Supramolecular polymerization techniques

In this review, the term macromer is used to describe oligomer or polymer precursors that undergo reversible association to form supramolecular polymers or networks. Macromer synthesis, although a crucial aspect of supramolecular science, is also out of the scope of this review. Several comprehensive reviews of the synthesis of H-bonding polymers are available [10, 11,42] and primarily describe the application of controlled radical polymerization techniques, including atom-transfer radical polymerization (ATRP), reversible addition-fragmentation chain transfer (RAFT) polymerization, and nitroxide-mediated polymerization (NMP). For synthesis of telechelic polymers, avoiding monofunctional impurities that can act as chain stoppers is crucially important [43],... 

Recent advances in polymerization techniques have made possible the synthesis of complex, including hierarchically branched, maaomolecules with perfectly controlled architecture. Analysis of interplay between complex maaomolecular topology and multiple competing interactions on conformations, routes of self-organization in solutions and at interfaces, and properties of resulting supramolecular stractures presents a major cuuent and future challenge for polymer theory. 

Polyion complex technique is a unique method of supramolecular polymerization of bilayer membranes without conventional polymerization procedures [14,50], Water-insoluble polyion complexes are precipitated when the aqueous solution of the charged bilayer membrane is mixed with a water solution of the countercharged polyelectrolyte. The polyion complexes can be formed as thin films by usual casting from organic solutions. The fundamental bilayer structure and characteristics are essentially maintained in the immobilized cast films of the polyion complexes. X-ray diffraction of the solvent cast polyion complex films reveals the layered structure with repeating spacing corresponding to the bilayer thickness [50-52]. 

Hoogenboom R, Schubert US (2006) The use of (metallo)supramolecular initiators for living/ controlled polymerization techniques. Chem Soc Rev 35 622-629... 

Organizational characteristics of surface-active molecules have been studied by several researchers due to their applications in many areas such as personal care, polymerization, catalysis, drug delivery, separation and purification, enhanced oil recovery and lubrication. The structure of supramolecular organized assemblies formed in different solvents, when a critical concentration is exceeded, determines their properties such as solubilization [1-3], catalysis [1,4-6], adsorption [7-11] and flocculation [12,13]. As such, many techniques have been used to determine their structural properties. In this paper, the results obtained using fluorescence probing for properties of assemblies in solution and at solid-liquid interfaces are discussed in detail after a brief review of relevant assemblies formed by them. 

This article is organized primarily on the geometry of the supramolecular structure (e.g., vesicle, planar supported film, etc.). Functionalization of poly(lipid) structures and their technological applications are presented in a separate section as these have expanded greatly as the field has matured. The analytical techniques available for characterization of substrate-supported, thin organic films have advanced considerably since polymerized lipid films were first reported in the early 1980s, and examples of the use of these techniques to study poly(lipid) membranes are presented throughout this review. 

In conclusion, it should be pointed out that none of the physicochemical techniques discussed above permits the direct measurement of the elements of the polymeric materials porous structure we measure the properties of the systems where the polymers interact with certain test substances (nitrogen, mercury, water, polystyrene standards, ions, etc.), and not the dimensions of the pores or other supramolecular elements of the material. Therefore, the evaluation of the surface area and diameters of pores available to the molecules of these substances must be considered as indirect methods of examining the porous structure. Because of this, all calculations are based on assuming certain models of the structure of the material and accepting certain assumptions as to the mechanism of interaction between the material and test molecules. Only transmittance, scanning, and, in particular, atomic force microscopy can be considered as direct methods of measuring dimensions and distances. However, up to now the last technique has not been appHed to microporous hypercrosslinked polymers. 

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