Contact angle measurement surface characterization

Jachim,X A., Freeman, G. B.,Turbini, L. X, Use of Surface Insulation Resistance and Contact Angle Measurements to Characterize the Interactions of Three Water Soluble Fluxes with FR Substrates, IEEE Transactions on Components, Packaging, and Manufacturing Technology, PartB,Vo. 20, No. 4,1997, pp. 443-451. 

Being sensitive to the chemical composition of the outermost layers of the surface, contact angle measurement is widely used for characterizing polymer surfaces. Surface characterization for polymers using contact angle measurement and XPS will now be described in detail, as these are the most widely used methods. 

In the third part of the chapter the solid state properties of our block copolymer are examined. The surface energies of these materials are characterized by contact angle measurements. The organization of the polymer chains in the solid state phase is investigated by small-angle X-ray scattering (SAXS) and the gas selectivity of porous membranes coated with these block copolymers is characterized by some preliminary permeation measurements. 

Once the durability testing of the fuel cells is finalized, the internal components are then characterized. For diffusion layers, some of these characterization techniques include SEM to visualize surface changes, porosimetry measurements to analyze any changes in porosity within the DL and MPL, IGC (inverse gas chromatography) to identify relative humidity effects on the hydrophobic properties of the DLs, contact angle measurements to observe any changes in the hydrophobic/hydrophilic coatings of the DL, etc. [254,255]. 

A number of methods are available for the characterization and examination of SAMs as well as for the observation of the reactions with the immobilized biomolecules. Only some of these methods are mentioned briefly here. These include surface plasmon resonance (SPR) [46], quartz crystal microbalance (QCM) [47,48], ellipsometry [12,49], contact angle measurement [50], infrared spectroscopy (FT-IR) [51,52], Raman spectroscopy [53], scanning tunneling microscopy (STM) [54], atomic force microscopy (AFM) [55,56], sum frequency spectroscopy. X-ray photoelectron spectroscopy (XPS) [57, 58], surface acoustic wave and acoustic plate mode devices, confocal imaging and optical microscopy, low-angle X-ray reflectometry, electrochemical methods [59] and Raster electron microscopy [60]. 

In order to calculate polymer/filler interaction, or more exactly the reversible work of adhesion characterizing it, the surface tension of the polymer must also be known. This quantity is usually determined by contact angle measurements or occasionally the pendant drop method is used. The former method is based on the Young, Dupre and Eowkes equations (Eqs. 21,8, and 10), but the result is influenced by the surface quality of the substrate. Moreover, the surface (structure, orientation, density) of polymers usually differs from the bulk, which might bias the results. Accuracy of the technique maybe increased by using two or more liquids for the measurements. The use of the pendant drop method is limited due to technical problems (long time to reach equilibrium, stability of the polymer, evaluation problems etc.). Occasionally IGC is also used for the characterization of polymers [30]. 

The surface characteristics of reworked substrates and several rework processes are described later in several tables and the discussion. The substrate condition following the rework process is characterized by the results of three tests ESCA or XPS [19] surface chemical composition spectra, actual lithographic resist pattern lift testing [2, 6], and water droplet contact angle measurement, 0HjO [3]. 

A series of SAMs formed on Au from mono- and dithiol conjugated aromatic molecules was characterized by cyclic voltammetry, grazing incidence Fourier transform infrared spectroscopy, contact angle measurement, and ellipsometry.43 The analyses indicated that the molecular orientation of conjugated phenylene- and thophene-based dithiols became less tilted with respect to the surface normal as the chain length of the organic molecules increased. 

The methods widely used in characterizing the surface grafting onto films are UV, attenuated total reflection (ATR) IR, X-ray-photoelectric spectroscopy (ESCA), contact angle measurement and other techniques applicable to the characterization of the surface treatments of polymeric substances. 

The applied pressure is related to the desired pore size via the Washburn Equation [1] which implies a cylindrical pore shape assumption. Mercury porosimetry is widely applied for catalyst characterization in both QC and research applications for several reasons including rapid reproducible analysis, a wide pore size range ( 2 nm to >100 / m, depending on the pressure range of the instrument), and the ability to obtain specific surface area and pore size distribution information from the same measurement. Accuracy of the method suffers from several factors including contact angle and surface tension uncertainty, pore shape effects, and sample compression. However, the largest discrepancy between a mercury porosimetry-derived pore size distribution (PSD) and the actual PSD usually... 

Profilometer and Contract Angle Measurements The copper surface after Pumice treatment was also examined by profilometry and characterized by contact angle measurement. The profilometer was supplied by Sheffield Measurement Division of Dayton, Ohio. The contact angle measurements were made using a microscope device supplied by Gilmont Instruments, Great Neck, New York. 

D.Y. Kwok, A.W. Neumann, Contact Angle Measurements, in Surface Characterization Methods. Principles, Techniques and Applications. Surfactant Series no. 87, A.J. Milting, Ekl., Marcel Dekker (1999) chapter 2, p. 37-86. (Review, many practical hints, 191 refs.)... 

Frieser292 has shown that hydrophobic, hydrophilic, and organophilic Si02 surfaces may be distinguished easily by two independent contact-angle measurements with different liquids. Interest in Si02 surface chemistry has centered, however, on the characterization (principally by means of i.r. and e.s.r. spectroscopy) of the functional groups present on surfaces subjected to... 

Bismarck, A. et al.. Surface characterization of glass fibers made from silicate waste Zeta potential and contact angle measurements, J. Mater. Sci., 39, 401, 2004. 

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