Hydrochromic polydiacetylene composite composition, hydrochromic thin film using same, and use thereof

Abstract

The present invention relates to a hydrochromic polydiacetylene composite composition, a hydrochromic thin film using same, and a use thereof, and more specifically, to a hydrochromic polydiacetylene composite composition reacting sensitively to moisture, providing the hydrochromic thin film using same, and to applying same to biorecognition or fingerprint recognition. According to the present invention, moisture secreted from a fingerprint or pores on the skin can be detected with high sensitivity. Thus, the position of pores unique to a fingerprint of an organism can be amplified and displayed through selective color change and fluorescent change patterns exhibited when moisture is absorbed.

Claims

1. A method of sensing moisture, comprising: providing a polydiacetylene composite composition including a polydiacetylene polymerized from diacetylene monomers that are complexed with an alkali metal ionic compound to give a diacetylene composite, and detecting color or fluorescent transition of the polydiacetylene composite composition after exposing the polydiacetylene composite composition to the moisture, wherein each of the diacetylene monomers is a compound represented by the following Chemical Formula (2), or an mBzA compound in which a benzamide group is incorporated into a diacetylene molecule,
CH3(CH2)m-CCCC(CH2)n-COOH[Chemical Formula 2] wherein m+n is an integer of 2 to 50.

2. The method of claim 1, wherein the alkali metal is any one selected from the group consisting of cesium, rubidium, and potassium.

3. The method of claim 1, wherein the diacetylene monomers include at least one selected from the group consisting of PCDA (10,12-pentacosadiynoic acid), TCDA (10,12-tricosadiynoic acid), HCDA (8, 10-heneicosadiynoic acid), PCDAmBzA, TCDA-mBzA and HCDA-mBzA.

4. The method of claim 1, wherein the diacetylene composite includes at least one selected from the compounds represented by the following Chemical Formula (3), Chemical Formula (4), and Chemical Formula {5}:
CH3-(CH2)m-CCCC(CH2)n-COO()Cs(+)[Chemical Formula 3] wherein m+n is an integer of 2 to 50,
CH3-(CH2)m-CCCC(CH2)n-COO()Rb(+)[Chemical Formula 4] wherein m+n is an integer of 2 to 50,
CH3-(CH2)m-CCCC(CH2)n-COO()K(+)[Chemical Formula 5] wherein m+n is an integer of 2 to 50.

5. The method of claim 1, wherein the moisture is included in the atmosphere, and the method is for sensing humidity.

6. The method of claim 1, wherein the moisture is sweat secreted from sweat pores, and the method is for sensing sweat pores.

7. The method of claim 6, wherein the polydiacetylene composite composition is provided as a layer on a thin film substrate, and the exposing the polydiacetylene composite composition to the sweat secreted from sweat pores is contacting a skin having the sweat pores against the layer.

8. The method of claim 7, wherein the skin having sweat pores is included in a finger and has a fingerprint.

9. The method of claim 1, wherein the polydiacetylene composite composition is provided as a layer on a thin film substrate.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 shows schematic views of polydiacetylene structures photopolymerized from diacetylene monomers complexed with lithium (a), sodium (b), potassium (c), rubidium (d), and cesium (e) in accordance with exemplary embodiment of the present invention.

(2) FIG. 2 is a schematic view illustrating a procedure of photopolymerizing diacetylene composites in accordance with an exemplary embodiment of the present invention.

(3) FIG. 3 illustrates the responsiveness to water of a hydrochromic thin film in accordance with an exemplary embodiment of the present invention.

(4) FIGS. 4 to 6 illustrate the structural change of a hydrochromic thin film in response to water absorption according to an exemplary embodiment of the present invention in SEM images (FIG. 4), XRD spectra (FIG. 5), and a schematic view (FIG. 6).

(5) FIG. 7 shows photographic images of a hydrochromic thin film that undergoes chromatic transition upon exposure to water in accordance with an exemplary embodiment of the present invention.

(6) FIG. 8 shows graphs illustrating properties of hydrochromic thin films according to an exemplary embodiment of the present invention: color changes are plotted against time after a water drop is applied to the thin film (a); hydrochromic properties are depicted according to a molar ratio of PCDA and Cs ions (b); UV-Vis spectra before and after water absorption (c); and emission spectra before and after water absorption (d).

(7) FIG. 9 shows photographic images of hydrochromic thin films that change in color with relative humidity in accordance with an exemplary embodiment of the present invention.

