Nanostructures via Self-Assembly

In the following Section 3.1.1, the morphology is discussed for block copolymer nanostructures via self-assembly (Section 3.1.1.1), in dependence on the chain architecture (Section 3.1.1.2), for blends of block copolymers with a constituent homopolymer (Section 3.1.1.3), for processing-induced influences (Section 3.1.1.4), and for block copolymer nanocomposites (Section 3.1.1.5). Section 3.1.2 gives an overview of nano- and micromechanical deformation effects. 

Hgure 3.3 Kraton SEBS triblock copolymer with about 30% PS showing cylindrical PS domains  

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Extraction of nano-size fibers from biosources Direct synthesis of nano-size polymers Precipitation of nanoparticles from solution Preparation of nanostructures via self-assembly Nanofibers by electrospinning... 

Linder, S. M. and Thelakkat, M. (2004) Nanostructures of n-type organic semiconductor in a p-type matrix via self-assembly of block copolymers. Macromolecules, 37, 8832-8835. 

Stupp, S.I., Messmsore, B.W., Arnold, M.S., and Zubarev, E.R. Encapsulation of Nanotubes Via Self-Assembled Nanostructures, 2003-US12111 2003090255 (2003d). 

M.R.J. Scherer, Nanostructured Materials via Self-Assembled Templates, University of Konstanz (2009)... 

S. M. Lindner, M. Thelakkat, Nanostructures of N-Type Organic Semiconductor in a P-Type Matrix via Self-Assembly of Block Copolymers. Macromolecules 2004, 37, 8832-8835. 

Wan, MJC., et al. 2003. Studies on nanostructures of conducting polymers via self-assembly method. Synth Met 135 175. 

Since the formation of the micelle-soft-template is strongly affected by the nature of polymeric chain and dopant as well as polymerization conditions, the structure of micelle-soft templates formed in a reaction solution can vary [5cj. Moreover, the micelle-soft template and the molecular interactions as the driving forces coexist in the reaction solution, resulting in cooperation between them that might be employed to complex micro/nanostructures of PANI via the self-assembly process. This prediction has been confirmed by the formation of hollow rambutan-like spheres [64], hollow dandelion-like microstructure [65] and hollow cube box-like 3D microstructures of PANI [66] as shown in Figure 17.4. These complex 3D micro/nanostructures are self-assembled from ID nanofibers and show electrical and supper-hydrophobic properties. The trick is to use perfluorooctane sulfuric acid (PFOSA) or perfluorosebadc acid (PFSEA) as the dopant, which has doping. 

Poly (thiophene)s are of particular interest as electfochromic materials owing to their chemical stability, ease of synthesis and processability. For the most part, current research has been focused on composites, blends and copolymer formations of several conjugated polyheterocyclics, polythiophene and its derivatives, especially PEIX)T. In one example, poly(3,4-ethylenedioxythiophene) (PEDOT)/poly(2-acrylamido-2-methyl-l-propanesulfonate) (PAMPS) composite films were prepared by Sonmez et al. for alternative electrochromic applications [50]. Thin composite films comprised of PEDOT/PAMPS were reported to switch rapidly between oxidized and neufial states, in less than 0.4 s, with an initial optical contrast of 76% at A.max. 615 nm. Nanostructured blends of electrochromic polymers such as polypyrrole and poly(3,4-ethylenedioxythiophene) were developed via self-assembly by Inganas etal. for application as an electrochromic window [26]. Uniir etal. developed a graft-type electrochromic copolymer of polythiophene and polytetrahydrofuran for use in elecfiochromic devices [51]. Two EDOT-based copolymers, poly[(3,4-ethylenedioxythiophene)-aZ/-(2,5-dioctyloxyphenylene)] and poly[(3,4-ethylenedioxythiophene)-aft-(9,9 -dioctylfluorene)] were developed by Aubert et al. as other candidates for electrochromic device development [52],... 

Frontiers in Nanofabrication via Self-Assembly of Hybrid Materials into Low Dimensional Nanostructures... 

This section has discussed a diverse range of self-assembled synthetic macromolecules such as block copolymers and elastm-like polymers for template-directed assembly of different types of inorganic nanoparticles into anisotropic ID nanostructures. In the next section, we introduce a simple and cost-effective approach for directing the assembly of gold nanoparticles into ID structures via self-assembly of a short commercially available surfactant. 

Mushroom Nanostructures Stupp et al. (34) have evolved strategies to create supramolecular units of various sizes and shapes via self-assembly. They found that rod-coil block copolymers can self-assemble into long striplike aggregates measuring 1 m or more in length and a few nanometers in other dimensions. The mushroom nanostructures in Figure 14.8 constitute yet another... 

Krausch, G. and Magerle, R. (2002) Nanostructured thin films via self-assembly of block copolymers. Advanced... 

Bonifazi D, Kiebele A, Stohr M, Cheng F, Jung T, Diederich F, Spillmann H (2007) Supramolecular nanostructuring of silver surfaces via self-assembly of [60]fullerene and porphyrin modules. Adv Funct Mater 17 1051-1062... 

Polymeric Nanostructures Prepared via Self-assembly and Co-assembly of Preformed Copolymers... 

Sithambaram, S., Garces, H.F. and Suib, S.L. (2009) Controlled synthesis of self-assembled metal oxide hollow spheres via tuning redox potentials versatile nanostructured cobalt and cobalt manganese oxides. Advanced Materials, 20, 1205-1209. 

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