An apparatus for measuring dissolution rates of solids in the form of disks was designed to possess the following features. The solvent flowed continuously and reproducibly past the disk at various rates associated with calculable Reynolds numbers, Re. The effluent solution was adequately mixed before analysis. The concentration of dissolved solute was much less than the solubility. The surface area of the disk in contact with the solvent was constant during measurements. The dissolution rate of the disk was reproducible, and the disk and its surface could be readily characterized. The apparatus was tested at 37 degrees with compressed potassium chloride and water. The intrinsic dissolution rate, G, was a linear function of Re from Re=360 to greater than 6000. This relationship enabled one unknown constant in each dissolution theory to be expressed in terms of Re. For the diffusion layer model, the thickness of this layer, calculated from the experimental value of G, agreed well with that calculated from the various physical properties, provided that natural convection did not predominate. The dissolution of potassium chloride in this system was, therefore, controlled by diffusion.
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http://dx.doi.org/10.1002/jps.2600650108 | DOI Listing |
Macromol Rapid Commun
January 2025
CP2M, UMR 5128, CNRS, Universite Claude Bernard Lyon 1, Villeurbanne, 69616, France.
Within the context of polypropylene recycling by dissolution, the potential degradation of polypropylene in solution has been investigated using in situ NIR and Raman spectroscopy. Pure polypropylene, completely free of additives, and commercial polypropylene, low in additives, are degraded on purpose under different conditions. Genetic algorithm combined with partial least squares (GA-PLS) models have been built based on near-infrared (NIR) spectra, and partial least squares (PLS) models based on Raman spectra, to predict the mass average molar mass and the chain-scission rate, respectively, during the degradation process.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
University of Zagreb, Faculty of Science, Department of Chemistry, Zagreb, HR-10000, Croatia.
The phenomenon of solid dissolution into a solution constitutes a fundamental aspect in both natural and industrial contexts. Nevertheless, its intricate nature at the microscale poses a significant challenge for precise quantitative characterization at a foundational level. In this work, the influence across three specific cleavage planes, namely (100), (111), and (110) on the dissolution kinetics of fluorite in aqueous environments was examined from both experimental and theoretical standpoints.
View Article and Find Full Text PDFInt J Pharm
January 2025
Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, Ontario M5S 3M2, Canada. Electronic address:
The objective of this study is to address the unanswered question whether sustained supersaturation generated from amorphous solid dispersions (ASDs) formulated in insoluble hydrogel carriers will result in better bioavailability over that of spring-and-parachute type of dissolution profiles of ASDs formulated in water-soluble carriers. This was achieved by investigating the effects of supersaturation generation rates and doses on the extent of absorption (i.e.
View Article and Find Full Text PDFSmall Methods
January 2025
School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
Electrochemical lithium extraction from salt lakes using LiMnO (LMO) presents an eco-friendly, highly controllable, and efficient method. However, its practical application is limited due to its structure instability and manganese dissolution in water. Herein, a high-performance LMO coated with ≈3.
View Article and Find Full Text PDFSmall
January 2025
Key Lab of Bamboo and Rattan Science & Technology, International Center for Bamboo and Rattan, Beijing, 100102, P. R. China.
A nitrogen-coordinated Fe single-atom catalyst (SA Fe-N/C) is synthesized using a homogeneous ethanol-based dissolution system with bamboo kraft lignin serving as the carbon source. Uniformly dispersed Fe atoms with an interatomic distance of less than 2 Å throughout the SA Fe-N/C structure are revealed through X-ray absorption spectral analysis and HAADF-STEM images, which possessed a high Fe loading of 2.69%.
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