Superhydrophobic composite materials and their multifunctional applications

Abstract

Controlling the hydration properties of any surface fundamentally determines its interaction with water. In this context, artificial highly water-repellent surfaces have become of particular interest. This invention relates to the synthesis and application of ceramic composites containing lanthanide / rare earth series phosphates and organic phosphonic acids that result in superhydrophobic materials that provide coatings with high water contact angles exceeding 150°, which are non-wettable, multi-substrate compatible, additive compatible, and antibacterial.

Description

[Technical Field]

[0001] The present invention relates to the synthesis and application of composite materials comprising lanthanide / rare earth series phosphates and organic phosphonic acids that result in superhydrophobic materials that provide coatings with high water contact angles greater than 150° that are non-wetting, multi-substrate compatible, additive compatible, and antibacterial. [Background technology]

[0002] Controlling the wettability of any surface fundamentally determines its interaction with water. Earth is often referred to as "Planet Water," and technologies that potentially allow for control of the hydrophobicity / hydrophilicity of surfaces have unparalleled potential to literally transform this "water world" (J.T. Simpson, S.R. Hunter, and T. Aytug, Rep. Prog. Phys., 2015, 78, 086501). In this context, artificial highly water-repellent surfaces have become of particular interest (J.T. Simpson, S.R. Hunter, and T. Aytug, Rep. Prog. Phys., 2015, vol. 78, pp. 086501; G. Wen, Z. Guo, and W. Liu, Nanoscale, 2017, vol. 9, pp. 3338–3366; Q. Wen and Z. Guo, Chem. Lett., 2016, vol. 45, pp. 1134–1149; X.-M. Li, D. Reinhoudt, and M. Crego-Calama, Chem. Soc. Rev., 2007, vol. 36, pp. 1350–1368). By combining the correct surface chemistry with the appropriate surface roughness, superhydrophobic surfaces have been engineered for a variety of applications (X. Zhang, F. Shi, J. Niu, Y. Jiang, and Z. Wang, J. Mat. Chem., 2008, Vol. 18, pp. 621–633; A. J. Meuler, G. H. McKinley, and R. E. Cohen, ACS Nano, 2010, Vol. 4, pp. 7048–7052; Y. Si and Z. Guo, Nanoscale, 2015, Vol. 7, pp. 5922–5946; M. Agrawal, S. Gupta, and M. Stamm, J. Mat. Chem., 2011, Vol. 21, pp. 615–627). Studies on hierarchical features with well-defined topographic nanoscale structures combined with low surface energy materials have revealed the scope and applicability of hydrophobic and superhydrophobic surfaces on a laboratory scale (A.J. Meuler, G.H. McKinley, and R.E. Cohen, ACS Nano, 2010, vol. 4, pp. 7048-7052; C. Yang, U. Tartaglino, and B.N.J. Persson, Phys. Rev. Lett., 2006, vol. 97, pp. 116103; M.Nosonovsky, and B. Bhushan, J. Phys.: Condens. Matter., 2008, vol. 20, pp. 225009; S. Alexander, J. Eastoe, A. L. Lord, F. Guittard, and A. R. Barron, ACS Appl. Mater. Interfaces, 2016, vol. 8, pp. 660-666; H. Mertaniemi, A. Laukkanen, J. E. Teirfolk, O. Ikkala, and R. H. A. Ras, RSC Adv., 2012, vol. 2, pp. 2882-2886). Superhydrophobic materials have been widely studied in terms of their self-cleaning, anti-corrosion, anti-icing, and anti-fouling applications as well as oil-water separation (J. Zhu, C.-M. Hsu, Z. Yu, S. Fan, and Y. Cui, Nano Lett., 2010, Vol. 10, pp. 1979-1984; S. J. Choi, and S. Y. Huh, Macromol. Rapid Commun., 2010, Vol. 31, pp. 539-544; A. Nakajima, K. Hashimoto, and T. Watanabe, Langmuir, 2000, Vol. 16, pp. 7044-7047; B. Bhushan, Y. C. Jung, and K. Koch, Langmuir, 2009, Vol. 25, pp. 3240-3248; E. Vazirinasab, R. Jafari, and G. Momen, Surface & Coatings Technology, 2018, vol. 341, pp. 40-56; G. Momen and M. Farzaneh, Appl. Surf. Sci., 2014, vol. 299, pp. 41-46; R. Jafari, R. Menini and M. Farzaneh, Appl. Surf. Sci., 2010, vol. 257, pp. 1540-1543; J.-L. Wang, K.-F. Re n, H. Chang, S.-M. Zhang, L.-J. Jin and J. Ji, Phys. Chem. Chem. Phys., 2014, vol. 16, pp. 2936-2943; C. R. Crick, J. A. Gibbins and I. P. Parkin, J. Mat. Chem. A, 2013, vol. 1, pp. 5943-5948; K. Li, X. Zeng, H. Lia and X. Lai, RSC Adv., 2014, vol. 4, pp. 23861-23868; Z. Chu, Y.Feng and S. Seeger, Angew. Chem. Int. Ed., 2015, Vol. 54, pp. 2328–2338; J. Zhang, W. Huang and Y. Han, Macromol. Rapid Commun., 2006, Vol. 27, pp. 804–808; C.-W. Tu, C.-H. Tsai, C.-F. Wang, S.-W. Kuo and F.-C. Chang, Macromol. Rapid Commun., 2007, Vol. 28, pp. 2262–2266; A. K. Kota, G. Kwon, W. Choi, J. M. Abry and A. Tuteja, Nature Commun., 2012, Vol. 3, p. 1025; L. Hu, S. Gao, X. Ding, D. Wang, J. Jiang, J. Jin and L. Jiang, ACS Nano, 2015, Vol. 9, pp. 4835-4842; C.-H. Xue, S.-T. Jia, J. Zhang and J.-Z. Ma, Sci Technol Adv Mater., 2010, Vol. 11, pp. 033002).

[0003] Several methods have been used to fabricate superhydrophobic surfaces, including lithography, plasma methods, electrochemical methods, and chemical vapor deposition (T.M. Henderson (ed.), Superhydrophobic Surfaces and Coatings: Investigations and Insights, 2017, Nova Science Publishers, Inc., USA; D. Oner and T.J. McCarthy, Langmuir, 2000, Vol. 16, pp. 7777-7782; T. Nakanishi, T. Michinobu, K. Yoshida, N. Shirahata, K. Ariga, H. Mohwald, and D.G. Kurth, Adv. Mater., 2008, Vol. 20, pp. 443-446; Y. Jiang, P. Wan, M. Smet, Z.W. (X. Zhang, F. Shi, X. Yu, H. Liu, Y. Fu, Z. Wang, L. Jiang, and X. Li, J. Am. Chem. Soc., 2004, vol. 126, pp. 3064-3065; J. T. Han, D. H. Lee, C. Y. Ryu, and K. Cho, J. Am. Chem. Soc., 2004, vol. 126, pp. 4796-4797). However, the application of these strategies, especially for large-area coatings, is limited by the size, type, and shape of these substrates.

