Self-assembly classification

Woolfson and Mahmoud have classified the routes to preparation of decorated self-assembling peptide materials [53] as (1) co-assembly, where the functional part is already attached to a self-assembling component prior to assembly, and (2) postassembly, where a non-functionahsed self-assembled structure is modified by covalent or non-covalent means. This discussion adheres to this classification. A third route, beyond the scope of this review, is the use of structured peptides as templates for inorganic materials. Section 4.1 discusses functionalised self-assemblies formed from co-assembly-type approaches, while post-assembly modifications of self-assembled structures are considered in Sect. 4.2. 

The discovery that members of the resorcin[4]arene family self-assemble to form 1, owing to its classification as an Archimedean solid, prompted us to examine the topologies of related spherical hosts with a view to understanding their structures on the basis of symmetry. In addition to providing grounds for classification, we anticipated that such an approach would allow us to identify similarities at the structural level, which, at the chemical level, may not seem obvious and may be used to design large, spherical host assemblies similar to 1. 

In 1991 Tindsey introduced a definitive classification scheme for various types of self-assembly across biochemistry and chemistry which still remains the basis for the way in which we think about self-assembly today. Lindsay s scheme divides self-assembly into seven broad, overlapping classes. 

Swiegers, G. F. and Malefetse, T. J., Classification of coordination polygons and polyhedra according to their mode of self-assembly , Chem. Eur. J. 2001, 7, 3637-3643. 

Classification of polygons and polyhedra of metallocycles and complexes with heterocyclic ligands according to their mode of self-assembly 02CCR(225)91. 

Surfactant additives have been studied intensively in recent years because of the self-reparability or self-assembly of their micro structures after degradation by mechanical or extensional stresses. This ability has led to many studies of their applications in DHC recirculation systems. Classifications of surfactant DR As and their self-assembly nature are described. Also discussed in this section are the main research results on microstructures, rheological properties, HTR of surfactant DR solutions, and approaches to enhance heat transfer coefficients. Significant field tests around the world are reviewed. 

Synthetic strategy, classification, and properties of self-assembled helicates... 

Classification and Nomenclature of Supramolecular Compounds, p. 267 Clathrate Hydrates, p. 274 Crystal Growth Mechanisms, p. 364 Self-Assembly Definition and Kinetic and Thermodynamic Considerations, p. 1248 Self-Assembly in Biochemistry , p. 1257 Supramolecular Polymers, p. 1443... 

In an attempt to provide a general framework for discussion and research, Lindsey introduced a wide-ranging classification scheme, built upon the work of others, that encompasses self-assembly processes in biology and chemistry.This definitive scheme is broken up into seven broad, overlapping, classes. 

Swiegers, G.F. Malafetse. T.J. Classification of coordination polygons and polyhedra according to their mode of self-assembly. Chem. Eur. J. 2001, 7. 3637-3643. Swiegers, G.F. Malefetse. T.J. Classification of coordination polygons and polyhedra according to their mode of self-assembly. 2. Review of the literature. Coord. Chem. Rev. 2002. 225, 91-121. 

To describe self-assembly, we need to consider the three components of any process the subunits the products, and the (complex) equilibrium that relates the two. As yet, there is no unification of these different aspects. Consequently, we will review the work from each category separateiy. In general, progress toward a quantitative description can be approached from two different fronts. The first of these is based on first principles, and produces detailed models that fully describe specific assembly processes. There are literally only a handful of systems described in this manner. For some recent examples, the reader is directed toward the literature.The basis of the second approach is philosophically different. Here, the developing classifications are not derived from first principles but are symmetry based. In this way, they are applicable to more than one specific type of self-assembly. In this entry we focus on this latter methodology. 

According to a widely accepted classification, there are three main categories of NRs biological, self-assembled, and natural or synthetic NRs [2,9]. 

Another very popular method is the template-free method. This method has mainly been used to prepare poly(aniline) tubes. It is assumed that organic acids such as p-naphthalene sulfonic acid and others initially form a salt with aniline which then self-assembles into the soft-template aiding in poly(aniline) tube formation. It could therefore also be classified under the soft-template heading. The following classification will be by type of template. 

Class D. The class of engineered assemblies includes systems that do not spontaneously form ordered structures under normal conditions. Their classification as SPs can be justified since elements of supramolecular interaction stfil assist the final organization. Some examples are layered assembly of complementary poly electrolytes obtained by stepwise deposition under kinetic control (cf. Chapter 19), and polymer brushes prepared by grafting a polymer chain over a SAM of an initiator [6]. Both approaches allow a fine-tuning of surface properties and patterning possibilities. Tailored performance in applications, such as biocompatibility, biocatalysis, integrated optics and electronics have been considered. Additional differences between self-assembled and engineered SPs are discussed in Section I.C. 

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