Functional monomers uncharged

UNCHARGED FUNCTIONAL MONOMERS GIVING ENHANCED REBINDING SELECTIVITY IN NON-COVALENT MOLECULAR IMPRINTING... 

A number of other studies using uncharged templates or acids imprinted using VPY as functional monomer show pH dependent selectivities that can be rationalised considering this type of ion exchange model [144]. 

The conformational properties of an uncharged molecular chain are well described by a (discrete) semiflexible chain model [33]. The chain is comprised of mass points, each one may represent several monomers, at positions r, (z =0,..., N). The (average) length of a bond is l. The partition function of such a chain is given by... 

The overall activation energy, Ea, of polymerization was determined for both monomers as a function of the nature of the initiator [66,79,81,90,92]. For styrene polymerization in cationic microemulsions, Ea was found to be much higher for KPS systems (E 95 kJ/mol) than for AIBN systems (48 kJ/mol) in spite of similar decomposition energies. This difference was attributed to different radical capture efficiencies between the anion radicals of KPS and the uncharged AIBN radicals and the positively charged... 

Recently, we were able to coat our monosize PS particles described above with styrene/acrylate copolymers. As acrylate monomers, 2-hydroxyethylmethacrylate (HEMA), acrylic acid (AA), and dimethylaminoethylmethacrylate (DMAEMA) were used in order to include functional groups, namely hydroxyl (OH, uncharged), carboxyl (COOH, negatively charged), dimethylamino (N(CH3)2, positively charged) on the surfaces of the PS particles. 

It has been postulated (3) that polar but uncharged functional groups of the monomer units orient themselves in the polymer-water interface so as to improve the stability of the latex. Acrylate esters are cited as examples of this type, e.g., the methyl ester gives a higher degree of orientation in the interface and a lesser adsorption of conventional emulsifier than the n-butyl ester. This concept has not yet been demonstrated for a wide variety of monomers, but offers a means of explaining hitherto unexplained latex stability data. 

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