[0004] Several patents have taught the development of superhydrophobic materials, formulations, and coatings. U.S. Patent No. 9,675,994 B2 (Schoenfisch et al.) disclosed the use of fluorinated particles containing methyltrimethoxysilane and fluorinated alkanes to achieve superhydrophobic coatings. U.S. Patent Application Publication No. 20180044541 (Jian et al.) described a non-fluorinated composition containing a fluorine-free hydrophobic polyolefin polymer, titanium dioxide nanoparticles as a filler, and water on a specific substrate as a water-repellent coating. U.S. Patent Application Publication No. 2011 / 0177252 (Kanagasbapathy et al.) disclosed a superhydrophobic coating containing hydrophobic nanoparticles of silsesquioxane containing adhesion-promoting groups and low surface energy groups. European Patent Application Publication No. 2,951,252 A1 (Sunder et al.) described a superhydrophobic coating incorporating a lotus leaf effect, consisting of organically modified silica or titanium nanoparticles and polyurethane, for application to multiple substrates. US Patent Application Publication No. 2011 / 0206925 (Kissel et al.) describes a polymer aerogel-based hydrophobic coating made in three steps, which when annealed at 150°C, resulted in a contact angle of 140°.Ajayaghosh et al. in International Application No. PCT / IN08 / 00538 and U.S. Patent Application Publication No. 12 / 678546 disclosed the use of carbon allotrope-based hybrid materials containing functional organic molecules as superhydrophobic materials (T. Nakanishi, T. Michinobu, K. Yoshida, N. Shirahata, K. Ariga, H. Mohwald, and D.G. Kurth, Adv. Mater., 2008, Vol. 20, pp. 443-446; Z. Han, B. Tay, C. Tan, M. Shakerzadeh, and K. Ostrikov, ACS Nano, 2009, vol. 3, pp. 3031-3036; S.C. Tan, F. Yan, L.I. Crouch, J. Robertson, M.R. Jones, and M.E. Welland, Adv. Funct. Mater., 2013, vol. 23, pp. 5556-5563; L.H. Li, Y.Y. Bai, L.L. Li, S.Q. Wang, and T. Zhang, Adv. Mater., 2017, vol. 29, pp. 1702-1717; Y. Lin, G.J. Ehlert, C. Bukowsky, and H.A. Sodano, ACS Appl. Mater. Interfaces, 2011, vol. 3, pp. 2200-2203). Several patents and reports have been found relating to the use of oxides of metals such as, but not limited to, silicon, titanium, zinc, manganese, aluminum, and zirconium, as well as nanoparticles of metals such as, but not limited to, gold, silver, and palladium, to impart anti-wetting properties to surfaces.

[0005] Chinese Patent No. 108976995 (Zang) teaches the use of lanthanum phosphate / water-based paints for wickerwork. The original lanthanum phosphate has not yet been shown to have inherent superhydrophobicity. Rare-earth phosphate-based nonreactive and nonwettable surfaces are described in European Patent No. 3197829A2 (Sasidharan et al.), but this invention is limited to hydrophobicity alone, achieving water contact angles in the 100° range on reactive surfaces, particularly for molten metals such as zinc and aluminum for applications in the foundry industry (S. Sasidharan BN Air, T. Suzuki, GM Anilkumar, M. Padmanabhan, U.S. Hareesh, and K.G. Warrier, Sci Rep, 2016, Vol. 6, 22732). Multifunctional superhydrophobicity compatible with multiple substrates and achieving water contact angles greater than 100° has rarely been achieved with these material classes.

[0006] Therefore, there is a need in the art for a composite material that is compatible with multiple substrates and has superhydrophobic properties with a water contact angle greater than 100°. Object of the invention

[0007] The main object of the present invention is to provide a composite material comprising a phosphate of a rare earth metal selected from lanthanum and cerium and an organic phosphonic acid.

[0008] Another object of the present invention is to provide a water repellent surface having a water contact angle of greater than 150° on multiple substrates.

[0009] It is yet another object of the present invention to provide a water-repellent surface such that the surface becomes emissive upon irradiation with light or conductive through the controlled addition of selected additives without losing the water contact angle of greater than 150°.

[0010] It is yet another object of the present invention to provide a composite material that has icephobic and antimicrobial activity such that surfaces in contact with or coated with the composite material retain a water contact angle of greater than 150° while providing access to an antimicrobial surface with negligible ice formation. Summary of the Invention

[0011] An aspect of the present invention is a composite material comprising a phosphate of an element selected from the lanthanide series and an organic phosphonic acid, the phosphate is a lanthanum or cerium phosphate or a mixture thereof, and the organic phosphonic acid is selected from the group consisting of alkyl phosphonic acids, aryl phosphonic acids, and aryl phosphonic acids; The alkyl group has the general formula C n H 2n+1 C2~C 25 The aryl group may include phenyl, benzyl, or heteroaryl, including pyridyl or terpyridinyl, and the aryl group may optionally include halogen, OH, —CN, OR 1~30 , N.H. 1~2 R 0~30 , N(R 1~30 )2, COOH, COOR 1~30 and R is C 1~30 is an alkyl group; The elemental phosphate and the organic phosphonic acid are in a ratio of 20:1 to 4:1 (w / w); A composite material is provided.

[0012] Another aspect of the present invention is a method of making said composite material, comprising the steps of: (a) activating a phosphate of an element selected from the lanthanide series by acid treatment to obtain an activated phosphate; (b) mixing the activated phosphate obtained in step (a) with an organic phosphonic acid in a ratio ranging from 20:1 to 4:1 (w / w) in an organic solvent to obtain a mixture; (c) stirring the mixture obtained in step (b) at 25-28°C for 72 hours, then centrifuging it twice at 5000 rpm for 10 minutes, and drying it in a hot air oven at 70°C for 12 hours to obtain the composite material; The present invention provides a method comprising:

[0013] In an aspect of the present invention, there is provided a method of making said composite material, wherein the acid treatment of said elemental phosphate is carried out by a step comprising: i. adding a mineral acid and a phosphate of said element to water and refluxing at 110°C for 12 hours to obtain a suspension; ii. cooling the suspension to room temperature and centrifuging at 5000 rpm for 10 minutes; iii. Redisperse in water and centrifuge twice at 5000 rpm for 10 minutes; iv. Redispersing in alcohol and centrifuging at 5000 rpm for 10 minutes to obtain a solid powder; and v. Drying the solid powder in a hot air oven at 70°C for 12 hours to obtain activated phosphate of the element.

[0014] In another aspect of the invention, there is provided a method of making a composite material, wherein the element from the lanthanide series is selected from lanthanum and cerium.

[0015] In yet another aspect of the present invention, there is provided a method of making the composite material, comprising the steps of: the organic phosphonic acid is selected from the group consisting of alkyl phosphonic acids, aryl phosphonic acids, and aryl phosphonic acids; The alkyl group is represented by the general formula C n H 2n+1 C2~C 25 alkyl chain, branched alkyl, or unsaturated alkyl, wherein the aryl group includes phenyl, benzyl, or heteroaryl, including pyridyl or terpyridinyl, wherein the aryl group optionally contains halogen, OH, —CN, OR 1~30 , N.H. 1~2 R 0~30 , N(R 1~30 )2, COOH, COOR1~30 and R is C 1~30 is an alkyl group, A method is provided.

[0016] In yet another aspect of the present invention, there is provided a method of making the composite material as described above, wherein the organic solvent is selected from the group consisting of tetrahydrofuran, methanol, ethanol, propanol, isopropanol, pentane, hexane, heptane, octane, decane, cyclohexane, benzene, toluene, acetonitrile, and ether.

[0017] In another aspect of the present invention, there is provided a method of making the composite material as described above, wherein the mineral acid is orthophosphoric acid and the alcohol is selected from propanol and isopropanol.

[0018] Yet another aspect of the present invention provides a composition comprising the composite material described above and an organic solvent, wherein the organic solvent is selected from the group consisting of methanol, ethanol, propanol, isopropanol, pentane, hexane, heptane, octane, decane, cyclohexane, benzene, toluene, acetonitrile, ether, and tetrahydrofuran.

[0019] In another aspect of the present invention, a composition is provided, optionally comprising a binder selected from polystyrene.

