Surface post-treatment

A surface post-treatment does take place, if the adhesive properties of a surface shall be further enhanced or bonded joints are exposed to particularly high stress, for example, by moisture and corrosion. Here, it has to be considered that longer periods under frequently uncontrolled storage conditions may occur between production and processing of the material to be bonded. 

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For the sake of completeness, climatization deserves attention within the context of the surface post-treatment. With fluctuation of temperature and humidity, water condensation on the adherends is possibly limiting the adhesive properties. 

Thus, the described possibilities of surface post-treatment serve two aims ... 

Keywords concrete surface, post-treatment, organic coating, XPS, FTIR, Raman... 

During ion implantation, some of the sp bonds are broken and thus an aimeal-ing step is advocated to restore the surface, providing the critical damage level has not been exceeded. Annealing in a hydrogen atmosphere or plasma is also thought to be necessary to bring the metal to the surface. Nanoscopic holes, up to 200 nm, are also observed on the surface post treatment. The presence of the metal is confirmed by XPS. 

Surface post-treatment power density (power setting relative to the discharge assembly length, line speed, and power level)... 

Post Treatment. Coated fabrics can be decorated and protected by applying inks and coatings to the surface. Often the finished product is an attempt to simulate the look of leather. This is most common ia upholstery, luggage, and athletic bag constmctions where natural leather is the main competitor, although any number of decorative effects can be created and are used ia produciag products such as waHcoveriag. 

Supplemental films The Batelle Memorial Institute has developed a post-treatment for nickel plus chromium coatings in which the plated part is made cathodic in a solution containing dichromate. A film thereby formed on the surface seals pores in the coating through which corrosion of the nickel might otherwise occur. Later work suggests, however, that micro-cracked chromium gives superior results. 

The surface of carbonaceous materials contains numerous chemical complexes that are formed during the manufacturing step by oxidation or introduced during post-treatment. The surface complexes are typically chemisorbed oxygen groups such as carbonyl, carboxyl, lactone, quinone, and phenol (see Fig. 3). 

In this communication a study of the catalytic behavior of the immobilized Rhizomucor miehei lipase in the transesterification reaction to biodiesel production has been reported. The main drawbacks associated to the current biodiesel production by basic homogeneous catalysis could be overcome by using immobilized lipases. Immobilization by adsorption and entrapment have been used as methods to prepare the heterogeneous biocatalyst. Zeolites and related materials have been used as inorganic lipase supports. To promote the enzyme adsorption, the surface of the supports have been functionalized by synthesis procedures or by post-treatments. While, the enzyme entrapping procedure has been carried out by sol-gel method in order to obtain the biocatalyst protected by a mesoporous matrix and to reduce its leaching after several catalytic uses. 

Carbon nanotubes inevitably contain defects, whose extent depends on the fabrication method but also on the CNT post-treatments. As already seen, oxidizing treatments, such as acid, plasma or electrochemical, can introduce defects that play an important role in the electrochemical performance of CNT electrodes. For instance, Collins and coworkers have published an interesting way to introduce very controlled functionalization points or defects on individual SWNTs by electrochemical means [96]. Other methodologies to introduce artificial defects comprise argon, hydrogen and electron irradiation. Under this context, a number of recent works have appeared with the goal of tailoring the electrochemical behavior of CNT surfaces by the controlled introduction of defects [97, 98]. 

In order to obtain maximum corrosion protection for painted metal articles, the metal parts are pretreated with an inorganic conversion coating prior to the painting operation. These zinc or iron phosphate coatings greatly increase both paint adhesion and corrosion protection. Traditionally, a chromic acid post-treatment has been applied to these phosphatized metal surfaces to further enhance corrosion protection. 

Fluorination of polyethylene surfaces leads to an increase in the surface energy, some degree of cross-linking and a reduction of the free volume of the polymer. All of these effects impart on the surface of the polymer a barrier that is very impermeable to hydrocarbon solvents. A blow-moulding process, in which a low concentration of fluorine in nitrogen is used as the blow-moulding gas, is used for the production of plastic fuel tanks for the automotive industry (Airopak , Air Products) [51]. Post-treatment of hydrocarbon surfaces with fluorine is an alternative technology and techniques for the surface fluorination of natural and synthetic rubber have been described [52]. 

These three problems will be dealt with in this presentation the MCM-48 support is prepared by a controlled extraction of the cationic gemini surfactant, in such a way that no thermal post-treatment step is required. Secondly, we present an approach of selective, partial hydrofobization of the silica walls, using dimethyldichlorosilane (DMDCS), rendering it essentially hydrophobic to withstand the water attack, but creating simultaneously sufficient active sites for a subsequent grafting of the surface. Finally, VOx surface species are grafted on the silylated MCM-48 surface, in such a way that leaching is almost completely suppressed. 

Spinel oxides obtained by LDHs showed greater specific surface area than those prepared by the classical methods at the same calcination temperature. The segregation of the Zn(II) from the structure, as well as the elimination of the ZnO increase both the SSA and the APS. Oxides obtained from an LDH or a MH precursor at relatively low temperatures (from 400 °C) present very high specific surface area for a spinel oxide (reaching more than 80 m2 g 1). Although these materials have low crystallinity, they present chemical stability (since these materials were not decomposed by the post-treatment with acid, pH = 0) and are thermally stable at least to the temperature of preparation. Therefore, these materials may be very usef >1 in catalytic applications. 

The phrase "normal phase" as used in liquid chromatography implies that the mobile phase in the chromatographic separation is nonpolar and the surface of the solid phase contains polar groups. Since silica surfaces terminate in a number of silanol moieties, this means that when silica is used as the solid phase, it is used "as-synthesized" or without any post-treatment. Hexane or hexane mixtures are often used as the mobile phase. 

Air. Concentrations of fenitrothion in air sampled 10 cm above treated ponds were highest in the first 24 hours post-treatment (Table III). GLC analysis of the extracts from polyurethane foam traps indicated that only fenitrothion was present. The levels of fenitrothion were generally higher above shaded ponds. This was expected because the polyethylene shelter reduced wind movement over the water surface which would dilute the observed concentrations. Recently Mallet and Volpe (7) reported the detection of ng/L levels of AF as well as fenitrothion in air samples collected near treated areas in New Brunswick (Canada) however, the source of AF was not clear from their study. 

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