Computational modeling of membrane materials is a rapidly growing field to investigate the properties of membrane materials beyond the limits of experimental techniques and to complement the experimental membrane studies by providing insights at the atomic-level. In this study, we first reviewed the fundamental approaches employed to describe the gas permeability/selectivity trade-off of polymer membranes and then addressed the great promise of mixed matrix membranes (MMMs) to overcome this trade-off. We then reviewed the current approaches for predicting the gas permeation through MMMs and specifically focused on MMMs composed of metal organic frameworks (MOFs). Computational tools such as atomically-detailed molecular simulations that can predict the gas separation performances of MOF-based MMMs prior to experimental investigation have been reviewed and the new computational methods that can provide information about the compatibility between the MOF and the polymer of the MMM have been discussed. We finally addressed the opportunities and challenges of using computational studies to analyze the barriers that must be overcome to advance the application of MOF-based membranes.

Polyoxometalates (POMs) were used, together with chitosan (CS), to obtain hybrid nanoaggregates. Three representative POMs were efficiently assembled into nanoparticles of few hundred nm diameter, featuring entangled ribbons substructure. In order to establish suitable preparation and stability conditions, the assemblies were characterized in solution by UV–Vis spectroscopy, dynamic light scattering and ζ-potential. The nanoparticles were tested against E. coli (10⁶ CFU/ml) in aqueous solution, showing a synergic activity of the heteropolyacid H₅PMo₁₀V₂O₄₀ and CS. For such components, a highly porous and antibacterial film was obtained upon lyophilisation of the colloidal mixture.

Producing block co-polymer-based nanofiltration (NF) membranes with sharp molecular weight cutoffs via an efficient method exhibiting persistent size-based separation quality is challenging. In this study, this challenge was addressed by reporting a facile approach to fabricate pentablock co-polymer (PBC)-based thin-film composite (TFC) NF membranes. The PBC, consisting of temperature-responsive Pluronic F127 (PEO-b-PPO-b-PEO) middle blocks and pH-responsive poly(N,N-(diethylamino)ethyl methacrylate) end blocks, were synthesized by atom-transfer radical polymerization. This polymer was then attached electrostatically to the surface of polysulfone/sulfonated polyether-sulfone support membranes fabricated using a non-solvent-induced phase separation technique. The conformational changes of the PBC chains in response to pH and temperature determined the pure water flux and neutral solute (PEG 1000) rejection performance of TFC membranes. Permeability of the membranes increased from 13.0 ± 0.63 to 15.9 ± 0.06 L/m²·h·bar and from 6.7 ± 0.00 to 13.9 ± 0.07 L/m²·h·bar by changing the solution pH from 4 to 8.5 and temperature from 4 to 25 °C, respectively. The pH- and temperature-responsive conformational changes did not affect the PEG 1000 rejection and membrane pore radius, which remained constant at ∼89% and ∼0.9 nm, respectively. This important finding was attributed to the high grafting density of co-polymer chains, resulting in spatial limitations among the grafted chains. The pore size of ∼0.9 nm achieved with the proposed membrane design is the smallest size reported so far for membranes fabricated from block co-polymers. TFC membranes demonstrated high stability and maintained their flux and rejection values under both static (storage in an acidic solution for up to 1 month) and dynamic (filtering PEG 1000 solution over 1 week) conditions. Pentablock co-polymers enable a NF membrane with a sharp molecular weight cutoff suitable for size-selective separations. The membrane fabrication technique proposed in this study is a scalable and promising alternative that does not involve complex synthetic routes.