(8) FIG. 10 shows humidity sensing ability of hydrochromic thin films in accordance with an exemplary embodiment of the present invention.

(9) FIG. 11 is a graph showing color changes with humidity of the hydrochromic thin films according to an exemplary embodiment of the present invention.

(10) FIG. 12 illustrates a sweat pore mapping process using a hydrochromic thin film according to an exemplary embodiment of the present invention.

(11) FIGS. 13 to 15 show analysis results of sweat pore maps manifested using hydrochromic thin films according to an exemplary embodiment of the present invention.

(12) FIG. 16 shows fluorescence microimages of sweat pore maps manifested using hydrochromic thin films according to an exemplary embodiment of the present invention.

(13) FIG. 17 shows fluorescence microimages of sweat pore maps manifested at different relative humidities using hydrochromic thin films according to an exemplary embodiment of the present invention.

(14) FIG. 18 illustrates the manifestation of a fingerprint on a thin film according to an exemplary embodiment of the present invention.

(15) FIG. 19 shows analysis results after data of a potential fingerprint obtained using a fingerprint reader and a fingerprint recognition program are compared.

MODE FOR INVENTION

(16) A better understanding of the present invention may be obtained through the following examples that are set forth to illustrate, but are not to be construed as limiting the present invention.

Example 1: Preparation of Polydiacetylene Composite Composition

Example 1-1: Preparation of PCDA-Cs Polydiacetylene Composite Composition

(17) A solution of 0.750 g of CsOH in deionized water was dropwise added to a solution of 1.87 g of PCDA (10,12-pentacosadiynoic acid) in 9.6 mL of THF (tetrahydrofuran), and mixed together by stirring for 1 hr. The mixed solution was left for self-assembly, and then subjected to photopolymerization under a 254 nm UV lamp to give a composite composition.

Example 1-2: Preparation of TCDA-Cs Polydiacetylene Composite Composition

(18) A composite composition was prepared in the same manner as in Example 1-1 with the exception that TCDA (10, 12-tricosadiynoic acid) was used instead of PCDA.

Example 1-3: Preparation of PCDA-Rb Polydiacetylene Composite Composition

(19) A composite composition was prepared in the same manner as in Example 1-1 with the exception that RbOH was used instead of CsOH.

Example 1-4: Preparation of HCDA-K Polydiacetylene Composite Composition

(20) A composite composition was prepared in the same manner as in Example 1-1 with the exception that K and HCDA (8, 10-heneicosadiynoic acid) were used instead of CsOH and PCDA, respectively.

Example 1-5: Preparation of TCDA-K Polydiacetylene Composite Composition

(21) A composite composition was prepared in the same manner as in Example 1-1 with the exception that K and TCDA (10, 12-tr icosadiynoic acid) were used instead of CsOH and PCDA, respectively.

Example 1-6: Preparation of TCDA-Rb Polydiacetylene Composite Composition

(22) A composite composition was prepared in the same manner as in Example 1-1 with the exception that RbOH and TCDA were used instead of CsOH and PCDA, respectively.

Example 1-7: Preparation of HCDA-Na Polydiacetylene Composite Composition

(23) A composite composition was prepared in the same manner as in Example 1-1 with the exception that Na and HCDA were used instead of CsOH and PCDA, respectively.

Example 2: Thin Film Fabrication 1

Example 2-1: Fabrication of PCDA-Cs Thin Film

(24) A solution of 0.750 g of CsOH in deionized water was dropwise added to a solution of 1.87 g of PCDA (10,12-pentacosadiynoic acid) in 9.6 mL of THF (tetrahydrofuran), and mixed together by stirring for 1 hr. The resulting solution composition was applied onto a PET film using a spin coater at 2,000 rpm for 1 min to give a coating 0.5 m thick. The coated thin film was dried at 70 C. for 1 min to give a photochromic or photopolymerizable supramolecule film, which was then exposed to 254 nm radiation from a UV lamp to afford a blue thin film.

Example 2-2: Fabrication of TCDA-Cs Thin Film

(25) A blue thin film was fabricated in the same manner as in Example 2-1 with the exception that TCDA (10, 12-tricosadiynoic acid) was used instead of PCDA.

Example 2-3: Fabrication of PCDA-Rb Thin Film

(26) A blue thin film was fabricated in the same manner as in Example 2-1 with the exception that RbOH was used instead of CsOH.

Example 2-4: Fabrication of HCDA-K Thin Film

(27) A blue thin film was fabricated in the same manner as in Example 2-1 with the exception that K and HCDA (8, 10-heneicosadiynoic acid) were used instead of CsOH and PCDA, respectively.

