Preparation of coatings

Preparation of Coated Pigments. A slurry of 50 g of titanium dioxide in 100 mL of distilled water with sufficient metal salt to provide the desired coating concentration was stirred on a steam bath to constant weight. The pigment was then ground in a mortar and dried in air at 100°C for 96 hr. 

Sakka S., Kozuka H., Sol-gel preparation of coating fdms containing noble metal colloids, J. Sol-Gel Sci. Technol. 1998 13 701-705. 

Preparation of coatings as free films. The oligomeric esterdlols were mixed with the crosslinkers HMMM or polyfunctional isocyanate. The molar ratio esterdlol/HMMM was 2 1 leading to an OH/OCH3 ratio of 4 6. The OH/NCO ratio was 1 1. Some 1 wt% diethanolamine salt of p-toluene sulphonlc acid, respectively 0.2 wt% Dabco were used as catalyst. The coatings were applied to Bonder 101 plates which had been sprayed with a thin layer (1-2 pm) of teflon. 

Sulfoxides yielded have the ( -configuration. A detailed mechanism of the origin of asymmetric induction is unknown. These chiral electrodes are reusable without loss of enantioselectivity. This approach is synthetically promising, but preparation of coated electrodes is a delicate undertaking, making the method difficult in practice unless robust chiral electrodes become commercially available. 

Pregelatinized starches are formed when a dispersion of starch is dried on a heated roll or in a hot air (flash) drier. Added surfactants will aid in rewetting. The use of a pregelatinized starch simplifies the preparation of coating colors, but this practice is restricted due to higher cost and difficulties in obtaining a homogeneous product. 

Starch can be enzymically converted in the presence of pigment. The conversion follows a similar time-temperature cycle as in neat starch conversion. The pigment will adsorb a portion of the enzyme adsorption can be minimized by the addition of sodium silicate to the mixture prior to the addition of the enzyme (Vanderbilt process). Even with silicate treatment, a higher quantity of enzyme will be required to reach a specific viscosity target. Other coating components, such as latex and lubricants, have to be added after the conversion. The Vanderbilt process is now rarely used for the preparation of coating binder. 

Cocoa Butter Substitute occurs as a white, waxy solid that is predominantly a mixture of triglycerides derived primarily from palm, safflower, sunflower, or coconut oils. The resulting products may be used directly or with cocoa butter in all proportions for the preparation of coatings. In contrast to many edible oils and hard butters, Cocoa Butter Substitute has an abrupt melting range, changing from a rather firm, plastic solid below 32° to a liquid at about 33.8° to 35.5°. 

Dip dispersion coating is a colloid processing technique used as a method for the preparation of coatings. There are two possible compaction modes when a porous substrate is withdrawn from a dispersion ... 

C. Agrafiotis, A. Tsetsekou, C.J. Stournaras, A. Julbe, L. Dalmazio, C. Guizard, Evaluation of sol-gel methods for the synthesis of doped-ceria environmental catalysis systems. Part I preparation of coatings, J. Eur. Ceram. Soc. 22 (2002) 15. 

This conclusion is based on immunogold localization of PrP in these organelles by electron microscopy inhibition of PrP internalization by incubation of cells in hypertonic sucrose, which disrupts clathrin lattices and detection of PrP in purified preparations of coated vesicles from brain. The N-terminal half of the PrP polypeptide chain is essential for efficient clathrin-mediated endocytosis, because... 

For the preparation of coatings of phthalocyanines on SiOa or Ti02 using method D two routes were used (Fig. 6-3) route a - after adsorption of metal carbonyls at T (40-60°C) their decomposition to metal at T2 (130-320°C) and subsequent reaction with the nitrile at T3 (200-350°C) route b - direct reaction of the adsorbed metal carbonyl at T4 (180-250°C with the nitrile) [96]. The loading of polymeric phthalocyanines 31 on quartz particles of 2 wt.% was calculated from the amount of metal carbonyl employed and by parallel experiments on the reaction of phthalonitrile with Co2(CO)g. 

Fig. 3.38 Schematic of the preparation of coated particles by the precipitation from solution onto dispersed particles. Produced with permission from [5]. Copyright 2003, CRC Press...

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