Macromol Rapid Commun
November 2024
'On-water' catalysis entails the significant enhancement of a chemical reaction by water, even when those reactions are known to be water-sensitive. Here, the findings about the anionic ring opening polymerization of epoxides at the static interface between oil and alkaline water are shared. Unexpectedly, high molar mass fractions are observed with the interfacial system presented herein, albeit at very low conversions (< 5%).
View Article and Find Full Text PDFThin films of crystalline and porous metal-organic frameworks (MOFs) have great potential in membranes, sensors, and microelectronic chips. While the morphology and crystallinity of MOF films can be evaluated using widely available techniques, characterizing their pore size, pore volume, and specific surface area is challenging due to the low amount of material and substrate effects. Positron annihilation lifetime spectroscopy (PALS) is introduced as a powerful method to obtain pore size information and depth profiling in MOF films.
View Article and Find Full Text PDFThere is no efficient wastewater treatment solution for removing organic micropollutants (OMPs), which, therefore, are continuously introduced to the Earth's surface waters. This creates a severe risk to aquatic ecosystems and human health. In emerging water treatment processes based on ion-exchange membranes (IEM), transport of OMPs through membranes remains unknown.
View Article and Find Full Text PDFIon-exchange membrane (IEM)-based processes are used in the industry or in the drinking water production to achieve selective separation. The transport mechanisms of organic solutes/micropollutants (i.e.
View Article and Find Full Text PDFThe landscape of possible polymorphs for some metal-organic frameworks (MOFs) can pose a challenge for controlling the outcome of their syntheses. Demonstrated here is the use of a template to control in the vapor-assisted formation of zeolitic imidazolate framework (ZIF) powders and thin films. Introducing a small amount of either ethanol or dimethylformamide vapor during the reaction between ZnO and 4,5-dichloroimidazole vapor results in the formation of the porous ZIF-71 phase, whereas other conditions lead to the formation of the dense ZIF-72 phase or amorphous materials.
View Article and Find Full Text PDFEnergy-efficient indoors temperature and humidity control can be realised by using the reversible adsorption and desorption of water in porous materials. Stable microporous aluminium-based metal-organic frameworks (MOFs) present promising water sorption properties for this goal. The development of synthesis routes that make use of available and affordable building blocks and avoid the use of organic solvents is crucial to advance this field.
View Article and Find Full Text PDFThe chlorine resistance of nanofiltration and reverse osmosis membranes is of high importance in the water treatment industry. Elastic recoil detection (ERD) is now presented as a powerful tool to uniquely provide elemental depth profiles, including hydrogen, of NaOCl-treated polyamide-based thin-film composite (TFC) membranes. The influence of pressure, pH, and chlorine feed concentration on the volume-averaged Cl uptake, the location of chlorine throughout the membrane, and the -gradient in the Cl/N ratio is demonstrated.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
February 2019
Metal-organic frameworks (MOFs) enable the design of host-guest systems with specific properties. In this work, we show how the confinement of anthracene in a well-chosen MOF host leads to reversible yellow-to-purple photoswitching of the fluorescence emission. This behavior has not been observed before for anthracene, either in pure form or adsorbed in other porous hosts.
View Article and Find Full Text PDFFollowing current strong demands from, among others, paper, food and mining industries, a novel type of nanofiltration membrane was developed, which displays excellent performance in terms of selectivity/flux with a unique combination of chemical stability over the full (0-14) pH-range and thermal stability up to 120 °C. The membrane consists of polyvinylidene fluoride grafted with polystyrene sulfonic acid. The optimum membrane showed water permeances of 2.
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