Abstract:The porous mixed oxide SiO2/TiO2/Sb2O5 obtained by the sol-gel processing method presented a good ion exchange property and a high exchange capacity towards the Li+, Na+ and K+ ions. In the H+/M+ ion exchange process, the H+ / Na+ could be described as presenting an ideal character. The ion exchange equilibria of Li+ and K+ were quantitatively described with the help of the model of fixed tetradentate centers. The results of simulation evidence that for the H+ / Li+ exchange the usual situation takes place: th… Show more
“…In general, for new kinds of hybrid materials, origins of nonideality and cooperativity are not clear enough. Thus, in contrast to the material studied in the present work, silica and cellulose/Al 2 O 3 carriers modified with pyridinium groups do not demonstrate nonideality effects when metal chlorides are adsorbed [18,23,24]. Many factors may affect the chemisorption process and the state of bound ligands and complexes, for instance, heterogeneous surface topography, porous structure of materials, peculiar conformation and accessibility of fixed reacting groups, electrostatic effects, solvation/desolvation effects, and so on.…”
Section: Resultscontrasting
confidence: 64%
“…, S. Each set θ vs included t Q corresponding to the vth model and the log β (Z) i values. The latter were uniformly distributed within ellipsoids with borders defined by condition (18). The membership functions for components of θ vs were assigned as…”
Section: Calculation Proceduresmentioning
confidence: 99%
“…They were used, in particular, to get keener insight into sorption and ion exchange equilibria on surfaces of such hybrids as cellulose acetate fibers (CAF) coated with Al 2 O 3 and modified with nitrogen-containing ligands [17], sol-gel derived SiO 2 /TiO 2 /Sb 2 O 5 mixed oxide [18], CAF coated with highly dispersed aluminum [19,20] and zirconium [21] phosphates, silica gel coated with 3-n-propyl(4-methylpyridinium) silsesquioxane chloride polymer [22,23], CAF coated with n-propyl-1,4-diazabicyclo(2.2.2)octane chloride [24], SiO 2 /Nb 2 O 5 prepared by the sol-gel method and modified with phosphoric acid [25], xerogels containing aniline [26] and xylenol orange groups [27], and others. This paper discusses the simulation of sorption equilibria of metal chlorides on the surface of 3-n-propylpyridinium silsesquioxane chloride polymer from ethanol media.…”
“…In general, for new kinds of hybrid materials, origins of nonideality and cooperativity are not clear enough. Thus, in contrast to the material studied in the present work, silica and cellulose/Al 2 O 3 carriers modified with pyridinium groups do not demonstrate nonideality effects when metal chlorides are adsorbed [18,23,24]. Many factors may affect the chemisorption process and the state of bound ligands and complexes, for instance, heterogeneous surface topography, porous structure of materials, peculiar conformation and accessibility of fixed reacting groups, electrostatic effects, solvation/desolvation effects, and so on.…”
Section: Resultscontrasting
confidence: 64%
“…, S. Each set θ vs included t Q corresponding to the vth model and the log β (Z) i values. The latter were uniformly distributed within ellipsoids with borders defined by condition (18). The membership functions for components of θ vs were assigned as…”
Section: Calculation Proceduresmentioning
confidence: 99%
“…They were used, in particular, to get keener insight into sorption and ion exchange equilibria on surfaces of such hybrids as cellulose acetate fibers (CAF) coated with Al 2 O 3 and modified with nitrogen-containing ligands [17], sol-gel derived SiO 2 /TiO 2 /Sb 2 O 5 mixed oxide [18], CAF coated with highly dispersed aluminum [19,20] and zirconium [21] phosphates, silica gel coated with 3-n-propyl(4-methylpyridinium) silsesquioxane chloride polymer [22,23], CAF coated with n-propyl-1,4-diazabicyclo(2.2.2)octane chloride [24], SiO 2 /Nb 2 O 5 prepared by the sol-gel method and modified with phosphoric acid [25], xerogels containing aniline [26] and xylenol orange groups [27], and others. This paper discusses the simulation of sorption equilibria of metal chlorides on the surface of 3-n-propylpyridinium silsesquioxane chloride polymer from ethanol media.…”
Porous solids are a rapidly developing class of materials with an ever-increasing range of applications. Among these materials, amorphous porous mixed oxides possess the extraordinary properties of fine tuning the chemical composition, microstructure, porosity and surface properties. The tailor made composition of the mixed oxides can be fabricated from the availability of variety of precursor, additives and modifiers. Besides, their performance can be found close to that of crystalline phase. These amorphous mixed oxides can easily be synthesized using acid / base catalyzed one-pot sol-gel procedure. Sol-gel processes allow for a relatively facile tailoring of the morphology of mixed oxides to the desired application in the field of nanotechnology. Pore volume, porosity, specific surface area, and surface acidity are typical parameters that can be tailored. This chapter deals with the preparation methodology, characterization techniques, and application of amorphous porous mixed oxides.
▪ Abstract This review discusses the preparation, characterization, and application of amorphous porous mixed oxides, a rapidly growing class of materials with wide applications and a huge potential for the tailoring of chemical composition, microstructure, porosity, and surface properties. In contrast to crystalline materials, these amorphous mixed oxides are prepared under mild reaction conditions in ambient atmosphere. An ever-increasing variety of precursors, additives, modifiers, solvents, catalysts, and posttreatment conditions provide ample fine-tuning options. These materials often display properties commonly associated with well-defined crystalline phases. The functional properties of such solids are largely unexplored and provide a tremendous opportunity for the development of new or alternative materials (solids with a function). Here, emphasis is paid to micro- and mesoporous mixed oxides and their catalytic properties. Easy access to these materials is offset by their much more problematic characterization. Microstructure, chemical structure, morphology, and pore sizes often show broad distributions, and materials description cannot compare with the precise data associated with crystalline phases. The facile preparation and accessibility of these materials make them ideally suited for the application of high-throughput technologies (HTT), which dramatically accelerate searches for new materials as well as fine tuning and optimization. HTT also allow investigators for the first time to access and optimize multinary mixed oxides on a realistic timescale.
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