Hierarchical Morphology of Poly(ether ether ketone) Aerogels

• DOI: 10.1021/acsami.9b09699
• Publication Date: 2019-08-05T09:02:46Z
• Authors: Samantha J. Talley; Stephanie L. Vivod; Baochau A. Nguyen; Mary Ann B. Meador; Aurel Radulescu; Robert B. Moore
• Keywords: Small-angle X-ray scattering

The phase diagram for the thermoreversible gelation of poly(ether ether ketone) (PEEK) in 4-chlorophenol (4CP) was constructed over broad temperature and concentration ranges, revealing that PEEK is capable dissolving forming gels both 4CP dichloroacetic acid (DCA) up to a 25 wt %. Highly porous aerogels were prepared through simple solvent exchange followed by one two drying methods removal from wet gel: freeze-drying or supercritical CO2 fluid extraction (SC-drying). field-emission scanning electron microscopy analysis showed 4CP, SC-drying, produced with well-defined lamellar aggregates as compared less ordered formed DCA. Mechanical properties (in compression) shown improve increasing density, resulting equivalent compressive moduli at comparable regardless preparation method (gelation selection, variation, method). Nitrogen adsorption–desorption isotherms indicate are comprised mesopores (2–50 nm diameter pores) stacked crystalline lamella. using SC-drying exhibit higher Brunauer–Emmett–Teller surface areas than freeze-dried density. ultra-small-angle X-ray scattering/small-angle scattering (SAXS)/wide-angle revealed hierarchical morphology structural features crystallites agglomerates lamella spanned wide range length scales. SANS contrast-matching confirmed morphological origin principle feature sorption measurements porosity specific area correlated SAXS reveal remarkably high attributed platelet-like, morphology. Contact angle contact hysteresis (CAH) low-density (ρ < 0.15 g/cm3) have water angles above superhydrophobicity cutoff (>150°) very low CAH near 1°.