Durable hydrophilic-super-hydrophobic bipolar self-cleaning composite film, and preparation method therefor

Patent metadata

Field	Value
Publication number	US-11149152-B2
Application number	US-201716309357-A
Country	US
Kind code	B2
Filing date	Oct 24, 2017
Priority date	Jan 18, 2017
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

The present invention belongs to the field of super-hydrophobic surface technology, and discloses a durable hydrophilic-super-hydrophobic bipolar self-cleaning composite film and a preparation method therefor. The preparation method is as follows: adding an epoxy silane coupling agent into an organic solvent; after stirring and mixing well, adding an amine curing agent and distilled water to the mixture; stirring and adding micron-sized solid particles and hydrophobic nano silicon dioxide particles; continuing stirring to obtain a hydrophilic layer solution; adding a hydrophobic modifier and a hydrophilic nano silicon dioxide particles into the solvent to obtain a hydrophobic layer solution; coating a pretreated substrate surface with the hydrophilic layer solution, and performing heating treatment at 60° C. to 80° C. for 10-50 min; then coating the surface with the hydrophobic layer solution, and performing heating treatment at 100° C. to 140° C. for 50-90 min to obtain the durable hydrophilic-super-hydrophobic bipolar self-cleaning composite film. The preparation method of the present invention is simple, and the super-hydrophobic surface of the obtained composite film has strong mechanical durability and a good industrial application prospect.

First claim

What is claimed is:

1. A method for preparing a durable hydrophilic-super-hydrophobic bipolar self-cleaning composite film, characterized in that this method comprises the following steps:
(1) adding an epoxy silane coupling agent into an organic solvent; after stirring and mixing well, adding an amine curing agent and distilled water; stirring for about 20-50 min and adding micron-sized solid particles and hydrophobic nano SiO 2 particles; continuing stirring for about 1-3 hours to obtain a hydrophilic layer solution;
(2) adding a hydrophobic modifier and a hydrophilic nano SiO 2 particles into a second solvent, and stirring and mixing to obtain a hydrophobic layer solution; and
(3) coating a pretreated substrate surface with the hydrophilic layer solution prepared in the step (1), performing heating treatment at about 60° C. to 80° C. for about 10-50 minutes; coating the surface with the hydrophobic layer solution obtained in the step (2), performing heating treatment at about 100° C. to 140° C. for about 50-90 minutes.

2. The method for preparing a durable hydrophilic-super-hydrophobic bipolar self-cleaning composite film according to claim 1 , characterized in that: the epoxy silane coupling agent in the step (1) refers to an organosilane compound containing an epoxy group and at least one group selected from a methoxy group, an ethoxy group, a chloro group, and an acetoxy group; the organic solvent is at least one of methanol, ethanol, and isopropyl alcohol.

3. The method for preparing a durable hydrophilic-super-hydrophobic bipolar self-cleaning composite film according to claim 1 , characterized in that: the amine curing agent described in the step (1) is at least one of octadecylamine, ethylenediamine, hexamethylenediamine, diethylenetriamine, and triethylenetetramine.

4. The method for preparing a durable hydrophilic-super-hydrophobic bipolar self-cleaning composite film according to claim 1 , characterized in that: the micron-sized solid particles in the step (1) are at least one of micron-sized silicon dioxide, aluminum oxide, zinc oxide, and corundum.

5. The method for preparing a durable hydrophilic-super-hydrophobic bipolar self-cleaning composite film according to claim 1 , characterized in that: the parts by weight of each material in the step (1) are as follows: about 2-5 parts of the epoxy silane coupling agent, about 20-50 parts of organic solvent, about 0.5-3 parts of the amine curing agent, about 0.5-3 parts of the distilled water, about 0-0.5 part of the micron-sized solid particles, and about 0.2-0.6 part of the hydrophobic nano SiO 2 particles.

6. The method of preparing a durable hydrophilic-super-hydrophobic bipolar self-cleaning composite film according to claim 1 , characterized in that: the temperature is maintained in the range about 25° C. to 40° C. during the preparation of the hydrophilic layer solution in the step (1).

7. The method for preparing a durable hydrophilic-super-hydrophobic bipolar self-cleaning composite film according to claim 1 , characterized in that: the hydrophobic modifier in the step (2) is at least one of hexamethyldisilazane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, methyltrimethoxysilane, and methyltriethoxysilane; the second solvent is at least one of methanol, ethanol, propylene glycol, isopropanol, isobutanol, butanol, glycerin, and tetrahydrofuran.

8. The method for preparing a durable hydrophilic-super-hydrophobic bipolar self-cleaning composite film according to claim 1 , characterized in that: the parts by weight of each material in the step (2) are as follows: about 2-6 parts of the hydrophobic modifier, about 10-50 parts of the second solvent, and about 0.05-0.3 part of the hydrophilic nano SiO 2 particles.

9. The method for preparing a durable hydrophilic-super-hydrophobic bipolar self-cleaning composite film according to claim 1 , characterized in that: the substrate in the step (3) is selected from glass, iron, copper, aluminum, and cement; the pretreatment comprises ultrasonic cleaning in a mixture of ethanol and acetone followed by washing with deionized water and drying.

10. A durable hydrophilic-super-hydrophobic bipolar self-cleaning composite film, made in accordance with method of claim 1 .

Assignees

• Univ South China Tech

Inventors

• Zhang Lizhi
• Zhi Jinghui

Classifications

• B05D2504/00

  Epoxy polymers · CPC title

• C08K3/36

  Silica · CPC title

• B05D7/546

  each layer being cured, at least partially, separately · CPC title

• C08K2201/005

  Additives being defined by their particle size in general · CPC title

• C09D5/1681 Primary

  Antifouling coatings characterised by surface structure, e.g. for roughness effect giving superhydrophobic coatings or Lotus effect · CPC title