Glass binding

Though the discussion above was aimed primarily at wood binders, many of the ideas carry over into foundry and glass binding applications. For example, potassium hydroxide is used extensively in foundry binders as are esters and... 

Figure 3. Glass binding of ts -THC showing the percent of drug added that remained in solution at various times for (A) TMS-treated 50-mL volumetric flasks from an aqueous drug concentration of 0.1 ng/mL (B) an aqueous drug concentration of 0.1 ng/mL in untreated 50-mL volumetric flasks (C) an aqueous drug concentration of 0.1 ng/mL in water-soluble silicone concentrate-treated 50-mL volumetric flasks (D) an aqueous drug concentration of 0.05 pg/mL in untreated 50-mL volumetric flasks and (E) an aqueous drug concentration of 0.1 pg/mL in a 20-mL stainless steel ultracentrifuge tube. Each point is the mean of four separate determinations (1).

The addition of an a-hydroxycarboxyhc acid to a tetraethylene, propylene, diethjiene, or hexylene glycol titanate gives water-soluble complexes suitable for gelling aqueous solutions of hydroxyl polymers, such as poly(vinyl alcohol) (PVA), or cellulose (qv) derivatives. These are useful as binding agents for glass fibers, clays (qv), and paper coatings (85). 

Ethjl Silicate-Bonded Investments. These investments are mixtures of powder and Uquid. The powder consists of refractory particles of sUica glass, crystobahte, and other metal oxides plus magnesium oxide. The Uquid is a hydrated sUica, tetrasUicic acid [10193-36-9] Si [OH], that is suppUed in a stabUized form it can be developed by mixing ethyl sUicate [78-10 ] denatured ethyl alcohol [64-17-5] and hydrochloric acid [7647-01 -OJ. The binding of the powder is accompUshed by the formation of a sUica gel according to the reaction ... 

Other immobilization methods are based on chemical and physical binding to soHd supports, eg, polysaccharides, polymers, glass, and other chemically and physically stable materials, which are usually modified with functional groups such as amine, carboxy, epoxy, phenyl, or alkane to enable covalent coupling to amino acid side chains on the enzyme surface. These supports may be macroporous, with pore diameters in the range 30—300 nm, to facihtate accommodation of enzyme within a support particle. Ionic and nonionic adsorption to macroporous supports is a gentle, simple, and often efficient method. Use of powdered enzyme, or enzyme precipitated on inert supports, may be adequate for use in nonaqueous media. Entrapment in polysaccharide/polymer gels is used for both cells and isolated enzymes. 

Schlieren /.pi. schlieren (regions of varying refraction, as in liquids) streaks, striae, schlieren (as in glass and igneous rocks). -ver-fahren n. (Photog.) schlieren process. schHerig a. streaked, striated, banded. Schliesse /. pin, peg, catch, anchor, clasp, schliessen, v.t. close shut, lock seal (tubes) bind embrace contract conclude. — v.r. close be related, be apropos. — v.i. close. 

Porous glass (PG) modified with covalently adsorbed poly(p-nitrophenyl acrylate), as described in Sect. 4.1, turned out to be a highly suitable carrier for immobilization of various biospecific ligands and enzymes. When the residual active ester groups of the carrier were blocked by ethanolamine, the immobilized ligands when bound to the solid support via hydrophilic and flexible poly(2-hydroxyethyl acrylamide). The effective biospecific binding provided by the ligands... 

DNA microarrays, or DNA chips consist of thousands of individual DNA sequences arrayed at a high density on a single matrix, usually glass slides or quartz wafers, but sometimes on nylon substrates. Probes with known identity are used to determine complementary binding, thus allowing the analysis of gene expression, DNA sequence variation or protein levels in a highly parallel format. 

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