Production of porous materials by the expansion of polymer gels

A method of producing a micro- or nano-porous polymer material,

• swelling a polymer starting material using a plasticizer at a predetermined temperature to make the polymer starting material visco-elastic deformable, wherein the polymer starting material is at least partially crosslinked and the crosslinker content in the polymer starting material is in a range from 0.01 to 10 mol %, wherein the predetermined temperature is in a range from 0 to 100° C.;
• subsequently, contacting the swollen polymer starting material with a foaming agent under a first pressure;
• and
• subsequently, depressurizing from the first pressure to a second pressure such that the swollen polymer starting material further expands and solidifies to obtain a micro- or nanoporous material.