Hotels at Pudong airport. Or am I allowed to go out of the Pudong airport?

I will be arriving at Pudong airport at 7:30 PM and departing at 12:50 PM the following day. Are there hotels at the airport? If not, will I be permitted to leave the airport for the night?
I am a US citizen going to Thailand, and am not required to have a Thailand visa. I will have a printed confirmation for my flight to Bangkod.