PPO based film with high surface area and procedures for the obtainment thereof

A procedure for preparing a polyphenylene oxide (PPO) film with crystalline nanoporous phases, comprising:

• preparing an amorphous PPO film,
• forming co-crystalline phases with a percentage of crystallinity higher than 10% by absorption of host molecules,
• forming crystalline nanoporous phases by total removal of said host molecules,
• wherein
• said absorption of host molecules is conducted up to a host molecule content equal to or greater than 20% w/w,
• said forming co-crystalline phases occurs with a crystallization rate equal to or greater than 0.5 percentage points per minute, and
• said total removal of said host molecules occurs before the content of said host molecules has dropped below 20% w/w.