Surface force schematic diagram

Figure C2.9.3 Schematic diagrams of the interfaces reaiized by (a) tire atomic force microscope, (b) tire surface forces apparatus and (c) tire quartz crystai microbaiance for achieving fundamentai measurements of friction in weii defined systems.

Fig. 1. Schematic diagram illustrating the mechanical instability for (a) a weak spring (spring constant k) a distance D from the surface, experiencing an arbitrary surface force (after [19]) and (b) the experimentally observed force-distance curve relative to the AFM sample position (piezo displacement) for the same interaction.

Figure 6.8 Schematic diagram of the balance in forces acting on a fluid element close to the surface of a large colloidal particle.

Figure 8.10 Schematic diagram of the forces acting on a beam separating a pure water surface from a surfactant coated surface.

Schematic diagrams of the Sverdrup transport in the North Atlantic, driven by sea surface topography and the Coriolis force. Arrows indicate flow direction and the thickness indicates magnitude. Numbers are the flow rate in Sverdrups (10 m s ). GS, Gulf Stream NAC, North Atlantic Current NEC, North Equatorial Current. (Redrafted from Pinet (1994).)...

Figure 1. Schematic diagram of a Langmuir trough. The monolayer is deposited to the right of the barrier, and the barrier can be moved across the surface to change the area accessible to the monolayer. The surface pressure can be measured either by determining the force on a float that separates the monolayer from a clean water surface, or from the difference in the force exerted on the Wilhelmy plate when the plate is suspended in pure water and in water covered by the monolayer.

The mechanical behavior of polymers is well recognized to be rate dependent. Transitions from ductile to brittle mode can be induced by increasing the test speed. The isotactic PP homopolymer with high molecular weight is ductile at low speed tensile tests. It is brittle at tension under high test speeds at room temperature. Grein et al. (62) determined the variation of Kiq with test speed for the a-PP CT samples (Fig. 11.22). The force-displacement (F-J) curves and the schematic diagrams of the fracture surfaces of CT samples are presented in Fig. 11.23. At a very low test speed of 1 mm s , the F-d curve exhibits a typical ductile behavior as expected. At 10 mm s, the F-d curve stiU displays some nonlinearity before the load reaches its maximum value, but this is substantially suppressed as test speeds increase further. The samples fail in brittle mode at test speeds >500 mm s . From Fig. 11.22, the Kiq values maintain at 3.2 MPam at test velocities from 1 to... 

Biosensors Using Atomic Force Microscopes, Fig. 1 (a) Basic components and working principle of AFM. A sharp tip fixed at the end of a fiexible cantilever is raster scanned over the surface of a sample. As the tip interacts with the surface, the cantilever deflects, and its deflections are monitored by a laser and a photodiode and then used to reconstruct the topography of the sample, (b) A schematic diagram of AFM as a biosensor in detecting... 

Figure 1 depicts a schematic diagram of the EDL next to the flat surface. The EDL consists of two parts compact and diffuse layers. The compact layer is an immobilized layer of counterions next to the surface of the material. Very strong electrostatic forces make this layer stationary. The thickness of this layer is about one ionic diameter. 

Once the interface crack has initiated inside a composite material, then traveled some distance along the interface, there may be a tendency for the crack to heal, if the crack surfaces come into close proximity, so that the molecular adhesion forces can pull the smooth crack faces together again. The simplest situation in which this interface crack healing arises is shown in Fig. 16.17. This schematic diagram illustrates the observations made on a model composite laminate made from four strips of smooth, transparent rubber. 

We remarked above that the force-distance curves do not appear to be particularly sensitive to the shape of the concentration profile normal to the surface used in the theoretical calculations. Evidently, it would be of value to obtain the concentration profile simultaneously with determination of the force-distance data. Cosgrove et al. (1995) have described a modified surface force apparatus that allows neutron reflectometry data to be collected figure 3.32 is a schematic diagram of the apparatus. 

Schematic diagram of the AFM showing the auxiliary STM used for detecting movement of the atomic force cantilever. Source Reprinted with permission from Woodruff DP, Delchar TA, Modern Techniques of Surface Science, Cambridge University Press, Cambridge, 460, 1994. Copyright 1994, Cambridge University Press.

Fig. 3.6. Schematic diagram of the van der Waals forces within a droplet. The van der Waals forces exerted on a given molecule by its neighbours are no longer balanced for molecules close to the surface of the droplet...

Figure 4. Schematic diagram of the friction force signal between an AFM tip and two different oxide surfaces. From the curves displayed, it becomes clear that the chemical contrast on oxide surfaces can be tailored by changing pH. On an appropriate sample even a reversal of the frictional contrast should be possible.

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