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CN-121975391-A - Anticorrosion and efficient water-collecting coating and preparation method thereof

CN121975391ACN 121975391 ACN121975391 ACN 121975391ACN-121975391-A

Abstract

The invention discloses an anti-corrosion and high-efficiency water-collecting coating and a preparation method thereof, wherein the coating is composed of organosilicon modified epoxy composite resin and graphene micro-nano filler with a two-dimensional structure, the coating body has elasticity, the surface layer also contains hydrophobic modified SiC filler, the content of SiC is in gradient distribution gradually reduced from the surface to the inside, the surface of the coating has super-hydrophobic property, the contact angle to water is more than 152 DEG, the surface super-hydrophobic gradient layer is prepared by spraying hydrophobic modified SiC particles on the surface of the coating which is solidified to a certain viscosity value by utilizing a powder spraying mode, the coating is suitable for metal substrates such as carbon steel, stainless steel, copper, aluminum and the like, and the coating has excellent anti-corrosion, wear-resisting, heat conduction, cold-heat shock resistance and super-hydrophobic property, and is favorable for realizing the long-term high-efficiency water-collecting aim of desulfurization flue gas water recovery heat exchange equipment.

Inventors

  • LIU GUICHANG
  • Ren Yine
  • LIU HUI
  • LIU HONGGANG
  • YU SHENGLI
  • YANG ZHENGQING
  • WANG LIDA
  • SUN WEN

Assignees

  • 大连理工大学
  • 西安热工研究院有限公司
  • 锡林郭勒热电有限责任公司

Dates

Publication Date
20260505
Application Date
20260115

Claims (10)

  1. 1. The anticorrosive and efficient water collecting coating is characterized in that the coating body consists of organosilicon modified epoxy composite resin and graphene micro-nano sheet filler, wherein the content of the graphene micro-nano sheet is 0.5-5wt%, the surface layer of the coating also contains hydrophobic modified SiC filler, the content of the SiC filler in the surface area of the coating is 8-25 wt%, and the coating is in a gradient decreasing structure from the surface to the inner.
  2. 2. The anti-corrosion and efficient water-collecting coating as claimed in claim 1, wherein the mass ratio of the epoxy resin to the organic silicon resin in the organic silicon modified epoxy composite resin is 9:1-2:1, the molecular weight of the organic silicon resin is 500-4000, the viscosity of the epoxy resin is 10-16 Pa s, and the viscosity of the organic silicon modified epoxy composite resin is 5-10 Pa s.
  3. 3. The anti-corrosion and efficient water-collecting coating as claimed in claim 1, wherein the surface of the coating has superhydrophobicity, the water contact angle is more than or equal to 160 DEG, and the pencil hardness of the surface is more than or equal to 6H.
  4. 4. A corrosion-resistant and water-collecting coating according to claim 1, wherein the particle size of the hydrophobically modified SiC filler is 50-nm μm.
  5. 5. The method for preparing the anti-corrosion and high-efficiency water-collecting coating according to any one of claims 1 to 4, which is characterized by comprising the following preparation steps: Preparing a graphene composite coating: Adding graphene micro-nano filler into composite resin, wherein the content of the graphene micro-nano filler is 0.5-5 wt% of the weight of the composite resin, stirring at the rotating speed of 800-1200 rpm until the graphene micro-nano filler is uniformly dispersed, removing bubbles under a vacuum condition, finally adding a3, 5-diethyl toluene diamine curing agent, wherein the content of the graphene micro-nano filler is 20-30 wt% of the epoxy resin, stirring to uniformly disperse the graphene micro-nano filler, and then coating the graphene micro-nano filler on the pretreated metal surface to prepare a composite coating, wherein the thickness of the coating is 30-200 mu m; preparing a surface super-hydrophobic gradient coating: And (3) curing the composite coating containing the graphene nano-sheet filler at room temperature, when the viscosity of the composite coating reaches 10-20 Pa.s, spraying the hydrophobically modified silicon carbide micro-nano particles at the spraying pressure of 0.3-0.5. 0.5 MPa to form a surface gradient layer, and standing for 5-15 min to enable the particles to self-assemble.
  6. 6. The method of claim 5, wherein the pretreatment of the metal surface is performed by cleaning, polishing, degreasing, and drying the metal substrate surface.
  7. 7. The preparation method of the hydrophobic modified silicon carbide micro-nano particles according to claim 5, wherein a certain amount of silicon carbide micro-nano particles are added into ethanol, the ratio of the silicon carbide micro-nano particles to the ethanol to the hydrophobic modifier is 1 g:200: 200 mL:0.1: 0.1 g, the mixture is stirred and reacted at the speed of 300-800 rpm at the temperature of 20-60 ℃ for 1-6 h, and the hydrophobic modified silicon carbide micro-nano particles are obtained after centrifugation, cleaning and drying.
  8. 8. The preparation method according to claim 5, wherein the preparation of the organosilicon modified epoxy composite resin is, Taking a certain amount of epoxy resin, firstly adding a diluent according to 3-10 wt% of the mass of the epoxy resin, stirring at the room temperature at the speed of 300-800 rpm for 10-30 min, then adding a silane coupling agent and an organic silicon resin, wherein the molar ratio of the silane coupling agent to the organic silicon resin is 3:1, finally adding 100-500 mu L of catalyst, increasing the rotating speed to 800-1200 rpm, increasing the temperature to 45-65 ℃, and reacting for 1-3 h to obtain the composite resin.
  9. 9. The method of manufacturing according to claim 8, wherein: the organic silicon resin is hydroxyl-terminated polydimethylsiloxane, and the molecular weight of the organic silicon resin is 500-4000; the epoxy resin is E51 type or E44 type; The diluent required in the preparation process is ethyl acetate or butyl acetate; The catalyst is dibutyl tin dilaurate; the silane coupling agent is aminopropyl triethoxysilane (KH 550); the curing agent is 3, 5-diethyl toluene diamine.
  10. 10. The process according to claim 5 to 9, wherein the hydrophobically modified SiC filler is 1H,2H or 2H Perfluorodecyl triethoxysilane.

