Physical property tests intrinsic viscosity

Solution viscosity measurements have sometimes been utilized as qioality control tests for this polymer. Chromatographs of three samples that showed Identical intrinsic viscosities (0.8 g/dl) in toluene are shown in Figure 9. These chromatographs indicate that the identical viscosities are the result of different combinations of high and low MW components. These three polymer samples probably have significantly different physical properties and if viscosity measurments alone are utilized for quality control purposes, they may be quite misleading. 

The detection of chemical analytes can be based on changes in one or more of physical characteristics of thin film or layer in contact with the device surface. Some of the intrinsic film properties that can be utilized for detection include mass/area, elastic stiffness (modulus) viscoelasticity, viscosity electrical conductivity, and permittivity. In addition, changes in extrinsic variables such as temperature and pressure also produce a sensor response [31, 32]. SAW sensor works as a mass sensor, when analytes of interest comes in contact of polymer film, which is coated, on SAW device. Desired toxic gas is exposed to the device through the carrier gas such as Na and then gas molecules are desorbed [5, 33, 34]. Device has been tested for determining the characteristics such as (i) frequency shift with different concentration of vapor (ii) transient response for response and recovery times (iii) transient response for reproducibility of the sensor. Since arrangement has been made to compensate the... 

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