Interlayer distance, intercalation

Z-4A), and zeolite H-ZSM-5. The interlayer distance varied by the intercalation was determined from X-ray diffraction patterns. The interlayer space of the crystalline zeolite is separated by the three-dimensional cage structures. The mean diameters of particles were approximately 1 ym. Such small particles formed very stable suspensions with no sign of sedimentation over the time course of the kinetic measurements. The analytical techniques used to obtain the equilibrium concentration are described elsewhere (10-22). All samples were equilibrated for 24-72 h after preparation. The temperature was controlled at 25 °C. 

The rate constants and interlayer distances determined from X-ray diffraction patterns for the intercalation studies described above are given in Table V. In those systems where intercalation causes large changes in the interfacial potential (ZrP and TiS2), Equations 32 and 33 were modified using intrinsic rate constants. In cases where steady state reactive intermediates were postulated, the rate constants in Equations 32 and 33 were modified as shown in Table V. 

Table V. Rate Constants and Interlayer Distance in Intercalation Studies a...

A small increase of the (d 001) basal spacing is observed for the Li containing Zr pillared clays. However, the thermal stability of these solids drastically decrease. At high temperature, the collapse of the strucutre is also supported by the decrease of the surface area which is, at 700°C, almost identical to those measured for the montmorillonite. Different hypothesis may be proposed to explain the increase of the interlayer distance at low temperature (i) a better polymerization of the intercalated complex (ii) a modification of the distribution of the pillars (iii) a lower interaction between the pillar and the silica layer. The first hypothesis may easily be eliminated since the small variation of the height of the pillars (less than 1 A) cannot be explained by structural changes of the... 

Correlation between calculated interaction energies of intercalated systems at the B3LYP/3-21G and the number of H-bonds, experimental interlayer distances [109, 114, 134] and calculated (B3LYP/3-21G ) molecular volumes of intercalated molecules ... 

On a global scale, the linear viscoelastic behavior of the polymer chains in the nanocomposites, as detected by conventional rheometry, is dramatically altered when the chains are tethered to the surface of the silicate or are in close proximity to the silicate layers as in intercalated nanocomposites. Some of these systems show close analogies to other intrinsically anisotropic materials such as block copolymers and smectic liquid crystalline polymers and provide model systems to understand the dynamics of polymer brushes. Finally, the polymer melt-brushes exhibit intriguing non-linear viscoelastic behavior, which shows strainhardening with a characteric critical strain amplitude that is only a function of the interlayer distance. These results provide complementary information to that obtained for solution brushes using the SFA, and are attributed to chain stretching associated with the space-filling requirements of a melt brush. 

Interlayer distance data of DA intercalated OL-l samples show that only one layer of amines was intercalated into the layers with average intercalation angles of about 40, 69, and 61°, respectively, for en-OL-1, 1,6-DHA-OL-l, and 1,10-HOA-OL-1. TMA intercalated H-OL-1 had two kinds of interlayer distances of 2.58 and 1.18 nm. The larger interlayer structure may include two layers of TMA and three layers of water molecules according to diameters of these molecules/ions. The small one included one layer of TMA cations and one layer of water molecules corresponded to the type II model of TMA manganese oxide prepared by redox methods using tetramethylammonium permanganate [33]. The structures of TEA, TPA, and TBA... 

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