Hydrogen permeability measurements have indicated that cross-linked polyphosphazene films formed from phloroglucinol Phg and hexachlorocyclotriphosphazene HCCP can display good H2 barrier properties. They could be used as innovative barrier layers incorporated in the liners of storage tanks in fuel-cell vehicles in order to significantly reduce H2 leakage. The H2 permeation properties of 36 molecular-level Phg-HCCP network models are investigated here up to pressures of 800 bar to predict the initial Phg:HCCP mixture stoichiometries that optimize their barrier effect. Several polyphosphazene networks are found to have very low permeabilities for H2 at 800 bar. These are either a) highly-cross-linked Phg-HCCP percolating networks originating from mixtures with Phg:HCCP ratios around 2:1 or b) lower-cross-linked networks with excess Phg monomers trapped in the network originating from mixtures with higher Phg:HCCP ratios up to 8:1. Their model H2 barrier properties are up to ten times better than those of storage tank HDPE liners.

Twenty-four molecular models for polyphosphazene networks were created via an in silico polymerization of phloroglucinol Phg (C6H6O3) and hexachlorocyclotriphosphazene HCCP (N3P3Cl6) mixtures at different Phg:HCCP ratios. A series of monomer mixtures at Phg-to-HCCP stoichiometric ratios ranging from 1:1 to 8:1 were created using molecular dynamics (MD) simulations. Alternating phases of reactions followed by relaxation steps led to the progressive formation of percolating polyphosphazene networks. The actual ratios of Phg to HCCP rings incorporated in the network polymers remained close to those in the mixtures for initial ratios up to 2:1. Above 2:1, there was a gradual divergence toward lower values in the networks as the limits to the number of possible bonds for each monomer started to take effect. The details of the structures were found to be very complex in terms of the probability distributions of links per Phg or HCCP ring. The highest degrees of connectivity and ring packing densities were found in the networks formed from the initial mixtures having Phg-to-HCCP ratios of around 2:1. Mechanical tests were carried out in order to ascertain the resistance of the model polyphosphazene networks to compression/decompression. There again, the networks obtained from the 2:1 initial mixture were found to have the highest Young's modulus and to display the most elasticity as they recovered their initial shape once the compression was removed. The influence of trapped excess monomers in the percolating networks was only noticeable at the highest mixture ratios. The most resistant Phg-HCCP networks are thus obtained from Phg-to-HCCP mixture ratios of around 2:1, with or without trapped excess monomers.

While blended learning holds considerable potential in higher education, suboptimal social interactions among students may lead to feelings of loneliness, isolation, and demotivation. To address this issue, a professional development programme was designed and assessed for its viability in helping university teachers promote a sense of community within the blended learning environment. This programme introduces a new visually-based theoretical model, equipping teachers with practical tools for implementing activities that foster a strong sense of community in the blended learning. Drawing upon the teachers' perceived experiences, the study identifies key recommendations to enhance the viability of this professional development programme. In particular, it is necessary to establish a strong theoretical foundation to dispel misconceptions among teachers about blended learning. Additionally, it provides several concrete strategies to support teachers' hands-on practice and suggests integrating a team-based approach to collectively enhance the quality of blended learning. Furthermore, the study underscores the importance of the institution's commitment, recognising its important role in the long-term success and sustainability of both blended learning and associated professional development initiatives for teachers.

A series of thermally stable, hyperbranched poly(aryletherketone)s (hbPAEKs), functionalized with 4-(phenyl-ethynyl)phenol (PEP) reactive end-groups, were synthesized and evaluated as potential membranes for high-temperature gas separation applications. Despite their all-aromatic nature, the hbPAEKs can easily be processed into thin films from cyclopentanone and thermally crosslinked to form glassy films with high glass transition temperatures (Tg). The effect of crosslinking on Tg and the excess free fractional volume (EFFV) were studied using in-situ spectroscopic ellipsometry. Crosslinking hbPAEKs results in a significant increase in both Tg (from 140 to 250 degrees C) and EFFV (from 5 to 9.5 %). High-pressure CO2 sorption experiments demonstrated that crosslinked hbPAEKs resist plasticization at CO2 pressures up to 50 bar. When evaluating the gas separation performance at 200 degrees C, a crosslinked hbPAEK membrane with 10 mol% PEP exhibited exceptional stability, maintaining constant H2 and N2 permeance and H2/N2 selectivity for 2 weeks. Our findings indicate that crosslinked hbPAEK membranes hold great promise for high temperature gas separation applications.

