Effect on adsorption

Jin X, Talbot J and Wang N FI L 1994 Analysis of steric hindrance effects on adsorption kinetics and equilibria AlChE J. 40 1685-96... 

Comparison of entries 4 and 8 of Table 16 shows that linear IOS 2024 and AOS 2024 adsorption values were the same within a modest experimental error. The major chemical structure difference between them is the position of the sulfonate group on the carbon chain and perhaps the position of the carbon-carbon double bond. These two factors do not appear to have an appreciable effect on adsorption. Therefore, the lower adsorption of IOS 1518 relative to AOS 1618 is probably due to the greater hydrophobe branching of the internal olefin sulfonate or the lower di.monosulfonate ratio. 

Parsons, R., Structural effect on adsorption at the solid metal/electrolyte interface,... 

The ability of STM to image at the atomic scale is particularly exemplified by the two other chapters in the book. Thornton and Pang discuss the identification of point defects at Ti02 surfaces, a material that has played an important role in model catalyst studies to date. Point defects have been suggested to be responsible for much of the activity at oxide surfaces and the ability to identify these features and track their reactions with such species as oxygen and water represents a major advance in our ability to explore surface reactions. Meanwhile, Baddeley and Richardson concentrate on the effects of chirality at surfaces, and on the important field of surface chirality and its effects on adsorption, in a chapter that touches on one of the fundamental questions in the whole of science - the origins of life itself ... 

An important aspect of the study of water under electrochemical conditions is that one is able to continuously modify the charge on the metal surface and thus apply a well-defined external electric field, which can have a dramatic effect on adsorption and on chemical reactions. Here we briefly discuss the effect of the external electric field on the properties of water at the solution/metal interface obtained from molecular dynamics computer simulations. A general discussion of the theoretical and experi-... 

Adsorption of a surfactant on solids is dependent, among other things, on the structure of both the hydro-phobic and hydrophilic portions of it. There are a number of mechanisms proposed for surfactant adsorption and an understanding of the effects of the structure of the surfactant can help in elucidating the role of these mechanisms. In this study, the effect on adsorption on alumina of some structure variations of sulfonates (chain length and the branching and the presence of ethyoxyl, phenyl, disulfonate and dialkyl groups) is examined above and below CMC as a function of surfactant concentration, pH and salinity. Co-operative action between an ionic alkyl sulfonate and a nonionic ethoxylated alcohol is also studied. 

While there is no ambiguity about the physical reality of heat effects on adsorption, at least when calorimeters are used, the same cannot be said of their interpretation. If the solid is perturbed, some of the entropy changes will take place in the solid and some in the adsorbed gas. Drain and Morrison i.88) have considered this point ... 

However, after the study of inosine-substituted ODN, there was evidence that the pretreatment improved the electrochemistry of purine bases, with a smaller effect on the interfacial accumulation [78]. The G oxidation signal was strongly affected by the surface pre-treatment of CP. However, the inosine-modified probe response was less affected by this treatment [78], suggesting a lesser effect on adsorption over the electrochemistry of purine base. However, if inosine (a non-purine base) substituted G in the ODN sequence, the stability of the adsorbed probe on CP was similar to that observed with G-containing ODN, i.e., being stable in a stirred PBS for up to 15 min. Such behavior indicated that the inosine substitution has little effect upon the stability of the adsorbed probe [78]. 

Purification of the clay did not seem to have a marked effect on adsorptive properties. In this connection, it should be mentioned that in bringing the sample to a controlled ionic form before measurement, alkaline earth carbonates, if present, were probably removed, because the operation usually involved equilibration at pH 5. However, oxidation to remove organic matter and treatment with complexing agents to remove iron oxides apparently had little effect. 

The heterogeneous nature of polycrystalline solid electrodes invalidates the approximation of uniform surface or one-dimensional model used for the mercury electrode. Variations of pzc occur with surface structure. Study of single crystal sp metal electrodes has shown structural effects on adsorption [99]. 

The studies reported in this paper have focused on more complete elucidation of the nature of the interaction between the hydronium ion and active carbon. Both rate and extent of reaction have been studied as a function of several variables to obtain data which ultimately should contribute to a meaningful interpretation of pH effects on adsorption of organic solutes by active carbon. 

The "solid-solution lattice theory" model of adsorption on zeolites has been shown to describe the experimental results in the literature with accuracy comparable to all existing theories, even though these theories are in many instances semi-empirical. Since the theory is related to actual physical phenomena, systematic studies can be made of the effect on adsorption of changing the zeolite. 

The adsorption of organic ligands onto metal oxides and the parameters that have the greatest effect on adsorption were also studied (Stone et al., 1993). The extent of adsorption was measured by determining the loss of the compound of interest from solution. The physical and chemical forces that control adsorption into two general categories were classified as either specific or nonspecific adsorptions. Specific adsorption involves the physical and chemical interaction of the adsorbent and adsorbate. Under specific adsorption, the chemical nature of the sites influences the adsorptive capacity. Nonspecific adsorption does not depend on the chemical nature of the sites but on characteristics such as surface charge density (Stone et al., 1993). The interactions of specific adsorption can be explained in two ways. The first approach uses activity coefficients to relate the electrochemical activity at the oxide/water interface to its electrochemical activity in bulk solution (Stone et al., 1993). This approach is useful in situations... 

Fractal geometry was employed to study surface geometry effects on adsorption conformations of polymers.1771 Using poly(styrene) for the case study, it was shown, that for highly porous objects, solution conformation changed very little after solvent adsorption. 

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