Ex husband slandering me to kids

I was just wondering if my ex husband can get in trouble for slandering me to my kids? He has been threatening that he's going to tell the kids how I am and they are going to hate me and he can't wait until they hate me and they will want to live with him. He tells me he's going to let them know how selfish I am and they will know the truth. I have this all in text messages. What can be done? I am over him trying to emotionally destroy my children because he's bitter I left the marriage.