Example 2-5: Fabrication of TCDA-K Thin Film

(28) A blue thin film was fabricated in the same manner as in Example 2-1 with the exception that K and TCDA (10,12-tricosadiynoic acid) were used instead of CsOH and PCDA, respectively.

Example 2-6: Fabrication of TCDA-Rb Thin Film

(29) A blue thin film was fabricated in the same manner as in Example 2-1 with the exception that RbOH and TCDA were used instead of CsOH and PCDA, respectively.

Example 2-7: Fabrication of HCDA-Na Thin Film

(30) A blue thin film was fabricated in the same manner as in Example 2-1 with the exception that Na and HCDA were used instead of CsOH and PCDA, respectively.

Example 3: Thin Film Fabrication 2

(31) A solution of 0.750 g of CsOH in deionized water was dropwise added to a solution of 1.87 g of PCDA (10,12-pentacosadiynoic acid) in 9.6 mL of THF (tetrahydrofuran), and mixed together by stirring for 1 hr. The resulting solution composition was 20-fold diluted in a solvent (dioxane/water 40% v/v), and then loaded to an inkjet cartridge mounted on an office inkjet printer. The dilution was printed on a PET film using the inkjet printer, and exposed to 245 nm radiation from a UV lamp to afford a thin film.

Test Example 1: Thin Film Characterization 1

(32) As illustrated in FIG. 3, the blue thin film of Example 2-1 was carefully picked up with a forceps. The blue film turned red (b, d) within 1 sec after it was manually blown on by a researcher exhaling with a wide open mouth (near body temperature) (a) or after a finger was approached to the film at a distance of 0.3 mm (c). However, the blue film remained unchanged in color when the film was strongly blown on by a researcher exhaling from a narrow open mouth (lower than the body temperature due to adiabatic expansion), or when the film was sealed with a transparent wrap or tape before being breathed on or pressed by fingers.

Test Example 2: SEM Image and XRD Spectrum Analysis

(33) SEM images and XRD spectra of the thin film fabricated in Example 2-1 are given in FIGS. 4 and 5, respectively. FIG. 4 shows SEM images of the surface of the polydiacetylene thin film before (upper panel) and after (lower panel) water absorption while FIG. 5 shows XRD spectra of the surface of the polydiacetylene thin film before (upper) and after (lower) water absorption. FIG. 6 is a schematic view illustrating a structural change of the thin film upon water absorption. As can be seen in FIGS. 4 to 6, water absorption makes the thin film undergo a structural change, with the consequent color transition from a blue to a red phase.

Test Example 3: Thin Film Characterization 2

(34) Properties of the thin films fabricated in Examples 2-1 and 3 were analyzed and the results are given in FIGS. 7 and 8. FIG. 7a shows the chromatic transition of the thin film fabricated in Example 2-1 from a blue to a red phase upon exposure to water while FIG. 7b shows the chromatic transition of the thin film according to Example 3, and the structural change of the thin film upon water absorption. FIG. 7c is an image of the thin film of Example 2-1 after chromatic transition occurred along letters written on the thin film with an aqueous ballpoint pen (letters appeared red). These thin films were observed to respond to water very quickly. It generally takes ones of seconds to ones of hours for typical hydrochromic materials to respond to water. In contrast, the hydrochromic polydiacetylene composite of the present invention responds to water as fast as 10 m/s. FIG. 8a is a graph in which red intensity is plotted against time after a water drop is applied to the thin film of Example 2-1, as measured by a high-speed camera. FIG. 8b shows hydrochromic properties of hydrochromic polydiacetylene composites prepared with various molar ratios of PCDA and Cs (in FIG. 8b, CR represents colorimetric response). For a desired colorimetric response to humidity, as can be seen in the graph, a molar ratio of PCDA:Cs is preferably set to be 1:0.8 or more, and more preferably 1:1. FIG. 8c shows UV-Vis spectra before and after water absorption, and FIG. 8d shows emission spectra before and after water absorption. In both graphs, water absorption caused chromatic transition.