[0020] In yet another aspect of the present invention, a composition is provided, optionally comprising a colorant selected from a dye and an ink.

[0021] In yet another aspect of the present invention, there is provided a composition optionally comprising a conductive additive selected from multi-walled carbon nanotubes.

[0022] Yet another aspect of the present invention provides a water-repellent surface comprising a substrate coated with the composition, wherein the substrate is selected from the group consisting of glass, wood, plastic, metal, fabric, and paper. [Brief explanation of the drawings]

[0023] [Figure 1] Figure 1 shows the X-ray photoelectron spectrum of a composite containing activated LaPO4 and octadecylphosphonic acid (4:1, w / w). [Figure 2] FIG. 2 shows the thermogravimetric analysis data of a composite material containing activated LaPO4 and octadecylphosphonic acid (4:1, w / w, solid line) and activated LaPO4 (dashed line). [Figure 3] Figure 3 shows TEM images showing the nanorod-like morphology of pristine LaPO4 (left), activated LaPO4 (center), and LaPO4-octadecylphosphonic acid composite (right). [Figure 4] Figure 4 shows the water contact angle (about 134°) of a composite containing activated LaPO4 and octylphosphonic acid (4:1, w / w) on a cleaned glass substrate without annealing. [Figure 5] Figure 5 shows the water contact angle (approximately 140°) of a composite containing activated LaPO4 and octylphosphonic acid (4:1, w / w) on a cleaned glass substrate annealed at 60 °C for 2 h. [Figure 6] Figure 6 shows the water contact angle (about 143°) of a composite containing activated LaPO4 and tetradecylphosphonic acid (4:1, w / w) on a cleaned glass substrate without annealing. [Figure 7] Figure 7 shows the water contact angle (approximately 145°) of a composite containing activated LaPO4 and tetradecylphosphonic acid (4:1, w / w) on a cleaned glass substrate annealed at 60 °C for 2 h. [Figure 8] Figure 8 shows the water contact angle (about 152°) of a composite containing activated LaPO4 and octadecylphosphonic acid (4:1, w / w) on a cleaned glass substrate without annealing. [Figure 9]Figure 9 shows the water contact angle (approximately 156°) of a composite containing activated LaPO4 and octadecylphosphonic acid (4:1, w / w) on a cleaned glass substrate annealed at 60 °C for 2 h. [Figure 10] Figure 10 shows a photograph of a water droplet on a glass substrate coated with a composite containing activated LaPO4 and octadecylphosphonic acid (4:1, w / w) that was annealed at 60 °C for 2 h. Colored water is used for clarity. [Figure 11] Figure 11 shows photographs of a large-area coating (7.5 cm x 11 cm): (A) water contact angle (approximately 153°) and a composite of activated LaPO4 and octadecylphosphonic acid (4:1, w / w) coated, (B) slide, and (C) water droplet on a glass substrate annealed at 60 °C for 2 h. [Figure 12] Figure 12 shows the water contact angle (approximately 153°) of a composite containing activated LaPO4, octadecylphosphonic acid (4:1, w / w), and 5% polystyrene on a cleaned glass substrate annealed at 60 °C for 2 h. [Figure 13] Figure 13 shows the water contact angle (approximately 154°) of a composite containing activated LaPO4 and octadecylphosphonic acid (4:1, w / w) fixed onto a cleaned glass substrate using PDMS adhesive and cured at 80 °C for 2 h. [Figure 14] Figure 14 shows the water contact angles of composites containing activated LaPO4 and octadecylphosphonic acid (4:1, w / w) fixed onto different substrates using PDMS adhesive and cured at 80 °C for 2 h. [Figure 15] Figure 15 shows photographs of water droplets on different substrates coated with a composite of activated LaPO4 and octadecylphosphonic acid (4:1, w / w), which was fixed onto the substrate using PDMS adhesive and cured at 80 °C for 2 h. [Figure 16]FIG. 16 shows the change in water contact angle of a composite containing activated LaPO4 and octadecylphosphonic acid (4:1, w / w) fixed onto a cleaned glass substrate with PDMS adhesive and cured at 80 °C for 2 h after five Scotch tape tests, confirming stability. [Figure 17] Figure 17 shows the stability and durability of a composite coating containing activated LaPO4 and octadecylphosphonic acid (4:1, w / w) fixed onto a wooden substrate using PDMS adhesive and cured at 80 °C for 2 h after 90 days of exposure to ambient conditions, with a water contact angle of approximately 154°. [Figure 18] Figure 18 shows a photograph of a water droplet (left) and the corresponding water contact angle (right, approximately 155°) of a glass substrate coated with a composite containing activated LaPO4, octadecylphosphonic acid (4:1, w / w), and a green colorant and annealed at 60 °C for 2 h. [Figure 19] Figure 19 shows a photograph of a water droplet (left) and the corresponding water contact angle (right, approximately 153°) of a glass substrate coated with a composite containing activated LaPO4, octadecylphosphonic acid (4:1, w / w), and a blue colorant and annealed at 60 °C for 2 h. [Figure 20] Figure 20 shows photographs under daylight (top row) and UV light (365 nm, bottom row) of glass substrates coated with a composite containing activated LaPO4 and octadecylphosphonic acid (4:1, w / w, left) and a cyan-emitting superhydrophobic coating obtained by adding pyrene to the composite (1:10, w / w), both of which were annealed at 60 °C for 2 hours. [Figure 21] Figure 21 shows a photograph under UV light (365 nm, left) of a water droplet on a cyan-emitting superhydrophobic coating of a glass substrate coated with a composite comprising activated LaPO4, octadecylphosphonic acid (4:1, w / w) and containing an additive (1(pyrene):10(composite), w / w) and annealed at 60 °C for 2 hours, and the corresponding water contact angle (right, approximately 153°). [Figure 22]Figure 22 shows photographs of glass substrates coated with a composite containing activated LaPO4, octadecylphosphonic acid (4:1, w / w, left) and with a conductive superhydrophobic coating obtained by adding MWCNTs to the composite (1:4, w / w), both of which were annealed at 60 °C for 2 h. [Figure 23] Figure 23 shows a photograph of a water droplet on a conductive superhydrophobic coating of a glass substrate coated with a composite comprising activated LaPO4, octadecylphosphonic acid (4:1, w / w) and containing an additive (1(MWCNT):10(composite), w / w) and annealed at 60 °C for 2 hours, and the corresponding water contact angle (right, approximately 157°). [Figure 24] Figure 24 shows the current vs. potential plot for a conductive superhydrophobic coating on a glass substrate annealed at 60°C for 2 hours using a composite comprising activated LaPO4, octadecylphosphonic acid (4:1, w / w) and containing an additive (1(MWCNT):4(composite), w / w). Estimated conductivity = 1.24 S / cm [Figure 25] Figure 25 shows the slippery superhydrophobicity of a LaPO4-cotadecyl phosphonic acid composite coating on a metal substrate. Stage 1 shows the water droplet just before impact, stage 2 shows the water droplet immediately after impact, stages 3-8 show bouncing and rolling off, and stages 9-10 show the stickiness of the uncoated area of ​​the substrate, confirming the icephobic properties of the coating. The line indicates the point of initial impact. [Figure 26] FIG. 26 shows a table showing the antibacterial properties of the LaPO4-cotadecyl phosphonic acid composite and photographs (control: left, and actual sample: right) showing the antibacterial activity (more than 90% inhibition) against E. coli (4-hour incubation time).

[0024] Abbreviations used PDMS: Polydimethylsiloxane wt%: weight percent cm: centimeters nm: nanometer MWCNT: multi-walled carbon nanotubes S / cm: Siemens per centimeter Rpm: Revolutions per minute mg: milligram mL: milliliter DETAILED DESCRIPTION OF THE INVENTION

[0025] This section describes the present invention in detail in preferred embodiments.

