Environmental crazing and properties of mesoporous and nanocomposite materials based on poly(tetrafluoroethylene) films

ABSTRACT The mechanism of environmental intercrystallite crazing (EIC) of semicrystalline poly(tetrafluoroethylene) (PTFE) films was studied. Stress-induced cavitation and fibrillation upon the EIC process provides the development of a marked porosity in PTFE (up to ∼40%) and pores with nanoscale dimensions (below 10 nm). Morphology and structural parameters of the mesoporous EIC PTFE samples were characterized, and the mechanism behind the EIC and low-temperature strain recovery of the EIC PTFE samples was proposed. The resultant mesoporous PTFE materials are shown to exhibit high chemical resistance, thermal stability, thermal conductivity, etc . The PTFE mesoporous materials can serve as matrices for diverse PTFE-based nanocomposite materials via the introduction and immobilization of various low-molecular-mass additives (alkali, metals, dyes). The bottom-up synthesis of silver nanoparticles within the mesoporous EIC PTFE as microreactors was described, and the structure of the silver-containing PTFE was characterized. Possible practical applications of the PTFE-based EIC nanomaterials were highlighted.