Sorption Kinetics in Finite-Bath Systems

1972 ◽  
Vol 98 (6) ◽  
pp. 1021-1036
Author(s):  
Francis A. DiGiano ◽  
Walter J. Weber
Keyword(s):  
Sorption Kinetics

Modeling of sorption kinetics of U(VI) micro-quantities nanostructured materials with anatase mesoporous structures

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Veniamin Zheleznov ◽  
Aleksey Golikov ◽  
Tatiana Sokolnitskaya ◽  
Sergey Ivannikov
Keyword(s):  
Nanostructured Materials ◽  
Sorption Kinetics ◽  
Uranyl Ion ◽  
Competitive Sorption ◽  
Hydroxyl Groups ◽  
Complex Ions ◽  
The Stability ◽  
Kinetics Of ◽  
Mesoporous Structures ◽  
Ionic Forms

Abstract The sorption kinetics of uranyl ions micro-quantities from fluoride solutions by nanostructured materials with anatase mesoporous structures has been studied. Using the model of competitive sorption of ions and positively charged complexes of uranyl ion on deprotonated hydroxyl groups of an anatase, kinetic curves of changes in the ratio of ionic forms of uranium in solution were calculated. Modeling was carried out under the assumption of a two-stage mechanism of uranium complex ions sorption. The modeling considered the influence of the uranyl ion carbonate complexes formation. The shift in equilibrium among ionic forms of uranyl correlates with the stability of the complexes in solution.

Nanocrystalline Mg-based hydrides for hydrogen storage

2001 ◽  
Vol 676 ◽  
Author(s):  
W. Oelerich ◽  
T. Klassen ◽  
R. Bormann
Keyword(s):  
Hydrogen Storage ◽  
Mobile Applications ◽  
Research Effort ◽  
Metal Hydrides ◽  
Clean Energy ◽  
High Energy ◽  
Sorption Kinetics ◽  
Desorption Kinetics ◽  
Gaseous State ◽  
Sorption Behaviour

ABSTRACTHydrogen is the ideal means of energy storage for transportation and conversion of energy in a comprehensive clean-energy concept. However, appropriate storage facilities, both for stationary and for mobile applications, are complicated, because of the very low boiling point of hydrogen (20.4 K at 1 atm) and its low density in the gaseous state (90 g/m3). Furthermore, the storage of hydrogen in liquid or gaseous form imposes safety problems, in particular for mobile applications, e.g. the future zero-emission vehicle. Metal hydrides are a safe alternative for H-storage and, in addition, have a high volumetric energy density that is about 60% higher than that of liquid hydrogen. Mg hydride has a high storage capacity by weight and is therefore favoured for automotive applications. However, so far light metal hydrides have not been considered competitive because of their rather sluggish sorption kinetics. Filling a tank could take several hours. Moreover, the hydrogen desorption temperature of about 300 °C is rather high for most applications. A breakthrough in hydrogen storage technology was achieved by preparing nanocrystalline hydrides using high-energy ball milling. These new materials show very fast aband desorption kinetics within few minutes, thus qualifying lightweight Mg-based hydrides for storage application. In this paper recent detailed results on the sorption behaviour of nanocrystalline Mg and Mg-based alloys are presented. In a following research effort the sorption kinetics of nanocrystalline Mg has been further enhanced by catalyst additions. Furthermore, different transition metals have been added to Mg to achieve a thermodynamic destabilisation of the hydride, thus lowering the desorption temperatures to about 230 °C. The newly developed materials are currently being tested in prototype storage tanks.

Assessing polymer sorption kinetics using micromachined resonators

2011 ◽  
Author(s):  
J.-J. Su ◽  
C. Carron ◽  
S. Truax ◽  
K.S. Demirci ◽  
L.A. Beardslee ◽  
...  
Keyword(s):  
Sorption Kinetics ◽  
Polymer Sorption

Model-based prediction of the moisture sorption kinetics and humidity-induced collapse for freeze–dried cakes

2022 ◽  
Vol 248 ◽  
pp. 117129
Author(s):  
Kyuya Nakagawa ◽  
Hiroki Kamisaki ◽  
Tetsuo Suzuki ◽  
Noriaki Sano
Keyword(s):  
Moisture Sorption ◽  
Sorption Kinetics ◽  
Model Based ◽  
Freeze Dried

Marangoni-enhanced capillary wetting in surfactant-driven superspreading

2018 ◽  
Vol 855 ◽  
pp. 181-209 ◽  
Author(s):  
Hsien-Hung Wei
Keyword(s):  
Contact Line ◽  
Stress Singularity ◽  
Marangoni Effect ◽  
Dynamic Contact ◽  
Sorption Kinetics ◽  
Colloid Interface ◽  
Hydrodynamic Approach ◽  
Interfacial Surfactant ◽  
Dynamic Contact Line ◽  
Air Liquid Interface

Superspreading is a phenomenon such that a drop of a certain class of surfactant on a substrate can spread with a radius that grows linearly with time much faster than the usual capillary wetting. Its origin, in spite of many efforts, is still not fully understood. Previous modelling and simulation studies (Karapetsas et al. J. Fluid Mech., vol. 670, 2011, pp. 5–37; Theodorakis et al. Langmuir, vol. 31, 2015, pp. 2304–2309) suggest that the transfer of the interfacial surfactant molecules onto the substrate in the vicinity of the contact line plays a crucial role in superspreading. Here, we construct a detailed theory to elaborate on this idea, showing that a rational account for superspreading can be made using a purely hydrodynamic approach without involving a specific surfactant structure or sorption kinetics. Using this theory it can be shown analytically, for both insoluble and soluble surfactants, that the curious linear spreading law can be derived from a new dynamic contact line structure due to a tiny surfactant leakage from the air–liquid interface to the substrate. Such a leak not only establishes a concentrated Marangoni shearing toward the contact line at a rate much faster than the usual viscous stress singularity, but also results in a microscopic surfactant-devoid zone in the vicinity of the contact line. The strong Marangoni shearing then turns into a local capillary force in the zone, making the contact line in effect advance in a surfactant-free manner. This local Marangoni-driven capillary wetting in turn renders a constant wetting speed governed by the de Gennes–Cox–Voinov law and hence the linear spreading law. We also determine the range of surfactant concentration within which superspreading can be sustained by local surfactant leakage without being mitigated by the contact line sweeping, explaining why only limited classes of surfactants can serve as superspreaders. We further show that spreading of surfactant spreaders can exhibit either the $1/6$ or $1/2$ power law, depending on the ability of interfacial surfactant to transfer/leak to the bulk/substrate. All these findings can account for a variety of results seen in experiments (Rafai et al. Langmuir, vol. 18, 2002, pp. 10486–10488; Nikolov & Wasan, Adv. Colloid Interface Sci., vol. 222, 2015, pp. 517–529) and simulations (Karapetsas et al. 2011). Analogy to thermocapillary spreading is also made, reverberating the ubiquitous role of the Marangoni effect in enhancing dynamic wetting driven by non-uniform surface tension.

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