[0026] The present invention relates to a composite material comprising a phosphate of an element selected from the lanthanide series and an organic phosphonic acid, the phosphate is a lanthanum or cerium phosphate or a mixture thereof, and the organic phosphonic acid is selected from the group consisting of alkyl phosphonic acids, aryl phosphonic acids, and aryl phosphonic acids; The alkyl group has the general formula C n H 2n+1 C2~C 25 The aryl group may include phenyl, benzyl, or heteroaryl, including pyridyl or terpyridinyl, and the aryl group may optionally include halogen, OH, —CN, OR 1~30 , N.H. 1~2 R 0~30 , N(R 1~30 )2, COOH, COOR 1~30 and R is C 1~30 is an alkyl group; The elemental phosphate and the organic phosphonic acid are in a ratio of 20:1 to 4:1 (w / w); It is directed towards composite materials.

[0027] In an embodiment of the present invention, there is provided a composite material comprising a phosphate of an element selected from the lanthanide series and an organic phosphonic acid, wherein the phosphate of said element and the organic phosphonic acid are in a ratio in the range of 10:1 (w / w).

[0028] In another embodiment of the present invention, there is provided a composite material comprising a phosphate of an element selected from the lanthanide series and an organic phosphonic acid, wherein the phosphate of the element and the organic phosphonic acid are in a ratio in the range of 4:1 (w / w).

[0029] The present invention also provides a method for making the composite material, comprising the steps of: (a) activating a phosphate of an element selected from the lanthanide series by acid treatment to obtain an activated phosphate; (b) mixing the activated phosphate obtained in step (a) with an organic phosphonic acid in a ratio ranging from 20:1 to 4:1 (w / w) in an organic solvent to obtain a mixture; (c) stirring the mixture obtained in step (b) at 25-28°C for 72 hours, then centrifuging it twice at 5000 rpm for 10 minutes, and drying it in a hot air oven at 70°C for 12 hours to obtain the composite material; The present invention is directed to a method, including:

[0030] In an embodiment of the present invention, a method for making said composite material is provided, wherein the acid treatment of said elemental phosphate is carried out by a step comprising: i. adding a mineral acid and a phosphate of said element to water and refluxing at 110°C for 12 hours to obtain a suspension; ii. cooling the suspension to room temperature and centrifuging at 5000 rpm for 10 minutes; iii. Redisperse in water and centrifuge twice at 5000 rpm for 10 minutes; iv. Redispersing in alcohol and centrifuging at 5000 rpm for 10 minutes to obtain a solid powder; and v. Drying the solid powder in a hot air oven at 70°C for 12 hours to obtain activated phosphate of the element.

[0031] In another embodiment of the present invention, a method of making a composite material is provided, wherein said element from the lanthanide series is selected from lanthanum and cerium.

[0032] In yet another embodiment of the present invention, there is provided a method of making said composite material, comprising the steps of: the organic phosphonic acid is selected from the group consisting of alkyl phosphonic acids, aryl phosphonic acids, and aryl phosphonic acids; The alkyl group is represented by the general formula C n H 2n+1 C2~C 25 alkyl chain, branched alkyl, or unsaturated alkyl, wherein the aryl group includes phenyl, benzyl, or heteroaryl, including pyridyl or terpyridinyl, wherein the aryl group optionally contains halogen, OH, —CN, OR 1~30 , N.H. 1~2 R 0~30 , N(R 1~30 )2, COOH, COOR 1~30 and R is C 1~30 is an alkyl group, A method is provided.

[0033] In yet another embodiment of the present invention, there is provided a method of making the composite material as described above, wherein the organic solvent is selected from the group consisting of tetrahydrofuran, methanol, ethanol, propanol, isopropanol, pentane, hexane, heptane, octane, decane, cyclohexane, benzene, toluene, acetonitrile, and ether.

[0034] In an embodiment of the present invention, there is provided a method for making the composite material, wherein the mineral acid is orthophosphoric acid and the alcohol is selected from propanol and isopropanol.

[0035] An embodiment of the present invention provides a composition comprising the composite material and an organic solvent, wherein the organic solvent is selected from the group consisting of methanol, ethanol, propanol, isopropanol, pentane, hexane, heptane, octane, decane, cyclohexane, benzene, toluene, acetonitrile, ether, and tetrahydrofuran.

[0036] In an embodiment of the present invention, there is provided a composition comprising the composite material and an organic solvent, optionally containing a binder selected from polystyrene, wherein the ratio of binder to composite material is 1:20 (w / w).

[0037] In another embodiment of the present invention, there is provided a composition comprising the composite material and an organic solvent, optionally including a colorant selected from a dye and an ink.

[0038] In yet another embodiment of the present invention, there is provided a composition comprising the composite material and an organic solvent, optionally containing a conductive additive selected from multi-walled carbon nanotubes, wherein the ratio of multi-walled carbon nanotubes to the composite material is within the range of 1:25 to 1:10 (w / w).

[0039] In yet another embodiment of the present invention, there is provided a composition comprising the composite material and an organic solvent, optionally containing an organic or inorganic fluorescent additive, wherein the ratio of the fluorescent additive to the composite material is within the range of 1:50 to 1:10 (w / w).

[0040] Yet another embodiment of the present invention provides a water-repellent surface comprising a substrate coated with the composition, wherein the substrate is selected from the group consisting of glass, wood, plastic, metal, fabric, and paper.

[0041] After extensive research into water-repellent coatings, the inventors of the present invention have discovered that organic modification of the surface of a ceramic material, comprising a phosphate of a rare earth metal selected from lanthanum and cerium, having a well-defined nanoscale morphology, and an organic phosphonic acid, confers an unprecedented high water contact angle of over 150° to the surface in contact with or coated with the composite material.

[0042] In one embodiment, the present invention is directed to a method for making superhydrophobic ceramic composites via a two-step process comprising activating a rare earth metal phosphate, preferably lanthanum phosphate and / or cerium phosphate, or a mixture thereof in a 1:10 to 10:1 ratio, and contacting the activated phosphate with an organic phosphonic acid. The phosphonic acid is independently selected from the group consisting of alkylphosphonic acid, arylphosphonic acid, and arylphosphonic acid. A preferred phosphate is lanthanum phosphate calcined at 200 to 250°C, having a well-defined nanoscale morphology. The phosphate is activated by acid treatment with a mineral acid selected from orthophosphoric acid, at a concentration of 1 mL / 25 mL water / 1 gram LnPO4. The phosphate salt is treated with mineral acid at 110° C. for 12 hours, cooled, centrifuged at 5000 rpm for 10 minutes, redispersed in water and centrifuged at 5000 rpm for 10 minutes (twice), then redispersed in alcohol, centrifuged at 5000 rpm for 10 minutes, and dried at 70° C. for 12 hours. The alcohol used is propanol, more preferably isopropanol.

[0043] The present invention provides a composite material comprising LnPO4 and an organic phosphonic acid in a ratio of less than 20:1, preferably a 10:1 ratio, and more preferably a 4:1 ratio, wherein Ln is independently selected from La 3+ and Ce 3+ or a mixture thereof, wherein the Ln / Ce ratio is 0:10 to 10:0, and preferably LaPO4 is obtained from its precursor, which is calcined at 200 to 250°C, and the composite material has a well-defined nanoscale morphology. The phosphonic acids are independently selected from the group consisting of alkylphosphonic acids, arylphosphonic acids, and arylphosphonic acids, and the alkyl groups are represented by the general formula C n H 2n+1 C2~C 25 The aryl group may include phenyl, benzyl, or heteroaryl, including pyridyl or terpyridinyl, and the aryl group may optionally include halogen, OH, —CN, OR 1~30 , N.H. 1~2 R 0~30, N(R 1~30 )2, COOH, COOR 1~30 and R is C 1~30 It is an alkyl group.

