STUDIES OF THE TRANSPORT PROPERTIES OF THE SYSTEM Tl2SO4-H2O. I. DIFFUSION COEFFICIENTS AT 25°1

1960 ◽  
Vol 64 (10) ◽  
pp. 1502-1506 ◽  
Author(s):  
J. M. Creeth ◽  
Beth E. Peter
Keyword(s):  
Transport Properties ◽  
Diffusion Coefficients

Self-diffusion, velocity cross-correlation, distinct diffusion and resistance coefficients of the ionic liquid [BMIM][Tf2N] at high pressure

2015 ◽  
Vol 17 (37) ◽  
pp. 23977-23993 ◽  
Author(s):  
Kenneth R. Harris ◽  
Mitsuhiro Kanakubo
Keyword(s):  
High Pressure ◽  
Ionic Liquid ◽  
Transport Properties ◽  
Diffusion Coefficients ◽  
Cross Correlation ◽  
Diffusion Velocity ◽  
Self Diffusion ◽  
Scaling Parameters ◽  
Resistance Coefficients ◽  
Viscosity Dependence

Distinct diffusion coefficients for 1-alkyl-3-imidazolium [Tf2N] salts show very similar viscosity dependence; thermodynamic scaling parameters for the reduced transport properties are equal.

scholarly journals Transport Properties for Pharmaceutical Controlled-Release Systems: A Brief Review of the Importance of Their Study in Biological Systems

Biomolecules ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 178 ◽  
Author(s):  
Ana C. F. Ribeiro ◽  
Miguel A. Esteso
Keyword(s):  
Controlled Release ◽  
Transport Properties ◽  
Diffusion Coefficients ◽  
Drug Carrier ◽  
Strong Association ◽  
Mutual Diffusion ◽  
Mixed Electrolytes ◽  
Coupled Transport ◽  
Concentration Gradients ◽  
Enhanced Solubility

: The goal of this work was to comprehensive study the transport properties of controlled-release systems for the safe and reliable delivery of drugs. Special emphasis has been placed on the measurement of the diffusion of drugs, alone or in combination with carrier molecules for enhanced solubility and facilitated transport. These studies have provided detailed comprehensive information—both kinetic and thermodynamic—for the design and operation of systems for the controlled release and delivery of drugs. Cyclodextrins are among the most important carriers used in these systems. The basis for their popularity is the ability of these materials to solubilize poorly soluble drugs, generally resulting in striking increases in their water solubilities. The techniques used in these investigations include pulse voltammetry, nuclear magnetic resonance (NMR) and Raman spectroscopy, ultrasonic relaxation, and dissolution kinetics. Transport in these systems is a mutual diffusion process involving coupled fluxes of drugs and carrier molecules driven by concentration gradients. Owing to a strong association in these multicomponent systems, it is not uncommon for a diffusing solute to drive substantial coupled fluxes of other solutes, mixed electrolytes, or polymers. Thus, diffusion data, including cross-diffusion coefficients for coupled transport, are essential in order to understand the rates of many processes involving mass transport driven by chemical concentration gradients, as crystal growth and dissolution, solubilization, membrane transport, and diffusion-limited chemical reactions are all relevant to the design of controlled-release systems. While numerous studies have been carried out on these systems, few have considered the transport behavior for controlled-release systems. To remedy this situation, we decided to measure mutual diffusion coefficients for coupled diffusion in a variety of drug–carrier solutions. In summary, the main objective of the present work was to understand the physical chemistry of carrier-mediated transport phenomena in systems of controlled drug release.

scholarly journals Liquid Structures and Transport Properties of Lithium Bis(fluorosulfonyl)amide/Glyme Solvate Ionic Liquids for Lithium Batteries

2019 ◽  
Vol 72 (2) ◽  
pp. 70 ◽  
Author(s):  
Shoshi Terada ◽  
Kohei Ikeda ◽  
Kazuhide Ueno ◽  
Kaoru Dokko ◽  
Masayoshi Watanabe
Keyword(s):  
Ionic Liquids ◽  
Transport Properties ◽  
Lithium Batteries ◽  
Diffusion Coefficients ◽  
The Self ◽  
Metal Anode ◽  
Self Diffusion ◽  
Molar Ratios ◽  
Li Metal Anode ◽  
A Current

