Architecturally driven property

The unique architecturally driven properties of the final products. 

Unique architecturally driven properties that may be expected from hyperbranched polymers will be largely derived from their (a) amplified number of terminal functional groups, (b) new rheological properties based on less chain entanglement and (c) new architectural arrangements that may modulate crystallinity, flow characteristics and glass transition properties in designed systems. 

Hopefully, the present collection of insights on dendritic polymers will serve to assist and enlighten those who are in quest of such new architecturally driven properties and behavior. 

This article will overview the dendritic architectural state, its unique architecturally driven properties, its role relative to traditional polymer science as well as describe the many enabling features that dendrimers are expected to offer to the emerging nanotechnology revolution. 

Table II Architecturally Driven Property Differences Between Dendrimers and Corresponding Linear Polymers...

Another most interesting aspect concerns the mechanical coupling of the polymer cushion with the membranes and their incorporated proteins. This could lead to interfacial architectures that show interesting features of structure formation by the coupling of the specific entropy driven properties of polymers in general with the self-organization capability of lipid bilayer structures. Experiments along these lines are under way. 

DA Tomaha, S Uppuluri, DR Swanson, HM Brothers E, LT Piehler, J LL DJ Meier, GL Hagnauer, L Balogh. Dendrihe Macromolecules A Eourth Major Class of Polymer Architecture—New Properties Driven by Architecture. Boston Materials Research Society, 1998. 

The synthesis-driven approach towards material science can be applied to create oligomers and polymers with optimized properties, e.g. maximized carrier mobilities and electrical conductivities or high photo- and electroluminescence quantum yields. It becomes obvious, however, that the ability to synthesize structurally defined -architectures is the key to these high performance materials. 

The urge of polymer scientists to develop new materials is driven by society s wish to substitute conventional materials by plastics and thereby gain in performance. One reason for the emerging interest in hyperbranched polymers and other macromolecular architectures is their different properties compared to conventional, linear polymers. 

Evolution of a constitutional dynamic library of dynamer strands may be driven by metal ion binding towards the generation of a specific metallo-supramolecular architecture, such as a [2x2] grid [54], or of a dynamer presenting specific interactions and properties (such as optical self-sensing) [57] (see also Figs. 7 and 8 in [9]). 

ATER-SOLUBLE MICROBIAL POLYSACCHARIDES represent an important class of compounds that are used to control the rheology of aqueous fluids and gels in applications ranging from foods to enhanced oil recovery (1-5). From a molecular perspective, the unique solution properties of many polysaccharides reflect a helical architecture that provides high viscosity and may encourage self-association in aqueous solution. Intermolecular association can be energetically driven by unfavorable polymer-solvent interactions and... 

Abstract The metal-driven construction of multi-porphyrin assemblies, which exploits the formation of coordination bonds between exocyclic donor site(s) on the porphyrins and metal centers, has recently allowed the design and preparation of sophisticated supra-molecular architectures whose complexity and function begin to approach the properties of naturally occurring systems. Within this framework, meso-pyridyl/phenyl porphyrins (PyPs), or strictly related chromophores, can provide geometrically well-defined connections to as many as four metal centers by coordination of the pyridyl peripheral groups. Several discrete assemblies of various nuclearities, in which the pyridylporphyrins are connected through external coordination compounds, have been constructed in recent years. In this review, we summarize recent work in this field from our and other laboratories. The photophysical properties of some ruthenium-mediated assemblies of porphyrins prepared by our group are also described. 

A remarkable property of polymer systems is their ability to self-assemble, driven by thermodynamic incompatibilities of the different monomers, which will be discussed in more detail in Chap. 4. The resulting repulsive forces make homopolymer blends to separate into macrostructures. In contrast, being covalently bonded, the thermodynamically incompatible blocks of copolymers are prevented from separating on a macroscopic level. Even for the most simple copolymer architecture, namely diblocks, this gives rise to the formation of a variety of highly ordered morphologies with nanoscale periodicities [3]. 

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