Organic solvent nanofiltration (OSN), also called solvent-resistant nanofiltration (SRNF), has emerged as a promising technology for the removal of impurities, recovery of solutes, and the regeneration of solvents in various industries, such as the pharmaceutical and the (petro)chemical industries. Despite the widespread use of OSN/SRNF, the presence of scattered, non-standardized data, and the absence of openly accessible data pose critical challenges to the development of new membrane materials and processes, their comparison to the state-of-the-art materials, and their fundamental understanding. To overcome these hurdles, data from peer-reviewed research articles and commercial datasheets were curated via a standardized procedure to obtain an extensive dataset on the membrane materials, synthesis parameters, operational conditions, physicochemical properties, and performance of OSN/SRNF membranes. Thanks to a truly impressive joint effort of the OSN/SRNF community, the dataset contains, as per April 2024, 5,006 unique membrane filtrations from 294 publications for 42 solvents under several process parameters. This findable, accessible, interoperable, reproducible, and open (FAIR/O) dataset is available on both the OSN Database and the newly inaugurated Open Membrane Database for SRNF (OMD4SRNF). These databases provide multiple visualization and data exploration tools. Here, the standardized procedure applied to curate the data and the functionality of the databases are outlined, as well as the online user interface to deposit new data by external users on the OMD4SRNF. This community-led project has been supported by all the co-authors of this work. Most importantly, they additionally agreed to systematically deposit their future peer-reviewed data on OSN/SRNF into the databases. We thereby pave the road for FAIR/O data in the field of OSN/SRNF to increase transparency, enable more accurate data analysis, and foster collaboration and innovation.

Metal-organic framework (MOF) films can be used in various applications. In this work, we propose a method that can be used to synthesize MOF films localized on a single side of an anion exchange membrane, preventing the transport of the metal precursor via Donnan exclusion. This is advantageous compared to the related contra-diffusion method that results in the growth of a MOF film on both sides of the support, differing in quality on both sides. Our proposed method has the advantage that the synthesis conditions can potentially be tuned to create the optimal conditions for crystal growth on a single side. The localized growth of the MOF is governed by Donnan exclusion of the anion exchange membrane, preventing metal ions from passing to the other compartment, and this leads to a local control of the precursor stoichiometry. In this work, we show that our method can localize the growth of both Cu-BTC and ZIF-8 in water and in methanol, respectively, highlighting that this method can used for preparing a variety of MOF films with varying characteristics using soluble precursors at room temperature.

Two existing generic force fields have been augmented with partial charges and tuned in order to give intercompatible all-atom empirical potentials that can satisfactorily represent the known crystal phase structures of the organic phloroglucinol (Phg) (C6H6O3) and inorganic hexachlorocyclotriphosphazene (HCCP) (N3P3Cl6) molecules at several temperatures. It has been proposed that HCCP-Phg network polymers could act as efficient H2 barrier layers in hydrogen storage tanks for cars. However, essential requirements for modeling such networks are adequate representations of both monomers in their pure dense phases using a common form of force field. Tests of their ability to maintain stable crystal structures have been made using classical molecular dynamics (MD) simulations on large 800-molecule supercells. The force fields have been optimized to match the densities calculated from the experimental unit cell dimensions at ambient conditions as well as the intermolecular potential energy, as estimated from experimental enthalpies of sublimation. For Phg, the crystal structure is stabilized by a network of hydrogen bonds and the Coulombic interactions contribute to over 55% of the total intermolecular potential energy. In contrast, the crystal structure of HCCP is intrinsically stabilized by the van der Waals terms. Both optimized force fields reproduce very well the orthorhombic symmetry of their respective crystals under constant-pressure NPT conditions. The model parameters tuned at ambient temperature also give reasonable agreement with crystallographic data at lower temperatures.

