Interfacial Properties on the Submicrometer Scale pptx

Interfacial Properties on the Submicrometer Scale In Interfacial Properties on the Submicrometer Scale; Frommer, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2000. About the Cover The background design is an atomic force microscopy image of an organosilane polymer film exposed toan oxygen plasma. The etching was performed through a mask, resulting in highly reticulated silicon oxide surfaces, smooth unexposed planes, and the gradient between the two featured in this image. The interface between reacted andunreacted areas displays anisotropic texture oriented perpendicular to the mask edge. The interfacial morphology is believed to result from a destabilization and pinning of the film during the conversion fromnonpolar organosilane to polar silicon oxide. Image dimensions are approximately 30 χ 40microm- eters in χ and y, and 50 nanometers in z. Collaborators contributing to this work include Gabriela Hernandez, Monika Balk, MarthaHarbison, Vanessa Chan, Edwin Thomas, Victor Leç Robert Miller, and Jane Frommer (Chem. Mater. 1998, 10, 3895). Assistance from Digital Instruments, Veeco Metrology Group in image processing is gratefully acknowledged. In Interfacial Properties on the Submicrometer Scale; Frommer, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2000. [...]... layers Little is known at this time about the mobility of the electrons, holes, and excitons at the interface of heteroj unctions Limited exciton diffusion lengths in the materials and the interfacial nature of the photogeneration process could explain these exotic transport properties in terms of topological constraints In Interfacial Properties on the Submicrometer Scale; Frommer, J., et al.; ACS Symposium... Interfacially confined hexadecane measured by SFM shear modulation spectroscopy The shear response is measured simultaneously with the normal force deflection of the cantilever as function of the cantilever-siicon sample distance The difference in the bending onset of the two curves defines the interfacially confined boundary layer thickness Critical Length Scales, Kinematics, and Dissipation Dimensional and... section 3; concluding remarks end the contribution 2 Position of the problem The first problem lies in the definition itself of roughness There are indeed several ways, non-equivalent, to define this quantity Consider to fix the ideas a surface z(x,y) such as represented in fig 3 The simplest way to introduce the roughness r is by computing the dispersion of the surface around its mean position ζ ,... deduct one degree of freedom for the constraining surface Thus, for a single molecule, the vibrational motion is like the 2D Brownian motion If we consider a molecularly thick planar horizontal sheet as our solid, the observed 2D Brownian motion results from the weighted average of the 2D-constrained vibrating sheet-molecules Thus as long as the vibrating molecules do not vibrate in registry, the thermal... describe the area of the solid surface, which may be in contact with the liquid More conveniently, we use in this context the so-called Wenzel's variable r defined as Area of the surface Wenzel = (3) Area of the projected surface on the tangential plane Many other possibilities may still be considered, but we will here, for the sake of clarity, concentrate on the last one In [3,4], Wenzel suggests that the. .. interactions in these simulations We simulate a molecular structure for the liquid by including a strong elastic bond between adjacent atoms within a molecule, of the form V = D f r with D = 1.0 The liquid molecules are always 16 atoms long This extra interaction forces the atoms within one molecule to stay together and reduces evaporation considerably ff S S Sf Sf +1 6 conf con conf We apply a harmonic... between the dragged atom or molecule and the "sliding" surface During the slip process, there is enough energy available to overcome the normal load component, and the dragged atom or molecule temporarily looses contact Thus, the applied load is a crucial parameter for the stick-slip motion Further, the qualitative behavior of the stick-slip motion, i.e., the slip distance, was rag t found to depend on the. .. sliding direction 60° to the row-like structure Reprinted with permission from reference 62 The American Physical Society, 1994 thermal energy can be reversibly transformed into mechanical energy, which contradicts the second law of thermodynamics There is an interesting aspect to this Gedanken-expenment, if one considers the sliding direction Frictional sliding is well directed in one dimension The sliding... Washington, DC, 2000 boundary conditions for the solid atoms, in the plane of the solid The cubic box containing all the atoms is set to be large enough so that the liquid atoms never reach the edges during the simulation We are thus considering a very simple chain like liquid system, made by 16 monomers with spherical symmetry, on top of a few layers of a fee solid lattice To compute the associated contact... Washington, DC, 2000 f the surface force apparatus Repulsive forces are provided by ke f . Interfacial Properties on the Submicrometer Scale In Interfacial Properties on the Submicrometer Scale; Frommer, J., et al.; ACS Symposium Series; American Chemical Society: Washington,. perpendicular to the mask edge. The interfacial morphology is believed to result from a destabilization and pinning of the film during the conversion fromnonpolar organosilane to polar silicon . is gratefully acknowledged. In Interfacial Properties on the Submicrometer Scale; Frommer, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2000.