Quartz, adsorptive properties

With a different quartz glass Benton and Williams have found a different law, namely that the rate varies as [QJ [CO]1/2. This illustrates the varying adsorptive properties of various kinds of quartz. 

If the elements 112 and 114 have a noble-gas like character [62], then, in a fictitious solid state, they would form non conducting colorless crystals. A physisorptive type of adsorption may occur and their adsorption properties, for example on quartz, can be calculated with this method [61], see Table 3. For physisorbed noble gas atoms a roughly uniform distance to different surfaces of about 2.47 0.2 A was deduced from experimental results [63]. 

Radeva E, Georgiev V, Spassov L, Koprinarov N, St K (1997) Humidity adsorptive properties of thin fullerene layers studied by means of quartz micro-balance. Sens Actuators B 42 11-13 Ramos MV, Al-Jumady A, Puli VS (2005) Conductive polymer-composite sensor for gas detection, In Proceedings of 1st international conference on sensing technology, Palmerston North, New Zealand, 21-23 November 2005, p 213-216... 

Zeolites consist of aluminium oxide, calcium oxide, iron oxide, magnesium oxide, potassium oxide, silicon oxide and sodium oxide within their strucmre with water molecules and/or cations in the pores and the cages [10, 20, 27, 46-48]. A certain fraction of the mass of the zeolites is lost on ignition because of loss of water. Researchers have suggested that, for a material to get zeolited, the ratio of (Si + Al)/0 in it should be equal to 0.5 [16, 46-48]. The cation exchange capacity (CEQ, adsorption properties, pH, and loss on acid immersion of zeolites are some of the chemical properties which are reported to depend on the chemical composition of the synthesized products. Table 2.4 presents typical chemical composition of a fly ash, its crystalline constituents (viz.. Quartz and Mullite), one commercial grade synthetic zeolite, a fly ash zeolite and their comparison with a natural zeolite [47, 48]. 

Egorova, T. S., Yu. A. Zarif Yants, V. F. Kiselev, K. G. Krasil Nikov, and V. V. Murina, 1962. Effect of the surfaces of silica gel and quartz on their adsorptive properties. VIII. Differential heats of adsorption of water vapor on silica. Zh. Fiz. Khim. 36 1458. 

Hybrid catalysts consisting of a zeolite (ZSM-5 or Beta) and bentonite as a binder were prepared and characterized by XRD, pyridine FTIR and nitrogen adsorption. The hybrid catalysts exhibited similar properties as the combined starting materials. Catalytic pyrolysis over pure ZSM-5 and Beta as well as hybrid catalysts has been successfully carried out in a dual-fluidized bed reactor. De-oxygenation of the produced bio-oil over the different zeolitic materials was increased compared to non-catalytic pyrolysis over quartz sand. 

The first two terms represent van der Waals interactions between the adsorbed SOC and the surface, which would apply to all SOC. The second two terms represent Lewis acid-base interactions, which can be important for compounds containing O, N, or aromatic rings, for example, the adsorption of alkyl ethers on the polar surface of quartz. The y coefficients (in mJ m 2) describe the surface properties, where yvdw is associated with its van der Waals interactions with adsorbing gases, y describes its electron-acceptor interactions, and y describes the electron-donor interactions of the surface. On the other hand, the properties of the adsorbing species are described by In pL for the van der Waals interactions and by the dimensionless parameters ft and which relate to the electron-donor and electron-acceptor properties (if any), respectively, of the adsorbing molecule. 

The oxide, a-quartz, was selected as the substrate for the present and continuing studies of metal ion adsorption. It is of considerable importance in several practical situations—e.g., water purification and ore flotation—and has the important property that it is negatively charged over a wide pH range since its zero-point-of-charge (z.p.c.) is circa pH 2. 

Barranco et. al. (1999) hypothesized that film formation results from the adsorption of asphaltenes at the coal tar-silica interface. Barranco et. al. (1999) further postulate that these asphaltene components are responsible for pH-dependent interfacial properties observed in coal tar-water-quartz systems. 

Abstract Investigations of alternate adsorption regularities of cationic polyelectrolytes a) copolymer of styrene and dimethylaminopropyl-maleimide (CSDAPM) and b) poly(diallyldimethylammonium chloride) (PDADMAC) and anionic surfactant - sodium dodecyl sulfate (SDS) on fused quartz surface were carried out by capillary electrokinetic method. The adsorption/desorption kinetics, structure and properties of adsorbed layers for both polyelectrolytes and also for the second adsorbed layer were studied in dependence on different conditions molecular weight of polyelectrolyte, surfactant and polyelectrolyte concentration, the solution flow rate through the capillary during the adsorption, adsorbed layer formation... 

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