Method for obtaining superhydrophobic corrosion-resistant coatings

Patent metadata

Field	Value
Publication number	US-2021292908-A1
Application number	US-202117176748-A
Country	US
Kind code	A1
Filing date	Feb 16, 2021
Priority date	Feb 21, 2020
Publication date	Sep 23, 2021
Grant date	—

Abstract

This disclosure relates to a method for obtaining superhydrophobic corrosion-resistant coatings. State-of-the-art approaches involve etching methods with elevated temperatures and/or longer duration which are complex and use high concentration of combination of acids, alkali, and salt solutions in etching process to obtain a roughness which makes it difficult to handle usage of chemicals and controlling process. The method of the present disclosure has addressed this issue by selection of optimum concentrations of combinations of one or more type of acids, oxidizing agents which are safe, easy to handle and provide better control over the process. The method of the present disclosure is easy, inexpensive, and environmentally friendly. The superhydrophobic corrosion-resistant coatings possess contact angles greater than 151° and coating efficiency more than 85 percent arrived at by using corrosion currents from polarization studies.

First claim

What is claimed is:

1 . A method for obtaining superhydrophobic corrosion-resistant coatings, the method comprising:
preprocessing surface of at least one of a plurality of iron-based low-carbon metallic materials; etching the preprocessed surface for a duration of 7 minutes to 15 minutes with one or more types of halogen acid solution in optimum concentration range of 0.5 Molar to 3 Molar, including a delayed addition of hydrogen peroxide (H 2 O 2 ) of concentration in range of 0.4 Molar to 1 Molar after 15 seconds to 60 seconds; rinsing the etched surface in a first ethanol solution to remove residual etching solution present on the surface; immersing the rinsed surface in a second ethanol solution comprising a low surface energy chemical hexa-decyl-tri-methoxysilane (HDTMS) of concentration in a range of 1 to 8 weight percentage for 0.5 hours to 3 hours; air drying the immersed surface; curing the air dried surface in temperature range of about 100 degree Celsius to 150 degree Celsius for about 0.5 hours to 6.5 hours; and cooling the cured surface to obtain the superhydrophobic corrosion-resistant coatings on the at least one of the plurality of iron-based low-carbon metallic materials.

2 . The method as claimed in claim 1 , wherein the plurality of iron-based low-carbon metallic materials comprises iron, low carbon steel, low alloyed steel, and micro alloyed steel.

3 . The method as claimed in claim 1 , wherein the preprocessing comprising polishing the surface of the at least one of the plurality of iron-based low-carbon metallic materials with emery papers to reach a predefined surface finish, cleaning the surface with water and acetone sequentially, and inspecting the surface for defects.

4 . The method as claimed in claim 1 , wherein the one or more types of halogen acid comprises Hydrochloric acid (HCl), Hydrobromic acid (HBr) and Hydriodic acid (HI).

5 . The method as claimed in claim 1 , wherein the superhydrophobic corrosion-resistant coatings obtained on the at least one of the plurality of iron-based low-carbon metallic materials possess contact angle more than 151°.

6 . The method as claimed in claim 1 , wherein the superhydrophobic corrosion-resistant coatings obtained on the at least one of the plurality of iron-based low-carbon metallic materials possess coating efficiency more than 85 percent arrived at by using corrosion currents from polarization.

Assignees

• Tata Consultancy Services Ltd

Inventors

• Bandi Pallavi
• Kanamarlapudi Venkata Muralidhar
• Kausley Shankar Balajirao
• Rai Beena

Classifications

• C09D4/00

  Coating compositions, e.g. paints, varnishes or lacquers, based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond {; Coating compositions, based on monomers of macromolecular compounds of groups C09D183/00 - C09D183/16} · CPC title

• C23C4/11

  Oxides · CPC title

• B05D2350/50

  Smoothing · CPC title

• B05D1/18

  performed by dipping · CPC title

• B05D5/08

  to obtain an anti-friction or anti-adhesive surface (rendering particulate materials free-flowing in general, e.g. making them hydrophobic B01J2/30) · CPC title