on monomer concentration), 0.03 mol % APS (based on monomer concentration), and 0.15 mol % TMED (based on monomer concentration) were each dissolved in deionized water. prepared, transferred to a glass mold and reacted at 50° C. for 4 hours.

Thereafter, the Na-alginate/PAAm hydrogel was separated from the glass mold, and then 0.5 M aq. It was immersed in a CaCl2 solution and reacted for 4 hours for ion crosslinking to obtain a calcium-alginate polyacrylamide hydrogel.

Example 1 (Preparation of double hydrophobic coating polyacrylamide hydrogel, DA/SA-oil@PAAM)

Radical initiator formation step (S200)

The polyacrylamide hydrogel of Comparative Example 1 was immersed in 4% by weight of AIBN/benzene solution at room temperature for 4 hours and at 120° C. for 20 minutes.

Hydrogel heating step (S300)

Thereafter, the hydrogel was dried at 120° C. for 2 minutes to allow benzene to evaporate and only AIBN to be formed on the surface of the hydrogel.

Hydrophobic polymer formation step (S400)

Next, the hydrogel was immersed in a hydrophobic monomer solution at 120° C. in which dodecyl acrylate (DA) and stearyl acrylate (SA) were mixed at a volume ratio of 1:1 for 30 minutes to be polymerized by AIBN to form a hydrophobic polymer layer. .

Oil adsorption step (S500)

Then, the hydrogel formed with the hydrophobic polymer layer was immersed in a silicone oil (1000 cSt viscosity at room temperature) solution at 120 ° C. for 15 minutes.

Quenching step (S600)

Then, the oil-adsorbed hydrogel was quenched by immersion in a silicone oil (1000 cSt viscosity at room temperature) solution at room temperature for 15 minutes.

Next, the hydrogel was taken out of the oil solution, and then excess oil was wiped off to obtain a double hydrophobic coated hydrogel.

For comparison according to the temperature of the silicone oil solution in the oil adsorption step (S500), different silicone oil solution temperatures (80 and 40 ℃) were applied and then quenched at room temperature (25 ℃).

Example 2: OA-oil@PAAM

Compared with Example 1, Example 2 was obtained by applying the same process as the rest, except that the octyl acrylate (OA) monomer was used for the hydrophobic monomer solution.

Example 3: DA-oil@PAAM

Compared with Example 1, Example 3 was obtained by applying the same process as the rest, except that dodecyl acrylate (DA) monomer was used for the hydrophobic monomer solution.

Example 4: SA-oil@PAAM

Compared with Example 1, except that the hydrophobic monomer solution was used as a stearyl acrylate (SA) monomer, Example 4 was obtained by applying the same process as the rest.

Example 5 (Preparation of double hydrophobic coating calcium-alginate polyacrylamide hydrogel)

In comparison with Example 1, except that the calcium-alginate polyacrylamide (Ca-alginate/PAAm) hydrogel of Comparative Example 4 rather than the polyacrylamide hydrogel of Comparative Example 1 was used, the remaining conditions and processes were the same. A double hydrophobic coating calcium-alginate polyacrylamide hydrogel was prepared by application.

Example 6 (Preparation of double hydrophobic coating polyacrylamide hydrogel applied with castor oil)

Compared with Example 1, except that castor oil, not silicone oil, was used in the step and quenching step, the remaining conditions and processes were applied in the same manner to prepare a double hydrophobic coated polyakiramide hydrogel.

Experimental Example 1 (dry characteristics)

In order to confirm the drying characteristics and swelling characteristics of the hydrogel, a disk-shaped hydrogel (diameter: 10mm, thickness: 3mm) was used.

In order to confirm the drying characteristics, the prepared disk-shaped hydrogel was exposed to the air and the weight was evaluated at regular intervals over 7 days.

4, in the case of Example 1 to which the double hydrophobic coating was applied, it was confirmed that there was no noticeable size change when exposed to air at room temperature for 7 days, but in Comparative Example 1 to which the coating layer was not applied, It was confirmed that the shrinkage progressed and completely dried within 2 days.

In addition, referring to FIG. 5 , in the case of Example 1, the moisture content of 4.1±0.07 wt% was lost after 7 days, whereas in Comparative Example 1, it was confirmed that the moisture content of 71.2±0.3 wt% was lost.

In addition, the moisture content of 71.5±0.2 wt% in Comparative Example 2 and 35±2.5 wt% in Comparative Example 3 was lost.

From these results, it was confirmed that the hydrophobic polymer layer and the double hydrophobic coating by oil had a synergistic effect in anti-drying properties.

