If you want to disconnect from work Slack but don't want to remove it totally:
For iPhones: in the App Store there is an app called Slack for EEM. This is another version of slack that is "for enterprise" but connects to most (any?) teams anyway. You can switch your work slack to this and then it's very easy to quarantine all notifications. Just turn em off for that app in Settings.
Also, on a computer, you can visit https://<team name>.slack.com/account/settings and click [Sign out all other sessions]. This will sign you out without removing the team from your sidebar. It puts a ⚠️ sign next to the icon and you won't receive any notifications! Come back Monday, visit that team and you'll only have to sign in again and you're back to business.
This Mastodon instance is for people interested in technology. Discussions aren't limited to technology, because tech folks shouldn't be limited to technology either!