If you wake up with knotted, frizzy hair, friction is likely the culprit....

https://mega-wiki.win/index.php/The_Ultimate_Overnight_Routine_for_Naturally_Dry_Curly_Hair:_Wake_Up_With_Your_Curls_Intact

If you wake up with knotted, frizzy hair, friction is likely the culprit. Cotton pillowcases can snag delicate strands, unlike silk which lets hair glide