Tianjin University of Science and Technology

Wei Du

Lei Zhang

Na Tang

Songbo Wang

Penggao Cheng

Jianping Zhang

Min Lu

Yangyang Song

Xingxing Shi

Jun Xiang

A superhydrophobic polypropylene porous film, including a polypropylene porous film substrate, titanium dioxide layers and a surface modifier layer, is disclosed. The titanium dioxide layers are deposited on the surface of the polypropylene porous film substrate by atomic deposition technology; a surface modifier is coated on the titanium dioxide layers; hydrophobic bonds are formed between the titanium dioxide layers and the surface modifier layer; the superhydrophobic polypropylene porous film has a water contact angle greater than 150 degrees, a rolling angle less than 10 degrees, an aperture of 0.1-0.4 &#x3bc;m, a porosity of 50%-80%, a tensile strength of 30-50 MPa, and an elongation at break of 10%-30%. The superhydrophobic polypropylene porous film maintains the chemical resistance, rigidity, and porosity of the polypropylene porous film, and has superhydrophobic properties and a good separation effect after working for 80 hours, thus greatly increasing the service life, and reducing operation costs and working costs in a membrane distillation process.

Superhydrophobic polypropylene porous film, preparation method therefor, and method for improving hydrophobicity of polypropylene porous film

A large-particle spherical salt with a particle size of 400-950 &#x3bc;m and a sphericity of 0.5-1.0 is disclosed, which overcomes the existing difficulty in this field for larger particle size as well as higher sphericity. A preparation method of the large-particle spherical salt is also disclosed, wherein in one preparation process, 2% of gum arabic (based on the mass percentage of solute sodium chloride in a sodium chloride saturated solution) is added, and under conditions of an evaporating temperature of 60&#xb0; C. a stirring rate of 350 rpm, and an evaporating time of 8 hours, a large-particle spherical salt with a particle size of 921.593 &#x3bc;m and an average sphericity of 0.904 is successfully prepared. The large-particle spherical salt prepared by the method has a uniform particle size distribution and good appearance, can be combined with other substances, adding some extra value to the salt. Meanwhile, the large-particle spherical salt prepared by the method has a high safety grade (e.g.: food grade) and can be used as edible salt, nutrient salt or foot bath salt.

Large-particle spherical salt and preparation method thereof

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Tianjin, China

Wei Du