Test Example 4: Thin Film Characterization 2

(35) The thin films fabricated in Examples 2-1 to 2-7 were analyzed for ability to sense water, and the results are shown in FIGS. 9 to 11. FIG. 9 shows color changes of the thin films with relative humidity (from 25% to 100%). All of the thin films appeared blue at 25% relative humidity, and turned red at 100% relative humidity. FIG. 10 shows humidity sensing test results of the thin films. Color transition started at about 50% relative humidity for Example 2-2, at about 60% relative humidity for Example 2-1, at about 70% relative humidity for Example 2-3, at about 80% relative humidity for Example 2-4, and at about 90% relative humidity for Example 2-5. FIG. 11 is a graph showing colors of the thin films according to humidity. As can be seen in FIGS. 10 and 11, the films can respond to 50%-100% relative humidity according to the structure of the diacetylene composite, implying that the structural control leads to adjusting the humidity sensitivity of the thin films. In addition, the data obtained above indicate that the thin films of the present invention can be used as humidity sensors highly responsive to a predetermined humidity value or higher.

Test Example 5: Manifestation of Sweat Pore Map by Hydrochromic Thin Film

(36) After sebaceous secretions and oils on a finger were cleaned off, the finger was lightly pressed against the hydrochromic thin film of Example 2-1 to obtain a sweat pore map as a trace amount of water from sweat pores made the thin film undergo chromatic transition selectively at the fingerprinted regions, and the map could be observed under a magnification glass or microscope, as shown in FIG. 12. Fluorescence microscopy of the sweat pores gave a fluorescent image manifesting the sweat pore distribution as a more distinct image, and thus is very suitable for comparative analysis. For examining a distribution of sweat pores, fingerprints were lightly impressed on two sheets of the blue thin film fabricated in Example 2-1, and observed under a microscope. The results are shown in FIG. 12. FIG. 12 shows images of the hydrochromic thin films that underwent chromatic transition due to a trace amount of water from sweat pores, taken by a camera (a), a microscope (b), and a fluorescence microscope (c). As can be seen in FIG. 12b, the thin films changed in color selectively in the impressed regions (appeared as red dots) due to water from sweat pores. In FIG. 12c, the red regions (dots) are more vividly observed. FIG. 12d shows Raman spectra of the microscopic images. Lower and upper portions of the circles correspond to the regions that have and have not undergone chromatic transition from a blue to a red phase in FIG. 12b, respectively. As can be seen in FIG. 12d, the diacetlyene composite was structurally transformed by water, which led to the chromatic transition. FIG. 12e is an image merged from an image obtained by a fingerprinting prism, showing a fingerprint and sweat glands, and the fluorescent image (c). FIG. 12f is a magnification of the image of FIG. 12e. As seen in FIG. 12f, the fluorescent results obtained from the film are consistent with the sweat pores identified by the prism. In FIG. 12f, the thin film was observed to not change in color at some regions corresponding to sweat pores (marked by circles), implying that some sweat pores do not secrete sweat. Therefore, the thin film of the present invention can be applied to medical data on whether sweat pores secrete sweat or not, as well as fingerprint recognition.

Test Example 6: Sweat Pore Mapping Using Hydrochromic Thin Film 1

(37) FIG. 13a is a threshold image of sweat pores alone manifested by position tracking on the film of Example 2-1 against which a finger was lightly pressed after the finger was washed to remove sebaceous secretions and oils, and dried. FIG. 13b is an image of sweat pores alone manifested by position tracking from a ninhydrin fingerprint image. FIGS. 13c (fluorescent image of FIG. 13a) and 13d are given to comparatively analyze whether the image of FIG. 13a is consistent with that of FIG. 13b. FIG. 13e is a magnified image of a specific part of FIG. 13c (red dots appeared only in the printed friction ridges due to sweat from sweat pores) while FIG. 13f is a magnified image of a specific part of FIG. 13d. FIG. 13g is an image merged from the fluorescent image of FIG. 13e and the image of FIG. 13f. As can be seen, the two images are consistent in sweat pore positions.

(38) For additional verification, the same experiments were performed with fingerprints provided from five people, and the same results were obtained. In addition, a potential fingerprint of interest was successfully identified from a database of 10 fingerprints. Furthermore, the thin film of the present invention was successfully used in identifying the fingerprint providers from distorted fingerprints or even a part of a potential fingerprint. Hence, the present invention guarantees accurate fingerprinting analysis.

Test Example 7: Sweat Pore Mapping Using Hydrochromic Thin Film 2

(39) A finger was impressed on three sheets of the thin film of Example 2-1 at regular time intervals (after the finger was washed to cleanse off sebaceous secretions and oils therefrom, and dried). Sweat pore maps were manifested and analyzed by fluorescence microscopy. The results are shown in FIG. 14. FIGS. 14a to 14c are sweat pore maps of the fingerprints impressed at different times (all the films changed in color selective in the friction ridges impressed thereon while the sweat pores appear as red dots (a), yellow dots (b), and blue dots (c)). FIG. 14d is a merged image of FIGS. 14a to 14c. FIGS. 14e to 14f are magnified images of FIG. 14d. As apparent from FIG. 14, the three images are consistent with one another.