That is, the continuous oil medium in the hydrophobic polymer layer produced a uniform shield on the hydrogel surface to prevent air drying, and this result was achieved with a single hydrophobic coating (oil-comparative example 2, hydrophobic polymer-comparative example 3). It has been confirmed that this cannot be

In addition, the coating density of Example 1 was calculated by the following formula, and it was confirmed to be ^{0.024 g·cm 2 .}

[Formula] Coating density (g·cm ² ) = Weight of hydrophobic polymer and oil (g)/gel surface area (cm ² )

6 is a result confirming the air drying characteristics of the hydrogel according to the chain length of the hydrophobic polymer.

Referring to FIG. 6 , in the case of Example 3 (medium-length hydrophobic monomer), it was confirmed to have superior anti-drying properties than Example 2 (short-chain hydrophobic monomer).

However, it was confirmed that Example 4 (the longest long-chain hydrophobic monomer) was rather lacking in anti-drying properties than Example 2.

This is considered to be due to the generation of a non-uniform rigid structure on the surface of the hydrogel because the glass transition temperature of the SA single polymer layer used in Example 4 is 48° C., and the ambient temperature is high.

In addition, in the case of Example 1, in which DA and SA were mixed in a volume ratio of 1:1 for copolymerization, non-uniformity was not observed on the surface of the hydrogel due to the decrease in the glass transition temperature.

Accordingly, it is confirmed that Example 1 maintains a uniform state while providing the best hydrophobicity, and has the best anti-drying properties.

7 is a result of confirming the air drying characteristics of the hydrogel according to the oil viscosity.

Referring to FIG. 7 , it was confirmed that coatings based on high-viscosity oils (1000 and 2000 cSt) had much better drying resistance than coatings of low-viscosity oils (100 cSt).

This is a result similar to human skin composed of high-viscosity fat. The polymer chain length and molecular weight of high-viscosity silicone oil is higher than that of low-viscosity oil, and the long polymer chain of high-viscosity oil creates a more stable entangled structure with the hydrophobic polymer layer in the coating area. , it is considered that the air drying performance is further increased.

8 is a graph confirming the drying characteristics of the double hydrophobic coating hydrogel according to the quenching temperature.

Referring to FIG. 8 , after immersion in an oil solution at a sufficiently high temperature (120° C.), and then performing rapid quenching at a low temperature (25° C.), the surface structure abruptly shrinks to entrap the oil, and the hydrophobic polymer layer provides a solid It was found to have the best drying resistance, producing a polymer-oil homogeneous surface.

That is, in the oil adsorption step, immersion in oil at high temperature (80°C, 120°C), and then performing the quenching process at low temperature (25°C) was confirmed to exhibit excellent drying resistance.

Experimental Example 2 (Tensile and Compression Test)

9 is a result of confirming the tensile properties of the double hydrophobic coated hydrogel according to the present invention, (a) is a tensile stress-strain curve, (b) is a young's module and tensile strength, (c) shows the work of extension.

10 is a result of confirming the compressive properties of the double hydrophobic coating hydrogel according to the present invention, (a) is a compressive stress-strain curve, (b) shows the young's module and compressive strength (compressive strain 0.9).

9 and 10, as a result of evaluating the mechanical properties of the double hydrophobic coating hydrogel according to the present invention, it was confirmed that the mechanical performance of the hydrogel did not decrease after the double hydrophobic coating process.

Rather, Example 1 was confirmed to have superior tensile properties compared to Comparative Example 1 by increasing the polymer density (volume shrinkage of about 15%) due to the double hydrophobic coating process.

In addition, as shown in FIG. 11 , it was confirmed that Example 1 was hardly affected by the rough mechanical treatment. More specifically, after 10 consecutive loading-unloading cycles (50% compressive strain), the air drying performance of Example 1 was confirmed to be similar to Example 1 to which no mechanical treatment was applied.

In addition, as shown in FIG. 12 , Example 1 to which no mechanical treatment was applied and Example 1 to which 10 consecutive loading-unloading cycles (50% compressive strain) were applied had similar loading-unloading paths. Confirmed.

Accordingly, it is considered that an interface with high durability was formed in Example 1 to cope with a harsh mechanical environment.

Experimental Example 3 (swelling properties)

In order to confirm the swelling characteristics, the prepared disk-shaped hydrogel was exposed to the air for 7 days, then immersed in water for 7 days to check the weight at regular intervals to evaluate the swelling characteristics, and the results are shown in FIGS. 13 and 14 shown in

In this case, distilled water, seawater, and a saline solution containing 0.16M NaCl was used as the water used.

