Mixed matrix membranes (MMMs) incorporating ZIF-8 nanoparticles through non-solvent induced phase separation (NIPS) hold great potential in the organic solvent nanofiltration (OSN) field, but their advancement and application have been significantly hindered by ZIF-8's instability in aqueous conditions and major interfacial incompatibilities with polymers. This study presents an innovative approach to overcome these obstacles by initially forming ZnO/polyimide (PI) MMMs via NIPS, followed by in-situ conversion of ZnO to ZIF-8 within the membrane structure. The resulting crosslinked ZIF-8/PI membranes exhibit an ultra-high ethanol (EtOH) permeance of 42.7 L m−2 h−1 bar−1 and a 99.5% rejection of Rose Bengal dye, surpassing the performance of all state-of-the-art OSN MMMs to our knowledge. Additionally, these membranes demonstrate excellent resistance to harsh solvents such as N,N-Dimethylformamide (DMF) and N-methyl-2-pyrrolidone (NMP). It is evident that, the strategic use of ZnO as a precursor, followed by its transformation to ZIF-8 within the membrane pores, significantly enhances both ethanol permeance and solute rejection capabilities. The crosslinking with hexanediamine and the formation of ZIF-8/PI MMMs not only preserve the structural integrity and flexibility of polyimide films but also improve their solvent and thermal stability. This work also underscores the importance of careful control of ZnO concentrations and optimization of NIPS process parameters, which can significantly influence membrane performance. The findings significantly advance the development of OSN membranes, reducing the environmental footprint of industrial filtration processes and paving the way for customized, high-performance OSN membrane solutions in critical applications.
In this study, the applicability of Ba(Ce,Co,Y)O3−δ (BCCY) for a cathode of proton-conducting ceramic fuel cells was investigated. The electrical conductivity and transference number of BCCY were significantly affected by a cobalt content in the oxide. It was found that this material showed a mixed conduction of proton, oxide ion, and electron. The addition of cobalt into Ba(Ce,Y)O3−δ mainly increased the electronic conductivity of materials. Composite electrodes with an optimum composition of La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF)–BaCe0.7Co0.2Y0.1O3−δ (50:50 wt.%) exhibited lower polarization for the symmetrical cell test with a BaCe0.8Y0.2O3−δ electrolyte in 6.5% humidified oxygen atmosphere, as compared with La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) itself and LSCF–BaCe0.9Y0.1O3−δ (50:50 wt.%) composite electrodes. The power generation test was performed at 600°C–700°C using a BaCe0.8Y0.2O3−δ electrolyte-supported single cell employing a LSCF–BaCe0.7Co0.2Y0.1O3−δ (50:50 wt.%) composite cathode, upon feeding 3% humidified hydrogen and pure oxygen to the anode and cathode, respectively. The cell with a LSCF–BaCe0.7Co0.2Y0.1O3−δ (50:50 wt.%) composite cathode exhibited much higher performance than that with a LSCF electrode. Consequently, the introduction of cobalt into Ba(Ce,Y)O3−δ was an effective strategy for an improvement in an oxygen reduction reaction activity of a cathode material.
Abstract Nanocrystals refer to materials with at least one dimension smaller than 100 nm, composing of atoms arranged in single crystals or polycrystals. Nanocrystals have significant research value as they offer unique advantages over conventional pharmaceutical formulations, such as high bioavailability, enhanced targeting selectivity and controlled release ability and are therefore suitable for the delivery of a wide range of drugs such as insoluble drugs, antitumor drugs and genetic drugs with broad application prospects. In recent years, research on nanocrystals has been progressively refined and new products have been launched or entered the clinical phase of studies. However, issues such as safety and stability still stand that need to be addressed for further development of nanocrystal formulations, and significant gaps do exist in research in various fields in this pharmaceutical arena. This paper presents a systematic overview of the advanced development of nanocrystals, ranging from the preparation approaches of nanocrystals with which the bioavailability of poorly water‐soluble drugs is improved, critical properties of nanocrystals and associated characterization techniques, the recent development of nanocrystals with different administration routes, the advantages and associated limitations of nanocrystal formulations, the mechanisms of physical instability, and the enhanced dissolution performance, to the future perspectives, with a final view to shed more light on the future development of nanocrystals as a means of optimizing the bioavailability of drug candidates. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology
The Ba1-xSrxTiO3 thin films were prepared by a sol-gel method using barium acetate (Ba(Ac)2). strontium acetate (Sr(Ac)2)and titanium-tetrabutoxide (TBT) as starting materials. Acetic acid and 2-methoxyethanol were selected as solvents separately. The efFects of addition of acetylacetone (HAcAc) on the characteristics of pyrolysis evolution and microstructures of thin films were investigated.The results showed that the addition of HAcAc changes the properties of inorganic intermediate-phases which transform into perovskite phase. Under the same heat treatment conditions, the grain size of the thin films modified by HAcAc is about 100urn, which is larger than that of the films without modification of HAcAc.
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