Tension probes

Ellingson PC, Strand DA, Cohen A, Sammler RL and Carriere C (1994) Molecular weight dependence of polystyrene/poly(methyl methacrylate) interfacial tension probed by imbedded-fiber retraction. Macromolecules 27 1643-7. 

Two novel sample holders for the Du Pom apparatus are shown in Figure 11.5. In ). volume coefficients of expansion can be determined, even of irregular shaped samples. A filling medium transfers the dimensional changes of the sample to the dilatometer probe. A film clamp assembly is shown in ifc). which is used to secure a film sample and increase ease of operation (7. SI. The clamps slip over the fused quartz hooks of the tension probe after the film has been secured between them. Nominal sample size is 0.05 x 0.04 in. x 0.0005 - 0.005 in. thick. 

Figure 4.58 TMA curves for PE film using a tension probe [77. Sample length, 2 mm load, 2 g heating rate, 5 C min". Amount of reinforcing agent I, 10% II, 20% III, 30%...

Figure 4.59 illustrates the results of penetration measurements for polyethylene (1), polypropylene (II) and Nylon (III) films. Figure 4.60 shows the TMA curves for polyethylene (PE) films measured using a tension probe at loads of 2,3,4 and... 

Figure 4.60 TMA curves for PE films measured using a tension probe at various loads (80]. Sample length, 10 mm. Load I, 2 g II, 3 g III, 4 g IV, 5 g...

Tension probes measure tensile properties such as stress and strain of thin films and fibers in addition, creep and stress relaxation measurements can be carried out in the tensile mode CLTE and hygroscopic expansion can also be measured in this mode (Prime et al. 1974). 

Thin film or fiber Film/fiber tension probe Significant load" penetration) Linear displacement (uniaxial Time Temperature temperatures creep and cure behavior T T - g) - m... 

Similar interactions were observed between the coagulant protein and the anionic surfactant sodium bis(2-ethyl-l-hexyl)sulfosuccinate (AOT) when monitored by surface tension probe [16]. 

H. M. Kwaambwa and R. Maikokera, Air-water interface interacaiion of anionic, cationic, and non-ionic surfactants with a coagulant protein extracaied from Moringa oleifera seeds studied using surface tension probe, Water SA, vol. 33,... 

We can then observe ( figure 2 ) the excitation coil length influence towards the range of the signal when the probe is moved in the tube, depending of the excitation source mode ( current I, tension U or power P constant) ... 

Surfa.ce Energy. The surface energies of Parylenes N, C, and D were measured by observing the contact angles for several standard probe hquids. AH three have surface energies of approximately 45 mj/m (= dyn/cm), ie, all test Hquids having less than 45 mj/m surface tension completely wet the as-deposited parylene surfaces (43). 

The molecular dipstick microscope is related to the AFM. It measures lubricant film thickness. The probe is lowered into the oil film on a surface (like the automobile engine crankcase dipstick). The tip is attracted to the surface by the surface tension of the film but repelled by van der Waal s forces from the hard substrate. By noting the height of the probe from the two surfaces as it makes contact, the film thickness can be measured with a precision of about 0.5 nm. 

One may also be able to determine the work of adhesion for cases in which the contact angle is zero by using probe liquids, as described later in this chapter. There are also other ways of determining the work of adhesion, such as inverse gas chromatography, which do not depend solely on capillary measurements (surface tension and contact angle). This too will be discussed later. 

Thus apolar probe liquids of sufficiently high surface tension to yield finite contact angles against many surfaces are especially valuable for this purpose. Popular examples of these include diiodomethane, with a surface tension of 50.8 mN/m at 23°C, and a-bromonaphthalene, with a surface tension of 44.4 mN/m at the same temperature. One should be cautioned, however, that both are sufficiently volatile that the 7re-effects may not be negligible with their use. 

Fig. 17. A schematic of the alkane line obtained by inverse gas chromatography (IGC) measurements. The relative retention volume of carrier gas required to elute a series of alkane probe gases is plotted against the molar area of the probe times the. square root of its surface tension. The slope of the plot is yielding the dispersion component of the surface energy of...

Zisman s plot cos 6 varies linearly with yi,. Zzisman = Predicts critical surface tension linearity does not hold universally y depends on probe liquids. [73-76]... 

Most work on the SR and diseased smooth muscle has concerned vascular smooth muscle in hypertensive animals, and bladders from animal models of outflow obstruction. The tools used to study SR function are mainly indirect, and include recording tension or intracellular [Ca2+] with fluorescent probes, measuring Ca2+ fluxes with 45Ca, and investigating the effects of drugs known to block SERCA or activate store release. More directly, some measurement of the activity of SERCA in microsomal preparations has been undertaken (e.g. Zderic et al 1996). 

Changes in the shape of the absorption spectrum correspond very well with micelle formation. The ratio of absorbance at 550 nm to that at 500 nm(both are absorptions of merocyanine) is constant below the CMC whereas the value increases continuously with concentration above CMC. This indicates that the merocyanine is a sensitive probe to detect micelle formation. During the photoirradiation experiment shown in Figure 2, the ratio of absorbance started to increase at the A /Aq value where the surface tension showed a sudden drop. 

Trioctylmethylammonium chloride [7] has been widely used as a phase transfer catalyst. This compound is slightly soluble in water and forms aggregates at very low concentrations (Okahata et al., 1977). Figure 3 shows surface tension data, which indicate aggregation occurring at 10-4-10-5 M. The dye probe method and conductance measurements suggest that the... 

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