Goniometer contact angle

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. 

Apparatus. Contact angle measurements were made on a Model A-100 Rame-Hart version of the NRL Contact Angle Goniometer. Exposures were carried out in a forced-draft hood with the unfiltered radiation from a General Electric UA-3 medium-pressure mercury lamp. Spectra were recorded on a Perkin-Elmer Model 350 ultraviolet spectrophotometer, a Beckman IR-12 infrared spectrophotometer with a Wilks Model 7 internal reflectance attachment, and an Aminco-Bowman Spec-trofluorometer with a 1P28 photocell. 

Wettability. A description of the contact angle goniometer and the scheme used in determining the critical surface tension of wetting (yc) are described elsewhere (15, 18). 

The chemical structure and composition of films deposited onto the Al substrates was determined by X-ray photoelectron spectroscopy (XPS) using a Perkin Elmer PHI 548 instrument. Measurement of advancing and receding water contact angles (aa and or, to 3°) were carried out by the sessile drop technique, using a Rame Hart contact angle goniometer (10 ). 

Spreading of drops on powder surface spreading Contact angle goniometer Contact angle Drop height or volume Spreading velocity References Kossen and Heertjes, Chem. Eng. Sd, 20, 593 (1965). Pan et al., Dynamic Properties of Interfaces and Association Structure, American Oil Chemists Society Press, 1995. 

Hydroxybutyric acid-hydroxyvaleric acid copolymer membranes were treated with ozone and grafted with acrylic acid. The membranes were further grafted with chitosan or chitooligosaccharide via esterification and immobilised with hyalmonic acid. Antibacterial activities were investigated. Surface properties were characterised using a water contact angle goniometer. 26 refs. 

Polymer composites. The composite research at the Institute is led by Prof. Wu Renjie, Deputy director of the Institute. Chen, et al. (14), studied the effect of oxidation of carbon fiber on the wettability by the binder resin. With the aid of ESCA, they showed that the Q/C ratio on the fiber surface increased with the oxidation time. The interlaminar shear strength also increased correspondingly. Cai Weizhen and her colleagues showed me their exceptional setup for a carbon-fiber composite study. They built their own torsion pendulum for the study of dynamic mechanical properties of the composite and a contact angle goniometer for the study of the composite interface. It was apparent that surface treatment of carbon fiber was their major concern. 

Studies on displacement dynamics and interfacial tensions were carried out to establish and improve recovery efficiencies of acidic crudes by alkaline agents. Displacement tests were carried out on restored state oil-field cores and on synthetic Ottawa sand-packs with permeabilities ranging from 100 to 3,500 millidarcies. Concomitant experiments were carried out with a spinning-drop tensiometer and a contact angle goniometer capillary pressure-determined wettability indices were measured and the type and stability of emulsions were characterized. These experiments indicate that the recovery mechanisms cited in the literature are valid under specific conditions of pH, electrolyte type and con-... 

The wettability indices, Qy of the non-reactive and reactive alkaline systems are listed in Table 4. The listed contact angle measurements were made with a contact angle goniometer (NRL Rame-... 

The octane-in-water contact angle was measured using the captive-bubble method described by HAMILTON. The measurements were carried out with a contact angle goniometer of the Fa. Lorentzen and Wettres (Stockholm),... 

Contact Angle Measurements. Static water contact angle ( s) measurements were performed on a Rame-Hart contact-angle goniometer on freshly prepared surfaces. A drop of 6—8 L was produced and then gently placed on the surface. For superhydrophobic... 

Details are given of the biocompatibility of hydroxybutyrate-hydroxyhexanoate copolymer with bone marrow stromal cells in vitro. The adsorption of fibronectin on the material was studied by enzyme-linked immunosorbent assay. The wettability and thermal properties of copolymer films were also studied by contact angle goniometer, TGAand DSC. Potential applications in bone tissue engineering are mentioned. 37 refs. 

In order to evaluate the surface free energy of the organosilane monolayers, static contact angle measurement was carried out The contact angles of die water and the methylene iodide droplets on the monolayer surface were measured with a contact angle goniometer CA-D (Kyowakaimenkagaku, Co., Ltd.) at 293 K. 

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