As shown in FIGS. 13 and 14 , in the case of Comparative Example 1, it swelled rapidly and greatly, whereas Example 1 was confirmed to have strong resistance to swelling.

In the case of Example 1, after immersion in water for 7 days, the swelling ratio (diameter ratio before and after immersion) was 1.06, and in Comparative Example 1, the swelling ratio was confirmed to be 1.90.

In addition, as a result of checking the weight change after immersing Example 1 in water (25 ° C), seawater (25 ° C) and saline (37 ° C) for 7 days, respectively, the weight was 33 ± 7%, 34 ± 4%, It was confirmed that the increase was 38 ± 6%, and the weight change after immersing Comparative Example 1 in water (25 ° C), seawater (25 ° C) and saline (37 ° C) for 7 days, respectively, was 520 ± 11%, 403 ± It was confirmed to increase by 5%, 453 ± 4%.

Experimental Example 4 (SEM image observation)

In order to confirm the surface and internal structure of the hydrogel, it was confirmed using a scanning electron microscope.

15 shows a surface SEM image of Comparative Example 1, and FIG. 16 shows a surface SEM image of Example 1.

FIG. 17 is a cross-sectional SEM image of Example 1, and FIG. 18 is a cross-sectional SEM image of the double hydrophobic coated hydrogel according to the polymerization time of the hydrophobic polymer formation step.

15 and 16 , in the case of Comparative Example 1, the surface of the hydrogel was flat, whereas in the case of Example 1, it was confirmed that the surface of the hydrogel had a compact and uniformly patterned texture, which is shown in FIG. It can be clearly identified through the cross-sectional SEM image shown in Fig.

Referring to FIG. 17 , it was confirmed that the hydrophobic polymer layer was tightly bonded to the bulk-type gel network, and no defects, that is, unbonded regions, were observed at the interface.

In addition, the thickness of the coated hydrophobic polymer layer was uniform, and after the quenching process, it was confirmed that it reached a thickness of about 200 μm and increased slightly.

18 is a cross-sectional SEM image of the double hydrophobic coating hydrogel according to the polymerization time of the hydrophobic polymer formation step, (a) is a polymerization time of 15 minutes, (b) is a polymerization time of 30 minutes, (c) is a The polymerization time is the result of 45 minutes treatment.

19 is a result confirming the air drying characteristics of the double hydrophobic coating hydrogel according to the polymerization time of the hydrophobic polymer formation step.

The thickness of the hydrophobic polymer layer can be controlled by controlling the polymerization time of the hydrophobic polymer forming step.

Referring to FIG. 18 , when the polymerization time of the hydrophobic polymer layer forming step was 15 minutes, a non-uniform coating layer having a thickness of 100 μm was formed, and when the polymerization time was 30 minutes, a uniform coating layer having a thickness of 200 μm was formed. and when the polymerization time was 45 minutes, a thick coating layer of 350 μm was formed.

Referring to FIG. 19 , it was confirmed that the hydrogel to which the polymerization time of 15 minutes was applied in the hydrophobic polymer layer forming step had poor anti-drying performance compared to the hydrogel to which the polymerization time of 30 minutes and 45 minutes was applied.

Accordingly, when the polymerization time of the hydrophobic polymer layer forming step is 30 minutes, ^{a uniform coating layer of about 200 μg, 0.024 g cm 2} is formed, and it is confirmed that it has the optimum anti-drying performance. It was confirmed that the conditions were optimal conditions.

Experimental Example 5 (Measurement of contact angle)

FIG. 20 is an image confirming the contact angle between the water droplet and the surface of Comparative Example 1, FIG. 21 is the contact angle between the water droplet and the surface of Comparative Example 3, and FIG. 22 is an image confirming the contact angle between the water droplet and the surface of Example 1.

20 to 22 , it is confirmed that the hydrophobic polymer formation step significantly increased the water contact angle on the hydrogel surface.

In more detail, in the case of Comparative Example 1, the contact angle is 30°, whereas in Comparative Example 3, it is confirmed that it is 111°.

These results mean that the hydrophobic polymer network effectively coated the hydrophilic surface of the hydrogel.

In addition, in the case of Example 1, the contact angle was 95°, and it was confirmed that the contact angle was slightly decreased compared to Comparative Example 3, which is thought to be because the surface roughness is reduced by the oil, and Example 1 is compared with Comparative Example 1 It was confirmed to have a sufficiently large contact angle by comparison.

