What's the noun for segregating? Here's the word you're looking for.
segregation
The setting apart or separation of things or people, as a natural process, a manner of organizing people that may be voluntary or enforced by law.
(Can we clean up(+) this sense?) (biology) The Mendelian Law of Segregation related to genetic transmission or geographical segregation of various species.
(sociology) The separation of people (geographically, residentially, or in businesses, public transit, etc) into various categories which occurs due to social forces (culture, etc).