Amphiphilic hydrogel particles for antifouling paint and method of fabricating the same

Abstract

This invention relates to amphiphilic hydrogel particles for antifouling paint, which are environmentally friendly and in which anti-corrosion and antifouling effects can be maximized through a single coating process. The amphiphilic hydrogel particles are fabricated by encapsulating conducting polymer particles having anti-corrosion functionality with functional nanoparticles having antifouling functionality and then immobilizing the functional nanoparticles on a hydrogel matrix, whereby the conducting polymer particles contained in the functional nanoparticles are slowly and continuously released or the release rate thereof can be controlled so as to release the corresponding particles in a specific environment, ultimately maintaining long-term functionality. The conducting polymer particles contained in the amphiphilic functional nanoparticles can exhibit anti-corrosion functionality, thus maximizing anti-corrosion and antifouling effects through a single coating process.

Claims

1. Amphiphilic hydrogel particles for antifouling paint, comprising: conducting polymers; functional nanoparticles in vesicle form containing the conducting polymers therein; and a hydrogel matrix on which the functional nanoparticles are immobilized.

2. The amphiphilic hydrogel particles of claim 1, wherein the functional nanoparticles comprise a lipid, perfluoropolyether (PFPE) and cholesterol.

3. The amphiphilic hydrogel particles of claim 2, wherein the functional nanoparticles comprise the lipid, the PFPE and the cholesterol at a molar ratio of 8 to 6:1 to 3:1.

4. The amphiphilic hydrogel particles of claim 1, wherein the functional nanoparticles have antifouling functionality.

5. The amphiphilic hydrogel particles of claim 1, comprising, based on a total weight of the amphiphilic hydrogel particles: 5 to 15 wt % of the conducting polymers; 30 to 50 wt % of the functional nanoparticles; and 35 to 65 wt % of the hydrogel matrix.

6. The amphiphilic hydrogel particles of claim 1, wherein the conducting polymers have anti-corrosion functionality.

7. The amphiphilic hydrogel particles of claim 1, wherein the conducting polymers comprise pyrrole-based polymers.

8. The amphiphilic hydrogel particles of claim 2, wherein the lipid has a hydrophilic head group and a hydrophobic tail group.

9. The amphiphilic hydrogel particles of claim 2, wherein the lipid comprises a surfactant-based lipid.

10. The amphiphilic hydrogel particles of claim 1, wherein the functional nanoparticles have a particle size of 60 to 150 nm.

11. A method of fabricating amphiphilic hydrogel particles for antifouling paint using a microfluidic chip, the microfluidic chip comprising: a platform; a main channel formed in the platform to provide a vesicle-forming space; a first inlet channel for feeding a first component into the main channel; a discharge part for discharging a vesicle from the main channel; a second inlet channel located between the first inlet channel for feeding the first component into the main channel and the discharge part and configured such that a second component is fed into the main channel; and a micro-stencil, which is disposed at an outlet of the second inlet channel and has a plurality of microholes through which the component fed into the second inlet channel passes, the method comprising: feeding conducting polymers into the first inlet channel; feeding a lipid, PFPE and cholesterol into the second inlet channel, thus forming functional nanoparticles in vesicle form containing the conducting polymers therein; and immobilizing the functional nanoparticles on a hydrogel matrix, wherein a flow rate of the component fed into the first inlet channel or the second inlet channel is adjusted, thereby controlling a particle size of the functional nanoparticles.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 schematically illustrates a process of fabricating antifouling paint particles according to an embodiment of the present invention (a: functional nanoparticles, b: hydrogel, c: amphiphilic hydrogel particles for antifouling paint);

(2) FIG. 2A schematically illustrates the cross-section of a microfluidic chip for fabricating amphiphilic nanoparticles according to an embodiment of the present invention, FIG. 2B is an enlarged view of Part E of FIG. 2A, and FIG. 2C schematically illustrates a micro-stencil disposed at the outlet of the second inlet channel;

(3) FIGS. 3A to 3C are transmission electron microscope (TEM) images illustrating functional nanoparticles fabricated according to an embodiment of the present invention, wherein FIG. 3A shows the functional nanoparticles at a molar ratio of lipid to PFPE to cholesterol of 8:1:1, FIG. 3B shows the functional nanoparticles at a molar ratio of lipid to PFPE to cholesterol of 7:2:1, and FIG. 3C shows the functional nanoparticles at a molar ratio of lipid to PFPE to cholesterol of 6:3:1;

