Metal-organic frameworks (MOFs) are a new class of microporous materials that possess framework flexibility, large surface areas, “tailor-made” framework functionalities, and tunable pore sizes. These features empower MOFs superior performances and broader application spectra than those of zeolites and phosphine-based molecular sieves. In parallel with designing new structures and new chemistry of MOFs, the observation of unique breathing behaviors upon adsorption of gases or solvents stimulates their potential applications as host materials in gas storage for renewable energy. This has attracted intense research energy to understand the causes at the atomic level, using in situ X-ray diffraction, calorimetry, Fourier transform infrared spectroscopy, and molecular dynamics simulations. This article is developed in the following order: first to introduce the definition of MOFs and the observation of their framework flexibility. Second, synthesis routes of MOFs are summarized with the emphasis on the hydrothermal synthesis, owing to the environmental-benign and economically availability of water. Third, MOFs exhibiting breathing behaviors are summarized, followed by rationales from thermodynamic viewpoint. Subsequently, effects of various functionalities on breathing behaviors are appraised, including using post-synthetic modification routes. Finally, possible framework spatial requirements of MOFs for yielding breathing behaviors are highlighted as the design strategies for new syntheses.

No abstract

No abstract

In this study, gaseous ozone was used as a fungicide to preserve stored wheat. The following operating parameters were investigated for their effects on the fungicidal efficacy of ozone: (1) the applied ozone dose; (2) ozonation time; (3) water activity of the wheat; and (4) temperature of the wheat. The effect of ozonation on germination of the wheat was also studied. Experimental results revealed that gaseous ozone was very effective in the inactivation of fungi associated with the wheat. Within 5 min of ozonation, 96.9% of the fungal spores were inactivated by applying 0.33 mg of ozone (g wheat) −1 min −1 . It was also found that increases in both water activity and temperature of the wheat enhanced the fungicidal efficacy of ozone. In addition, results of this study indicated that the inactivation processes could be controlled by simply monitoring the ozone exiting from the reactor and, consequently, the time-consuming microbial examination processes could be avoided. This finding would make the application of ozone in the preservation of cereal grains easier, simpler, and more cost-effective. It was also found that although the applied ozone doses above certain thresholds may reduce the germination of wheat, the inactivation of fungi could be achieved using applied ozone doses far below those thresholds.

Polysulfone (PSU) membranes have been widely applied in microfiltration and ultrafiltration processes due to their excellent properties, such as chemical inertness across the entire pH range, compressive strength, and thermal stability. Despite these advantages, the application of PSU membranes in filtration processes has often been restricted due to their hydrophobic nature, which results in serious membrane fouling and a reduced permeate flux. Moreover, PSU membranes suffer from several disadvantages, including bulky structure, low binding force between fibers, and poor mechanical properties. The key factor in the development and application of polymeric membranes is the control of its polymeric morphology due to the significant influence of membrane morphology on the membrane performance. Effective techniques of controlling PSU membrane morphology are accessed, and the effects of the morphological control on mechanical properties, chemical stability, membrane performance, and membrane fouling are investigated. Findings from various individual studies were analyzed and discussed in order to provide a critical review of this subject. The results emphasized that the membrane pore size and surface porosity mostly governs PSU membrane morphology, which enhances membrane performance and reduces membrane fouling.