Antifouling, antibacterial and drag-reducing agent, and preparation method and application thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NINGBO INST OF MATERIALS TECH & ENG CHINESE ACAD OF SCI
- Filing Date
- 2022-07-15
- Publication Date
- 2026-06-23
Smart Images
Figure CN117432687B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of fluid drag-reducing agent technology, specifically relating to an antifouling and antibacterial drag-reducing agent, its preparation method, and its application. Background Technology
[0002] Water transport, with its advantages of low cost, large carrying capacity, small land occupation, low energy consumption, low pollution, and high efficiency, plays an important role in global trade, represented by ships and vessels, and is hailed as a "green resource." However, the movement of these vessels compresses the water, causing it to flow around the vessel. The viscosity of the water and the waves create fluctuations in the flow field near the vessel, resulting in significant resistance, consuming large amounts of fossil fuels, and emitting large amounts of CO2.
[0003] Currently, superhydrophobic drag reduction technology has broad application prospects, and there are two relatively classic theories regarding its drag reduction mechanism. Navier's wall slip model states that when fluid flows over a superhydrophobic surface, velocity slip occurs in the near-wall region, thereby reducing the fluid's shear stress, effectively increasing the boundary layer thickness, and thus reducing fluid resistance. McHale points out that the microstructure of the superhydrophobic surface traps some air, forming an air layer. When water flows over the superhydrophobic surface, the presence of this air layer transforms the traditional solid-liquid contact into a solid-gas / gas-liquid contact, thereby reducing the significant drag caused by solid-liquid contact. Superhydrophobic drag-reducing coatings have complex compositions, with drag-reducing agents at their core. Summary of the Invention
[0004] The main objective of this invention is to provide an antifouling, antibacterial, and drag-reducing agent, its preparation method, and its application, so as to overcome the shortcomings of the prior art.
[0005] To achieve the aforementioned objectives, the technical solutions adopted in the embodiments of the present invention include:
[0006] This invention provides an antifouling, antibacterial, and drag-reducing agent, comprising dual-charge modified organic nanoparticles, nano-carbon materials, and polydimethylsiloxane; wherein the mass ratio of the dual-charge modified organic nanoparticles, nano-carbon materials, and polydimethylsiloxane in the antifouling, antibacterial, and drag-reducing agent is 1:(1-5):(1-10), and the dual-charge modified organic nanoparticles and nano-carbon materials synergistically generate a multi-level nanostructure.
[0007] Furthermore, the dual-charge modified organic nanoparticles are prepared from polyphenolic compounds and their surfaces are modified by cationic polymers and anionic polymers; wherein the particle size of the dual-charge modified organic nanoparticles is 10-200 nm.
[0008] Further, the nanocarbon material includes at least one of carbon nanotubes and graphene oxide; wherein the carbon nanotubes have a diameter of 2-20 nm and a length-diameter ratio of 50 / 1-200 / 1; and the graphene oxide has a sheet thickness of 0.3-5 nm and a sheet diameter of 0.5-5 μm.
[0009] Further, the antifouling, antibacterial and drag-reducing agent has a water contact angle of 152-156°, a sterilization rate of 98-99%, a bovine serum albumin adsorption amount of 1.2-1.7 mg / g, and a drag-reducing rate of 16-24%.
[0010] The embodiment of the present application also provides a preparation method of the antifouling, antibacterial and drag-reducing agent.
[0011] The organic nanoparticle is provided with double charges.
[0012] The double-charged organic nanoparticle and the nanocarbon material are dispersed in a mixed solvent to obtain a black viscous nanosolution.
[0013] The black viscous nanosolution is mixed with polydimethylsiloxane and fully stirred to obtain the antifouling, antibacterial and drag-reducing agent.
[0014] Further, the preparation method of the antifouling, antibacterial and drag-reducing agent comprises:
[0015] 0.5-5 wt% of a polyphenol compound is dissolved in water and stirred and reacted at 20-60 °C for 1-12 hours to self-polymerize into organic nanoparticles with a particle size of 10-200 nm; then 0.5-5 wt% of a cationic polymer is added and reacted for 5-30 minutes to obtain the cationically modified organic nanoparticle.
[0016] 0.5-5 wt% of an anionic polymer is dissolved in water, the cationically modified organic nanoparticle is added, and fully stirred and reacted for 5-30 minutes to obtain the double-charged organic nanoparticle.
[0017] The polyphenol compound includes any one or combination of multiple of dopamine, catechol and tannic acid.
