Surface preparation glass

Tor [7] developed a new method for the preparation of thin, uniform, self-mounted enzyme membrane, directly coating the surface of glass pH electrodes. The enzyme was dissolved in a solution containing synthetic prepolymers. The electrode was dipped in the solution, dried, and drained carefully. The backbone polymer was then cross-linked under controlled conditions to generate a thin enzyme membrane. The method was demonstrated and characterized by the determination of acetylcholine by an acetylcholine esterase electrode, urea by a urease electrode, and penicillin G by a penicillinase electrode. Linear response in a wide range of substrate concentrations and high storage and operational stability were recorded for all the enzymes tested. 

The highest mass fragment, obtained from the fresh HAPS-coated glass surface, occurred at m/z = 477 and contains four Si—O bonds in its structure. This is twice the size of the largest HAPS fragment (m/z = 221) obtained from the as-coated surface prepared with the previously used batch of APS. 

Ludwig, J. D., Avis, K. E. Recovery of endotoxin preparations from the surface of glass capilliary tubes. J Parenter Drug Assoc 43 276 (1989). 

Work on sample preparation for lead speciation has raised a number of questions about accuracy of results of analyses. Sampling procedures should be restricted to the minimum number of steps. TAL and other lead compounds are readily adsorbed on container surfaces, including glass from aqueous solutions. In... 

Oxidative stability depends on the adherend surface as well as on the adhesive itself. Some metal adhesive interfaces are chemically capable of accelerating the rate of oxidation. For example, it has been found that nearly all types of structural adhesives exhibit better thermal stability when bonded to glass or aluminum than when bonded to stainless steel or titanium.12 For any given metal, the method of surface preparation can also determine oxide characteristics, and hence bond durability. Thus, the use of primers is common practice with high-temperature structural adhesives. 

It is apparent that all glass and other apparatus used for the preparation of derivatives must be perfectly clean in order to prevent contamination. If septa are used to close reaction vessels, they should be used repeatedly only with caution in order that substances accidentally adsorbed on the septum do not cause the same difficulties. The surface of glass vessels is modified in special instances only when the reagents used for the derivatives are extremely sensitive to the activity of the glass. Silanization is a common modification of the surface of glass vessels. It is performed, e.g., by treatment with a 5% solution of dichlorodimethylsilane in toluene [22]. The silanized glass is then rinsed with methanol and dried. Other silanization agents can also be applied. 

Fig. 10 demonstrates the special aptitude of SIMS measurements for investigating silyl modified surfaces prepared by the treatment of glass, quartz, or silica gel with different silanes CH3S1X3 (X = OEt, OMe, Cl). 

Influence of Acid Treatment. The presence of free alkali on the surface of glass and its influence on adsorption and allied phenomena are well known. McBain (17) pointed out the significance of acid treatment of glass vessels to remove the alkali in quantitative treatment of the phenomenon mentioned. The removal of surface alkali caused a marked change in the production of —Az (20). This last effect was studied in Siemens-type vessels, some of which were prewashed with chromic acid and boiling distilled water and dried under vacuum for 24 hours others were used as they were prepared from fresh glass. 

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