(4) FIG. 4 illustrates the results of dynamic light scattering (DLS) analysis of the particle size distribution of the functional nanoparticles at a molar ratio of lipid to PFPE to cholesterol of 8:1:1 (average particle size: 158 nm);

(5) FIG. 5 illustrates the results of DLS analysis of the particle size distribution of the functional nanoparticles at a molar ratio of lipid to PFPE to cholesterol of 7:2:1 (average particle size: 130 nm);

(6) FIG. 6 illustrates the results of DLS analysis of the particle size distribution of the functional nanoparticles at a molar ratio of lipid to PFPE to cholesterol of 6:3:1 (average particle size: 120 nm);

(7) FIG. 7 illustrates the results of DLS analysis of the particle size distribution of the functional nanoparticles fabricated under the conditions that the flow rate for the first inlet channel (inlet 1) of the microfluidic chip is fixed to 60 ml/h and the flow rate for the second inlet channel (inlet 2) thereof is fixed to 1.5 ml/h (the molar ratio of lipid to PFPE to cholesterol=6:3:1);

(8) FIG. 8 illustrates the results of DLS analysis of the particle size distribution of the functional nanoparticles fabricated under the conditions that the flow rate for the first inlet channel (inlet 1) of the microfluidic chip is fixed to 60 ml/h and the flow rate for the second inlet channel (inlet 2) thereof is fixed to 3 ml/h (the molar ratio of lipid to PFPE to cholesterol=6:3:1);

(9) FIG. 9 illustrates the results of DLS analysis of the particle size distribution of the functional nanoparticles fabricated under the conditions that the flow rate for the first inlet channel (inlet 1) of the microfluidic chip is fixed to 60 ml/h and the flow rate for the second inlet channel (inlet 2) thereof is fixed to 6 ml/h (the molar ratio of lipid to PFPE to cholesterol=6:3:1);

(10) FIGS. 10A to 10D are optical fluorescence microscope images illustrating the amphiphilic nanoparticles of Example 1 (the molar ratio of lipid to PFPE to cholesterol=6:3:1, the flow rate for the first inlet channel (inlet 1) of the microfluidic chip is fixed to 60 ml/h, and the flow rate for the second inlet channel (inlet 2) thereof is fixed to 1.5 ml/h), wherein FIGS. 10A to 10C show the alginate hydrogel, and FIG. 10D shows the PDMP hydrogel;

(11) FIG. 11 is an optical fluorescence microscope image illustrating the amphiphilic hydrogel particles of FIG. 10C; and

(12) FIGS. 12A, 12B, and 12C respectively illustrate SUS, hydrogel particles, and amphiphilic hydrogel particles in order to compare the antifouling properties of the amphiphilic hydrogel particles of Example 2 with those of the other samples.

(13) TABLE-US-00001 <Description of the Reference Numerals in the Drawings> 10: microfluidic chip A: conducting polymer B: functional nanoparticle composition (lipid + PFPE + cholesterol) C: functional nanoparticles in vesicle form 12: first feed pipe 14: second feed pipe 16: discharge pipe 20: platform 21: main channel 22: first inlet channel 23: second inlet channel 24: discharge channel 25: outlet of second inlet channel 26: interface between A and B 27: upper end of main channel 30: microhole array of micro-stencil 32: microhole 34: micro-stencil

MODE FOR INVENTION

(14) Hereinafter, a detailed description will be given of the present invention with reference to the following examples. The purposes, features, and advantages of the present invention will be easily understood through the following examples. The present invention is not limited to such examples, but may be embodied in other forms. The following examples are provided such that the spirit of the present invention may be sufficiently transferred to those skilled in the art to which the present invention belongs. Therefore, the following examples are not to be construed as limiting the present invention.

