Tailoring the structural properties of macroporous electron-beam polymerized cryogels by pore forming agents and the monomer selection

• Electron-beam derived synthesis of tailor-made cryogels in water at subzero temperatures.
• Successful application of poly(ethylene glycol) as pore forming agent in cryogel synthesis.
• Lower molecular weight PEGs are more effective pore forming agents.

In this study the influence of polyethylene glycol pore forming agents and the monomer selection on the conversion, the morphology and swelling properties of electron-beam derived macroporous cryogels was investigated. The cryogels were synthesized at subzero temperatures from aqueous solutions by applying a pulsed electron beam of a high-energy linear accelerator. The macroporous structure is templated by the ice crystals and the morphology and swelling characteristics depend on the type of monomers used. Pore forming agents introduce smaller pores in the naturally non-porous cryogel walls. The porous structure and swelling properties can be tailored by the choice of the monomer. The systems were thoroughly analyzed by scanning electron microscopy, X-ray photoelectron spectroscopy, thermogravimetrical analysis and mercury intrusion porosimetry.