An interfacial polymerization process is introduced for the fabrication of thermally stable cyclomatrix poly(phenoxy)phosphazenes thin‐film composite membranes that can sieve hydrogen from hot gas mixtures. By replacing the conventionally used aqueous phase with dimethyl sulfoxide/potassium hydroxide, a variety of biphenol molecules are deprotonated to aryloxide anions that react with hexachlorocyclotriphosphazene dissolved in cyclohexane to form a thin film of a highly cross‐linked polymer film. The film membranes have persistent permselectivities for hydrogen over nitrogen (16–27) and methane (14–30) while maintaining hydrogen permeances in the order of (10 −8 –10 −7 mol m −2 s −1 Pa −1 ) at temperatures as high as 260 °C and do not lose their performance after exposure to 450 °C. The unprecedented thermal stability of these polymer membranes opens the potential for industrial membrane gas separations at elevated temperatures.

Highly selective thin-film composite membranes for hot hydrogen sieving are prepared via the pyrolysis of thin cyclomatric polyphenoxy phosphazene films that are prepared via a non-conventional interfacial polymerization of hexachlorocyclotriphosphazene with 1,3,5-trihydroxybenzene or m-dihydroxybenzene. The presence of the cyclic phosphazene ring within the weakly branched polymer films gives rise to a distinct thermal degradation evolution, with an onset temperature of around 200 & DEG;C. For the trihydroxybenzene derived material, the hydrogen permselectivity of the films shows a maximum pyrolysis temperature of around 450 & DEG;C. At this temperature a compact atomic structure is obtained that comprises mostly disordered carbon and accommodates P-O-C and P-O-P bonds. During thermal treatment, these films reveal molecular sieving with permselectivities exceeding 100 for H2/N2, H2/CH4, and H2/CO2, and a hydrogen permeance of 2 x 10-10 to 1.5 x 10-8 mol/m2/ s/Pa (0.6-44.8GPU), at 200 & DEG;C. At ambient temperatures, thin films are very effective barriers for small gas molecules. Because of the inexpensive facile synthesis and low- temperature pyrolysis, the polyphosphazene films have the potential for use in high-temperature industrial gas separations, as well as for use as barriers such as liners in high- pressure hydrogen storage vessels at ambient temperature.

A series of cyclomatrix polyphosphazene films have been prepared by nonaqueous interfacial polymerization (IP) of small aromatic hydroxyl compounds in a potassium hydroxide dimethylsulfoxide solution and hexachlorocyclotriphosphazene in cyclohexane on top of ceramic supports. Via the amount of dissolved potassium hydroxide, the extent of deprotonation of the aromatic hydroxyl compounds can be changed, in turn affecting the molecular structure and permselective properties of the thin polymer networks ranging from hydrogen/oxygen barriers to membranes with persisting hydrogen permselectivities at high temperatures. Barrier films are obtained with a high potassium hydroxide concentration, revealing permeabilities as low as 9.4 × 10–17 cm3 cm cm–2 s–1 Pa–1 for hydrogen and 1.1 × 10–16 cm3 cm cm–2 s–1 Pa–1 for oxygen. For films obtained with a lower concentration of potassium hydroxide, single gas permeation experiments reveal a molecular sieving behavior, with a hydrogen permeance of around 10–8 mol m–2 s–1 Pa–1 and permselectivities of H2/N2 (52.8), H2/CH4 (100), and H2/CO2 (10.1) at 200 °C.