Examples 1 and 2

Formation of Amphiphilic Hydrogel Particles for Antifouling Paint

(15) Formation of Functional Nanoparticles

(16) Amphiphilic nanoparticles were fabricated using a microfluidic chip provided with a micro-stencil. The microfluidic chip comprises a platform, a main channel formed in the platform to provide a vesicle-forming space, a first inlet channel (inlet 1) for feeding conducting polymers, a second inlet channel (inlet 2) for feeding a composition for forming functional nanoparticles, and a discharge channel for discharging the functional nanoparticles in vesicle form from the main channel (FIGS. 2A to 2C). The micro-stencil was fabricated through a dewetting-assisted molding process in which a silicone wafer with a pillar structure and PUA (polyurethane acrylate) are used.

(17) A 5 mM conducting polymer polypyrrole aqueous solution was fed at a flow rate of 60 ml/h into the first inlet channel, and a composition for functional nanoparticles comprising sodium dodecyl sulfate (SDS), PFPE, and cholesterol (CH) at the following molar ratio was fed at a flow rate of 1.5 ml/h into the second inlet channel, thus obtaining functional nanoparticles in vesicle form. As such, the molar ratio of lipid (SDS) to PFPE to cholesterol corresponding to the composition for functional nanoparticles fed into the second inlet channel was set to 8:1:1, 7:2:1, and 6:3:1.

(18) TEM Image and Particle Size Distribution Analysis of Functional Nanoparticles

(19) The shapes of the particles at different molar ratios were analyzed through TEM. The results are illustrated in FIGS. 3A to 3C. The results of DLS analysis of the particle size distribution depending on the molar ratio are illustrated in FIGS. 4 to 6. Based on the results of analysis of TEM images, the uniformity of the particle size distribution can be seen to vary depending on the constituent ratio of lipid to PFPE to cholesterol. As the amount of PFPE was increased, uniform particles could be realized. As for the results of DLS analysis, when the molar ratio of lipid to PFPE to cholesterol was 8:1:1, particles having an average particle size of 158 nm were present in an amount of 54%, and microsized particles were distributed. Also, when the molar ratio of lipid to PFPE to cholesterol was 7:2:1, particles having an average particle size of 130 nm were present in an amount of 60%, and a large number of microsized particles were present. Also, when the molar ratio of lipid to PFPE to cholesterol was 6:3:1, particles having an average particle size of 120 nm were present in an amount of 86%, and had an almost uniform particle size distribution.

(20) The particle size of the functional nanoparticles depending on the flow rate (1.5, 3.0, and 6.0 ml/h) for the second inlet channel was analyzed. The results are shown in Table 1 below and in FIGS. 7 to 9. The molar ratio of lipid to PFPE to cholesterol corresponding to the composition for functional nanoparticles fed into the second inlet channel was set to 6:3:1.

(21) TABLE-US-00002 TABLE 1 Flow rate 60 ml/h-1.5 ml/h 60 ml/h-3 ml/h 60 ml/h-6 ml/h Size, Amount Size (nm) Amount (%) Size (nm) Amount (%) Size (nm) Amount (%) 1 63.7672 23.41065 78.22465 35.60465 96.93386 31.31882 2 75.29761 33.12682 92.50484 32.21644 115.5789 30.0843 3 88.91296 23.26963 109.392 20.13168 137.8102 24.34466 4 104.9903 12.67082 129.3619 7.923722 164.3176 9.53383 5 123.9746 5.160104 152.9774 2.825472 195.9238 3.355517 6 146.3918 1.815303 180.904 0.914489 233.6093 1.036227 7 172.8625 0.455785 213.9287 0.298615 278.5434 0.272389 8 204.1195 0.084349 252.9822 0.073368 332.1206 0.048997 9 241.0285 0.006526 299.165 0.011562 396.0032 0.005255 Total 100% 100% 100%

(22) FIGS. 7 to 9 illustrate the particle size distributions as analyzed using DLS. As illustrated in FIGS. 7 to 9, the particle size distribution uniformity of 90% or more was exhibited.

(23) As is apparent from Table 1, when the flow rate for the second inlet channel (inlet 2) was 1.5 ml/h, nanoparticles having a particle size of 100 nm or less could be prepared. When the flow rate therefor was 6 ml/h, a particle size distribution of 120 nm was manifested. It was possible to control the particle size of the nanoparticles by adjusting the flow rate for the microfluidic chip.

