Molecularly imprinted polymers monomer template ratio

Organic Molecularly imprinted polymers Functional monomer(s) Template concentration Cross-linker Porogen Monomer(s)/template ratio Physical conditions during polymerization... 

Andersson, H.S. Karlsson, J.G. PUetsky, S.A. Koch-Schmidt, A.C. Mosbach, K. Nicholls, I.A. Study of the nature of recognition in molecularly imprinted polymers, II [1]—Influence of monomer template ratio and sample load on retention and selectivity. J. Chromatogr. A 1999, 848, 39 9. 

Imprinted polymer membranes are prepared using atrazine as the template, methacrylic acid as a functional monomer, and tri(ethylene glycol) dimethacrylate (TEDMA) as a cross-linker. The molar ratio of the functional monomer to the template is 5 1. This ratio has to be optimized for each template. In order to obtain thin, flexible and mechanically stable membranes, oligourethane acrylate (molecular mass 2600) is added to the monomer mixture. Preparation of the molecularly imprinted polymer membrane is done as follows. Atrazine (20 mg) is mixed with methacrylic acid (40 mg), TEDMA (289 mg), oligourethane acrylate (51 mg), AIBN (2 mg) and 30% v/v of chloroform. Then a 60-120 pm gap between two quartz slides is filled with the monomer mixture. To initiate polymerization, the slides with the mixture are exposed to UV radiation (365 nm, intensity 20 W m ) for 30 min. After polymerization, atrazine is extracted with ethanol in a Soxhlet apparatus for 2h. This should not cause any visible changes in the MIP membrane. A membrane for control experiments can be prepared similarly except that no atrazine is added to the monomer mixture. 

The HPLC-vial based approach has been successfully applied to the optimization of imprinted polymers for a range of low molecular weight targets. Most of these studies have focused on the search for optimal functional monomers, although some describe the optimization of monomer ratios, type of cross-linker, template, and solvent. 

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