Characterization of silicas

De Jong, G. J. Optimization and characterization of silica-based reversed-phase liquid chromatographic systems for the analysis of basic pharmaceuticals./. Chromatogr. A 2000, 897,1-22. 

Leinweber, F.C., Lubda, D., Cabrera, K., Tallarek, U. (2002). Characterization of silica-based monoliths with bimodal pore size distribution. Anal. Chem. 74, 2470-2477. 

Surface chemistry characterization, of silica, 22 372-373 Surface cleaning nozzles, 23 197 Surface coatings, 10 12-13... 

C. Ingemar Odenbrand, S. Andersson, L. Andersson, J. Brandin, and G. Busca, Characterization of silica-titania mixed oxides, J. Catal. 125,541-553 (1990). 

Kazuhiro, K., Tanaka, N., Iwaguchi, K., Onishi, S., Jinno, K., Eksteen, R., Hosoya, K. and Araki, M., Chromatographic Characterization of Silica Cjg Packing Materials. Correlation between a Preparation Method and Retention Behavior of Stationary Phase./. Chromatogr. Sci., 27 721—728, 1989. 

Synthesis and Characterization of Silica Supported Ta Imido Complexes... 

Among the various oxides that are used as substrates, aliunina [2] and silica [3] have been extensively studied however, the structural characterization of silica is certainly the most complete. Studies carried out on porous catalyst supports showed that the - OH concentration on a M O surface can vary... 

Royston E, Lee SY, Culver JN, Harris MT (2006) Characterization of silica-coated tobacco mosaic virus. J Colloid Interface Sci 298 706-712... 

H. Engehardt and H. Muller, Chromatographic characterization of silica surfaces J. Chromatogr., 218 395 (1981). 

As an illustration of the use of SEM, micrographs obtained from the characterization of silica materials are described here [47], This SEM study was carried out with a JEOL 5800 LV model SEM. The acceleration of the electron beam was 20 kV. The sample grains were glued with silver colloid to the sample holder and were coated at vacuum by cathode sputtering with a 30-40 am gold film [47], in order to make the nonconducting silica powder sample conductive. 

Krumeich, F., Nesper, R., Ren, L., Wark, M., Electron microscopy characterization of silica nanotubes, paper in preparation. 

Tabatabaei S, Shukohfar A, Mirhabibi A. Experimental study of the synthesis and characterization of silica nanoparticle via sol-gel method. J Phys Conf Series 2006 26 371-374. 

Furusawa, K., Muramatsu, H., and Majima, T., Characterization of silica-coated hematite and application to the formation of composite particles including egg yoUc PC liposomes, J. Colloid Interface ScL, 264, 95, 2003. 

Klotz M, Ayral A, Guizard C, and Cot L. S3mthesis and characterization of silica membranes exhibiting an ordered mesoporosity. Control of the porous texture and effect on membrane permeability. Sep. Purif. Technol. 2001 25(l-3) 71-78. 

In spite of these efforts, silica based modified columns are still widely used. Many column-manufacturers have introduced quality control procedures for the synthesis and characterization of silica based columns. Therefore, lot to lot variations from the same manufacturers have been considerably reduced. However, identical phases from different manufacturers can yield different separation behaviors of the same analyte under identical instrumental and mobile phase conditions. (Of 13 phenyl columns investigated for an oncolytics, we found only three columns providing similar separation profile for a 13-component impurity mixture.)... 

Some contributions cover the development of specific materials and analytical methods to measure the characteristic properties of solid particles, such as particle sizes, surfaces areas, mechanical strengths, or solid-matrix interactions. Thus, papers from M. Heinematm and S. Hild deal with the characterization of silica-polymer interactions using Scanning Force Microscopy, while C. Panz uses the combination of special basic silica, fitting silanes, and adequate hydrophobization conditions to generate high-performance silica with new properties. 

