Polymer side-chain assembly

In this chapter, we present a brief overview of supramolecular polymers and polymerization and supramolecular interactions of polymer side chains. We provide examples of the control over the solution state polymer strucmre that can be achieved at the molecular level and then extended to micro- and macroscale assemblies. 

To overcome the above mentioned problems, we developed a self-assembly DNA-conjugated polymer for novel DNA chip fabrication [66-68]. The system developed uses ssDNA as a probe and disulfide bridges located in the polymer side chain for self-assembly immobilization. This polymer can be immobilized on gold substrate with the self-assembly technique. On the surface, DNA (hydrophilic) is exposed to a solution site without lying due to the hydrophobic polymer main chain (Fig. 4). Finally, we have discriminated differential of one base mismatched sequences using DNA-conjugated polymer. 

A self-assembly DNA-conjugated polymer-based DNA detection method was previously mentioned. This study showed specific immobilization to a gold substrate with the self-assembly technique, not physical adsorption and great selectivity to fully matched DNA instead of nonspecific adsorption due to self-assembly DNA-conjugated polyallylamine and PAA coating [67,68]. However, a major problem was that we needed to prepare many kinds of DNA-conjugated polymer to analyze many kinds of target DNA due to direct modification of probe DNA to the polymer side chain. 

This chapter concentrates on the design of efficient dipolar NLO chromophores and the different approaches for their incorporation in non-centrosymmetric materials, including guest-host polymer systems, chromophore-functionalized polymers (side-chain and main-chain), cross-linked chromophore-macromolecule matrices, dendrimers, and intrinsically acentric self-assembled chromophoric superlattices. The different architectures will be compared together with the requirements (e.g., large EO coefficient, low optical absorption, high stability, and processability) for their incorporation into practical EO devices. First, a brief introduction to nonlinear optics is presented. 

Schematic illustration of the structure of a typical side-chain LC polymer is shown in Scheme I. Mesogenic units are covalently attached to the polymer backbone via a flexible spacer.Our aim in the present study is to construct new type of side-chain liquid crystalline polymers through intermolecular hydrogen bonding in place of covalent bonding. Hydrogen bonding may be used to connect the part where the broken line shows in Sceme I. We describe self-assembly of LC polymers through selective recognition between a polymer side chain and low-molecular-weight molecules.

To be successful in these applications, it is important that materials can self-assemble into precisely defined structures. Peptide-based polymers have many advantages over conventional synthetic polymers since they are able to hierarchically assemble into stable, ordered conformations [4]. Depending on the substituents of the amino acid side chain, polypeptides are able to adopt a multitude of... 

If the backbone as well as the side chains consist of flexible units, the molecular conformation arises out of the competition of the entropic elasticity of the confined side chains and the backbone [ 153 -155]. In this case, coiling of the side chains can occur only at the expense of the stretching of the backbone. In addition to the excluded volume effects, short range enthalpic interactions may become important. This is particularly the case for densely substituted monoden-dron jacketed polymers, where the molecular conformation can be controlled by the optimum assembly of the dendrons [22-26,156]. If the brush contains io-nizable groups, the conformation and flexibility may be additionally affected by Coulomb forces depending on the ionic strength of the solvent [79,80]. 

The polymer-bound p-nitrobenzophenone oxime (71d) has been found to be a suitable support for stepwise peptide synthesis. Protected peptides can be assembled on 70d by coupling and deprotection steps similar to those employed in the usual Merrifield solid-phase procedures (Scheme 39). Cleavage of peptides from 71d can be accomplished with hydrazine and amino acid esters under mild conditions, which do not affect benzyl ester side-chain protecting groups. 

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