Supramolecular structures fabrication approaches

Many natural biomolecules, like peptides and proteins, interact and self-assemble to form delicate structures that are associated with specific functions (33). Ligaments and hair, for example, are assembled from collagen and keratin, respectively. DNA transcription is initiated by self-assembly of transcription factors, RNA polymerase, and DNA. Systematic studies and analysis of these natural existing self-assembly systems provide insight into the chemical and structural principles of peptide self-assembly, which inspires the development of molecular self-assembly as a new approach for fabrication of novel supramolecular architectures. 

Abstract The electrostatic Layer-by-Layer (LbL) technique allows the fabrication of polyelectrolyte multilayers that can be considered as a special type of interpolyelectrolyte complexes supported by a template (fluid or soUd). The main characteristic that confers special interest to these interpolyelectrolyte complexes is the simplicity and versatility of the method used for their fabrication, although in some cases this may hide the complex influence of the different physico-chemical variables. The possibility to change ionic strength, pH, temperature, etc. and/or the composition makes possible to control the properties and structure of these systems. Furthermore, the compositional and structural richness of these systems opens multiple possibilities for the fabrication of nano-structured materials with tailored properties for numerous applications (from optical to nanomedical devices). This chapter deal with the physico-chemical background of the fabrication of supramolecular films by the LbL method as well as the key properties that should be managed in order to obtain functional materials following this approach. 

In this chapter, a revision of the most important physico-chemical aspects involved in the fabrication and properties of PEMs has been presented. The simplicity and versatility of the LbL method in the fabrication of supramolecular materials have allowed a strong development of this approach in different applications. However, this can not hide the complex physico-chemical bases under this process. The main advantage of the LbL method in the fabrication of nano-architecmres is the infinite number of control possibilities over the properties and structure of the formed systems due to subtle changes in the assembling conditions. 

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