Chloride surface treatments

Zinc ammonium chloride surface treatment, titanium dioxide pigments Zirconium sulfate surface-finishing agent Ethylene distearamide surface-finishing agent, food Beeswax Carnauba (Copernica cerifera) wax Dextrin Mono- and diglycerides of fatty acids Shellac... 

Sa.lts Salting out metal chlorides from aqueous solutions by the common ion effect upon addition of HCl is utilized in many practical apphcations. Typical data for ferrous chloride [13478-10-9] FeCl2, potassium chloride [7447-40-7] KCl, and NaCl are shown in Table 9. The properties of the FeCl2-HCL-H2 0 system are important to the steel-pickling industry (see Metal SURFACE TREATMENTS Steel). Other metal chlorides that are salted out by the addition of hydrogen chloride to aqueous solutions include those of magnesium, strontium, and barium. 

In addition to the possibiUty of selecting alloys having minimum SCC susceptibiUty while retaining other properties as needed, there are other steps possible to reduce the SCC probabiUty (/) avoid designs that permit water to accumulate (2) avoid conditions in which salts, especially chlorides, can concentrate and (i) where available and otherwise acceptable, use a clad alloy (2) (see Metal surface treatments). 

Although there is considerable evidence that chemical surface treatments improve the substrate bondability of stainless steels, there is no general agreement on which is the best. One etchant commonly used with stainless steels is an HNO3-HF mixture [128-131] others are chromic acid and ferric chloride/hydrochloric... 

Calorising Also spelled Calorizing. A proprietary process for protecting the surface of iron or steel by applying a layer of aluminum. Several methods of application may be used dipping, spraying, or chemical reaction with aluminum chloride. See also metal surface treatment. 

As with many polymers, the limits of strength are due to the presence of voids. For glass fibers, these voids generally occur on the surface, thus care is taken to protect these surfaces through surface treatments with methacrylatochromic chloride, vinyl trichlorosilanes, and other silanes. These surface agents chemically react with the fiber surface acting to repel and protect the surface from harmful agents such as moisture. 

Literature presents numerous data on the syntheses by ML method of oxide layers of titanium, aluminum, chromium, phosphorus, tantalum and series of other elements on silica and alumina surfaces, when appropriate chloride and vapour of water are used as initial reagents [13,35,18,42]. The synthesis thus proceeds without the change of oxidation state of elements. But the stability of Si-O-M bonds in the process of gaseous treatment of element-chloride surface structures is of significant importance. Our researches have shown [44,68], that the strength of Si-O-M bonds is influenced by the thermal stability of element-oxide chloride groups, quantity of their bonds with surfaces (factor m) and series other ones. The reason for the destruction is the hydrogen chloride which educes in the process of vapour hydrolysis [68]. 

Adsorption, where the preservative attaches itself to the surface of a plastic, tends to vary according to the type of plastic, constituents in the plastic, surface treatment, surface area of the plastic. Adsorption has been found with most mercurials, including Thiomersal, benzalkonium chloride and bromide, etc. Small amounts of chlorhexidine, benzoic acid and hydroxybenzoates have also had losses reported for certain plastics. 

Other materials were prepared by converting silica to silica chloride by treatment with thionyl chloride, and then reacting the surface chloride groups with amines as shown below ... 

More recently, quaternary organic tetraalkylammonium hydroxides have been grafted on to an MTS surface by reaction with 3-trimethoxysilyl(trimethyl)ammo-nium chloride then treatment of the resulting solid with a methanolic solution of tetramethylammonium hydroxide [21],... 

Various researchers have tested the effect of coatings (and other surface treatments) on active reinforcement corrosion. Due to the extreme variation of materials (both coatings and concrete) and test methods and conditions, it is beyond the present scope to summarise that work. The overall impression is that coatings do not effectively reduce the rate of chloride-induced corrosion, see for example [13]. Subject to many practical influences, it is possible that coatings reduce the rate of carbonation-induced corrosion. 

The beneficial action of surface treatments generally hes in the fact that they prolong the period of initiation of corrosion. Once corrosion has begun, only those treatments that effectively obstruct the penetration of water, both hquid and vapour, will reduce the corrosion rate. This effect may be significant, in particular, if corrosion is due to carbonation [27]. Chloride-induced corrosion processes attract moisture so strongly that in general, surface treatments cannot stop it [13]. 

L. Basheer, D. J. Cleland, Protection provided by surface treatment against chloride-induced corrosion , Materials and Structures, 1998, 31, 459-464. 

Surface treatment of concrete. Surface treatment of concrete may be used in association with conventional repair to achieve the required service life of the repair. A specific type of treatment may be used to delay penetration of carbonation or chlorides or to decrease the moisture content (Chapter 14) either in the original concrete or in the repair mortar. The effect of this treatment can be taken into consideration in the evaluation of the residual service fife of the structure, both in the repaired and unrepaired zones. This can lead to a reduction in the extent of the areas to be repaired or in the thickness of the repair material. 

Alkali and acid treatments have also been used to modify surface properties of polymers sulfonated polyethylene films treated first with ethylenediamine and then with a terpolymer of vinyhdene chloride, acrylonitrile, and acrylic acid exhibited better clarity and scuff resistance and reduced permeabihty. Permanently amber-colored polyethylene containers suitable for storing light-sensitive compoimds have been produced by treating fluorosulfonated polyethylene with alkali. Poly(ethylene terephthalate) dipped into trichloroacetic/chromic acid mixture has improved adhesion to polyethylene and nylons. Antifogging lenses have been prepared by exposing polystyrene films to sulfonating conditions. Acid and alkali surface treatments have also been used to produce desired properties in polymethylmethacrylates, polyacrylonitrile, styrene-butadiene resins, polyisobutylene, and natural rubber. Surface halogenation of the diene polymers natural rubber and polyisobutylene resulted in increased adhesion to polar surfaces. 

Fibrinogen/platelet interaction changes due to surface treatment on polyvinyl chloride. 

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