Pore glass

The synthetic scheme typically involves chain-extending addition of protected mononucleotides to a nucleoside bound covalentiy at the 3 -hydroxyl to an inert siUca-based soHd support, such as controlled pore glass (Fig. 11). The initial base-protected 5 -O-dimethoxytrityl (DMT) deoxynucleoside is linked to the soHd support via the reaction of a siUca-bound amino-silane and the -nitrophenylester of the 3 -succinylated nucleoside, yielding a 3 -terminal nucleoside attached to the soHd support (1) (Fig. 11). Chain elongation requites the removal of the 5 -DMT protecting group. 

Supported aqueous phase (SAP) catalysts (16) employ an aqueous film of TPPTS or similar ligand, deposited on a soHd support, eg, controlled pore glass. Whereas these supported catalysts overcome some of the principal limitations experienced using heterogeneous catalysts, including rhodium leaching and rapid catalyst deactivation, SAP catalysts have not found commercial appHcation as of this writing. 

Ion Removal and Metal Oxide Electrodes. The ethylenediamine ( )-functional silane, shown in Table 3 (No. 5), has been studied extensively as a sdylating agent on siUca gel to preconcentrate polyvalent anions and cations from dilute aqueous solutions (26,27). Numerous other chelate-functional silanes have been immobilized on siUca gel, controUed-pore glass, and fiber glass for removal of metal ions from solution (28,29). 

Polypeptide Synthesis and Analysis. Sihca or controUed-pore glass supports treated with (chloromethyl)phenylethyltrimethoxysilane [68128-25-6] or its derivatives are replacing chloromethylated styrene—divinylbenzene (Merrifield resin) as supports in polypeptide synthesis. The sdylated support reacts with the triethyl ammonium salt of a protected amino acid. Once the initial amino acid residue has been coupled to the support, a variety of peptide synthesis methods can be used (34). At the completion of synthesis, the anchored peptide is separated from the support with hydrogen bromide in acetic acid (see Protein engineering Proteins). 

Besides shear-induced phase transitions, Uquid-gas equilibria in confined phases have been extensively studied in recent years, both experimentally [149-155] and theoretically [156-163]. For example, using a volumetric technique, Thommes et al. [149,150] have measured the excess coverage T of SF in controlled pore glasses (CPG) as a function of T along subcritical isochoric paths in bulk SF. The experimental apparatus, fully described in Ref. 149, consists of a reference cell filled with pure SF and a sorption cell containing the adsorbent in thermodynamic equilibrium with bulk SF gas at a given initial temperature T,- of the fluid in both cells. The pressure P in the reference cell and the pressure difference AP between sorption and reference cell are measured. The density of (pure) SF at T, is calculated from P via an equation of state. 

M. Thommes, G. H. Findenegg. Pore condensation and critical-point shift of a fluid in controlled-pore glass. Langmuir 70 4270-4277, 1994. 

D. Comparison of Separation by Controlled Pore Glass and Silica Gels... 

Haller, W. (1983). Application of Controlled Pore Glass in Solid Phase Biochemistry (W. Haller, ed.), pp. 535-597. Wiley, New York. 

CPG = Controlled Pore Glass (solid support) 1 and 2 (Bj, B2, B3, B4), commercially available... 

Furusawa and Yamamoto [16] studied the adsorption process of polystyrene samples (M ranging from 16700 to 2xl06) with narrow molecular weight distribution (Mw/M = 1.01-1.07) at the -conditions (cyclohexane, 35 °C). Controlled pore glass with pore diameter of 1000 A was used as an adsorbent. 

Poly (p-nitrophenyl acrylate)-coated wide-pore glass (WPG) was also used as an activated carrier for the immobilization of biospecific ligands and enzymes, A detailed description of properties of these sorbents and catalysts as well as some specific features of their functioning is given in Sect. 6. 

Waldmann-Meyer, H, Structure Parameters of Molecules and Media Evalnated hy Chromatographic Partition I. Controlled-Pore Glasses, Journal of Chromatography 350, 1, 1985. 

The packing material, used for the LEG work was Controlled-Pore Glass (CPG) from Electronucleonics, Fairfield, N.J. with various pore diameters similar to those used by others (6,2 ) (500-10,000 A). Each k.6 mm I.D. x 100 cm column was dry packed with the CPG of a specific pore size by tapping and vibration until a terminal, bed volume was reached. Stainless steel 20-ym frits were used on each end of the column along with the appropriate low-dead volume end-fittings. 

Experimentation with Controlled-Pore Glass involved the use of several column sets packed with the pore diameters in angstrom inits shown in Table III. 

Three column sets were used in this study. All consisted of 0.95 X 122 cm stainless steel columns slurry packed with Control-led-Pore Glass from Electronucleonics. The configurations were ... 

On the other hand, Seebach and Heckel have demonstrated that sulfur-containing TADDOL derivatives could be immobilised on hydrophobic con-trolled-pore glass silica gel. Indeed, controlled-pore glass (CPG) is a rigid support that offers an openly accessible pore structure in all possible solvents... 

Since catalysts immobilised on hydrophilic silica gel often give superior performances to their polymer-bound or polymer-incorporated analogues for multiple applications, Heckel and Seebach have immobilised TADDOL derivatives on hydrophobic controlled-pore glass (CPG) silica gel. Indeed, CPG is... 

XCPS-1 Controlled pore Glass, CPG-10 (324 and 1038 A) Electronucleonics 0.05 M Na2S04 Ultraviolet absorbance (A, = 206 nm)... 

Glass Ceramics Sealing Glasses Catalyst Supports Fiber Optic Preforms Contolled Pore Glasses... 

Fig. 11. Dendron 23 of 3rd generation containing 87 nucleotides. Two key intermediates in the synthesis of dendra such as 23. The box represents long-chain alkylamine controlled-pore glass [53]...

The adsorbent should have a high affinity and capacity for the enzyme and it should not absorb the reaction product or enzyme inhibitors. Among the materials used the more popular are cation and anion exchange resins, activated charcoal, silica gel, alumina, control pore glasses and ceramics. 

Haller, W., Application of controlled pore glass in solid phase biochemistry, In W.H. Scouten, ed. Solid Phase Biochemistry New York Wiley, 1983 535-597. 

The other sensor makes use of two dyes, bromophenol blue (BPB) and thymol blue (TB), to cover the range of interest26. The chromophores, immobilised on controlled pore glasses, are fixed at the end of plastic optical fibres. The distal end of the fibres is then heated and the CPGs form a very thin pH-sensitive layer on the fibre tips. The probe has four fibres (two for each chromophore) and its sketch is shown in Figure 5. A Teflon diffuse... 

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