Barrer

1 Examples of Polymers with Low Permeability of Small Molecules (e.g., P02 50 Barrer) 

7 Molecular Modeling, A Tool for the Knowledge-Based Design Design of Polymer-Based 

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The detailed consideration of these equations is due largely to Kozeny [50] the reader is also referred to Collins [51]. However, it is apparent that, subject to assumptions concerning the topology of the porous system, the determination of K provides an estimate of Ao- It should be remembered that Ao will be the external area of the particles and will not include internal area due to pores (note Ref. 52). Somewhat similar equations apply in the case of gas flow the reader is referred to Barrer [53] and Kraus and co-workers [54]. 

R. M. Barrer, Proc. 10th Colston Symp., Butterworths, London, 1958, p. 6. 

Barrer R M 1982 Fiydrothermai Chemistry of Zeoiites (London Academic)... 

The dynamic viscosity, or coefficient of viscosity, 77 of a Newtonian fluid is defined as the force per unit area necessary to maintain a unit velocity gradient at right angles to the direction of flow between two parallel planes a unit distance apart. The SI unit is pascal-second or newton-second per meter squared [N s m ]. The c.g.s. unit of viscosity is the poise [P] 1 cP = 1 mN s m . The dynamic viscosity decreases with the temperature approximately according to the equation log rj = A + BIT. Values of A and B for a large number of liquids are given by Barrer, Trans. Faraday Soc. 39 48 (1943). 

R. M. Barrer, Zeolites and Clay Minerals as Sorbents and Molecular Sieves , p. 174, Academic Press, London and New York (1978). 

Fig. 3.17 Isotherms on a natural sodium-rich montmorillonite. Circles denote adsorption, crosses desorption. (Courtesy Barrer.)...

Alternatively one may note (with Barrer ) that, from Equation (4.1) with substitution of n/n = 0, we have... 

Fig. 4.4 Plot of the logarithm of the Langmuir quotient 0/p( - 0) against 0 for adsorption on H-chabasite at various temperatures." (a) Argon (h) carbon dioxide. (After Barrer and Davies.)...

Fig. 4.28 Isotherms for polar adsorbates on natural montmorillonite at 323 K. (Courtesy Barrer.) O, adsorption x, desorption.

The total potential energy of adsorption interaction may be subdivided into parts representing contributions of the different types of interactions between adsorbed molecules and adsorbents. Adopting the terminology of Barrer (3), the total energy of interaction is the sum of contributions... 

R. M. Barrer and B. Coughlin, Molecular Sieves, Society of Chemical Industry, London, 1968, p. 141. 

In the contact lens field, barrer units are typically used for the oxygen permeabiUty coefficient (Dk). 

Fig. 1. Correlation of Dk with percent water (log-linear plot). 1 barrer = 10 cm O2 (at STP)-cm/(cm -s-mm Hg).

USAN name Material composition Dk barrer Trade name Manufacturer... 

USAN name CAS Registry Number Composition Water content, % Dk, barrer Modulus, MPa" Trade name Manufacturer... 

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