Mixtures of deliquescent solids are susceptible to deliquescence lowering, where water vapor condensation occurs in mixtures at a lower critical relative humidity (RH(0mix)) than individual component critical relative humidities (RH(0)s). The purpose of this study was to evaluate the effect of deliquescence lowering on chemical reactivity. Sucrose, citric acid and their physical mixtures were characterized using vapor sorption analysis to determine RH(0) and RH(0mix). Acid-catalyzed sucrose hydrolysis kinetics was determined using polarimetric analysis. Physical mixtures of sucrose and citric acid crystals were prepared and stored at various relative humidities at 22 degrees C. For these physical mixtures, sucrose hydrolysis was found to occur only when the environmental RH exceeded RH(0mix). Degradation kinetics correlated with the storage RH, being fastest at higher RH. In addition, a lag period was initially observed, which was most prominent for samples stored close to RH(0mix). With exposure to RHs below RH(0mix), no sucrose degradation was detected over the experimental time period. In conclusion, mixtures of deliquescent solids showed increased water sorption at lower RHs, which caused solid dissolution and subsequently led to an increase in the chemical reactivity.
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http://dx.doi.org/10.1021/jp0612376 | DOI Listing |
Sensors (Basel)
December 2024
Laboratoire d'Analyse et d'Architecture des Systèmes (LAAS), Université de Toulouse, CNRS, UPS, 7 Avenue du Colonel Roche, 31031 Toulouse, France.
The need for odor measurement and pollution source identification in various sectors (aeronautic, automobile, healthcare…) has increased in the last decade. Multisensor modules, such as electronic noses, seem to be a promising and inexpensive alternative to traditional sensors that were only sensitive to one gas at a time. However, the selectivity, the non-repetitiveness of their manufacture, and their drift remain major obstacles to the use of electronic noses.
View Article and Find Full Text PDFPharmaceutics
December 2024
Department of Pharmaceutics and Drug Delivery, School of Pharmacy, The University of Mississippi, Oxford, MS 38677, USA.
This study evaluates the efficacy of twin screw melt granulation (TSMG), and hot-melt extrusion (HME) techniques in enhancing the solubility and dissolution of simvastatin (SIM), a poorly water-soluble drug with low bioavailability. Additionally, the study explores the impact of binary polymer blends on the drug's miscibility, solubility, and in vitro release profile. SIM was processed with various polymeric combinations at a 30% / drug load, and a 1:1 ratio of binary polymer blends, including Soluplus (SOP), Kollidon K12 (K12), Kollidon VA64 (KVA), and Kollicoat IR (KIR).
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Special and Key Laboratory for Development and Utilization of Guizhou Superior Bio-Based Materials, Guizhou Minzu University, Guiyang 550025, China.
Improving the physical, mechanical, and creep properties of wood fiber-reinforced polymer composites is crucial for broadening their application prospect. In this research, seven types of high-density polyethylene (HDPE) composites reinforced with different mass ratios of Masson pine ( Lamb.) and Chinese fir [ (Lamb.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1, 119991 Moscow, Russia.
The scope of this work was to develop a thin-film composite (TFC) membrane for the separation of CO/CO mixtures, which are relevant for many processes of gas processing and gasification of carbon-based feedstock. Special attention was given to the development of highly permeable porous polysulfone (PSF) supports (more than 26,000 GPU for CO) since both the selective and support layers contribute significantly to the overall performance of the TFC membrane. The PSF porous support is widely used in commercial and lab-scale TFC membranes, and its porous structure and other exploitation parameters are set during the non-solvent-induced phase separation (NIPS) process.
View Article and Find Full Text PDFMolecules
December 2024
Department of Inorganic & Analytical Chemistry, Faculty of Science & Technology, University of Debrecen, H-4032 Debrecen, Hungary.
Heterobimetallic complexes of an ambidentate deferiprone derivative, 3-hydroxy-2-methyl-1-(3-((pyridin-2-ylmethyl)amino)propyl)pyridin-4(1H)-one (PyPropHpH), incorporating an octahedral [Co(4N)] (4N = tris(2-aminoethyl)amine (tren) or tris(2-pyridylmethyl)amine (tpa)) and a half-sandwich type [(η--cym)Ru] (-cym = -cymene) entity have been synthesized and characterized by various analytical techniques. The reaction between PyPropHpH and [Co(4N)Cl]Cl resulted in the exclusive (O,O) coordination of the ligand to Co(III) yielding [Co(tren)PyPropHp](PF) () and [Co(tpa)PyPropHp](PF) (). This binding mode was further supported by the molecular structure of [Co(tpa)PyPropHp](ClO)(OH)·6HO () and [Co(tren)PyPropHpH]Cl(PF)·2HO·CHOH (), respectively, obtained via the slow evaporation of the appropriate reaction mixtures and analyzed using X-ray crystallography.
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