(24) Preparation of Amphiphilic Hydrogel Particles for Antifouling Paint

(25) The functional nanoparticles, which were fabricated by the above method using lipid, PFPE and cholesterol at a molar ratio of 6:3:1 under the condition that the flow rate for the second inlet channel (inlet 2) was 1.5 ml/h, were immobilized on a hydrogel matrix through the following method, thus obtaining amphiphilic hydrogel particles for antifouling paint.

Example 1

Formation of Amphiphilic Hydrogel Particles for Antifouling Paint Using Alginate Polymer

(26) In order to immobilize the functional nanoparticles on a hydrogel matrix, a dropping system using a centrifuge was adopted. Specifically, two 1 ml syringes were fixed to a 50 ml tube, and two 4 cm sized 25 G needles were set so that the ends thereof were in contact with each other. A CaCl.sub.2 solution for cross-linking an alginate polymer was placed in the bottom of the tube. A mixture solution comprising 0.5 to 4 wt % of an alginate solution and a functional nanoparticle solution mixed at a ratio of 2:1 was placed in one syringe, and a 0.5 to 4 wt % alginate solution was placed in the other 1 ml syringe. Then, dropping was performed using a centrifuge at 100 g for 5 min, yielding a hydrogel matrix having functional nanoparticles immobilized thereon.

Example 2

Formation of Amphiphilic Hydrogel Particles for Antifouling Paint Using PDMP Polymer

(27) PDMP hydrogel particles were obtained by radiating UV light (365 nm) to the bottom of the channel at regular intervals while passing a mixture solution comprising a solution of PDMP polymer dissolved in 1,4-dioxane (10 w/v %) and functional nanoparticles mixed at a ratio of 2:1 through the channel at a flow rate of 10 ml/h using a microfluidic chip.

Test Example 1

Analysis of Shape of Amphiphilic Hydrogel Particles for Antifouling Paint

(28) The surface of the amphiphilic hydrogel particles of Example 1 was observed using an optical fluorescence microscope (Nikon). The results are shown in FIGS. 10A to 10D. As illustrated in FIGS. 10A to 10C, the density and shape of the produced particles became different depending on the amount of alginate. When the amount of alginate was 4 wt %, a large amount of gel type spherical particles could be efficiently formed (FIG. 10C). When using PDMP, the particles were fabricated to be small and irregular (FIG. 10D). FIG. 11 is an optical fluorescence microscope image illustrating the amphiphilic hydrogel particles obtained using 4 wt % of alginate. The amphiphilic hydrogel particles can be seen to have a spherical shape. In FIG. 11, the black portions correspond to the functional particles.

Test Example 2

Analysis of Antifouling Properties of Amphiphilic Hydrogel Particles for Antifouling Paint

(29) In order to evaluate the antifouling properties of the amphiphilic hydrogel particles, three samples were prepared as follows.

(30) Sample 1: Control sample (SUS 304, stainless steel)

(31) SUS having a size of 1 T30 mm60 mm was used as a control sample.

(32) Sample 2: Hydrogel coating sample

(33) A hydrogel obtained using a PDMP polymer (which was used after having been dissolved in 1,4-dioxane (10 w/v %)) was applied on Sample 1.

(34) Sample 3: Sample Coated with Amphiphilic Hydrogel Particles

(35) Sample 1 was coated, using a spray process, with the amphiphilic hydrogel particles (Example 2) obtained by immobilizing, on the hydrogel matrix using a PDMP polymer, the functional nanoparticles (average particle size: 100 nm) fabricated by the above method using lipid, PFPE and cholesterol at a molar ratio of 6:3:1 under the condition that the flow rate for the second inlet channel (inlet 2) was 1.5 ml/h.

(36) For analysis, each of the three samples was placed in an Uldolmok microbe diluted solution (a solution (10% v/v) obtained by diluting an incubated solution of Bacillus firmus, one of the microbes sampled near Uldolmok Tidal Current Power Pilot Plant, 2012, with an artificial seawater solution). After ten days, the extent of surface pollution of the samples was observed. The results are shown in FIGS. 12A to 12C (Test conditions: enrichment brothArtificial Marin Broth, enrichment conditions25 C./100 r/m/240 hr). Consequently, the amphiphilic hydrogel particles exhibited the lowest surface pollution.

(37) Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims