Goniometer Rame-Hart

Analytical Techniques. Sessile drop contact angles were measured with a NRL C.A. Goniometer (Rame -Hart, Inc.) using triply distilled water. The contact angles reported are averages of 2-8 identically treated samples with at least three measurements taken on each sample. ESCA spectra were obtained on a Kratos ES-300 X-ray Photoelectron Spectrometer under the control of a DS-300 Data System. Peak area measurements and band resolutions were performed with a DuPont 310 Curve Resolver. 

Static water contact angles were determined by the sessile-drop method employing a Rame-Hart goniometer (Rame-Hart Instrument Co., Model-100, Netcong, NJ) at all stages of the surface-modification process, i.e., after cleaning of the Si02 substrates, after vapor deposition of the photoiniferter, and after photopolymerization of the PMAA brushes. 

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. 

Determination of Critical Surface Tension. The method for the determination of contact angles was described in previous papers (37, 38). For this study, we used only one goniometer manufactured by Rame-Hart, Inc. The temperature was controlled at 20 °C. with an environmental chamber. The precision was 2° for the contact angle measurement. The liquids used were alcohols, Polyglycols P-1200, 15-200, and E-200, ethylene glycol, formamide, glycerol, and water. 

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 ). 

Residual solvent was removed by placing slides In a vacuum for 2 days prior to measurement or ozone exposure. Measurements were made using a Rame Hart, Inc. Model 100-00-00 NLR Goniometer. Five liquids were measured for each sample and data for at least four of these were Included for calculations of K. Six measure-ments of angle were made for each liquid on each sample. The substrate used for the XPS samples was aluminum foil. XPS spectra were obtained on a McPherson 36 Instrument and were measured at normal Incidence. 

Water contact angles (drop volume 10 pi) were measured using a Rame-Hart Inc. goniometer with x 10 objective. 

Contact An e Measurements. Advancing contact angles were measured on a Rame-Hart NRL model goniometer at room temperature and ambient humidity. For the measurements, 6 gh of water was put on the surface, followed by adding another 6 gh to the first drop. The contact angle was measured immediately within 1 min. They are 30°, 44°, 60°, and 45° for surfaces Ti, A, MH, and GMH, respectively. The experimental error of this method is estimated to be 3°. 

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... 

Advancing contact angle were measured either by goniometry or Wilhelmy plate method. The former was carried out with an NRL A-100 Contact Angle Goniometer (commercially available through Rame-Hart, Inc). Sample films were prepared from 10 wt% solution in THF, cast into aluminum pans lined with Teflon, and dried in a hood for one week. The films were kept imder inverted beakers in the hood to reduce contact with contaminants. Only the surface formed at the air-solution interface was examined. The Wilhelmy plate method was performed with a Cahn dynamic contact angle analyzer (DCA 312). 

Equipments. IR (both ATR and Transmission) spectra were obtained with a Bruker spectrometer Mod IPS 88. Contact angle determinations were carried out with a RAME -HART goniometer at 25 C. UV spectra were measured with a Perkin Elmer spectrophotometer Mod 320. and 31p NMR spectra were performed using a... 

Fig. 2.2 Photographs of goniometers (a) classic rame-hart model A100 [7] and (b) model OCA20 from Dataphysics...

Statie water eontact angle measmcments were eonducted rising sessile drop teehniqne by a rame-hart goniometer eoupled with DROPimage data analysis software. An average of 5 different measurements was taken and all the valnes were within 2 degrees. 

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