[0018] The cationic polymer includes any one or combination of multiple of polyethyleneimine, polyacrylamide and polydiallyldimethylammonium chloride.
[0019] The anionic polymer includes any one or combination of multiple of sodium polyacrylate, sodium polystyrene sulfonate and sodium polyacryloyldimethyltaurate.
[0020] Further, the nanocarbon material includes carbon nanotubes and / or graphene oxide.
[0021] The mass ratio of the double-charge modified organic nanoparticle and the nanocarbon material is 5:(1-50).
[0022] Further, the mixed solvent comprises a combination of water and ethanol.
[0023] The volume ratio of the water and the ethanol is 1:1-10.
[0024] Further, the volume ratio of the nanosolution and the polydimethylsiloxane is 1:1-10.
[0025] The application also provides a drag-reducing coating formed by the aforementioned antifouling and antibacterial drag-reducing agent.
[0026] Compared with the prior art, the application has the following beneficial effects:
[0027] The application generates a multi-level nanostructure by cooperation of the organic nanoparticle and the nanocarbon material, and forms the super-hydrophobic nanomaterial by cooperation of the low-surface-energy polydimethylsiloxane (PDMS), the double-charge groups on the surface of the organic nanoparticle have the antifouling and antibacterial effects, and finally the composite drag-reducing agent with the antifouling and antibacterial functions is obtained. BRIEF DESCRIPTION OF DRAWINGS
[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments described in the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.
[0029] Figure 1 The electron microscope graph of the antifouling and antibacterial drag-reducing agent in the embodiment 4 of the present application. DETAILED DESCRIPTION
[0030] The present application will be more fully understood from the following detailed description, taken in connection with the accompanying drawings, in which: Detailed embodiments of the present application are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the present application and can be embodied in various forms. Therefore, specific functional details disclosed herein are not to be interpreted as limiting, but only as a representative basis for teaching one skilled in the art to employ the present application in virtually any appropriate detailed embodiment. The present application is based on and claims priority to U.S. Provisional Patent Application No. 62 / 692, 1 10, filed on June 28, 2018, the disclosure of which is incorporated by reference in its entirety.
[0031] In view of the deficiencies of the prior art, the present inventors have long studied and practiced to propose the technical solution of the present application, which mainly forms a composite drag-reducing agent with antifouling and antibacterial functions through the synergistic effect of double-charge modified organic nanoparticles, nanocarbon materials and polydimethylsiloxane. The technical solution, its implementation process and principles will be further explained and described as follows.
[0032] One aspect of the embodiments of the present application provides an antifouling and antibacterial drag-reducing agent, which comprises double-charge modified organic nanoparticles, nanocarbon materials and polydimethylsiloxane; wherein the mass ratio of the double-charge modified organic nanoparticles, nanocarbon materials and polydimethylsiloxane in the antifouling and antibacterial drag-reducing agent is 1:(1-5):(1-10), and the double-charge modified organic nanoparticles and nanocarbon materials synergistically generate a multi-level nanostructure.
[0033] In some preferred embodiments, the double-charge modified organic nanoparticles are prepared from a polyphenol compound and modified on the surface by a cationic polymer and an anionic polymer; wherein the particle size of the double-charge modified organic nanoparticles is 10-200 nm.
[0034] In some preferred embodiments, the nanocarbon materials can include at least any one of carbon nanotubes and graphene oxide, but are not limited thereto; wherein the carbon nanotubes have a diameter of 2-20 nm and an aspect ratio of 50 / 1-200 / 1; and the graphene oxide has a sheet thickness of 0.3-5 nm and a sheet diameter of 0.5-5 μm.
[0035] In some preferred embodiments, the antifouling and antibacterial drag-reducing agent has a water contact angle of 152-156°, a bactericidal rate of 98-99%, a bovine serum albumin adsorption amount of 1.2-1.7 mg / g and a drag-reducing rate of 16-24%.
[0036] Another aspect of the embodiments of the present application provides a preparation method of the aforementioned antifouling and antibacterial drag-reducing agent, which comprises:
[0037] providing double-charge modified organic nanoparticles;
[0038] dispersing the double-charge modified organic nanoparticles and nanocarbon materials in a mixed solvent to obtain a black viscous nano-solution;
[0039] mixing the black viscous nano-solution with polydimethylsiloxane and fully stirring to obtain the antifouling and antibacterial drag-reducing agent.
