Influence of Supercritical Carbon Dioxide Extraction Temperature on the Crystalline Structure and the Morphology of Syndiotactic Polystyrene Aerogels

Abstract

Summary: In this manuscript the influence of supercritical carbon dioxide extraction temperature on the morphology, the porosity, and the crystalline structure of syndiotactic polystyrene aerogels is investigated. Results show that depending on the extraction temperature, δ‐form, γ‐form, and β‐form high porosity aerogels characterized by a fibrillar morphology can be obtained.

Syndiotactic Polystyrene / Fullerene Composites: Elucidation of Structural Aspect

“…[2] Due to the formation of the solvent induced crystalline d form sPS has a tendency to form polymer-solvent crystallosolvates or chlathrate type compound with a wide range of solvents like benzene, [3] toluene, [4] chloroform, [5] decalin, [6] dichloroethane [7] and even in solid solvent like benzophenone, [8] naphthalene [9] etc. The easy way to form sPS chlathrate has recognized recently to prepare porous material, [10] gas sensors, [11][12][13] chiro-optical materials. [14] On the other hand, fullerene (C 60 ) has attracted the great interest because of its high symmetry, novel p-conjugated systems, and unique chemical and physical properties.…”

“…Due to the formation of the solvent induced crystalline δ form sPS has a tendency to form polymer‐solvent crystallosolvates or chlathrate type compound with a wide range of solvents like benzene,3 toluene,4 chloroform,5 decalin,6 dichloroethane7 and even in solid solvent like benzophenone,8 naphthalene9 etc. The easy way to form sPS chlathrate has recognized recently to prepare porous material,10 gas sensors,11–13 chiro‐optical materials 14…”

Electrostatically Active Polymer Hybrid Aerogels for Airborne Nanoparticle Filtration

“…The crystalline structures of sPS and PVDF chains in hybrid aerogels are also evident from the 2θ peaks of XRD patterns presented in Figure . Figure (a) shows the typical X-ray diffraction pattern for δ-phase sPS with peaks at 8.22, 13.35, 16.46, 20.52, and 23.67°. , The introduction of PVDF did not change the crystalline form of sPS in hybrid aerogel specimens as inferred from the presence of δ-form peaks in Figure (b) and (c), although the δ-form peaks shifted and the peak at 23.67° disappeared in the case of the sPS_PVDF-3 hybrid specimen. The 2θ peaks for crystalline PVDF are also present for hybrid aerogels in Figure (b) and (c); e.g., the β-phase PVDF is characterized with a single peak at 20.26°, while additional crystalline peaks of PVDF indicate the presence of γ- and α-phases in corroboration with the IR data.…”