Standard contact angle measurement

Table 2.4 Standard Contact Angle Measurement Methods for Various Materials...

Films of purified PVCa were cast from methylene chloride solution on quartz plates. The solvent was allowed to slowly evaporate to give smooth, clear films with a thickness of ca. 5.0 nm. Contact angle measurements using water droplets were measured with a standard contact angle goniometer. Samples were photo-lysed in air with polychromatic light from a 150 watt xenon arc. Contact angles were measured after various times of irradiation to monitor the formation of oxidation products at the surface of the polymer films. 

Table 20.1 illustrates the results of six successive contact angle measurements on each of ten powders, along with the reproducibility, expressed as standard deviation using the anglometer described above. 

To reduce these effects, LDPE samples were cross-linked by e-beam irradiation and then subjected to the photosulfonation process. Compared to standard LDPE, crosslinked LDPE displayed a higher content of — SO3H groups and higher surface polarity after photosulfonation. This was evidenced both by zeta potential and contact angle measurements. It is thus demonstrated that sample pretreatment by crosslinking provides more stable surfaces which maintain their polar properties during water contact. This is explained by a lower amount of extractable components as a result of radiation-induced network formation. 

Standard test method for corona-treated polymer films using water contact angle measurements, ASTM D5946-96. 

This experiment uses the FTA200 table interface analyzer to measure the contact angle and surface tension between the liquid and solid. Surface analyzer survey liquid and solid, shows the interfacid tension. The standard deviation of the contact angle measurement is smaller than 1°. The standard deviation of surface tension measurement is smaller than 0.5 m N m . 

ASTM D5946-96 Standard Test Method for Corona-Treated Polymer Films Using Water Contact Angle Measurement— This method covers the measurement of the contact angle of water droplets on corona-treated polymer film surfaces the results are used to estimate the film s wetting tension. 

To characterise the test surfaces, standard static contact angle measurements were made with water at the temperature of 23°C in an atmosphere of 23°C and 50% rh. 

Surfactant testing and reagent screening can be performed in a variety of ways. The simplest and most common technique used in the petroleum industry is the standard blender test [7]. Other test methods [4] include Ross-Miles foam height test, flow loop testing, capillary foam testers, contact angle measurements, tensiometers and actual field evaluations. Due to its low cost, easy duplication and ability to be used in the field, blender testing has become the norm in the industry for foam based fluids. 

While contact angle measurements provided clearly some indication of the immediate surface composition of block copolymer membranes, provided solvent standards are available for direct comparison, ESCA offers the possibility of obtaining quantitative information on compositions, structures, and bondings in not only the immediate surface but also the subsurface typically to a depth of A (26, 27). 

Schultz et al. [175] used fl(yP) " as a comparison scale. The parameter a is the area of the adsorbed probe molecule [176]. It is obtained from IGC measurements on neutral reference solids such as polyethylene or PTFE. Some examples are n-hexane, 51.5A ether, 47A chloroform, 44A and acetone, 42.5A. In standard fashion, yP is determined from contact angle measurements on reference solids [176]. Once again, some probes fall under the reference line of the n-alkanes, and the data are difficult to interpret. This constitutes a limiting factor of this method. 

ASTM C813-90 (1994)e1 Standard Test Method for Hydrophobic Contamination on Glass by Contact Angle Measurement. Method covers the detection of hydrophobic contamination on glass surfaces by means of contact angle measurement. 

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