Related Experiment Video
Updated: Jul 17, 2025

Surface Functionalization of Metal-Organic Frameworks for Improved Moisture Resistance
Published on: September 5, 2018
Fabrication of a uniform chromate conversion coating on Zn alloy for improved corrosion resistance in humid
Seonghye Ha1, Jakyung Eun1, Changhoon Choi2
1Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Pohang, Gyeongbuk, Republic of Korea.
Abstract:
We developed a facile method to produce a uniform chromate conversion (CC) coating on zinc alloy-plated steel substrates (ZS). When an acidic CC solution is applied to ZS (C-ZS), zinc is dissolved and chromium ions are reduced to form a chromate coating. In localized areas where zinc is excessively dissolved, zinc hydroxide particles are formed, which hinders the formation of a uniform chromate film, leaving the areas vulnerable to further corrosion (i.e., the formation of dark spots) when exposed to high humidity conditions. To suppress the excessive dissolution of zinc, the ZS surface was pretreated with thiolated polyethylene oxide to form a hydrophilic self-assembled monolayer. A more uniform protective CC coating was obtained on the pretreated ZS, resulting in superior corrosion resistance under high humidity conditions.
Related Concept Videos
Corrosion
Corrosion of Reinforcement
However, over time and under certain conditions like carbonation, chloride ingress, and cracking this protective state can be compromised. Steel has areas with...
Waterproofing and Anti-Bacterial Admixtures in Concrete
Waterproofing admixtures render concrete hydrophobic,...
Preparation of Samples for Electron Microscopy
Properties of Transition Metals

