Adsorbents styrene/divinyl benzene resin

As common examples of monomers used for the production of resins, methacrylate and styrene can be mentioned, where the cross-linkers are ethylene dimethacrylate (EDMA) or divinyl benzene (DVB), respectively [205], The most important resins of this type are the poly(styrene-divinyl benzene) type or Amberlite resins, as well as the Wofatit and Lewatit [192] types. These materials have been widely applied as adsorbents [191,192,207] and as ion exchangers [193,194,208],... 

A partial listing of available resins is given in Table 9. The Sepabeads adsorbents were introduced commercially in the mid 1980s (Mitsubushi Kasei) and were designed with a density of approx 1.2 g/L, achieved by bromination of the styrene divinyl benzene copolymer base matrix. A beneficial side effect of the bromination was that the surface hydrophobicity was increased relative to the naked polymer. In the case of P-lactam antibiotics such as cephalosporin C, the capacity was more than doubled from 25-50 g/L for the HP series (Mitsubushi Kasei Corp.) to 90-120g/L for Sepabeads. The Streamline adsorbents for proteins were introduced in 1993 (Pharmacia) and also feature a well-defined density of 1.2 g/L achieved by inclusion of an inert core material m the matrix. 

Zeohtes also have considerable application as catalysts. Iron in the +3 oxidation state is introduced by ion-exchange methods [103]. However, attempted adsorption of Fe " " ions causes complete breakdown of the structure with any retained iron being in the +3 state. Dehydration of the zeolite causes non-reversible reduction of the iron. Adsorption of Fe salts on ion-exchange resins of the sulphonated styrene-divinyl benzene and quaternary ammonium types has httle effect on the iron resonances and indicates very weak binding of the ions to the resin [104]. Spin-relaxation effects and temperature-dependent paramagnetic hyperfine structure have been recorded and interpreted in detail for Fe ions adsorbed on exchange resins [105, 106], and a number of other recent papers have shown interest in this new field [107]. 

Reagents used in the test, including sodium hydroxide, hydrochloric acid, sulfuric acid and cobalt sulfate were analytical grade without farther purification. PC88A extractant was industrial-grade products with a purity of 93%. Acetic acid-sodium acetate buffer solution was prepared on our laboratory. The resin used in the test was the HPD-100 Styrene-divinyl benzene porous adsorbing resins. The cobalt raw materials used in the test are listed in Table 1. 

Resins such as phenol formaldehyde and highly sulphonated styrene/divinyl benzene macroporous ion exchange resins can be pyrolysed to produce carbonaceous adsorbents which have macro-, meso- and microporosity. Surface areas may range up to 1100 m /g. These adsorbents tend to be more hydrophobic than granular activated carbon and therefore one important application is the removal of organic compounds from water. 

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