Adsorption organic polymer

New areas in adsorption technology include carbonaceous and polymeric resins (3). Based on synthetic organic polymer materials, these resins may find special uses where compound selectivity is important, low effluent concentrations are required, carbon regeneration is impractical, or the waste to be treated contains high levels of inorganic dissolved soHds. 

Recent efforts have concentrated on the immobilization of these materials onto both organic polymers(11) and metal oxides(12) to simplify, by filtration, the separation, recovery and recycle process. These supported catalysts now function in a triphasic environment in either a liquid-solid-liquid or solid-liquid-solid reaction mixture. In this case, the catalyst must transfer the anion from the surface of the crystal lattice to the liquid phase. Here adsorption phenomena often significantly affect the reaction rate(13). 

Type 3 metal complexes involve the physical interaction of a metal complex, chelates, or metal cluster with an organic polymer or inorganic high molecular weight compound. The preparation of type 3 compounds differs from those of type 1 and type 2, as they are ultimately achieved through the use of adsorption, deposition by evaporation, microencapsulation, and various other methods. 

The behavior of the nonpolar bonded phases, as well as the column packings based on crossbnked organic polymers of low polarity, however, differs from that of polar column packings and the classical solvent strength concept should be reevaluated. This is especially important for the alkyl bonded phases (Section 16.8.1). In this case, surface and interface adsorption of polymer species (Section 16.3.5) plays a less important role and macromolecules are mainly retained by the enthalpic partition (absorption) (Section 16.3.6). In order to ensure this kind of retention of polymer species, the mobile phase must push them into the solvated bonded phase. Therefore the interactions of mobile phase with both the bonded phase and (especially) with the sample macromolecules—that is, the solvent quality—extensively controls retention of latter species within the alkyl bonded phases. 

Enzymes can be adsorbed on various types of materials e.g. silica gel, metal oxides, glass and organic polymers. Depending on the natnre of the carrier material, adsorption can be accomplished by hydrogen bonding hydrophobic interaction and ionic forces. 

Research has continued apace over the years to develop new organic ion-cxchangc organic polymers—the details of most are proprietary. Both natural and synthetic zeolites also are used in ion-exchange processes, but their extreme importance as catalysts has tended to overshadow their applications for deionizing purposes. See also Adsorption and Zeolite Group. 

These can be immobilized by either electrostatic adsorption on ion-exchangers [81] or sulfonated polystyrene [82], by hydrophobic interactions on organic polymers [83], by covalent binding to cellulose [68,84] and chloro-sulfonated polystyrene [71], or by entrapment in hydrogels [69,85]. Sol-gel based methods were established particularly for the preparation of fiber optic sensors [86-88]. 

Carbon molecular sieves are produced by controlled pyrolysis and subsequent oxidation of coal, anthracite, or organic polymer materials. They differ from zeolites in that the micropores are not determined by the crystal structure and there is therefore always some distribution of micropore size. However, by careful control of the manufacturing process the micropore size distribution can be kept surprisingly narrow, so that efficient size-selective adsorption separations are possible with such adsorbents. Carbon molecular sieves also have a well-defined bi-modal (macropore-micropore) size distribution, so there are many similarities between the adsorption kinetic behavior of zeolitic and carbon molecular sieve systems. 

Enzymes are immobilized by attachment to or confinement in water-insoluble materials (Fig. 1). Enzymes can be immobilized by adsorption on biologically inert carriers like organic polymers, glass, mineral salts, metal oxides, and different silicates. Since enzymes retain their activity for a longer time in an undissolved form, many reactions catalyzed by enzymes can be carried out in continuous systems. Immobilized enzymes can be used in agitated vessels, fluidized or Fixed bed tower reactors40). 

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