Test Example 8: Sweat Pore Mapping Using Hydrochromic Thin Film 3

(40) A finger was impressed on five sheets of the thin film of Example 2-1 at regular time intervals (after the finger was washed to cleanse off sebaceous secretions and oils therefrom, and dried). Sweat pore maps were manifested and analyzed by fluorescence microscopy. The results are shown in FIG. 15. FIGS. 15a to 15e are sweat pore maps of the fingerprints impressed at different times (in FIGS. 15a to 15e, active sweat pores are marked by red dotted shade circles while inactive sweat pores are marked by blue dotted circles). FIG. 15f is an image analyzing the results of FIGS. 15a to 15e. In FIG. 15f, consistently active sweat pores are marked by red shaded circles, partially active sweat pores by yellow triangles, and consistently inactive sweat pores by blue circles. As a rule, innumerable sweat pores are on the human body, but become inactive with age. That is, many sweat pores are present in the body, but not all release sweat. The degree of inactivation is different from one sweat pore to another. According to the present invention, therefore, it is possible to examine whether sweat pores are active or inactive, which may be used as medical data. Further, an additional experiment showed that sweat pore maps can be obtained from any region of the body where sweat pores are present, like a sole of the foot, a face, an arm, etc.

Test Example 9: Sweat Pore Mapping Using Hydrochromic Thin Film 4

(41) Images were respectively obtained by lightly pressing a finger against the films of Examples 2-3 and 2-5 after the finger was washed to remove sebaceous secretions and oils therefrom, and dried. The images were analyzed by fluorescence microscopy. The results are depicted in FIG. 16. As can be seen in FIG. 16, the thin films underwent chromatic transition selectively at the friction ridges impressed, and allowed for the construction of detailed sweat maps (color changed portions represented as dots). The hydrochromic thin films of Examples 2-3 (PCDA-Rb) and 2-5 (TCDA-K) were also observed to manifest sweat pore maps.

(42) Moreover, the hydrochromic thin film of Example 2-5 (TCDA-K) was analyzed for sweat pore mapping according to humidity by fluorescence microscopy. The results are given in FIG. 17. As can be seen in FIG. 17, the hydrochromic thin film allowed for sweat pore mapping even at a relative humidity of 90% or higher, demonstrating its stability to humidity.

Test Example 10

(43) Fingerprint Manifestation and Analysis as shown in FIG. 18, a finger was strongly pressed against a blue thin film that was fabricated by applying a composition of the present invention onto a PET film substrate and photopolymerizing the composition. In this regard, the fingerprint impressed on the blue thin film was not visualized with the naked eye. When the blue film was exhaled upon, the impressed fingerprint remained blue and the other portions turned red as sebaceous secretions and oils distributed over the friction ridges acted as a protective layer against water penetration. Thus the fingerprint was manifested.

(44) The manifested fingerprint was compared with the fingerprint data of the fingerprint provider. The manifested fingerprint of the provider was analyzed for characteristics (core, delta, ridge end, bifurcation, etc.) using commercially available software, and the result is given in FIG. 19a. And the result from the fingerprint data of the fingerprint provider obtained using a commercially available fingerprint reader is given in FIG. 19b. As can be seen in FIG. 19, the results are correctly consistent with each other.

(45) The present invention can visualize even a partial sweat pore distribution as well as a fingerprint image, whether vivid or faint, into an amplified fluorescent image, thereby achieving fingerprint recognition at near 100% accuracy. Because people have their own characteristic sweat pore distributions, even a sweat pore map containing a very small portion of sweat pore distribution can be used to identify a person of interest. In other words, results obtained by analyzing sweat pore features of a fingerprint provider using a fingerprint reader, and results obtained by manifesting fluorescent sweat pore patterns of a fingerprint using fingerprint recognition software can be combined with each other to identify the acquired fingerprints at near 100% accuracy. Thus, the present invention can be used in edge-cutting forensic science and for developing new dermatoglyphics technology. In addition, the present invention is very advantageous in that even a part of sweat pore distribution can be useful for fingerprint recognition.

(46) All patents, applications, standards, and articles noted herein are hereby incorporated by reference in their entirety.