Solution processing spray-coating

Paint-base phosphate coatings could be appHed in two to five minutes. In 1934, this time constraint was shortened even further when phosphate solutions were sprayed onto the metal surface. Processing times as short as 60 seconds became possible. 

Acrylics Powder, solutions Easily processed. Form strong films. Temperature range 200-250 F. Adaptable for paint or spray. Coatings. 

Water is used in this subcategory as solution makeup and for rinsing in the surface preparation process, as the vehicle for the coating in the application process (normally done by spray coating), and for cooling and cleanup in the ball milling operation. 

After the precursor stock solution is prepared, various techniques can be used to coat the substrate, depending on the solution viscosity, required film thickness and coverage. The most common methods in the semiconductor industry are spin- and dip-coating. Other processes that are used for deposition include spray coating and stamping. A summary of the uses, limitations, and advantages of the various thin film deposition methods is reported in Table 2.2. 

With the methods discussed in Chapter 6.5. we are able to produce small polymer particles from solutions of polymers in compressed gases [52,53], First results indicate that, depending on the process conditions and the nozzle design, a wide variety of spherical particles, small fibrils, or longer fibres can be obtained. Sometimes the particle-size distribution obtained is very uniform, in other cases, a wide variety of sizes is obtained. In some cases, the monomer was used as solvent for the equivalent polymer. The particles, fibrils, etc., obtained may be used for direct spray-coating of surfaces but they also offer new opportunities as raw materials in their own right. New products are underway that are based on such technologies. 

A recently reported alternative to spin or spray coating is screen printing of polyimide solutions (82, 85, 90). Screen printing is a low-cost, high-throughput process capable of directly patterning the polyimide films as they are deposited. Another alternative is the vapor deposition of polyimides, which was reported by researchers who co-evaporated the diamine and dianhydride monomers at stoichiometric rates (140). The evaporated films had better adhesion, a lower dielectric constant, and a lower dissipation factor compared with spin-coated polyimides. With this process, uniform, defect-free, conformal films can be cured in situ during deposition. 

For a few tissue samples, the matrix deposition can be performed manually. A matrix solution is sprayed onto the tissue section with a hand-held thin layer chromatography (TLC) sprayer or an artist airbrush. The reproducibility of manual matrix deposition is an issue. When the manual sprayer is used, the MALDI target plate with the tissue section is held vertically about 15-25 cm from the sprayer nozzle. It is recommended to spray multiple coats of matrix across the tissue section and each coating cycle consists of passing the sprayer two to hve times across the tissue section and allowing the tissue to dry for about 1-5 min. This process is usually repeated between 10 and 20 cycles. 

Polyimide Deposition. The most accurate processes for depositing thin, uniform coatings of PAA or PI solutions are spin coating, spray coating, and a recently reported screening process (12). 

Fig. 35 Spray-dried extracts and pantothenate solution. Spray-dried calcium pantothenate overview (A) and detail (B), showing mainly particles that were damaged during preparation of the SEM sample either by the high vacuum of the SEM or by the heat created during the sputter coating process. Spray-dried Tussilago farfara extract prepared by a system using atomizing air to form droplets and leading to small particle sizes (C) and a magnification thereof (D).

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