Direct molecular dynamics mixed techniques

CP dynamics has also been very useful technique for estimation of the connectivities in the porous solids. Classic example in this case would be a clear distinction between Q2, Q3 and Q4 silicate sites in the molecular sieves on the basis of not only the chemical shift but also Tcp times which, as a result of no protons connected directly are much longer for Q4 sites (Si(OSi)4). Introduction of guest species in the pores has a dramatic effect on the CP-dynamics of the different silica sites. Thus, in the MCM-41 impregnated with the mixed metal clusters/counter-cation species, presence of embedded organic counter-cation lead to a significant reduction of Tcp and Tiph due to the presence of a different source of protons at the porous silica surface.21... 

The dynamical behavior of molecular liquids is directly observed via femtosecond optical Kerr effect (OKE) measurement in the time domain. The signal intensity, 5oke( ")i obtained by the measurement using an optically heterodyne-detected (OHD) technique (mixing the OKE signal with a local oscillator) can be expressed in the form ... 

In order to better understand miscibility in polyimide-based systems. Sun et al. (1991) prepared pairs of polyimide blends with different molecular structures by two ways, mixing of the polyamic acid precursors with subsequent imidization and direct solution mixing of the polyimides. Dynamic mechanical analysis (DMA) techniques showed that aU of the blends prepared in the two different ways were miscible, as evidenced by the existence of only one Tg for all of the blends. It was proposed that the miscibility of these polyimide/polyimide blends is a result of the strong intermolecular charge-transfer interaction between the chains of the blend components. 

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