[0044] The present invention is also directed to a thin film coating of the composite material prepared from its dispersion in an organic solvent, including, but not limited to, alcohols selected from the group consisting of methanol, ethanol, propanol, and isopropanol, and hydrocarbons selected from the group consisting of pentane, hexane, heptane, octane, decane, cyclohexane, benzene, toluene, acetonitrile, ether, and tetrahydrofuran, with a minimum composition of 1 wt% solvent to a maximum composition of 99 wt% solvent, wherein the composite material has a weighted composition relative to the solvent of 50 mg / mL, preferably 30 mg / mL, and more preferably 20 mg / mL, and is drop-cast or spin-cast onto a solid substrate.

[0045] In certain embodiments, the solid substrate is composed of organic materials (at least 50% organic composition) such as, but not limited to, polymers, fabrics, or paper, with or without oxides, nitrides, carbides, borides, phosphates, sulfides, etc.; inorganic materials (at least 50% organic composition) such as, but not limited to, metallic materials and alloys; and non-metallic materials such as, but not limited to, carbon, semiconductors, glass, and ceramics. In certain embodiments, the substrate is selected from the group consisting of glass, wood, plastic, metal, fabric, and paper. When the substrate is contacted with or coated with a composition comprising the composite material, dried, and annealed at 60°C for 2 hours, it exhibits water repellency with a water contact angle of greater than 150°.

[0046] Another embodiment of the present invention involves a spray-, spin-, dip-, or drop-coatable formulation of a composite dispersed in a solvent selected from tetrahydrofuran and containing a binder, preferably polystyrene with a molecular weight of 35,000, at a ratio of 1:20 (binder:composite, w / w). Furthermore, stable films of the composite are formed on substrates selected from the group consisting of glass, wood, plastic, metal, fabric, and paper, by doctor-blading a thin film of polydimethylsiloxane (PDMS) containing a suitable curing agent at a 10:1 (w / w) ratio. The composite is then adhesively fixed to the substrate via a "powder-on-glue" process. Excess powder is removed with an aspirator and then cured at 80°C for 3 hours. These strategies result in high water repellency, with a water contact angle exceeding 150°.

[0047] In certain embodiments, the present invention relates to the stability and durability of the composite material and the contacted or coated substrate, as expressed by the shelf life of the composite material or modified substrate. Scotch tape tests of the modified substrate and exposure to environmental conditions for one week, preferably one month, and more preferably one year were performed, preferably with 80% performance retention, more preferably 90% performance retention. The shelf life of the composite material and coated substrate under laboratory conditions was estimated to be greater than one year. After five Scotch tape tests, contact angles greater than 150° were obtained, and greater than 90% of the water repellency of the modified substrate was retained after more than one month of exposure to environmental conditions.

[0048] Another embodiment of the present invention provides a method for reducing condensation or ice formation on a surface modified with a composite material through the slippery hydrophobic properties of the substrate induced by the composite material. Substrates contacted with or coated with the composite material will not allow water droplets to adhere, and the coating will thus impart ice protection to the substrate, resulting in an icephobic surface with a rolling angle of less than 5°, preferably less than 3°, and more preferably less than 2°, resulting in a composite material, coating, or formulation with high water repellency and a water contact angle of greater than 150° on suitable substrates with slippery superhydrophobic properties.

[0049] In another embodiment of the present invention, a formulation of a composite material in an organic solvent, non-limiting examples of which include alcohols selected from the group consisting of methanol, ethanol, propanol, and isopropanol; hydrocarbons selected from the group consisting of pentane, hexane, heptane, octane, decane, cyclohexane, benzene, toluene, acetonitrile, ethers, and tetrahydrofuran, preferably tetrahydrofuran, containing a suitable colorant selected from inks and dyes soluble in the tetrahydrofuran of the formulation, the formulation having a composite to solvent ratio of 50:1 to 1:1 (w / v), preferably 20 mg of composite material in 1 mL of tetrahydrofuran containing 0.1 to 2.0 mg of colorant, preferably 0.5 to 1.0 mg of colorant, provides the colored superhydrophobic, non-wettable surface without losing a water contact angle greater than 150°.

[0050] Another aspect of the present invention is the induced multifunctional properties including, but not limited to, non-wetting luminescent fluorescent coatings through the controlled addition of organic or inorganic fluorescent additives at a correct composition of 1:50 (w / w), preferably at a correct composition of 1:25 (w / w), more preferably at a correct composition of 1:10 (w / w) as LaPO4 composites, and through the controlled addition of conductive additives, preferably conductive carbon allotropes, more preferably multi-walled carbon nanotubes (MWCNTs) with a diameter greater than 100 nm, at a correct composition of 1:25 (w / w), preferably at a correct composition of 1:10 (w / w), more preferably at a correct composition of 1:4 (w / w) as LaPO4 composites, wherein said coatings have a conductivity greater than 1.2 S / cm and a coating without MWCNTs has a conductivity greater than 10 -9 Conductivity of less than 10 S / cm, resulting in a conductivity of at least 10 for non-wettable conductive surfaces 9 induced a fold increase, and the coatings in each of the above are directed to induced multifunctional properties with no detectable difference in wettability as judged by water contact angle values ​​greater than 150°.

[0051] In particular, composite materials, formulations, and coatings exhibiting superhydrophobic, ice-resistant, and anti-wetting properties with slipperiness and broad-spectrum antimicrobial activity against common pathogens reduce adhesion and survival of microorganisms selected from both Gram-positive and Gram-negative strains by 70%, preferably 80%, and more preferably 90%. In certain embodiments, the bacterial species are selected from E. coli, M. smegmatis, and S. aureus. However, with the addition of a functional biocidal component, preferably up to 5 wt%, the antimicrobial activity of the material or coating can be tailored to partially inhibit, prevent, reduce, or eliminate the growth and coverage of one or more undesirable organisms, including but not limited to bacteria, fungi, viruses, insects, and the like, in close proximity to or in contact with the coated surface. [Example]

[0052] The following examples are illustrative and not intended to be limiting.

[0053] Example 1: Activation of rare earth metal phosphates LnPO4 (Ln is independently La 3+ and Ce 3+ or Ln 3+ and Ce 3+ LaPO4 (a mixture of 1000 and 10 ...

[0054] Example 2: Synthesis of LaPO4-Alkyl / Cycloalkyl / Arylphosphonic Acid Composite Materials Activated LaPO4 with well-defined rod-like morphology and the corresponding alkylphosphonic acid were mixed in an organic solvent, preferably tetrahydrofuran, in a 4:1 (w / w) ratio to obtain a final composition of 50 mg phosphonic acid / 200 mg activated LaPO4 / 25 mL tetrahydrofuran. The mixture was stirred at 25-28 °C for 72 h, then centrifuged at 5000 rpm for 10 min (twice) and dried in a hot air oven at 70 °C for 12 h.

[0055] Although tetrahydrofuran was the preferred solvent, non-limiting examples of solvents include alcohols such as methanol, ethanol, propanol, isopropanol, etc., hydrocarbons such as pentane, hexane, heptane, octane, decane, cyclohexane, benzene, toluene, acetonitrile, ethers, etc.

