I used my home as collateral for a friend''s student loans.My home is now paid in full, will I be able to sell it if those loans are still outstanding?

If in fact you used your home as "collateral" for a friend's student loan, that means a mortgage or deed of trust was executed for the loan amount and placed of record.  If that did not happen, then your property was not used as collateral.  You can confirm that by having an attorney (or an agent of a title company) inspect the public records to confirm the status.  If there is a mortgage or deed of trust placed of record on your property, you will be unable to sell it without paying off the liens.