Experimental Example 6 (Evaluation of Surface Adhesion)

As shown in FIG. 23 , for evaluation of adhesion on the hydrogel surface, a standard tack test evaluation using a glass substrate was performed.

The results are shown in FIG. 24, and referring to FIG. 24, the adhesive strength of Example 1 was 6.4 ± 0.4 kPa (0.5 ± 0.03 N), and the debonding energy was 2.2 ± 0.2 J·m ^-2 was confirmed.

Experimental Example 7 (Anti-drying/anti-swelling properties of Example 5)

In order to confirm the drying characteristics, the prepared disk-shaped hydrogel was exposed to the air and the weight was evaluated at regular intervals over 7 days.

Referring to FIG. 25 , in the case of Example 5, the moisture content of 8.1±0.9% by weight was lost after 7 days, whereas in Comparative Example 4, it was completely dried within 2 days.

In order to confirm the swelling characteristics, the prepared disk-shaped hydrogel was exposed to air for 7 days, and then immersed in water for 7 days to check the weight at regular intervals to evaluate the swelling characteristics, and the results are shown in FIG. 26 .

As shown in FIG. 26 , in the case of Comparative Example 4, 116 ± 2.1 wt% increased within 2 days after immersion in water, and expansion equilibrium was reached, whereas in the case of Example 5, after immersion in water After 7 days there was an increase of 22.6 ± 3.3 wt%.

That is, even when the double hydrophobic coating is applied using the calcium-alginate polyacrylamide hydrogel, it can be confirmed that both the anti-drying properties and the anti-swelling properties are retained as in the case of applying the double hydrophobic coating using the polyacrylamide hydrogel. there was.

Experimental Example 8 (Mechanical properties of Example 5)

27 is a result of confirming the tensile properties using Example 5, showing a tensile stress-strain curve, FIG. 28 is a result of confirming the tensile properties using Example 5, (a) is the young's module and tensile strength , (b) shows the work of extension.

29 is a result of confirming the compressive properties using Example 5, (a) is a compressive stress-strain curve, (b) shows the young's module and compressive strength (compressive strain 0.9).

Referring to FIGS. 27 to 29, the results of evaluating the mechanical properties of the double hydrophobic coating hydrogel to which the calcium-alginate polyacrylamide hydrogel is applied,

It was confirmed that it did not significantly affect the internal chemical structure of the hydrogel,

The average tensile modulus, strength, and strain of Example 5 were found to be 0.05 ± 0.004 MPa, 0.4 ± 0.06 MPa, and 21 ± 2 mm/mm, respectively.

In addition, it was confirmed that the average compressive modulus and strength of Example 5 were 0.16 ± 0.02 and 3.3 ± 0.2 MPa (compressive strain 0.9), respectively.

Accordingly, the double hydrophobic coated hydrogel according to the present invention has strong resistance to drying and swelling, so it is considered to be applied to numerous applications in both dry and wet environments.

Experimental Example 9 (Application of Castor Oil)

Using Example 6 to which castor oil (cater oil) known as edible and biocompatible real oil was applied, anti-drying properties were evaluated, and the results are shown in FIG. 30 .

As shown in FIG. 30, Example 6 was confirmed to have a significantly higher anti-drying performance compared to Comparative Example 1, although the anti-drying performance was slightly reduced compared to Example 1.

Accordingly, the double hydrophobic coating hydrogel according to the present invention can be applied with various oils, and is applied as a vegetable oil that can solve the concern of potential toxicity, a bio-based drug delivery system, a hydrogel lens, and a hydrogel. It is thought that it can be applied to various fields such as film.

As described above, the double hydrophobic coating hydrogel according to the present invention does not change the chemical structure, and has a double hydrophobic coating structure composed of a hydrophobic polymer layer on the surface of the hydrogel and an oil quenched and adsorbed on the hydrophobic polymer layer. As such, it has excellent advantages in both anti-drying and anti-swelling properties with a mechanism similar to that of mammalian skin.

As described above, the present invention has been illustrated and described with reference to preferred embodiments, but it is not limited to the above-described embodiments, and those of ordinary skill in the art to which the present invention pertains within the scope not departing from the spirit of the present invention Various changes and modifications will be possible.