In the electrochemical reduction of CO 2 , copper electrodes are well known to be active and selective for a variety of products, depending on process conditions. However, the effect of feed composition on performance has not been exten-sively investigated, especially with respect to the conversion of CO 2 to CO. We now show for copper electrodes in a porous tubular configuration (Hollow Fibre Electrodes, HFEs) at a relatively low working potential ( − 1.1 V vs Ag/AgCl), that an increasing concentration of CO in the feed results in a decreasing CO 2 conversion rate to CO. Contrary, it is observed that the concomitant hydrogen production rate does not depend on the concentration of CO in the feed. These observations are in good agreement with thermodynamic predictions applying the equation for the Gibbs energy of reaction. On the basis of this conclusion, we anticipate that mass transfer limitations are minimized by the tubular morphol-ogy and flow-through mode of operation. Most importantly, this study shows the necessity of a low CO concentration in the feed, to obtain a high CO 2 conversion rate.

This work compares eight classical H2 molecular models in the gas phase taken from the existing literature. All models are based on Lennard-Jones (LJ) 12-6 terms for the van der Waals interactions and hence easier to transfer to multiphase molecular simulations than more sophisticated potentials. The H2 potentials tested include one-site, two-site, three-site, and five-site models, with the sites being either the H atoms, the center-of-mass of the H2 molecule, or massless sites. For the multisite models, high-frequency H-H stretching modes can lead to poor equipartition of the kinetic energy, and the timestep for molecular dynamics (MD) simulations should be reduced to maintain a stable numerical integration of the equations of motion. As such, only those models with rigid bonds are considered. In the present case, 600 MD simulations of H2 gas were carried out over a large range of temperatures (-50 to +90 °C) and at densities corresponding to a pressure range of 50 to 2000 bar, which include the operating conditions of on-board storage tanks in hydrogen-fueled vehicles. Most of the models under study were found to reproduce reasonably well the experimental pVT phase diagram as well as the solubility. Discrepancies only became significant at the highest densities tested, and these could be used to rank the different models. All model diffusion coefficients were essentially indistinguishable from experimental results, and as such, kinetically dominated dynamic properties could not be used as a criterion for the choice of model. Among the eight models tested, two of them, i.e., the two-site model of Yang and Zhong and the one-site model derived from Buch performed very well over the range of conditions tested. They represent a good compromise between realism, simplicity, and computational efficiency.

Universities have renewed interest in blended learning in preparation for post-COVID education. However, unsatisfactory social interactions hinder the quality of blended learning, despite its potential for flexible and personalized learning. In this situation, a sense of community would provide essential academic and social benefits. To develop a sense of community among students, we need to further understand students' and teachers' perceptions concerning this subject by exploring their experiences in blended learning. Therefore, we investigated this for three blended courses using a qualitative case study approach. We conducted: (1) classroom observation; (2) document analysis of course content, assignments, and assessments; and (3) individual interviews with teachers ( n = 3) and group interviews with students ( n = 18). The results showed the main factors that appeared to contribute to sense of community: group learning activities within courses, non-academic and extracurricular activities across courses, and the campus as a physical place integrating academic and social life after COVID. Further, we identified two obstacles: students valued group learning but struggled to manage group dynamics, and despite teachers' efforts to encourage learning autonomy, students viewed teachers as the ultimate authority in the learning process, which strained the student–teacher relationship. Additionally, this study revealed the limitations that digital tools have for promoting sense of community, as students questioned whether these tools have added value for supporting intricate and in-depth conversations. Finally, based on these findings, we provided practical recommendations for the future development of sense of community in blended learning.

