Super-hydrophobic coating layer used for oil-water separation and having hierarchical structure, super-hydrophobic material thereof, and preparation method of material

Abstract

The invention belongs to the technical field of preparation of nano-materials, and relates to a super-hydrophobic oil-water separation material containing a hierarchical structure coating layer. The hierarchical structure coating layer is formed by a layer of solid spherical SiO2 nano-particles with the particle size of 10-50nm and the particle size of 70-500nm, and the surface of the coating layer is provided with a layer of a low surface energy substance. The coating layer is obtained through layer-by-layer electrostatic in situ self-assembling, and can be used on stainless steel wire nets, stainless steel fiber sintered felts and other metal net products. The water contact angle of the stainless steel sintered nets coated with the hierarchical structure coating layer can exceed 150DEG. The material is simple to prepare, can be used to process filter core materials in coalescence separators, can be repeatedly used in oil-water separation, especially has a good separation effect on an oil-water emulsion, and can be widely used in oil-containing sewage treatment in the petroleum chemical industry, the metallurgy industry, the chemical engineering industry, the beverage industry, the food industry and the pharmacy industry.

Description

technical field [0001] The invention belongs to the technical field of nanomaterial preparation, in particular to a superhydrophobic coating with a hierarchical rough structure for oil-water separation, a superhydrophobic material containing the coating and a preparation method thereof. Background technique [0002] Petroleum exploration, petrochemical, chemical, transportation, mechanical processing, textile, leather, medicine, food manufacturing and other industries discharge a large amount of oily sewage every day. According to reports, about 5 to 10 million tons of oil flow into the ocean through various channels in the world every year. Due to the high chemical oxygen demand (COD) and large oil content of oily sewage, it has seriously polluted the environment, especially the oil spills that have occurred in recent years, which have caused great harm to the environment on which we live and human health. Effective separation and treatment of oily sewage has both scientif...

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Problems solved by technology

The thickness of the coating obtained by spraying is not easy to control, which will cause uneven pore size, and cannot be applied to metal meshes above 200 mesh

CN100344341C discloses a kind of fully utilizing perfluoroalkyl siloxane to form a gel film. Although the performance is better, a large amount of fluorine-containing chemical substances are required, and the cost and pollution are relatively large.

CN1907549A discloses a stainless steel sintered polytetrafluoroethylene film and its preparation process. After impregnated with polytetrafluoroethylene emulsion and sintered three to four times, a porous film is formed on the surface of the stainless steel mesh. This method is difficult to control the pore size, and polytetrafluoroethylene It needs to be melted and formed at a temperature of more than 380 degrees, and has higher requirements on the substrate

CN101708384A discloses a preparation method of an oil-water separation net, which uses chemical etching technology to obtain nanoscale microscopic protrusions to obtain a super-hydrophobic oil-water separation net. The net will not block the mesh and has a high pore permeability, but requires Acid etching the substrate to obtain roughness, which reduces the mechanical strength of the woven mesh and also causes a lot of environmental pollution

The invention is to first deposit SiO with a particle size of 10-50 nm on a flat glass substrate. 2 particles, and then deposit a layer of 70-200nm SiO 2 Particles, which can only be applied on flat glass to achieve super-hydrophilic self-cleaning and anti-fog anti-reflection and anti-reflection coatings, which cannot be directly applied to porous materials to achieve oil-water separation

[0008] At present, although various oil-water separation membranes have been successfully prepared, it is still difficult to separate a small amount of oil in a large amount of water, especially emulsified oil. How to treat sewage containing emulsified oil in a green, environmentally friendly, and low-energy technical challenge

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