Nanoscale polymers, characteristics

Covalent polymers comprising regions of more than one type of monomer (block co-polymers) have interesting, designer conformational characteristics leading to their assembly into useful nanoscale morphologies with novel interfacial properties. 

Block copolymers self-assemble to form nanoscale organized structures in a selective solvent. The most common structures are spheres, with the insoluble core surrounded by a solvent-swollen corona. In some instances, disk- or worm-like micelles form, and are of particular interest, since the control of their association can lead to a broad range of new applications [1,2]. An important subset of block copolymer micelles are those which contain metal atoms, through covalent attachment or by complexa-tion [3], These structures are interesting because they take advantage of the intrinsic properties of their components, such as the mechanical properties of the polymer micelles and the optical and magnetic characteristics of the metal atoms. Moreover, the assembly permits the control of the uniformity in size and shape of the nanoparticles, and it stabilizes them. 

Type A plasma polymers (see Chapter 8), so far as the transport characteristics are concerned, could be viewed as nanoscale molecular sieves, which are not solution-diffusion membranes. Therefore, the increase of oc by reducing the transport rate of the denominator permeant with the minimal reduction in the transport rate of the numerator permeant is the main viable principle for LCVD and LGT modification of membranes. 

The dimensions of the added nanoelements also contribute to the characteristic properties of PNCs. Thus, when the dimensions of the particles approach the fundamental length scale of a physical property, they exhibit unique mechanical, optical and electrical properties, not observed for the macroscopic counterpart. Bulk materials comprising dispersions of these nanoelements thus display properties related to solid-state physics of the nanoscale. A list of potential nanoparticulate components includes metal, layered graphite, layered chalcogenides, metal oxide, nitride, carbide, carbon nanotubes and nanofibers. The performance of PNCs thus depends on three major attributes nanoscopically confined matrix polymer, nanosize inorganic constituents, and nanoscale arrangement of these constituents. The current research is focused on developing tools that would enable optimum combination of these unique characteristics for best performance of PNCs. 

H.J. Lee and S.M. Park, Electrochemistry of conductive polymers. 30. Nanoscale measurements of doping distributions and current-voltage characteristics of electrochemically deposited polypyrrole films. J. Phys. Chem. B, 108, 1590 (2004). 

One-dimensional nanostructured polymer composite materials include nanowires, nanorods, nanotubes, nanobelts, and nanoribbons. Compared to the other three dimensions, the first characteristic of one-dimensional nanostructure is its smaller dimension structure and high aspect ratio, which could efficiently transport electrical carriers along one controllable direction, thus is highly suitable for moving charges in integrated nanoscale systems (Tran et al., 2009). The second characteristic of one-dimensional nanostructure is its device function, which can be exploited as device elements in many kinds of nanodevices. With a rational synthetic design, nanostructures with different diameters/... 

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