In this work, we report the synthesis and characteristics of cyclomatrix polyphosphazene membranes based on interfacial polymerization between 1,1-tris(4-hydroxyphenyl)ethane and hexachlorocyclotriphosphazene on top of alumina or polyacrylonitrile supports. The potential of alumina-supported thin film composite membranes as organic solvent nanofiltration membranes has been confirmed with a polystyrene-based molecular weight cutoff of 347 +/- 120 Da and 503 +/- 220 Da in acetone and toluene, respectively. Also, the resulting alumina-supported TFC membrane showed a methylene blue rejection (Mw = 319 g mol-1) of 98.2 +/- 2.3%, 92 +/- 1.7%, and 93 +/- 0.5% in water, ethanol, and acetone, respectively. Furthermore, a thin film composite membrane has been prepared with a polyacrylonitrile support via interfacial polymerization to validate the preparation technique for polymeric supports and facilitate industrial implementation. The resulting membrane showed higher permeance and lower rejection than the alumina-supported membrane due to the presence of pinholes in the selective layer on top of the polyacrylonitrile supports. Our results clearly show the great potential of cyclomatrix polyphosphazene membranes as organic solvent nanofiltration membranes. However, for polyacrylonitrile-supported membranes, the preparation method needs further investigation.

Molecular dynamics (MD) simulations have previously identified four hybrid inorganic-organic membranes based on POSS or OAPS silsesquioxanes hyper-cross-linked with small PMDA or 6FDA imides, which are able to maintain reasonable CO2/N2 and CO2/CH4 permselectivities at very high temperatures (300 degrees C and 400 degrees C) and pressure (60 bar). Experimentally, the polyPOSS-imides are known to degrade above 300 degrees C while the polyOAPSimides can resist up to above 400 degrees C. In the present work, the same four model polyOAPS/POSS-imide networks are further tested for their gas separation abilities of H2S-containing mixtures. Indeed, hydrogen sulfide is a hazardous gas present in many gas feeds, and, within the context of a toxic penetrant under harsh conditions, simulations are a useful task to perform before embarking on difficult experiments. The separations of H2S with respect to N2, CH4 and CO2 by the polyOAPS/POSS-imide matrices were studied at 300 degrees C, 400 degrees C and at 60 bar, firstly with H2S as a single-gas in order to obtain its ideal permselectivities, secondly as part of binary 90%/10% N2/H2S and CH4/H2S feeds and thirdly as part of ternary 90%/9%/1% N2/ CO2/H2S and CH4/CO2/H2S feeds. They were compared to separations of binary 90%/10% N2/CO2 and CH4/CO2 feeds under exactly the same conditions. At 300 degrees C, H2S is much more soluble in the networks than the other three penetrants. It is the only one leading to a non-negligible volume swelling at 60 bar, although this does not happen for the mixed-gas feeds due to their low H2S partial pressures. Differences are attenuated at 400 degrees C because of the decrease in solubilities upon heating. The linear N2 and CO2 move faster than the non-linear CH4 and H2S penetrants, but the diffusion selectivities are moderate. As such, the ideal permselectivities under harsh conditions are mainly governed by the solubility selectivities. With binary 90%/10% N2/H2S, CH4/H2S, N2/CO2 and CH4/CO2 feeds, the transport parameters of the major N2 or CH4 components remain similar to their ideal values, whereas the solubilities of the minor H2S and CO2 components increase. This leads to some of the real separation factors for H2S being different from their ideal permselectivities, and approximately twice as high as those with CO2. In the ternary 90%/9%/1% N2/CO2/H2S and CH4/CO2/H2S mixtures, replacing 1% CO2 by 1% H2S in the feeds leads to small changes but, in pratice, these are not significant enough to make a difference. Under the conditions tested, the ternary separation factors are the same than for the 90%/10% binary mixtures. In all cases, the denser polyPOSS-imides show better sieving properties than the more open polyOAPS-imides. As such, the former should preferably be used in applications up to 300 degrees C, i.e. in the temperature range below their degradation. However, it is also possible to use the polyOAPS-imides at higher temperatures, since they still manage maintaining separation factors between 2 and 6 for CO2 and H2S at 400 degrees C, which is outstanding for polymer-based membranes at such high temperatures.

Tubular porous Ti electrodes show unprecedented performance in the electrochemical reduction of nitrate to ammonia, which increased from −33 to −75 mA cm2by applying an inert gas flow exiting through the pores of the Ti tube.

