How does active carbon filters work?

[engineheat]

I wonder how the active carbon filters found in respirators work. How are they built/designed to filter air while allowing air to pass through? Are the carbon particles suspended in a membrane? Or are the carbon particles packed into a tube that air flows through?
Thanks

[thm_w]

https://science.howstuffworks.com/gas-mask2.htm
https://en.wikipedia.org/wiki/Carbon_filtering
https://molekule.science/activated-carbon-air-filter/

[Alex Eisenhut]

https://en.wikipedia.org/wiki/Adsorption

That's the principle.