Domain size, evaluation

Figure C2.17.9. Size-dependent changes in PXRD linewidtlis. PXRD can be used to evaluate tire average size of a sample. In tliese cases, different samples of nanocrystalline titania were analysed for tlieir grain size using tire Debye-Scherr fonnula. As tire domain size increases, tire widtlis of tire diffraction peaks decrease.

To get a better insight into the dynamics of prepared ICs, more advanced NMR experiments were carried out [19]. Distinctive cross-polarization parameters were observed for guest polymer and host a-cyclodextrin in the inclusion complex. For a-CD, as expected from the relatively rigid molecule, the intensity quickly rises to a maximum, and then quickly decays. The behaviour is quite different for the PCL-PEO-PCL block copolymer, which has a slow rise in intensity followed by a slower decay. Maximum intensity was observed at 1 ms and 0.5 ms CP-time for PCL-PEO-PCL and a-CD. To evaluate the domain size... 

SAXS is a more precise tool to quantitatively evaluate the two-phase structure of PU by providing the data of interdomain spacing, domain size, and interfacial thickness [40]. Figure 7.28 illustrated typical SAXS intensity profiles (/(S)S vs. 20) for PU/C20A nanocomposites. The one-dimensional correlation function F(Z) that is related to the electron density distribution within specimens is expressed as follows ... 

By investigating the development of magnetization distribution with mixing time, a quantitative evaluation of the degree of miscibility and domain size can be made. 

Combining Eqs [3.5] and [3.6], the volume fraction of soft phase 0, and hard phase 1 - can be calculated. With the phase composition, the domain sizes can also be evaluated. The Porod s law constant K is related to the interfacial surface-to-volume ratio S/V ... 

The mechanical properties, morphology and cryo-fractured surface of blends were evaluated to determine the efficiency of OBC as a blend compatibilizer. It was found that OBC multi-block copolymers can efficiently compatibilize PP/HDPE blends. The addition of OBC results in a significant reduction of domain size forming a shell around a HDPE core. The mechanical property of the blend has been... 

This modified density Is a more slowly varying function of x than the density. The domain of Interest, 0 < x < h, Is discretized uniformly and the trapezoidal rule Is used to evaluate the Integrals In Equations 8 and 9. This results In a system of nonlinear, coupled, algebraic equations for the nodal values of n and n. Newton s method Is used to solve for n and n simultaneously. The domain Is discretized finely enough so that the solution changes negligibly with further refinement. A mesh size of 0.05a was adopted In our calculations. 

In the main body, this sechon presents recently employed mesoscale computational methods that can be uhlized to evaluate structural factors during fabrication of PEMs. These simulations provide density distributions or maps and structural correlahon functions that can be employed to analyze the sizes, shapes, and connectivihes of phase domains of water and polymer the internal porosity and pore size distributions and the abundance and wetting properties of polymer-water interfaces. 

Pulsed field gradient (PFG)-NMR experiments have been employed in the groups of Zawodzinski and Kreuer to measure the self-diffusivity of water in the membrane as a function of the water content. From QENS, the typical time and length scales of the molecular motions can be evaluated. It was observed that water mobility increases with water content up to almost bulk-like values above T 10, where the water content A = nn o/ nsojH is defined as the ratio of the number of moles of water molecules per moles of acid head groups (-SO3H). In Perrin et al., QENS data for hydrated Nation were analyzed with a Gaussian model for localized translational diffusion. Typical sizes of confining domains and diffusion coefficients, as well as characteristic times for the elementary jump processes, were obtained as functions of A the results were discussed with respect to membrane structure and sorption characteristics. ... 

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