In 2013, our university has implemented a new educational model that puts team projects at the core of all BSc programmes, requiring that students develop teamwork skills. On top of this, in 2018, our Chemical Science & Engineering BSc has become an English-taught, international programme. In consideration of this challenging transition, we have developed additional training to facilitate students' acquisition of knowledge, skills, tools, and attitudes to aid conscientious intercultural teamwork. For this, it is paramount that students become aware of, and learn to appreciate, differences in the educational and cultural backgrounds of themselves and their peers. Concurrently, students should practice what they have learned and adjust their behaviour when appropriate. In this paper, we share our experiences, best practices, and lessons learned. More specifically, our study: i) explores which factors are key to a successful intercultural team, ii) investigates how diversity in teams can be cherished and used for the benefit of the team, its members, and its goals, and iii) how these teamwork skills can effectively be taught in engineering programmes. Building on this, the paper describes how the new curricular education has been designed, what is taught, and how an inclusive, regardful, and pleasant atmosphere has been created for the intercultural project teams.

In performing electrochemical reduction of CO 2 over Cu electrodes, the anions present in solution typically do not participate in the formation of reaction products. NO 3 - is an exception, and previous reports indicate the formation of urea in certain process conditions. Here we demonstrate by use of Surface Enhanced Raman Spectroscopy and Electrochemical Mass spectrometry that simultaneous reduction of NO 3 - and CO 2 on Cu surfaces forms carbon-nitrogen bonds in the form of cyanide. The Raman peak position of C≡N is dependent on the oxidation state of the Cu surface, and Cu-C≡N can be oxidized by anodic polarization yielding NO. More importantly, Cyanide likely forms soluble Cu-C≡N complexes, which cause catalyst surface instability. The implications of this observation for practical application of a process for electrochemical formation of urea, are discussed.

Here we present the preparation of a novel positively charged covalent organic polymer (COP) based nano -filtration membrane. The porous COP selective layer grows on top of a polybenzimidazole (PBI) support from coupling reaction of 1,3,5-tris(bromomethyl)benzene and 4,4 '-dipyridyl in alkaline conditions. Chemical and morphological analyses confirm the formation of a thin layer of COP (less than 50 nm), which is also evidenced by its high water permeance and salt retentions. Moreover, it is shown that COP membranes can form hydrogen bonds with HNO3, leading to a tighter membrane pore size that increases the NaCl retention from 46% to 75% without significantly losing its permeance. Further, the composite membranes demonstrated exceptional solvent and pH stabilities. The COP membranes showed a molecular weight cut off between 400 and 1000 g mol-1 together with pure solvent permeances of 0.91, 2.4, 3.3, 7.1 and 9.5 Lm- 2h-1bar-1 toward dimethylformamide (DMF), ethanol, acetone, methanol an acetonitrile, respectively. The remarkable performance together with the stability in harsh environments make the newly developed COP membranes an attractive candidate for extreme nanofiltration.

Reduction of nitric oxide was investigated using Cu electrodes in acid and neutral pH conditions. Analysis of Cu discs in stagnant electrolyte by Electrochemical Mass Spectrometry (EC-MS), revealed the favorable formation of ammonia (and hydrogen) in acidic electrolyte, while N2O and N-2 are formed in significant quantities at neutral conditions. Additional performance evaluation of Cu electrodes in hollow fiber geometry, was performed using 10 vol % NO in Ar supplied through the porous electrode structure and off-line determination of ammonia by H-1 NMR spectroscopy. The pH dependent performance of the Cu hollow fiber is in agreement with EC-MS data at low gas flow rates, showing the highest ammonia selectivity in acidic conditions. However, at relatively high gas flow rates, almost 90 % faradaic efficiency and a NH3 production rate of 400 mu mol h(-2) cm(-2) were obtained in neutral electrolyte at -0.6 V vs RHE, likely due to enhanced availability of NO at the electrode surface, suppressing the hydrogen evolution reaction. This approach shows conversion of waste NO gas to valuable green fertilizer components is possible.