Molecular weight carbon adsorption

The effects of polymer molecular weight on the rate and extent of adsorption on carbon black at equilibrium is fundamentally no different from other polymeric adsorbate-adsorbent systems (95). When microporosity is present in carbon black, the adsorption is governed by the external surface area (96), but with very high molecular weight polymers adsorption is also limited by the inability of the molecular coils to penetrate the internal void space of the primary structure aggregates (95). 

Adsorption on a nonpolar surface such as pure siUca or an unoxidized carbon is dominated by van der Waals forces. The affinity sequence on such a surface generally follows the sequence of molecular weights since the polarizabiUty, which is the main factor governing the magnitude of the van der Waals interaction energy, is itself roughly proportional to the molecular weight. 

Sacrificial adsorption agents such as lignosulfonates (148—151) can be used to reduce the adsorption of more expensive polymers and surfactants. Other chemicals tested include poly(vinyl alcohol) (152), sulfonated poly(vinyl alcohol) (153), sulfonatedpoly(vinylpyrrohdinone) (153), low molecular weight polyacrylates (154), and sodium carbonate (155). 

The processes of reversible adsorption of the coordination" inhibitors (including the adsorption of organometallic compounds) result in an increase in the lifetime of the transition metal-carbon bond. It is possible that due to this, in the case of propylene polymerization by two-component catalysts based on TiCU, at low temperatures a long-term increase of molecular weight with time was observed (192,193). 

IOS 1518 is more highly branched than AOS (entry 7, Table 16). IOS 1518 also has the sulfonate group and the carbon-carbon double bond in different relative positions than AOS 1618. IOS 1518 exhibits a significantly lower adsorption than AOS 1618. Study of Table 16 shows that the molecular weights of these two surfactants are quite similar. The AOS 1618 does have a higher di monosulfonate ratio. 

Adsorbents (Activated carbons and charcoals) Large adsorption capacity for VOCs and odors Immediately noticeable effects Operates wall avuri uniter vary humid uundiliuris. Inefficient for removing tow molecular weight pollutants such as formaldehyde end ammonia, Adsorption decreases rapidly with time snd frequent ruplautmerit is requited. 

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