[0056] Example 2.1: Synthesis of LaPO4-hexylphosphonic acid composite material Activated LaPO4 with well-defined rod-like morphology and hexylphosphonic acid were mixed in a 4:1 (w / w) ratio in an organic solvent, preferably tetrahydrofuran, to obtain a final composition of 50 mg phosphonic acid / 200 mg activated LaPO4 / 25 mL tetrahydrofuran. The mixture was stirred at 25-28 °C for 72 h, then centrifuged at 5000 rpm for 10 min (twice) and dried in a hot air oven at 70 °C for 12 h.

[0057] Example 2.2: Synthesis of LaPO4-octylphosphonic acid composite Activated LaPO4 with well-defined rod-like morphology and octylphosphonic acid were mixed in a 4:1 (w / w) ratio in an organic solvent, preferably tetrahydrofuran, to obtain a final composition of 50 mg phosphonic acid / 200 mg activated LaPO4 / 25 mL tetrahydrofuran. The mixture was stirred at 25-28 °C for 72 h, then centrifuged at 5000 rpm for 10 min (twice), and dried in a hot air oven at 70 °C for 12 h.

[0058] Example 2.3: Synthesis of LaPO4-Decylphosphonic Acid Composite Activated LaPO4 with well-defined rod-like morphology and decylphosphonic acid were mixed in a 4:1 (w / w) ratio in an organic solvent, preferably tetrahydrofuran, to obtain a final composition of 50 mg phosphonic acid / 200 mg activated LaPO4 / 25 mL tetrahydrofuran. The mixture was stirred at 25-28 °C for 72 h, then centrifuged at 5000 rpm for 10 min (twice), and dried in a hot air oven at 70 °C for 12 h.

[0059] Example 2.4: Synthesis of LaPO4-dodecylphosphonic acid composite material Activated LaPO4 with well-defined rod-like morphology and dodecylphosphonic acid were mixed in a 4:1 (w / w) ratio in an organic solvent, preferably tetrahydrofuran, to obtain a final composition of 50 mg phosphonic acid / 200 mg activated LaPO4 / 25 mL tetrahydrofuran. The mixture was stirred at 25-28 °C for 72 h, then centrifuged at 5000 rpm for 10 min (twice), and dried in a hot air oven at 70 °C for 12 h.

[0060] Example 2.5: Synthesis of LaPO4-tetradecylphosphonic acid composite material Activated LaPO4 with well-defined rod-like morphology and tetradecylphosphonic acid were mixed in an organic solvent, preferably tetrahydrofuran, in a 4:1 (w / w) ratio to obtain a final composition of 50 mg phosphonic acid / 200 mg activated LaPO4 / 25 mL tetrahydrofuran. The mixture was stirred at 25-28 °C for 72 h, then centrifuged at 5000 rpm for 10 min (twice) and dried in a hot air oven at 70 °C for 12 h.

[0061] Example 2.6: Synthesis of LaPO4-octadecylphosphonic acid composite material Activated LaPO4 with well-defined rod-like morphology and octylphosphonic acid were mixed in a 4:1 (w / w) ratio in an organic solvent, preferably tetrahydrofuran, to obtain a final composition of 50 mg phosphonic acid / 200 mg activated LaPO4 / 25 mL tetrahydrofuran. The mixture was stirred at 25-28 °C for 72 h, then centrifuged at 5000 rpm for 10 min (twice), and dried in a hot air oven at 70 °C for 12 h.

[0062] Example 2.7: Synthesis of LaPO4-cyclohexylphosphonic acid composite material Activated LaPO4 with well-defined rod-like morphology and cyclohexylphosphonic acid were mixed in a 4:1 (w / w) ratio in an organic solvent, preferably tetrahydrofuran, to obtain a final composition of 50 mg phosphonic acid / 200 mg activated LaPO4 / 25 mL tetrahydrofuran. The mixture was stirred at 25-28 °C for 72 h, then centrifuged at 5000 rpm for 10 min (twice) and dried in a hot air oven at 70 °C for 12 h.

[0063] Example 2.8: Synthesis of LaPO4-allylphosphonic acid composite material Activated LaPO4 with well-defined rod-like morphology and allylphosphonic acid were mixed in a 4:1 (w / w) ratio in an organic solvent, preferably tetrahydrofuran, to obtain a final composition of 50 mg phosphonic acid / 200 mg activated LaPO4 / 25 mL tetrahydrofuran. The mixture was stirred at 25-28 °C for 72 h, then centrifuged at 5000 rpm for 10 min (twice), and dried in a hot air oven at 70 °C for 12 h.

[0064] Example 3: Synthesis of LaPO4-arylphosphonic acid composite materials Activated LaPO4 with well-defined rod-like morphology and the corresponding arylphosphonic acid were mixed in an organic solvent, preferably tetrahydrofuran, in a 4:1 (w / w) ratio to obtain a final composition of 50 mg phosphonic acid / 200 mg activated LaPO4 / 25 mL tetrahydrofuran. The mixture was stirred at 25-28 °C for 72 h, then centrifuged at 5000 rpm for 10 min (twice), and dried in a hot air oven at 70 °C for 12 h.

[0065] Although tetrahydrofuran was the preferred solvent, non-limiting examples of solvents include alcohols such as methanol, ethanol, propanol, isopropanol, etc., hydrocarbons such as pentane, hexane, heptane, octane, decane, cyclohexane, benzene, toluene, acetonitrile, ethers, etc.

[0066] Example 3.1: Synthesis of LaPO4-phenylphosphonic acid composite material Activated LaPO4 with well-defined rod-like morphology and phenylphosphonic acid were mixed in an organic solvent, preferably tetrahydrofuran, in a 4:1 (w / w) ratio to obtain a final composition of 50 mg phosphonic acid / 200 mg activated LaPO4 / 25 mL tetrahydrofuran. The mixture was stirred at 25-28 °C for 72 h, then centrifuged at 5000 rpm for 10 min (twice) and dried in a hot air oven at 70 °C for 12 h.

[0067] Example 3.2: Synthesis of LaPO4-benzylphosphonic acid composite material Activated LaPO4 with well-defined rod-like morphology and benzylphosphonic acid were mixed in an organic solvent, preferably tetrahydrofuran, in a 4:1 (w / w) ratio to obtain a final composition of 50 mg phosphonic acid / 200 mg activated LaPO4 / 25 mL tetrahydrofuran. The mixture was stirred at 25-28 °C for 72 h, then centrifuged at 5000 rpm for 10 min (twice), and dried in a hot air oven at 70 °C for 12 h.

[0068] Example 3.3: Synthesis of LaPO4-p-(4-[2,2':6',2"-terpyridin]-4'-ylphenyl)phosphonic acid composite material Activated LaPO4 with well-defined rod-like morphology and p-(4-[2,2':6',2"-terpyridin]-4'-ylphenyl)phosphonic acid were mixed in a 4:1 (w / w) ratio in an organic solvent, preferably tetrahydrofuran, to obtain a final composition of 50 mg phosphonic acid / 200 mg activated LaPO4 / 25 mL tetrahydrofuran. The mixture was stirred at 25-28 °C for 72 h, then centrifuged at 5000 rpm for 10 min (twice) and dried in a hot air oven at 70 °C for 12 h.

[0069] Example 4: Synthesis of CePO4-Alkyl / Cycloalkylarylphosphonic Acid Composite Materials The experimental procedure detailed in Example 3 was extended to other metal phosphates of the rare lanthanide series as follows: activated CePO4 + corresponding alkylphosphonic acid (4:1, w / w) in THF (final composition: 50 mg phosphonic acid / 200 mg activated CePO4 / 25 mL tetrahydrofuran), stirred at 25-28 °C for 72 h, then centrifuged at 5000 rpm for 10 min (twice), and dried in a hot air oven at 70 °C for 12 h.

