Test Inks Used

We carried out tests with two different series of commercially available test inks for all samples  

Acrylonitrile butadiene styrene Technical (Arthur Rriiger, Germany) ABS 

Glass Finished product (Microscope Slides, Carl Roth GmbH, Germany) Glass 

Mica Chemically homogeneous mono-crystal, freshly cleaved (Highest Grade V1 Mica Discs, Ted Pella Inc., USA) Mica 

Poly( dimethylsiloxane) Pure, synthesized (Dow Corning Sylgard 184 Silicone Elastomer) PDMS 

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Zirconium propionate is a polymeric zirconium carboxylate its structure is illustrated in Fig. 10. Use of zirconium propionate markedly increases the adhesion of an ink applied to treated polypropylene film. Figure 11 compares zirconium propionate with titanium acetylacetonate, which is commonly regarded as the industry standard. The standard test method used in the ink industry is the so-called tape test . Sticky tape is placed on the printed film and pressure is applied by the operator s thumb. The tape is then pulled off, by hand, and the amount of ink removed is visually assessed. Although extremely crude, it can be, and is, used for control in the ink industry. 

On the other hand, all the organic solvents used are either flammable or toxic or expensive. Some are poisonous, or hazardous to health, and others dissolve, or cause feathering in, dyes and inks used on paper. Substances such as magnesium acetate, barium hydroxide, cyclohexylamine and its carbonate and acetate and magnesium methoxide have been tested for their safety and effectiveness. 

Low surface tension (poor wettability ) may be a factor, with apparent repulsion of the paint and prevention of its rapid, even spread over the whole surface test inks of different values are available so that wettability can be assessed in advance with samples of the items concerned for satisfactory use with paints based on organic solvents, surface values of greater than 50 mN m 1 are desirable, and for water-based systems values greater than 70 mN m. ... 

Lead Determine as directed in the Flame Atomic Absorption Spectrophotometric Method under Lead Limit Test, Appendix INK, using a 10-g sample. 

Most organic residues on assemblies are not detected by ionic contamination meters. However, such residues do change the surface tension of assemblies, thereby influencing the adhesion of subsequent coatings. This method determines the surface tension by iterative use of corresponding testing inks. 

High-performance liquid chromatography, or HPLC, is an analytical technique capable of detecting specific components in a sample. In forensic science this test is used for drug analysis, toxicology (study of poisons), explosives analysis, ink analysis, fibres and plastics. 

If information about a solid surface free energy (SFE) is needed, contact angle measurements and ink tests are two of the most frequently used methods. Here we present a comparative study of contact angle measurements and ink tests on 13 different materials. We observed major differences in the SFE values obtained by these two techniques and explained the differences on the basis of basic theoretical concepts of both methods. We found that test inks fail to monitor the efficiency of atmospheric plasma treatments on low surface energy solids. Moreover, we determined the polar and dispersion contributions to the test inks total surface tension (ST) in order to provide a more detailed understanding of these methods to determine a solid SFE. 

ST interact with the different parts of the soHd SFE. However, almost all of these make the same basic assumption that one specific part of the liquid ST solely and exclusively interacts with the corresponding part of the sohd SFE. Thus, for the here used most basic distribution into dispersion and polar parts of SFE and ST, a simple rule of thumb describing the IFT is found when a liquid gets in contact with a solid, the polar part of the liquid interacts only with the polar part of the solid and the dispersion part only with the dispersion one. Later in the text, it will be shown that this most basic assumption / model already helps to explain the major differences between test inks and contact angle measurements. 

The ink test is based on the assumption that the SFE of the sohd is equal to the ST of the hquid which just fully wets the solid. Test inks consist of a series of liquid mixtures, each with a set ST, usually in increments of 2 mN/m. During the test, one of the inks is apphed to the sample with a brush stroke. If the applied film of the ink contracts, the ink with the next lower ST is used xmtil the brush stroke produces a stable film on the soHd. This corresponds to complete wetting of the sample. If the first stroke is stable, the ink with the next higher ST is applied xmtil the brush stroke does not produce a stable film. The ST of the test ink which just forms a stable film is equated to the SFE of the material. 

Sample SFE by OWRK Method Using Measured Contact Angles [mN/m, Polar Component in %] Test ink A [mN/m] Test inkB [mN/m]... 

The difference between SFE values using contact angle measurements and test inks was most obvious in the case of plasma-treated samples. Tables 17.3a), b) and c) show the results for PDMS, PVC and PET before and after plasma treatment for different exposure times. We have documented the wetting patterns, i.e. images of brush strokes, for the test inks. 

The risk of contaminating the whole ink supply in a test ink bottle after a measurement on a dirty sample is rather high. As a result the total ST of the test ink can change and thus falsify further measurements. This cannot happen to the test liquids used for contact angle measurements as the test liquid reservoir never gets in direct contact with the samples. 

The MEAs tested, 63-65, were prepared by using an ultrasonic bath to prepare the inks, using an air brush to coat the inks onto the GDLs chosen, and to minimize differences between 63 and 65, 12 cm GDLs were prepared and cut into 4 cm pieces. Extra care was taken to spray the ink as a single layer, dry with an ordinary blow-drier, weigh the sample, and then apply the next layer. 

Mark 20 or more test tubes in water-insoluble ink, using a code to indicate the following pieces of information fraction number, sample identification, run number. 

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