RESUMO
Nowadays, the practical applications of metal-organic framework (MOF)-based fluorescence detectors are severely hindered because of the complex synthesis process of linkers or heavy metal contamination. The development of a simple, inexpensive, and environmentally friendly fluorescence sensing system remains a huge challenge. In this study, we designed and synthesized a TPE@γ-CD-MOF-K complex using the facile in situ encapsulation method. The unique pore structure of γ-CD-MOF allowed it to effectively include TPE and explosives as guests simultaneously. The TPE@γ-CD-MOF-K showed stronger fluorescence emission than TPE and sensitive fluorescence quenching activities in response to nitro-aromatic compounds in the liquid phase with detection limits as low as 3 ppm. Furthermore, TPE@γ-CD-MOF-K can also effectively detect nitro-aromatic compounds in the solid state, which is very convenient for practical detection of explosives. The unique pore structure of γ-CD-MOF-K and the interaction between K+ and nitro compounds play important roles in solid-state quenching.
RESUMO
Fibers with good flame retardant (FR) and smoke suppression performances are highly desirable for the purpose of eliminating fire hazard. This study developed a novel FR fiber by wet-spinning poly (vinyl alcohol)/ß-cyclodextrin (PVA/ßCD) composite fiber and crosslinking it with hexamethylene diisocyanate (HDI). ßCDs showed good compatibility with PVA matrix, and the resulting PVA/CD/HDI fibers showed mechanical strength at the same level as natural cotton fiber. The PVA/CD/HDI fibers also showed excellent flame retardance (the LOI value of PVA/CD/HDI could reach 41.7%, and their peak of heat release (PHRR) could be reduced by up to 77.7% by neat PVA), and super-smoke suppression (the value of total smoke production (TSP) was only 28.6% compared to PVA). These dramatic reductions of fire hazard were ascribed to the char formation of ßCD and crosslinking structure of PVA/CD/HDI, which formed a compact char layer during combustion, thus preventing heat transmission and smoke release.
RESUMO
The adsorption of CO2 by conventional liquid alkanolamine adsorbents does not meet the requirements for green-friendly development in industrial applications. In this work, we constructed NH2-ß-CD-MOF for the first time through the amino-functionalization of the lowest-priced, readily available, and biocompatible ß-CD. Subsequently, the samples were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, elemental analysis, and N2 adsorption/desorption. The CO2 adsorption capacity of NH2-ß-CD-MOF was found to be 12.3 cm3/g, which is 10 times that of ß-CD-MOF. In addition, NH2-ß-CD-MOF has outstanding selective adsorption of CO2/N2 (947.52) compared with the reported materials. The adsorption mechanism of CO2 was analyzed by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Furthermore, we have found that NH2-ß-CD-MOF has better water stability relative to ß-CD-MOF and γ-CD-MOF, and it can be recycled by an ultrasonic method.
RESUMO
Airborne particulate matter (PM) pollution has become a serious environmental problem. Thus, there is a need for the development of air filters with satisfactory overall performance. In this paper, we develop a kind of ß-cyclodextrin (ß-CD) based air filter with high strength, which has not only high filtration efficiency (about 99%) but also good air permeability (the pressure drop is only 45Pa). Especially after long-term application, the pression drop of ß-cyclodextrin based was less than half of the commercial air-filter. Additionally, the material can capture the toxic gasous chemicals (e.g. formaldehyde and SO2). The introduction of ß-CD is supposed to be the key factor for improvement of air filter.