[0070] Example 5: Synthesis of LaPO4-CePO4 mixture-alkyl / cycloalkyl / aryl / arylphosphonic acid composite materials The experimental procedure detailed in Example 3 was extended to rare lanthanide series metal phosphate mixtures as follows: LaPO4-CePO4 + the corresponding alkylphosphonic acid (4:1, w / w) were activated (mixed) in THF in any ratio from 0:10 to 10:0 (final composition: 50 mg phosphonic acid / 200 mg activated (mixed) LaPO4-CePO4 / 25 mL tetrahydrofuran), stirred at 25-28 °C for 72 h, centrifuged at 5000 rpm for 10 min (twice), and dried in a hot air oven at 70 °C for 12 h.

[0071] Example 6: Preparation of thin film coatings of composite materials on solid substrates and multi-substrate compatibility The LaPO4-octadecylphosphonic acid composite (20 mg) was dispersed in an organic solvent, preferably tetrahydrofuran (1.0 mL), at a concentration of 20 mg / mL. The mixture was stirred overnight to obtain a stable dispersion. The dispersion was drop-cast or spin-cast onto substrates independently selected from glass, wood, plastic, metal, fabric, and paper, dried at room temperature, and optionally annealed at 60°C for 2 hours to yield surface-modified substrates exhibiting water repellency with water contact angles exceeding 150°, confirming substrate-independent or multi-substrate compatible anti-wetting properties.

[0072] Following exactly the same procedure as for octadecylphosphonic acid, other phosphonic acids also resulted in coatings on suitable substrates.

[0073] Although tetrahydrofuran was the preferred solvent, non-limiting examples of solvents include alcohols such as methanol, ethanol, propanol, isopropanol, etc., hydrocarbons such as pentane, hexane, heptane, octane, decane, cyclohexane, benzene, toluene, acetonitrile, ethers, etc.

[0074] Example 7: Formulation of composite materials containing polystyrene binder The composite formulations, which can be spray-coated, spin-coated, dip-coated, or drop-coated, were prepared using an organic solvent, preferably tetrahydrofuran. LaPO4-octadecylphosphonic acid composite (20 mg) was dispersed in tetrahydrofuran (1.0 mL) at a concentration of 20 mg / mL. Polystyrene (1 mg, molecular weight 35,000) was added as a binder at a ratio of 1:20 (binder:composite, w / w) and stirred overnight at room temperature to obtain a stable dispersion. The dispersions were drop- or spin-cast onto substrates independently selected from glass, wood, plastic, metal, fabric, and paper. After drying at room temperature and optional annealing at 60 °C for 2 hours, the surface-modified substrates exhibited water repellency with water contact angles exceeding 150°, confirming substrate-independent or multi-substrate compatibility.

[0075] Following exactly the same procedure as for octadecylphosphonic acid, other phosphonic acids also resulted in coatings on suitable substrates.

[0076] Although tetrahydrofuran was the preferred solvent, non-limiting examples of solvents include alcohols such as methanol, ethanol, propanol, isopropanol, etc., hydrocarbons such as pentane, hexane, heptane, octane, decane, cyclohexane, benzene, toluene, acetonitrile, ethers, etc.

[0077] Example 8: Stable films of composite materials using the "Powder-on-Glue" method Stable films of LaPO4-octadecylphosphonic acid composites were formed on suitable substrates by the "powder-on-glue" method. Doctor-bladed thin films of polydimethylsiloxane (PDMS) containing a suitable curing agent at a weighted ratio of 10:1 (w / w) were used as adhesive, and the composite was applied as a powder. In a typical procedure, an ultrathin film of PDMS and curing agent (100 μL) was deposited on a glass substrate (2 cm × 2 cm). A thin film of PDMS adhesive was obtained by doctor-blading. 20 mg of dry fine powder of LaPO4-octadecylphosphonic acid composite was sprinkled onto the adhesive. Excess powder was removed by aspirator, and the composite was cured at 80°C for 3 hours to yield a stable film of the composite on glass.

[0078] Substrate independence and multi-substrate compatibility was demonstrated using substrates independently selected from glass, wood, plastic, metal, fabric, and paper.

[0079] Example 9: Scorch Tape Test to Determine Coating Stability and Ambient Durability Stable films of LaPO4-octadecylphosphonic acid composites on glass were prepared using the "powder-on-glue" method, as described in Example 9. The water contact angles of the modified substrates were experimentally determined. Commercially available Scotch tape was applied to the coated substrate and quickly removed. The water contact angles of the resulting coatings were measured. This Scotch tape test was repeated five times, and the water contact angles corresponding to these five Scotch tape tests were subsequently determined. In all cases, water contact angles greater than 150° were obtained, confirming the stability of the coatings.

[0080] The durability and shelf life of the composites were tested by comparing the water contact angles of glass substrates coated with the composites one year after their preparation. Water contact angles greater than 150° were observed, confirming a shelf life of at least one year for the composites. Drop-cast glass slides maintained under laboratory conditions were subjected to water contact angle measurements one year after their preparation. Water contact angles greater than 150° confirmed the durability of the coating. Wood substrates coated with the composites using the "powder-on-glue" method were exposed to ambient conditions for several weeks, and the water contact angle after four weeks was approximately 154°, further confirming the durability of the coating under ambient conditions.

[0081] Example 10: Slippery Hydrophobic and Icephobic Stable films of LaPO4-octadecylphosphonic acid composites on glass were formed using the "powder-on-glue" method, as described in Example 9. The water contact angles of the modified substrates were experimentally determined. Reduced condensation or ice formation on the composite-modified surfaces was confirmed through the demonstration of the slippery hydrophobicity of the substrates. The composite coating prevented water droplets from adhering to the surface and allowed them to roll off at angles as small as 2° on metal substrates and 0° on wood substrates. The modified substrates were further placed in a commercial freezer for 12 hours without any noticeable ice formation.

[0082] Example 11: Preparation of a colored coating LaPO4-octadecylphosphonic acid composites, which can be spray-coated, spin-coated, dip-coated, or drop-coated, were prepared using an organic solvent, preferably tetrahydrofuran. This composite (20 mg) was dispersed in tetrahydrofuran (1.0 mL) at a concentration of 20 mg / mL. Commercially available green or blue ink was added as a colorant (1.0 mg) and stirred overnight at room temperature to obtain a stable dispersion. The dispersion was drop- or spin-cast onto substrates independently selected from glass, wood, plastic, metal, fabric, and paper, dried at room temperature, and optionally annealed at 60°C for 2 hours to obtain greenish or bluish-colored surface-modified substrates exhibiting water repellency with a water contact angle of more than 150°, resulting in colored, superhydrophobic, non-wettable surfaces.

[0083] Although tetrahydrofuran was the preferred solvent, non-limiting examples of solvents include alcohols such as methanol, ethanol, propanol, isopropanol, etc., hydrocarbons such as pentane, hexane, heptane, octane, decane, cyclohexane, benzene, toluene, acetonitrile, ethers, etc. Additionally, any pigment of any color that is soluble in this solvent can be used to make a pigmented non-wetting coating.

[0084] Example 12: Preparation of a luminescent coating LaPO4-octadecylphosphonic acid composites, which can be spray-coated, spin-coated, dip-coated, or drop-coated, were prepared using an organic solvent, preferably tetrahydrofuran. This composite (20 mg) was dispersed in tetrahydrofuran (1.0 mL) at a concentration of 20 mg / mL. A commercially available fluorescent compound (pyrene, 2.0 mg, 1:10 w / w concentration) was added and stirred overnight at room temperature to obtain a stable dispersion. The dispersion was drop- or spin-cast onto substrates independently selected from glass, wood, plastic, metal, fabric, and paper. The resulting surface-modified substrates were then dried at room temperature and optionally annealed at 60 °C for 2 hours. These substrates exhibited luminescence (cyan emission in this case) under UV illumination (365 nm) and water repellency with a water contact angle of more than 150°, resulting in emissive, superhydrophobic, non-wettable surfaces.

