Properties, layered materials

What could we do with layered structures with just the right layers What would the properties of materials be if we could really arrange the atoms the way we want them They would be very interesting to investigate. 

A key feature of the chemistry of layered materials is their ability to locate and orient guest molecules of interest within constrained interlayer regions. Once intercalated, the guest molecules can demonstrate a range of interesting properties [3,66]. In... 

The formation of closed polyhedra and nanotubes is expected to be a common property of materials with anisotropic 2D-layered structures, when their dimensions diminish to the nanometer range (thousands of atoms). This is due to the increasing instability of the planar structure on this scale, since too many dangling bonds would result. In fact, if the crystallites are not... 

To date, the transport properties of inorganic nanotubes have not been reported. A wealth of information exists on the transport properties of the bulk 2D layered materials, which is summarized in a few review articles [see, e.g., (72 and 89)]. 

The selective intercalation of guests into solid hosts offers the potential for application in catalysis and separation science. An excellent case in point is zeolites, which exhibit shape and size selective inclusion properties and are used for an enormous variety of processes [44,45]. Additionally, a munber of layered materials have been reported to possess selective intercalation properties, including layered metal phosphonates [46,47], montmorUlonite [48], magnesium aluminum oxide [49], and layered double hydroxides [50-59]. 

Williams, P. M. (1976) Optical and Electrical Properties of Layered Materials (ed. Lee, P. A.) D. Reidel, Dordrecht, Holland. 

It is clear that intermolecular effects strongly influence the properties of materials. The point is that one may make use of them in a controlled fashion to induce specific changes when and where desired. The self-assembly of membranes, molecular layers, films, vesicules, etc. incorporates interactions such as hydrophobic effects, hydrogen bonding, electrostatic forces and surface binding [7.1-7.13, 7.45, 7.87, 9.134-9.141], which may be used to produce specific structural and functional properties. 

Various mechanical testing methods have been used to assess the bioadhesive properties of materials and formulations. Review of the literature reveals that the technique most commonly used is the tensile test [82,85]. This test provides the measure of the force needed to detach a layer of the tested material or formulation from a mucosal substrate as a function of the displacement occurring at the bioadhesive interface. Besides maximum force of detachment, another parameter provided by tensile test is the work of adhesion calculated as the area under the force versus displacement curve. Such a parameter gives more complete... 

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