Mixed Matrix Membranes

Abstract

In recent decades, mixed matrix membranes (MMMs) have attracted considerable interest in research laboratories worldwide, motivated by the gap between the growing interest in developing novel mixed matrix membranes by various research groups and the lack of large-scale implementation. This Special Issue contains six publications dealing with the current opportunities and challenges of mixed matrix membranes development and applications as solutions for the environmental and health challenges of 21st century society.

Sustainable Membrane‐Coated Electrodes for CO2 Electroreduction to Methanol in Alkaline Media

“…The values obtained for d were 196 cm, 264 cm, 241 cm and 230 cm, for the CS : PVA, Cu/CS : PVA, Cu-UZAR-S3/ CS : PVA and Cu-Y/CS : PVA MCE, respectively. These values are higher than those reported in literature, [58,59] though, confirming the additional resistance opposed by the membrane over-layer and expecting the existence of non-idealities when this membrane over-layer is a mixed matrix membrane (MMM), [61,62] but yet the diffusion layer values correlated with the SEM observations taken of the surface morphologies of the electrodes after the electroreduction experiments, discussed below regarding Figure 4.…”

“…When the membrane over-layer was functionalized by the inclusion of ion-exchangeable inorganic fillers, the physicochemical properties and electrode activity were improved, but the membrane over-layer was partially dissolved upon reaction and entered the pores of the carbonaceous substrate beneath. Further work should be directed to the understanding of the role of the membrane over-layer from the MMM non-idealities, [62] which agreed with those observed in the electrochemical reduction of CO 2 to CH 3 OH, as well as investigating the performance in a continuous flow filter press cell reactor where the closed environment is expected to prevent the local effects affecting the overall performance, as well as allowing us to complete the mass balance by measuring the gas phase. This way, current system limitations, i. e. no division between the electrodes, which could cause re-oxidation of methanol at the anode or the low solubility of CO 2 in aqueous solutions, could be overcome.…”

Comparison of Flat and Hollow‐Fiber Mixed‐Matrix Composite Membranes for CO2 Separation with Temperature

“…The dried membranes were removed from the Petri dish, neutralized in 1 M NaOH, and rinsed with abundant distilled water before permeation experiments in order to ion-exchange the NH 3 + functional groups of the polymer matrix [19,29]. As the IL is in a very small proportion, i.e., 5 wt % to the total amount of solid membrane, it is not expected to be in the liquid form, but as a sort of binder between chains or nanoparticles as observed in previous works [28,29].…”

“…In our previous works, we have investigated the performance of MMMs made from highly CO 2-selective and permeable materials that overcome the Robeson upper bound [26] in selfstanding configuration, in two approaches: (i) the selectivity and aging resistance of PTMSP has been improved by adding small-pore zeolites of varying Si/Al ratio [15] and topology [27], and (ii) the thermal and mechanical resistance and selectivity of CS biopolymer has been improved by adding [emim][Ac] [19], microporous titanosilicate ETS-10 [28], and ZIF-8 and HKUST-1 nanoparticles [29]. The effect of temperature on CO 2 /N 2 separation has been studied in the range 298-333 K and the highest CO 2 /N 2 -permselective membrane materials were selected in this work to fully explore the effect of the change of geometry on membrane performance.…”

Effect of Humidity on CO2/N2 and CO2/CH4 Separation Using Novel Robust Mixed Matrix Composite Hollow Fiber Membranes: Experimental and Model Evaluation

“…Among these, mixed matrix membranes (MMMs) combine the processability of polymers with the molecular sieving effect of inorganic fillers, and have been investigated intensively for light gas separation [8]. Despite the achievements carried out in material development in the last decades at lab scale, there is still a gap between lab and practical conditions because of the difficulty of fabrication of membranes from new materials [9]. Multilayer composite membranes offer the possibility to optimize membrane layer materials independently and reduce the overall transport resistance by coating ultrathin highly selective and permeable layers on mechanically robust and processable supports [10].…”