Description

Anticorrosion and efficient water-collecting coating and preparation method thereof Technical Field The invention relates to a functional coating, which has the functions of corrosion prevention and high-efficiency water collection, is mainly used for a desulfurization flue gas water recovery heat exchanger, and can also be used in other chemical fields. Background In order to reduce environmental pollution, a desulfurization system is arranged before the emission of the coal-fired flue gas, and the wet limestone-gypsum desulfurization technology is the most widely used desulfurization method due to high efficiency and low cost. The desulfurized flue gas contains a small amount of SOx, dust and a large amount of steam, wherein the concentration ratio of the steam is about 12-16%, and the flue gas has important significance for recovering water from the flue gas and simultaneously recovering waste heat in water resource shortage areas in the western and northern parts of China. The condensing heat exchanger is used as main equipment for recovering water and waste heat in flue gas, and the water yield and the service life of the condensing heat exchanger are two key indexes for evaluating whether the condensing heat exchanger has advanced. The heat exchangers made of traditional metals and alloys thereof are easy to corrode in the corrosive desulfurization flue gas environment containing SOx, so that the heat transfer efficiency is reduced, the service life is shortened, and safety and environmental risks are brought. Coatings are a common type of protective means. However, in desulfurization flue gas, the coating not only faces the corrosion of corrosive media, but also suffers from the challenges of cold and hot impact, dust scour and abrasion and the like, and the traditional common resin coating is difficult to play a long-acting protective role in the complex environment, for example, the coating is easy to crack and fall off due to insufficient elasticity under the cold and hot alternating working condition because the coating has poor compactness, the dust scour leads to the accelerated failure of the coating, and in addition, the heat transfer efficiency of the heat exchanger is reduced because of the larger heat resistance of the coating. Disclosure of Invention The invention aims to develop a composite coating which is suitable for high-efficiency water collection and long-acting protection of heat exchange equipment for recycling desulfurization flue gas water, and improves the heat transfer efficiency of a heat exchanger by improving the heat conductivity and the surface hydrophobicity of the coating, and meanwhile, improves the service life of the coating by increasing the compactness, the elasticity and the surface hardness of the coating so as to meet the long-term and high-efficiency water collection requirement in a complex desulfurization flue gas environment. The technical scheme adopted by the invention is as follows: The anticorrosion and efficient water-collecting coating consists of organosilicon modified epoxy composite resin and graphene micro-nano sheet stuffing, wherein the content of the graphene micro-nano sheet is 0.5-5wt%, the coating has elasticity, the surface layer of the coating also contains hydrophobic modified SiC stuffing, the content of the SiC stuffing in the surface area of the coating is 8-25 wt%, and the coating is in a gradient decreasing structure from the surface to the inner. The contact angle of the coating to water is more than or equal to 160 degrees, the surface hardness is more than or equal to 6H. Further, the mass ratio of the epoxy resin to the organic silicon resin in the organic silicon modified epoxy composite resin is 9:1-2:1, the molecular weight of the organic silicon resin is 500-4000, and the viscosity of the epoxy resin is 10-16 Pa s, preferably 13 Pa s. The viscosity of the composite resin is 5-10 Pa.s. Further, in the technical scheme, the content of the graphene nano sheets is 0.5-5 wt%. Further, in the above technical scheme, the particle size of the hydrophobically modified SiC nanoparticles distributed on the surface of the coating is 50 nm-1 μm, preferably 50 nm, and the SiC content of the coating surface is 8-25 wt%. The hydrophobically modified silicon carbide filler is silicon carbide particles modified by a perfluoroalkyl silane hydrophobically modifier. Alternatively, the hydrophobically modified SiC nanoparticles may be replaced with other hard particles that are hydrophobically modified, such as SiO 2、Al2O3, WC, etc. Further, the surface super-hydrophobic gradient layer is prepared by spraying hydrophobic modified SiC nano particles on the surface of a coating solidified to a certain viscosity value in a powder spraying mode, and the preparation method comprises the following steps: preparation of graphene composite coating Adding graphene micro-nano filler into composite resin, wherein the content of the graphene micro-nano filler