110: hydrogel
120: hydrophobic polymer layer
130: oil

Claims (24)

hydrogel;
a hydrophobic polymer layer formed on the outer surface of the hydrogel; and
A double hydrophobic coating hydrogel comprising; an oil quenched and contained in the hydrophobic polymer layer.
The method of claim 1,
The hydrogel is a double hydrophobic coating hydrogel, characterized in that the polyacrylamide (PAAm) hydrogel or calcium-alginate polyacrylamide (Ca-alginate/PAAm) hydrogel.
The method of claim 1,
The hydrophobic polymer layer is a double hydrophobic coating hydrogel, characterized in that the octyl acrylate polymer, dodecyl acrylate polymer or stearyl acrylate polymer.
The method of claim 1,
The hydrophobic polymer layer is a double hydrophobic coating hydrogel, characterized in that dodecyl acrylate and stearyl acrylate are polymerized in a volume ratio of 1:1.
The method of claim 1,
Double hydrophobic coating hydrogel, characterized in that the thickness of the hydrophobic polymer layer is 200㎛ to 350㎛.
The method of claim 1,
The oil is a double hydrophobic coating hydrogel, characterized in that the silicone oil (silicone oil) or castor oil (caster oil).
The method of claim 1,
The double hydrophobic coating hydrogel, characterized in that the viscosity of the oil is 1000cSt to 2000cSt at room temperature.
The method of claim 1,
The double hydrophobic coating hydrogel, characterized in that the contact angle of the double hydrophobic coating hydrogel is 90 ° or more.
The double hydrophobic coating hydrogel of any one of claims 1 to 8; and
A drug delivery system comprising a drug supported on the hydrogel.
A hydrogel lens comprising the double hydrophobic coating hydrogel of any one of claims 1 to 8.
A hydrogel film comprising the double hydrophobic coating hydrogel of any one of claims 1 to 8.
A hydrogel preparation step of preparing a hydrogel;
a radical initiator forming step of immersing the prepared hydrogel in a radical initiator solution to form a radical initiator on the surface of the hydrogel;
forming a hydrophobic polymer by immersing the hydrogel in which the radical initiator is formed in a hydrophobic monomer solution, whereby the radical initiator formed on the surface of the hydrogel is polymerized to form a hydrophobic polymer layer;
an oil adsorption step of immersing the hydrogel on which the hydrophobic polymer layer is formed in an oil solution at a first temperature to adsorb the oil to the hydrophobic polymer layer; and
Double hydrophobic coating hydro, comprising: immersing the hydrogel to which the oil is adsorbed in an oil solution of a second temperature lower than the first temperature, and quenching so that the oil is confined in the hydrophobic polymer layer A method for producing a gel.
13. The method of claim 12,
The hydrogel is a polyacrylamide (PAAm) hydrogel or a calcium-alginate polyacrylamide (Ca-alginate/PAAm) method for producing a double hydrophobic coating hydrogel, characterized in that the hydrogel.
13. The method of claim 12,
The radical initiator is 2,2-azobisisobutyronitrile (AIBN) is a method for producing a double hydrophobic coating hydrogel, characterized in that used.
13. The method of claim 12,
The radical initiator solution is a method for producing a double hydrophobic coating hydrogel, characterized in that it contains 2,2-azobisisobutyronitrile (AIBN) and an organic solvent.
16. The method of claim 15,
After the radical initiator forming step,
Method for producing a double hydrophobic coating hydrogel, characterized in that it further comprises a; hydrogel heating step of heat-treating the hydrogel to remove the organic solvent.
13. The method of claim 12,
The hydrophobic monomer is a method for producing a double hydrophobic coating hardgel, characterized in that the acrylate-based monomer is used.
18. The method of claim 17,
The acrylate-based monomer is a method of producing a double hydrophobic coating hard gel, characterized in that octyl acrylate, dodecyl acrylate or stearyl acrylate.
18. The method of claim 17,
The acrylate-based monomer is a method for producing a double hydrophobic coating hard gel, characterized in that a mixture of dodecyl acrylate and stearyl acrylate in a volume ratio of 1:1.
13. The method of claim 12,
The hydrophobic polymer forming step is a method for producing a double hydrophobic coating hardgel, characterized in that the reaction for 30 minutes to 45 minutes at 120 ℃.
13. The method of claim 12,
The method for producing a double hydrophobic coating hydrogel, characterized in that the temperature of the oil solution in the oil adsorption step is 80 ℃ to 120 ℃.
22. The method of claim 21,
The method for producing a double hydrophobic coating hardgel, characterized in that the temperature of the oil solution in the quenching step is room temperature.
13. The method of claim 12,
The oil is a method of producing a double hydrophobic coating hard gel, characterized in that silicone oil (silicone oil) or castor oil (caster oil) is used.
13. The method of claim 12,
The viscosity of the oil is a method for producing a double hydrophobic coating hardgel, characterized in that 1000cSt to 2000cSt at room temperature.

Images