Liquid-phase deposition-impregnation preparation method of micro/nano low-surface hydrophobic composite anti-scaling coating

Abstract

The invention discloses a liquid-phase deposition-impregnation preparation method of a micro / nano low-surface hydrophobic composite anti-scaling coating, which includes the following steps of (a) grinding, polishing and cleaning a stainless steel substrate to be deposited; (b) treating the stainless steel substrate with diluted acid ultrasonically, forming a coarse structural layer on the surface of the stainless steel substrate, washing and cleaning the surface with distilled water and then drying the same at the room temperature; (c) placing the stainless steel substrate with the surface having the coarse structural layer into mixed solution in a constant-temperature water bath with the temperature ranging from 20 degrees to 80 degrees to prepare a substrate chip by means of deposition; (e) sintering the dried substrate chip in a resistance furnace under protection of N2 and taking the sintered substrate chip out of the resistance furnace after reducing the temperature of the sintered substrate chip to the normal temperature; (f) impregnating the substrate chip with a TiO2 coating into fluorosilane hydrophobic solution of the mass concentration ranging from 0.1% to3%, taking out the same and then drying in an oven with the temperature ranging from 100 DEG C to 200 DEG C. The coating prepared by the method is thin, compact, uniform and free of cracking and can be combined with the substrate firmly.

Description

technical field [0001] The invention relates to a method for preparing a nanometer film surface with low surface energy, in particular to a method for preparing a hydrophobic nanometer-thick film surface on a stainless steel surface by using a liquid phase deposition method combined with an immersion method. Background technique [0002] At present, there are fouling problems in the operation of heat exchange equipment. The deposition of dirt leads to increased heat exchange resistance and lower heat exchange efficiency, resulting in energy waste and equipment wear, and even threatens the safe operation of equipment. In order to reduce the deposition of dirt, mechanical cleaning or chemical cleaning agents are used to remove scale, which generally has the problems of high cost and secondary pollution. Studies have shown that reducing the surface energy of heat transfer surfaces can significantly reduce fouling formation. The researchers adopted surface treatment technology ...

AI Technical Summary

Problems solved by technology

Chinese patent 200710168732.1 provides a method for preparing titanium dioxide coated capillary column by liquid phase deposition method. Using ammonium fluorotitanate as raw material, a titanium dioxide film layer is deposited on the inner wall of quartz capillary by liquid phase deposition method, and is used for the separation of proteins and polypeptides , because the capillary column is not resistant to high temperature, the sintering temperature of the film is low, and the bond between the film and the capillary is not strong, so it is difficult to apply to the fields of heat transfer and dirt

Chinese patent ZL 200710060653.9 reports a method of preparing a nanometer-thick titanium dioxide film on a copper substrate by liquid phase deposition. Not resistant to high temperature sintering, coating sintering temperature is low

Chinese patent CN 101760737A reports the preparation of dense micro-nano TiO on stainless steel substrates by liquid phase deposition 2 Coating, but the surface energy of the coating is high and the hydrophobicity is not very good

The relevant documents on improving the hydrophobicity of the film are: Akamatsu Y et al. (Akamatsu Y et al. Thin Solid Films, 2001, 389: 138-145) studied the principle of the hydrolysis process of heptadecafluorodecyltrimethoxysilane, and prepared anti- Foggy automotive glass improves the hydrophobicity of the glass, but the prepared film is not heat-treated, so it is difficult to apply to the field of heat transfer

Chinese patent ZL 02115493.7 discloses the method for preparing hydrophobic liquid and manufacturing hydrophobic glass with tridecafluorooctyl trioxysilane, tetraethyl orthosilicate, hydrochloric acid, deionized water and hydrochloric acid, and the reported hydrophobic glass The contact angle can reach 90-100°, but this method is more suitable for surface modification of glass before installation. However, after the glass is coated with hydrophobic liquid, it needs to be heat treated at 200-350°C. This method is difficult to use after installation. and glass coating during use

Chinese patent CN1211500C uses ethyl acetoacetate, ethanol, water and tetrabutyl titanate to prepare TiO 2 Sol, TiO on Metal Substrates by Pulling Method 2 film, the surface of the film was treated with fluorosilylation to improve the TiO 2 The hydrophobicity of the film reduces the corrosion current of the metal by about 3 orders of magnitude; although the film prepared by the sol-gel method has a good anti-corrosion effect, the film is thick and easy to crack, and the TiO 2 The preparation method of the coating is more complicated

Chinese patent CN100429009C reports a method for forming a hydrophobic transparent film on the surface of substrates such as glass, ceramics, metal or paint, modifying the surface of the substrate with aluminum oxide, silicon oxide or titanium oxide, and using a hydroxylated fluorosilane solution Prepare a hydrophobic film with a thickness of several to tens of nanometers, and the water contact angle of the prepared film is 105-111°, but when using titanium oxide sol to treat the surface of the metal substrate, no sintering technology is used, which will make the film Poor combination with metal substrates, difficult to apply to boiling heat transfer and fouling fields

Throughout the literature, there is no report on the use of low-energy fluorosilane hydrophobic composite coatings for micro-nano enhanced boiling heat transfer and anti-fouling methods.

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