The combination of well-defined molecular cavities and chemical functionality makes crystalline porous solids attractive for a great number of technological applications, from catalysis to gas separation. However, in contrast to other widely applied synthetic solids such as polymers, the lack of processability of crystalline extended solids hampers their application. In this work, we demonstrate that highly crystalline porous solids, metal-organic frameworks, can be made solution processable via outer surface functionalization using N-heterocyclic carbene ligands. Selective outer surface functionalization of relatively large nanoparticles (250 nm) of the well-known metal organic framework ZIF-67 allows for the stabilization of processable dispersions exhibiting permanent porosity. The resulting type III porous liquids can either be directly deployed as liquid adsorbents or be co-processed with state-of-the-art polymers to yield highly loaded mixed matrix membranes with excellent mechanical properties and an outstanding performance in the challenging separation of propylene from propane. We anticipate that this approach can be extended to other metal-organic frameworks, and for other applications.

Conventional separation technologies to separate valuable commodities are energy intensive, consuming 15% of the worldwide energy. Mixed-matrix membranes, combining processable polymers and selective adsorbents, offer the potential to deploy adsorbent distinct separation properties into processable matrix. We report the rational design and construction of a highly efficient, mixed-matrix metal-organic framework membrane based on three interlocked criteria: (i) a fluorinated metal-organic framework, AlFFIVE-1-Ni, as a molecular sieve adsorbent that selectively enhances hydrogen sulfide and carbon dioxide diffusion while excluding methane; (ii) tailoring crystal morphology into nanosheets with maximally exposed (001) facets; and (iii) in-plane alignment of (001) nanosheets in polymer matrix and attainment of [001]-oriented membrane. The membrane demonstrated exceptionally high hydrogen sulfide and carbon dioxide separation from natural gas under practical working conditions. This approach offers great potential to translate other key adsorbents into processable matrix.

New silica-containing hybrid films were prepared using a fluorinated poly(amide-imide) having hydroxyl groups and tetraethoxysilane, via the sol-gel technique. The polymer was synthesized by solution polycondensation reaction of a mixture of two diamines, 4,4 0 -diamino-4 00 -hydroxy-triphenylmethane and 1,3-bis(4-aminophenoxy)benzene (molar ratio 3/7), with a fluorinated diacid chloride containing imide rings, 2,2-bis[N-(4-chloroformylphenyl)-phthalimidyl]hexafluoroisopropane. To improve the compatibility between the polymer and silica, the pendant hydroxyl groups of the polymer were reacted with 3-(triethoxysilyl)propyl isocyanate. The hybrid films were flexible, tough, and exhibited high thermal stability, having the initial decomposition temperature above 420 C. The surface morphology of the hybrid films was investigated by scanning electron microscopy. Dynamic mechanical analysis and dielectric spectroscopy revealed subglass transitions, g and b, and an a relaxation corresponding to the glass transition temperature. Electrical insulating properties were evaluated on the basis of dielectric constant and dielectric loss and their variation with the frequency and temperature. The values of the dielectric constant at 10 kHz and 20 C were in the range of 3.18-3.48. The influence of the silica content on the polymer properties was examined.