Characterization of Silica-Polymer Interactions on the Microscopic Scale Using Scanning Force Microscopy... 

Zhang, Q.H. Feng, Y.Q. Da, S.L. Preparation and characterization of silica-zirconia supports for normal-phase liquid chromatograply. J. Liq. Chromatogr. Relat. Technol. 2000, 23, 1461-1470. 

T. Dabadie, A. Ayral, C. Guizard, L. Cot, C. Lurin, W. Nie and D. Rioult, S)mthesis and characterization of silica gels obtained in lamellar media. Mater. Sci. Forum, 152-153 (1994) 267. 

Procedure proposed by Papirer et al. [28,37-39,53] was used in characterization of silicas, modified silicas, oxides and minerals. Authors of refs. [23-28,30,54] used this method for characterization of carbon fibers, solid polymers, i.e. conducting polypyrroles, polycarbonates and poly (dimethacrylates), respectively. Voelkel and Krysztafkiewicz [55] characterized silicas modified by organic compounds. 

Luna-Xavier, J.L., Guyot, A., and Bourgeat-Lami, E., Synthesis and characterization of silica/polyjmethyl methacrylate) nanocomposite latex particles through emulsion polymerization using a cationic azo initiator, J. Colloid Inteif. Sci., 250. 82, 2002. 

During the past decade, the main advances in the spectroscopic characterization of silica powders have come from 29Si NMR, Raman diffusion, and Fourier transform infrared (FTTR) studies. NMR studies have given two types of results. First, single and geminal silanols have been quantitatively differentiated as a function of dehydroxylation by thermal treatment and subsequent rehydroxylation by liquid water (7). The fraction of geminal silanols... 

The Raman characterization of silica gels is a by-product of researches on the sol-gel process to obtain silica glasses at low temperature from solutions of tetraalkoxysilanes. These spectra have two puzzling features that are also observed in the Raman spectrum of fused, vitreous (v) silica. Two peaks, at 490 cm-1 (called Di) and 604 cm-1 (called D2), are superimposed on the broad band at about 440 cm-1, which is the most intense signal in the spectrum of u-Si02. These two peaks are unusually... 

Selection of the mobile phase is critical in the characterization of silica sols by SEC. As with the other separation methods, pH should be slightly basic, and low ionic strength must be used to prevent particle aggregation. In addition, the mobile phase must interact with the surface of the packing-particle pores to neutralize undesirable charge effects. Negatively charged surfaces within the pore can result in ion-exclusion effects whereby... 

Research of Soviet scientists is surveyed. Contributions to various aspects of the colloid chemistry of silica are examined preparation and stabilization of silica hydrosols preparation of silica gels structural characterization of silicas surface chemistry elucidation adsorption and ion-exchange property examination and geometric and chemical modification of silicas, silica coatings, and so forth. 

Adsorption from solutions, research, 653-654 Adsorption isotherm, 253, 254f Adsorption methods, characterization of silica surface, 170, 175-177/... 

GL Rice, SL Scott. Characterization of silica-supported vanadium(V) complexes derived from molecular precursors and their ligand exchange reactions. Langmuir 13 1545-1551,1997. 

Characterization of silica immobilised fluorinated acid (surfactant)... 

This chapter does not cover the most common aspects of the solid-state NMR techniques employed in the study of heterogeneous catalysts such techniques are described in Chapter 4. Since this chapter emphasizes the surface characterization of silica and alumina systems and silica aluminas by NMR methods, only those technical aspects highly relevant to surface characterization and not otherwise emphasized in this volume are explicitly discussed here. NMR studies of zeolites and clays are treated in separate chapters, and the bulk structures of silica and alumina systems are covered by Eckert. Unavoidably this chapter is also concerned with dynamics at the surface, although the amount of detailed work on that subject to date is limited. With the increasing availability of variable-temperature solid-state NMR equipment, however, one can expect that attention devoted to dynamics at surfaces will increase markedly during the next few years. 

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