[0085] Although tetrahydrofuran was the preferred solvent, non-limiting examples of solvents include alcohols such as methanol, ethanol, propanol, isopropanol, etc., hydrocarbons such as pentane, hexane, heptane, octane, decane, cyclohexane, benzene, toluene, acetonitrile, ethers, etc. Additionally, any organic or inorganic fluorescent material that is soluble in this solvent can be used to make the emissive non-wetting coating.

[0086] Example 13: Preparation of conductive coating A commercially available conductive additive (in this case, 5.0 mg of multi-walled carbon nanotubes (MWCNTs) with a diameter greater than 100 nm) was dispersed in 1.0 mL of tetrahydrofuran via ultrasonication for 30 minutes. Next, 20 mg of LaPO4-octadecylphosphonic acid composite was added to the sonicated dispersion in 1.0 mL of tetrahydrofuran to a final concentration of 20 mg / mL, with a 1:4 (w / w) MWCNT / composite ratio. The mixture was stirred overnight at room temperature to obtain a stable dispersion. The dispersion was drop- or spin-cast onto substrates independently selected from glass, wood, plastic, metal, fabric, and paper, dried at room temperature, and optionally annealed at 60 °C for 2 hours to obtain a surface-modified conductive substrate exhibiting water repellency with a water contact angle greater than 150°, resulting in a conductive, superhydrophobic, non-wettable surface. The measured conductivity was 1.2 S / cm, compared with 10 S / cm for the coating without MWCNTs. -9 The conductivity was less than 10 S / cm. 9 A 50-fold increase in conductivity was observed. The conductivity can be further tuned by varying the amount of MWCNT added.

[0087] Although tetrahydrofuran was the preferred solvent, non-limiting examples of solvents include alcohols such as methanol, ethanol, propanol, isopropanol, etc., hydrocarbons such as pentane, hexane, heptane, octane, decane, cyclohexane, benzene, toluene, acetonitrile, ethers, etc. Additionally, any organic or inorganic conductive additive that can be dispersed in the solvent can be used to make the emissive non-wetting coating.

[0088] Example 14: Antibacterial Activity A single colony of the corresponding bacteria from the nutrient agar plate was transferred to 10 mL of nutrient broth medium and grown at 37°C for 24 hours. LaPO4-octadecylphosphonic acid was suspended in sterile distilled water at a concentration of 25 mg / mL. 100 μL of this solution and 20 μL of bacteria were added to 5 mL of nutrient broth and incubated in the dark for 2 hours. A control was maintained using 100 μL of sterile water instead of the compound solution. After incubation, 100 μL of this solution was added to 10 mL of nutrient broth. -4 The cultures were serially diluted to 1000 and plated on nutrient agar plates, and the colonies formed after 24 hours of incubation at 37°C were counted as colony-forming units (CFU). The experiment was performed in triplicate, and the data were recorded.

[0089] The antibacterial results are shown in Figure 26. E. coli showed more than 90% growth reduction when treated with the superhydrophobic composite material.

[0090] Advantages of the Invention Simple synthesis procedure without purification Know-how / commercial availability to prepare starting materials Fluorine / fluoride-free compositions White, multiple colors available Scalable and cost-effective High water contact angle (152±5°) Tunable sticky or slippery superhydrophobicity Easy to process (drop cast, dip cast, spin cast, or spray cast) Compatible with multiple substrates (glass, metal, plastic, wood, fabric, paper) Multifunctional non-wetting coatings Icephobic, multicolored, fluorescent, conductive superhydrophobic coating Adjustable for multiple uses

Claims

1. 1. A composite material comprising a phosphate of an element selected from the lanthanide series and an organic phosphonic acid, the phosphate is a lanthanum or cerium phosphate or a mixture thereof, and the organic phosphonic acid is selected from the group consisting of alkyl phosphonic acids, aryl phosphonic acids, and aryl phosphonic acids; The alkyl group has the general formula C ｎ H ２ｎ＋１ C ２ ~C ２５ alkyl chains, branched alkyls, or unsaturated alkyls, and the aryl groups include phenyl, benzyl, or heteroaryls, including pyridyl or terpyridinyl; The elemental phosphate and the organic phosphonic acid are in a ratio of 4:1 (w / w); Composite material.

2. 10. A method of making the composite material of claim 1, comprising: (a) activating a phosphate of an element selected from the lanthanide series by acid treatment to obtain an activated phosphate; (b) mixing the activated phosphate obtained in step (a) with an organic phosphonic acid in a ratio in the range of 4:1 (w / w) in an organic solvent to obtain a mixture; (c) stirring the mixture obtained in step (b) at 25-28°C for 72 hours, then centrifuging it twice at 5000 rpm for 10 minutes, and drying it in a hot air oven at 70°C for 12 hours to obtain the composite material; A method comprising:

3. 3. A method of making the composite material of claim 2, wherein the acid treatment of the elemental phosphate is carried out by a process comprising: i. Adding mineral acid and phosphate of said element to water and refluxing at 110°C for 12 hours to obtain a suspension; ii. Cooling the suspension to room temperature and centrifuging at 5000 rpm for 10 minutes; iii. Redisperse in water and centrifuge twice at 5000 rpm for 10 minutes; iv. Redisperse in alcohol and centrifuge at 5000 rpm for 10 minutes to obtain a solid powder; and v. Drying the solid powder in a hot air oven at 70°C for 12 hours to obtain activated phosphate of the element.

4. 4. The method of claim 2 or claim 3, wherein the element from the lanthanide series is selected from lanthanum and cerium.

5. the organic phosphonic acid is selected from the group consisting of alkyl phosphonic acids, aryl phosphonic acids, and aryl phosphonic acids; The alkyl group is represented by the general formula C ｎ H ２ｎ＋１ C ２ ~C ２５ 3. The method of claim 2, wherein the aryl group comprises an alkyl chain, a branched alkyl, or an unsaturated alkyl, and the aryl group comprises phenyl, benzyl, or a heteroaryl, including pyridyl or terpyridinyl.

6. 3. The method of claim 2, wherein the organic solvent is selected from the group consisting of tetrahydrofuran, methanol, ethanol, propanol, isopropanol, pentane, hexane, heptane, octane, decane, cyclohexane, benzene, toluene, acetonitrile, and ether.

7. 4. The method of claim 3, wherein the mineral acid is orthophosphoric acid and the alcohol is selected from propanol and isopropanol.

8. 10. A composition comprising the composite material of claim 1 and an organic solvent, wherein the organic solvent is selected from the group consisting of methanol, ethanol, propanol, isopropanol, pentane, hexane, heptane, octane, decane, cyclohexane, benzene, toluene, acetonitrile, ether, and tetrahydrofuran.

9. 9. The composition of claim 8, comprising a binder selected from polystyrene, the binder to composite ratio being 1:20 (w / w).

10. The composition of claim 8 comprising a colorant selected from dyes and inks.

11. 9. The composition of claim 8, comprising a conductive additive selected from multi-walled carbon nanotubes, wherein the ratio of multi-walled carbon nanotubes to composite is in the range of 1:25 to 1:10 (w / w).

12. 9. The composition of claim 8, comprising an organic or inorganic fluorescent additive, wherein the ratio of fluorescent additive to composite material is in the range of 1:50 to 1:10 (w / w).

13. 10. A water-repellent surface comprising a substrate coated with the composition of claim 8, wherein the substrate is selected from the group consisting of glass, wood, plastic, metal, fabric, and paper.

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