Template polymerization future

In a large majority of controlled chain polymerizations (except the living ones), there is a certain level of unavoidable, at least in 2011 onward, side reactions, namely, termination and/or irreversible chain transfers. For the future, one could hope to find ways of modifying the reactivities of the active centers in such a way that it will be possible to change the ratios of the rate constants of propagation and termination in radical polymerization, further decreasing the proportion of the dead chains at the complete monomer conversion. The PCR is the template-controlled polymerization (cf. Chapter 4.33 on template polymerization). Perhaps a combination of the template... 

Experimental investigation of the kinetics of template step polymerization, determination of average molecular weights of the product, and molecular weight distribution are still available for future studies. 

Colloidal MIPs enable for the future use of fully synthetic affinity receptors in possibly a vast range of applications. The attractive concept of generating bio-mimetic binding sites in chemically and structurally robust polymer materials was to date possibly but limited by the traditional preparation methods of MIPs. Bulk polymerization of the initial reaction mixture containing monomer, crosslinker, and template, followed by crushing of the formed polymer monolith networks and sieving to find the portion of useful sized polymer particles is not the way of choice for the production of technically widely applicable material. 

Einally, the enormous number of possible combinations of oppositely charged polymeric components that can be involved in interpolyelectrolyte complexation offers attractive perspectives for the preparation of water-soluble multicompartment nanosized macromolecular co-assemblies with desired properties. We believe that such novel IPECs are very promising and will be in demand for their future applications in nanomedicine (e.g., gene and drug delivery, and diagnostic systems), biotechnology, and nanotechnology as nanocontainers, nanoreactors, and molecular templates for nanoelectronic devices. 

The templating methods developed in order to control and to order the porosity of colloidal or polymeric gels can be advantageously applied to membranes. These methods have been thoroughly investigated in recent years and an extension of membrane fimctionalities as well as an increase of their permselectivity are expected for the future. 

Compounds other than nucleic acids can also serve as templates for polymerization to an extent. Tjivikua et al. [33] showed that an adenosine derivative will couple with a pentafluorophenyl ester derivative to form an amide bond. The product is self-complementary hydrogen bonds form between two products in a manner analogous to Watson-Crick base pairing, though the products are not nucleotides. The formation of one product enhances the formation of future products therefore the system is autocatalytic, and may be a model for self-repUcating systems using alternate chemistry (Fig. 9.7). 

An approach taken to overcome these deficiencies is the use of the so-called sacrificial spacers [29]. In this method the intermediate species used during the pre-polymerization of the MIP to link the monomers and the template is chosen so that it is eliminated—or in other words sacrificed—during the removal of the template. This way not only is the template attached to the monomer, the chances of steric influences of the residual moe-ities during the future rebindings with the target species are also avoided. Instances of the common sacrificial intermediate species are spacers with carbonyl groups [59-70] or the less frequent instances of salicylate (2-hydroxybenzoate) [60,71], dimethyl silyl group of silyl ethers [72] and silyl esters [73]. 

Fig. 53 Defect induced inside a colloidal PhC template by photopolymerizing the immersed resin, a Schematic of the experimental procedure and its future use, b fluorescence image of the PhC structures that contain the polymerized defect, c magnibed view of b, and d SEM image...

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