[0040] In some preferred embodiments, the preparation method of the antifouling and antibacterial drag-reducing agent comprises:
[0041] 0.5–5 wt% of a polyphenol compound is dissolved in water and stirred at 20–60 °C for 1–12 hours to self-polymerize into organic nanoparticles with a particle size of 10–200 nm; then 0.5–5 wt% of a cationic polymer is added and reacted for 5–30 minutes to obtain cationic modified organic nanoparticles.
[0042] Dissolve 0.5-5 wt% of anionic polymer in water, add the cationic modified organic nanoparticles, and stir the reaction thoroughly for 5-30 minutes to obtain the dual-charge modified organic nanoparticles.
[0043] The polyphenolic compound may include any one or more combinations of dopamine, catechol, tannic acid, etc., but is not limited thereto;
[0044] The cationic polymer may include any one or more combinations of polyethyleneimine, polyacrylamide, polydiallyldimethylammonium chloride, etc., but is not limited thereto;
[0045] The anionic polymer may include any one or a combination of sodium polyacrylate, sodium polystyrene sulfonate, sodium polyacrylamide dimethyl taurate, etc., but is not limited thereto.
[0046] In some preferred embodiments, the nanomaterials include carbon nanotubes and / or graphene oxide;
[0047] The mass ratio of the dual-charge modified organic nanoparticles to the carbon nanomaterials is 5:(1-50).
[0048] In some preferred embodiments, the mixed solvent comprises a combination of water and ethanol;
[0049] The volume ratio of water to ethanol is 1:1 to 10.
[0050] In some preferred embodiments, the volume ratio of the nanosolution to polydimethylsiloxane is 1:1 to 10.
[0051] This invention also provides a drag-reducing coating, which is formed from the aforementioned antifouling, antibacterial, and drag-reducing agent.
[0052] In specific implementation, a method for preparing an antifouling, antibacterial, and drag-reducing composite coating includes the following steps:
[0053] (1) Dissolve 0.5-5 wt% of polyphenol compound in water, stir at 20-60℃ for 1-12 hours, stir thoroughly for 1-12 hours to generate organic nanoparticles; add 0.5-5 wt% cationic polymer, react for 5-30 minutes, centrifuge to obtain cationic modified organic nanoparticles;
[0054] (2) Dissolve 0.5-5 wt% of anionic polymer in water, add the cationic modified organic nanoparticles prepared in step (1) above, stir the reaction thoroughly for 5-30 minutes, centrifuge to obtain double-charge modified organic nanoparticles;
[0055] (3) The double-charge modified organic nanoparticles and nano-carbon materials prepared in step (2) are dispersed in a mixed solvent of water and ethanol to obtain a black viscous nano solution with a concentration of 25 wt%.
[0056] (4) Mix the black viscous nano solution prepared in step (3) with polysiloxane PDMS and stir thoroughly to obtain a composite drag reducer.
[0057] Another aspect of the present invention provides a drag-reducing coating formed from the aforementioned antifouling, antibacterial, and drag-reducing agent.
[0058] In some preferred embodiments, the drag-reducing coating includes a drag-reducing coating for underwater vehicles or water-phase transport pipelines.
[0059] In this invention, organic nanoparticles and carbon nanomaterials synergistically generate multi-level nanostructures, which, in conjunction with low surface energy polydimethylsiloxane (PDMS), form superhydrophobic nanomaterials. The double-charged groups on the surface of the organic nanoparticles have antifouling and antibacterial effects, ultimately resulting in a composite drag-reducing agent with antifouling and antibacterial functions.
[0060] The present invention will now be described in more detail with reference to embodiments, but these embodiments do not constitute a limitation thereof. All modifications that are conceived of or derived from the content disclosed in this invention are considered to be within the scope of protection of this invention.
[0061] Example 1
[0062] (1) Dissolve 0.5wt% dopamine in water and stir at 20℃ for 12 hours to generate organic nanoparticles; add 0.5wt% polyethyleneimine, react for 5 minutes, and centrifuge to obtain cationic modified organic nanoparticles.
[0063] (2) Dissolve 5wt% sodium polyacrylate in water, add the cationic modified organic nanoparticles prepared in step (1) above, stir the reaction thoroughly for 5 minutes, centrifuge to obtain double-charge modified organic nanoparticles.
[0064] (3) The double-charge modified organic nanoparticles and carbon nanotubes prepared in step (2) are dispersed in a mixed solvent of water and ethanol (volume ratio 1:1) to obtain a black viscous nano solution with a concentration of 25wt%.