The liquid structures and transport properties of electrolytes composed of lithium bis(fluorosulfonyl)amide (Li[FSA]) and glyme (triglyme (G3) or tetraglyme (G4)) were investigated. Raman spectroscopy indicated that the 1:1 mixtures of Li[FSA] and glyme (G3 or G4) are solvate ionic liquids (SILs) comprising a cationic [Li(glyme)]+ complex and the [FSA]− anion. In Li[FSA]-excess liquids with Li[FSA]/glyme molar ratios greater than 1, anionic Lix[FSA]y(y–x)– complexes were formed in addition to the cationic [Li(glyme)]+ complex. Pulsed field gradient NMR measurements revealed that the self-diffusion coefficients of Li+ (DLi) and glyme (Dglyme) are identical in the Li[FSA]/glyme=1 liquid, suggesting that Li+ and glyme diffuse together and that a long-lived cationic [Li(glyme)]+ complex is formed in the SIL. The ratio of the self-diffusion coefficients of [FSA]− and Li+, DFSA/DLi, was essentially constant at ~1.1–1.3 in the Li[FSA]/glyme<1 liquid. However, DFSA/DLi increased rapidly as the amount of Li[FSA] increased in the Li[FSA]/glyme>1 liquid, indicating that the ion transport mechanism in the electrolyte changed at the composition of Li[FSA]/glyme=1. The oxidative stability of the electrolytes was enhanced as the Li[FSA] concentration increased. Furthermore, Al corrosion was suppressed in the electrolytes for which Li[FSA]/glyme>1. A battery consisting of a Li metal anode, a LiNi1/3Mn1/3Co1/3O2 cathode, and Li[FSA]/G3=2 electrolyte exhibited a discharge capacity of 105mAhg−1 at a current density of 1.3mAcm−2, regardless of its low ionic conductivity of 0.2mScm−1.

scholarly journals Size Sensitive Transport Behavior of Liquid Metallic Mixtures

2015 ◽  
Vol 20 (2) ◽  
pp. 140-144
Author(s):  
Bhrigunandan Prasad Singh ◽  
Ishwar Koirala
Keyword(s):  
Size Effect ◽  
Transport Properties ◽  
Diffusion Coefficients ◽  
Liquid Alloys ◽  
Long Wavelength ◽  
Binary Liquid ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing ◽  
Gibb’S Free Energy ◽  
Limit Diffusion

We have used a formalism that connects thermodynamic and transport properties. The formalism has been used to calculate the Gibb’s free energy of mixing, concentration fluctuations in the long wavelength limit, diffusion coefficients and viscosity in Cu-Tl, Cu-Pb and Sn-Tl binary liquid alloys at 1573K, 1473K and 723K respectively with aid of size effect and no size effect. Our calculations show that appreciable size ratio has more effects on the transport properties as compared to thermodynamic properties of homo-coordinated liquid alloys Cu-Tl, Cu-Pb and Sn-Tl.Journal of Institute of Science and Technology, 2015, 20(2): 140-144  

scholarly journals Effect of Environmental Exposure on the Pore Structure and Transport Properties of Carbon Nanotube-Modified Mortars

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4543
Author(s):  
Panagiota Alafogianni ◽  
Konstantinos Dassios ◽  
Christos D. Tsakiroglou ◽  
Theodore E. Matikas ◽  
Nektaria-Marianthi Barkoula
Keyword(s):  
Carbon Nanotube ◽  
Pore Structure ◽  
Transport Properties ◽  
Environmental Exposure ◽  
Diffusion Coefficients ◽  
Gas Permeability ◽  
Small Diameter ◽  
Sulfate Attack ◽  
Significant Drop ◽  
Freeze Thaw

Τhe present study investigates the pore structure and transport properties of carbon nanotube-modified cementitious mortars after exposure to freeze-thaw cycles and immersion to sulfate ion solution (sulfate attack) and compares them to those of un-exposed mortars. The effect of parameters related to carbon nanotube content (within the range of 0.2–0.8 wt.%) and type of dispersant (superplasticizer/surfactant) are investigated. It is found that carbon nanotube inclusion results, overall, in a significant drop of the total porosity before exposure. Results demonstrate that environmental exposure leads to a reduction of the fraction of small diameter pores and a respective increase in capillary porosity for both dispersive agents compared to un-exposed specimens. Diffusion coefficients of nano-modified specimens are lower compared to those of un-modified mortars, both before exposure and after sulfate attack. In the case of freeze-thaw cycling, the diffusion coefficients were found to be higher in carbon nanotube-modified mortars when surfactants were used as dispersants, although with improved gas permeability values.

Sign in / Sign up

Export Citation Format

Share Document