Reasons for the darkening of colored silica gel in the laboratory
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Gentlemen: What is the mechanism behind the darkening of silicone when exposed to coke oven gas over time?
What mechanism is still needed for this? The darkening indicates that some of the heavier components in the coke oven gas remain on the silica gel.
The principle is that hydrogen sulfide in coke oven gas reacts with the color-changing component in the color-changing silica gel (cobalt chloride) to form black cobalt sulfide.
Yes, blue color-changing silica gel turns blue due to the addition of cobalt chloride, and it becomes light pink after absorbing water. You can look it up on Baidu and you’ll find out.
Thank you, I just want to know which macromolecular substances are involved and the physicochemical changes that occur