[0065] (4) Mix the black viscous nano solution prepared in step (3) with polysiloxane PDMS (volume ratio 1:1) and stir thoroughly to obtain a composite drag reducer with antifouling and antibacterial functions.
[0066] The composite drag-reducing agent was vacuum dried at 60℃ to obtain a black powder with a 98% bactericidal rate against Escherichia coli, an adsorption capacity of 1.5 mg / g of bovine serum albumin, and a water contact angle of 156°. The drag-reducing agent was applied to the wall of an Ubbelohde viscometer before and after application, and the change in time taken for deionized water to flow through the Ubbelohde viscometer (from scale line m1 to scale line m2) was measured. The drag reduction rate was calculated to be 16%.
[0067] Example 2
[0068] (1) Dissolve 5 wt% catechol in water and stir at 60°C for 1 hour to generate organic nanoparticles; add 5 wt% polyacrylamide, react for 30 minutes, and centrifuge to obtain cationic modified organic nanoparticles.
[0069] (2) Dissolve 0.5wt% sodium polystyrene sulfonate in water, add the cationic modified organic nanoparticles prepared in step (1) above, stir the reaction thoroughly for 30 minutes, centrifuge to obtain double-charge modified organic nanoparticles.
[0070] (3) The double-charge modified organic nanoparticles and graphene oxide prepared in step (2) are dispersed in a mixed solvent of water and ethanol (volume ratio of 1:10) to obtain a black viscous nano solution with a concentration of 25wt%.
[0071] (4) Mix the black viscous nano solution prepared in step (3) with polysiloxane PDMS (volume ratio of 1:10) and stir thoroughly to obtain a composite drag reducer with antifouling and antibacterial functions.
[0072] The composite drag-reducing agent was vacuum dried at 60℃ to obtain a black powder with a 99% bactericidal rate against Escherichia coli, an adsorption capacity of 1.2 mg / g of bovine serum albumin, and a water contact angle of 152°. The drag-reducing agent was applied to the wall of an Ubbelohde viscometer before and after application. The change in time taken for deionized water to flow through the Ubbelohde viscometer (from scale line m1 to scale line m2) was measured, and the drag reduction rate was calculated to be 24%.
[0073] Example 3
[0074] (1) Dissolve 3wt% tannic acid in water and stir at 50℃ for 10 hours to generate organic nanoparticles; add 2wt% polydiallyldimethylammonium chloride, react for 10 minutes, and centrifuge to obtain cation-modified organic nanoparticles.
[0075] (2) Dissolve 4wt% sodium polyacrylamide dimethyl taurate in water, add the cationic modified organic nanoparticles prepared in step (1) above, stir the reaction thoroughly for 15 minutes, centrifuge to obtain double-charge modified organic nanoparticles.
[0076] (3) The double-charge modified organic nanoparticles and graphene oxide prepared in step (2) are dispersed in a mixed solvent of water and ethanol (volume ratio of 1:5) to obtain a black viscous nano solution with a concentration of 25wt%.
[0077] (4) Mix the black viscous nano solution prepared in step (3) with polysiloxane PDMS (volume ratio of 1:4) and stir thoroughly to obtain a composite drag reducer with antifouling and antibacterial functions.
[0078] The composite drag-reducing agent was vacuum dried at 60℃ to obtain a black powder with a 99% bactericidal rate against Escherichia coli, an adsorption capacity of 1.6 mg / g of bovine serum albumin, and a water contact angle of 153°. The drag-reducing agent was applied to the wall of an Ubbelohde viscometer before and after application. The change in time taken for deionized water to flow through the Ubbelohde viscometer (from scale line m1 to scale line m2) was measured, and the drag reduction rate was calculated to be 19%.
[0079] Example 4
[0080] (1) Dissolve 3 wt% dopamine in water and stir at 50°C for 12 hours to generate organic nanoparticles; add 4 wt% polyethyleneimine, react for 15 minutes, and centrifuge to obtain cationic modified organic nanoparticles.
[0081] (2) Dissolve 4wt% sodium polyacrylamide dimethyl taurate in water, add the cationic modified organic nanoparticles prepared in step (1) above, stir the reaction thoroughly for 20 minutes, centrifuge to obtain double-charge modified organic nanoparticles.
