Fickian relationship: A material and permeant
pair are considered Fickian coefficient does not change with time or concentration.
Path tortuosity for permeant water molecules at the nanoscale can be increased by addition of nanoclay to the PA-6 phase, which has an affinity for water due to the formation of hydrogen bonds.
This approach would be particularly effective when the more permeable phase is dispersed, by isolating it from the permeant.
Gravimetric measurements were performed to determine how the shape and size of the permeant molecules would influence their diffusion behaviour into the polyester matrix and each permeant will be discussed separately.
Increase of the temperature lowers the amount of permeant required to achieve plasticization and increases the rate at which the chains can reorganise.
On the other hand, the free-volume group of parameters require the calculation of the ratio of permeant
to polymer jump size units ([xi]), which can be obtained through the glass transition temperature of the polymer .
The net result of this is that larger spherulites are more effective in creating increased tortuosity in the path of penetrating permeant
It is generally recognized that the molecular composition and structure in the amorphous phase of the polymer can greatly affect its barrier properties, since the permeant
molecules are believed to enter and diffuse through the polymer mostly by penetrating through its amorphous regions.
On the other hand, the results of recent studies suggest that gap junctions are permeant
to calcium ions when intracellular calcium concentrations are below 1 [[micro]molar] (3, 4).
must dissolve into the barrier (the rate is governed by the solubility coefficient, S), diffuse through the barrier (governed by the diffusion constant, D) and emerge on the other side of the barrier.
PARIS, Nov 1 (KUNA) -- Kuwait pins substantial hopes on the UNESCO 38th General Conference, the country's permeant
envoy to the organization Dr.
The parallel coupling of components implies that all constituents (phases) are continuous in the direction of the permeant
flux [16, 24] (or acting force in the case of mechanical properties).
However, the use of a laminar structure is based on the idea that the laminar dispersed phase acts as barrier to the permeant
molecule by providing a long, tortuous path.
Hassan Al-Ibrahim added in a speech he gave on the occasion of the 197th session of UNESCO's Executive Council held in Paris, which was attended by Kuwait's Permeant
envoy to UNESCO Dr.
CAIRO, Nov 9 (KUNA) -- Egypt on Sunday called for holding an urgent meeting at the Arab League at the level of permeant
delegates to discuss the current crisis between Somali President Hassan Sheikh Mahmud and his Prime Minister Abdiweli Sheikh Ahmed.