Properties and Potential Applications

On the basis of the chiral building block 105, a series of enantiopure helical macrocycles (110,112, and 114) containing tetraphenylene motifs were obtained. Platinum(II) complexes 110 and 112 were assembled in tetrahydrofuran (THF) 

Studies of syntheses and properties of multicyclic polymers are still in their infancy. The following properties are known or predictable and allow for speculations about certain applications. Due to the compact structure and the lack of long linear chain ends both melt and solution viscosities are particularly low. Yet, 

As their structures define, polyrotaxanes are polymeric composites. Their ultimate properties are related both to the chemical compositions of the cyclic and backbone and to their relative proportions. However, because of its different topology relative to simple mixtures, the interpenetrated structure introduces new outcomes in terms of properties. Because the applications of materials rely on their properties, these aspects are incorporated into this section. 

A glass transition temperature (Tg) is the temperature at which polymer is transformed from the glassy state to a rubbery state. The T values observed for polyrotaxanes might differ from the starting backbone if only one phase is formed, i.e., when the cyclic is compatible with the backbone. If the cyclic is immiscible with the backbone, two phases corresponding to two components might be formed. For these polyrotaxanes, two Te values might be observed if both components are amorphous. 

CD are very rigid molecules and polyrotaxanes derived from them are expected to be more rigid than the starting backbone. Poly(methyl methacrylate side chain rotaxane) 56 had a Tg 20°C higher than the backbone itself. The same observation was also seen in side chain poly(ether ketone) and poly(ether sulfone) systems [96-102]. 

Paraquat, an ionic molecule, is more rigid than polymeric crown ethers. In addition, die crown ether has to adopt a restricted conformation for complexation to occur. The total increase of the rigidity for derived polyrotaxanes 84 depended on the min value [118, 119]. The higher the value of min, the higher Tg of the poly-rotaxane. Paraquat is a crystalline material but the polyrotaxanes are amorphous. 

For a crystalline polymer, the melting temperature (Tm) may be observed for both the cyclic and the backbone in some cases. Poly(alkylene sebacate crown ether rotaxane)s 60 have two Tm values, those of the cyclic and the backbone [19, 111]. The crystallization of the crown ether on the backbone was attributed to aggregation enabled by the mobility of the crown ether along the backbone in solution or melt states. The crystallization process is driven by the tendency for these immiscible components to form their own separate phases to minimize interfacial energy. According to an X-ray diffraction study of polystyrene rotaxane)s 26 

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The many papers in this proceedings are partitioned into very abstruse theoretical analyses of structure and stability of quasicrystals on the one hand, and practical studies of surface structures, mechanical properties and potential applications. The subject shows signs of becoming as deeply divided between theorists and practical investigators, out of touch with each other, as magnetism became in the preceding century. 

This area of research is receiving increasing attention due to a better understanding (and recognition) of the properties and potential applications of siloxane containing copolymers. A detailed discussion of this type of graft copolymers and their uses will be given in later sections. 

J. R. Groza 2002, in Nanostructured Materials - Processing, Properties and Potential Applications, ed. C. C. Koch, William Andrew Publishing, New York, chap. 4. 

Burt, S. (2004) Essential oils their antibacterial properties and potential applications in foods-a review . International Journal of Food Microbiology, 94, 223-253. 

One-dimensional colloidal gold and silver nano-structures by Murphy et al. (2006). Recent advances in the synthesis of metallic nanorods and nanowires are reviewed. The increasing relevance of the bottom-up chemical synthesis is underlined. Physical properties and potential applications are described with emphasis on silver and gold. 

Finally, the combination of dendrimers and organometallic entities as fundamental building blocks affords an opportunity to construct an infinite variety of organometallic starburst polymeric superstructures of nanoscopic, microscopic, and even macroscopic dimensions. These may represent a promising class of organometallic materials due to their specific properties, and potential applications as magnetic ceramic precursors, nonlinear optical materials, and liquid crystal devices in nanoscale technology. 

One area related to gold clusters is the field of nanoparticles and nanoclusters. These materials have actually been known since ancient times when they were used for their esthetic appeal and also for their therapeutic properties in the form of colloidal gold. In recent decades, the field of nanoparticle research has emerged and in-depth research has dealt with the properties and potential applications of these systems. 

Polymer-stabilized Au NPs have been the object of intense research in recent years because, apart from their intrinsic synthetic interest, these hybrid materials have interesting properties and potential applications. There are also several advantages in the use of polymers as stabilizers enhancement of long-term stability adjustment of solubility or amphiphilicity of nanoparticles, tuning of the properties of Au NPs, and the promotion of compatibility and processability. 

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