[0082] (3) The double-charge modified organic nanoparticles, carbon nanotubes and graphene oxide prepared in step (2) are dispersed in a mixed solvent of water and ethanol (volume ratio of 1:4) to obtain a black viscous nano solution with a concentration of 25wt%.
[0083] (4) Mix the black viscous nanosolution prepared in step (3) with polysiloxane PDMS (volume ratio 1:3), and stir thoroughly to obtain a composite drag-reducing agent with antifouling and antibacterial functions, such as... Figure 1 As shown, the prepared composite drag reducer is composed of nanomaterials of different sizes.
[0084] The composite drag-reducing agent was vacuum dried at 60℃ to obtain a black powder with a 99% bactericidal rate against Escherichia coli, an adsorption capacity of 1.7 mg / g of bovine serum albumin, and a water contact angle of 154°. The drag-reducing agent was applied to the wall of an Ubbelohde viscometer before and after application. The change in time taken for deionized water to flow through the Ubbelohde viscometer (from scale line m1 to scale line m2) was measured, and the drag reduction rate was calculated to be 17%.
[0085] Comparative Example 1: This comparative example is basically the same as Example 4, except that no catechin compounds are added.
[0086] The composite drag-reducing agent was vacuum dried at 60℃ to obtain a black powder. Its bactericidal rate against *E. coli* was 2%, its bovine serum albumin adsorption capacity was 5.6 mg / g, and its water contact angle was 112°. Before and after the drag-reducing agent was applied to the wall of an Ubbelohde viscometer, the change in time taken for deionized water to flow through the Ubbelohde viscometer (from scale line m1 to scale line m2) was measured, and the drag reduction rate was calculated to be 0.3%.
[0087] Comparative Example 2: This comparative example is basically the same as Example 4, except that no cationic polymer is added.
[0088] The composite drag-reducing agent was vacuum dried at 60℃ to obtain a black powder. Its bactericidal rate against *E. coli* was 1%, its bovine serum albumin adsorption capacity was 7.6 mg / g, and its water contact angle was 114°. Before and after the drag-reducing agent was applied to the wall of an Ubbelohde viscometer, the change in time taken for deionized water to flow through the Ubbelohde viscometer (from scale line m1 to scale line m2) was measured, and the drag reduction rate was calculated to be 0.4%.
[0089] Comparative Example 3: This comparative example is basically the same as Example 4, except that no anionic polymer is added.
[0090] The composite drag-reducing agent was vacuum dried at 60℃ to obtain a black powder. Its bactericidal rate against *E. coli* was 1%, its bovine serum albumin adsorption capacity was 6.4 mg / g, and its water contact angle was 109°. Before and after the drag-reducing agent was applied to the wall of an Ubbelohde viscometer, the change in time taken for deionized water to flow through the Ubbelohde viscometer (from scale line m1 to scale line m2) was measured, and the drag reduction rate was calculated to be 1%.
[0091] Comparative Example 4: This comparative example is basically the same as Example 4, except that no carbon nanomaterials are added.
[0092] The composite drag-reducing agent was vacuum dried at 60℃ to obtain a light brown powder. It exhibited a 56% bactericidal rate against *E. coli*, an adsorption capacity of 4.6 mg / g of bovine serum albumin, and a water contact angle of 121°. Before and after the drag-reducing agent was applied to the wall of an Ubbelohde viscometer, the change in time taken for deionized water to flow through the Ubbelohde viscometer (from scale line m1 to scale line m2) was measured, and the drag reduction rate was calculated to be 2%.
[0093] Comparative Example 5: This comparative example is basically the same as Example 4, except that polysiloxane PDMS is not added.
[0094] The composite drag-reducing agent was vacuum dried at 60℃ to obtain a black powder. It exhibited a 61% bactericidal rate against *E. coli*, an adsorption capacity of 110 mg / g of bovine serum albumin, and a water contact angle of 36°. Before and after the drag-reducing agent was applied to the wall of an Ubbelohde viscometer, the change in time taken for deionized water to flow through the Ubbelohde viscometer (from scale line m1 to scale line m2) was measured, and the drag reduction rate was calculated to be 0%.
[0095] As can be seen from Comparative Examples 1-5 and Example 4, the drag-reducing agent composed of dual-charge modified organic nanoparticles, nano-carbon materials, and polydimethylsiloxane exhibits significant antifouling and antibacterial properties and excellent drag-reducing effect. Without any of the components, it is impossible to obtain an antifouling, antibacterial, and drag-reducing agent with excellent performance. Furthermore, the inventors of this invention also conducted experiments using other raw materials and conditions listed in this specification, referring to the methods in Examples 1-4, and similarly obtained a composite drag-reducing agent with antifouling and antibacterial properties.
