Molecular Mobility and Gas Transport Properties of Mixed Matrix Membranes Based on PIM‑1 and a Phosphinine Containing Covalent Organic Framework

Polymers with intrinsic microporosity (PIMs) are gaining attention as gas separation membranes. Nevertheless, they face limitations due to their pronounced physical aging. In this study, a covalent organic framework containing λ5-phosphinine moieties, CPSF-EtO, was incorporated as a nanofiller (concentration range 0–10 wt %) into a PIM-1 matrix forming dense films with a thickness of ca. 100 μm. The aim of the investigation was to investigate possible enhancements of gas transport properties and mitigating effects on physical aging. The incorporation of the nanofiller occurred on an nanoaggregate level with domains up to 100 nm, as observed by T-SEM and confirmed by X-ray scattering. Moreover, the X-ray data show that the structure of the microporous network of the PIM-1 matrix is changed by the nanofiller. As molecular mobility is fundamental for gas transport as well as for physical aging, the study includes dielectric investigations of pure PIM-1 and PIM-1/CPSF-EtO mixed matrix membranes to establish a correlation between the molecular mobility and the gas transport properties. Using the time-lag method, the gas permeability and the permselectivity were determined for N2, O2, CH4, and CO2 for samples with variation in filler content. A significant increase in the permeability of CH4 and CO2 (50% increase compared to pure PIM-1) was observed for a concentration of 5 wt % of the nanofiller. Furthermore, the most pronounced change in the permselectivity was found for the gas pair CO2/N2 at a filler concentration of 7 wt %

Conjugated Polymer Nanoparticles by Suzuki–Miyaura Cross-Coupling Reactions in an Emulsion at Room Temperature

A range of stable emulsions of spherical and rod-like conjugated polymer nanoparticles (CPN) were synthesized via Suzuki−Miyaura cross-coupling reactions of 9,9-dioctylfluorene-2,7-diboronic acid bis­(1,3-propanediol) ester with a number of different dibromoarene monomers in xylene, stabilized in water by the nonionic surfactant, Triton X-102. High molar mass poly­(9,9-dioctylfluorene) (PF8), poly­(9,9-dioctylfluorene-<i>alt</i>-benzothiadiazole) (PF8BT), poly­(9,9-dioctylfluorene-<i>alt</i>-4-<i>sec</i>-butylphenyldiphenylamine) (PF8TAA) and poly­(9,9-dioctylfluorene-<i>alt</i>-bithiophene) (PF8T2) emulsions were obtained, at high overall conjugated polymer concentrations (up to 11,000 ppm), in the presence of the palladium complex, (IPr*)­PdCl₂(TEA) and base, tetraethylammonium hydroxide, in nitrogen atmosphere at 30 °C after 24–48 h. TEM analysis of the PF8 and PF8T2 emulsions revealed regular rod-like structures, up to 200 nm in length with aspect ratios of 4–5. PF8BT and PF8TAA formed spherical particles with diameters of between 20–40 nm in TEM analysis. UV–vis absorption spectra of the PF8 emulsions indicated high levels of ordered β-phase configuration (9–10%) in their respective nanoparticles. Absolute photoluminescence quantum yields (Φ) of 21–25% were recorded for these emulsions