[0096] Although the invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions, and / or additions can be made without departing from the spirit and scope of the invention, and that elements of the embodiments can be substituted with substantially equivalents. Furthermore, many modifications can be made without departing from the scope of the invention to adapt particular situations or materials to the teachings of the invention. Therefore, this invention is not intended to be limited to the specific embodiments disclosed for carrying out the invention, but rather is intended to encompass all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated otherwise, any use of the terms first, second, etc., does not indicate any order or importance, but is used to distinguish one element from another.
Claims
1. A stain-resistant, antibacterial, and drag-reducing agent, characterized in that, The product comprises dual-charge modified organic nanoparticles, nano-carbon materials, and polydimethylsiloxane; wherein the mass ratio of the dual-charge modified organic nanoparticles, nano-carbon materials, and polydimethylsiloxane in the antifouling, antibacterial, and drag-reducing agent is 1:(1-5):(1-10), the dual-charge modified organic nanoparticles and nano-carbon materials synergistically generate a multi-level nanostructure, the dual-charge modified organic nanoparticles are prepared from polyphenolic compounds and their surfaces are modified by cationic polymers and anionic polymers, the water contact angle of the antifouling, antibacterial, and drag-reducing agent is 152-156°, the bactericidal rate is 98-99%, the bovine serum albumin adsorption capacity is 1.2-1.7 mg / g, and the drag reduction rate is 16-24%.
2. The antifouling, antibacterial, and drag-reducing agent according to claim 1, characterized in that: The particle size of the dual-charge modified organic nanoparticles is 10~200 nm.
3. The antifouling, antibacterial, and drag-reducing agent according to claim 1, characterized in that: The nanomaterials include at least one of carbon nanotubes and graphene oxide; wherein the carbon nanotubes have a diameter of 2-20 nm and an aspect ratio of 50 / 1-200 / 1; and the graphene oxide sheets have a thickness of 0.3-5 nm and a diameter of 0.5-5 μm.
4. The method for preparing the antifouling, antibacterial, and drag-reducing agent according to any one of claims 1-3, characterized in that, include: Dissolve 0.5–5 wt% of a polyphenol compound in water and stir at 20–60 °C for 1–12 hours to self-polymerize into organic nanoparticles with a particle size of 10–200 nm; then add 0.5–5 wt% of a cationic polymer and react for 5–30 minutes to obtain cationic modified organic nanoparticles. Dissolve 0.5-5 wt% of the anionic polymer in water, add the cationic modified organic nanoparticles, and stir the reaction thoroughly for 5-30 minutes to obtain the dual-charge modified organic nanoparticles. Organic nanoparticles and carbon nanomaterials modified with dual charges were dispersed in a mixed solvent to obtain a black viscous nanosolution. The black, viscous nanosolution is mixed with polydimethylsiloxane and stirred thoroughly to obtain the antifouling, antibacterial, and drag-reducing agent.
5. The method for preparing the antifouling, antibacterial, and drag-reducing agent according to claim 4, characterized in that: The polyphenolic compounds include any one or more combinations of dopamine, catechol, and tannic acid; The cationic polymer includes any one or more combinations of polyethyleneimine, polyacrylamide, and polydiallyldimethylammonium chloride. The anionic polymer includes any one or a combination of sodium polyacrylate, sodium polystyrene sulfonate, and sodium polyacrylamide dimethyl taurate.
6. The method for preparing the antifouling, antibacterial, and drag-reducing agent according to claim 4 or 5, characterized in that: The nanomaterials include carbon nanotubes and / or graphene oxide; The mass ratio of the dual-charge modified organic nanoparticles to the carbon nanomaterials is 5:(1~50).
7. The method for preparing the antifouling, antibacterial, and drag-reducing agent according to claim 4 or 5, characterized in that: The mixed solvent includes a combination of water and ethanol; The volume ratio of water to ethanol is 1:1 to 10.
8. The method for preparing the antifouling, antibacterial, and drag-reducing agent according to claim 4 or 5, characterized in that: The volume ratio of the nanosolution to polydimethylsiloxane is 1:1 to 10.
9. A drag-reducing coating formed from the antifouling, antibacterial, and drag-reducing agent according to any one of claims 1-3.