Nanostructures directed self-assembly

A unique feature of such DNA-directed self-assemblies is their site-selective immobilization, which makes it possible to construct well-defined nanostructures. On the other hand, the possibility of the introduction of a vast number of substitutes (like peptidic sequences, nucleoproteins, of hydrophobic hydrocarbon chains) to an adamantane core (adamantyl) makes such a process capable of designing steric colloidal and supramolecular conformations by setting hydrophobic/hydrophilic and other interactions. In addition, the rigidity of the adamantane structure can provide strength and rigidity to such self-assemblies [150]. 

Das AK, Collins R, Ulijn RV (2008) Exploiting enzymatic (reversed) hydrolysis in directed self-assembly of peptide nanostructures. Small 4 279-287... 

Tsonchev, S., Schatz, G.C., Ratner, M.A. (2004). Electrostatically-directed self-assembly of cylindrical peptide amphiphile nanostructures. Journal of Physical Chemistry B, 108, 8817-8822. 

In the second approach to self-assembly of polymer-silica nanocomposites, polymerizable surfactants are employed both to direct self-assembly into ordered mesophases and to serve as organic monomers which can be subsequently polymerized. For instance, Brinker et al. developed nonionic surfactants incorporating diacy-telene groups which could be polymerized upon irradiation by UV light.68 69 Similarly, poly(thiophene)70 and poly(pyrrole)71 have been successfully integrated into silica nanostructures in this manner. Importantly, this in situ polymerization produces isolated molecular wires, rather than clustered bundles of conductive polymer.70... 

The interest in nanostmctures extends beyond their individual properties. We have learned to exploit the natural self-assembly of atoms/molecules into crystals. The directed self-assembly of nanostructures into more conqilex, hierarchical systems is also an important goal. Without direct self-assembly, manu cturing costs will severely limit the nanotechnology impact... 

Biswas and Drzal integrated the polymerized nanostructure PPy with GNS in a directed self-assembly approach governed by the large van der Waal s force of attraction between the graphene basal plane and the tt... 

PS-fc-PMMA (diblock polystyrene polymethylmethacrylate) is one of title typical diblock polymers. " Nanostructure fabrication of direct self-assembly... 

Stacking of ring-shaped compounds can be another good alternative to create hollow tubular structures [26,27]. However, despite recent advances in synthetic tubular nanostructure using the self-assembly, the tubules have a limitation on the dynamic response characteristics. As a part of an effort to generate the stimuli-responsive tubular nanostructures, the self-assembled tubular nanostructure that can undergo a reversible expansion-contraction motion and chirality inversion was reported. Bent-shaped aromatic amphiphiles (enantiomers 1, 2) self-assembled into hexam-eric macrocyclic nanostructures in an aqueous solution (Fig. 2.1) [28]. When the concentration of the solution was increased, the chiral tubules were formed by spontaneous ID stacking of hexameric macrocycles with a mutual rotation in the one direction (Fig. 2.1c). 

Supramoleciflar directed self-assembly of inorganic and inorganic-organic hybrid nanostructures has emerged as an active area of recent research. The recent advance shows a remarkable feasibihty to mimic natoal mineralization systems by a designed artificial organic template, where a supramolecular functional polymer can be directly employed as minerahzation template for the synthesis of novel inorganic nanoarchitectures [165] such as CdS helices [166] and hydroxyapatite (HAP) nanofibers [167]. 

Directed self-assembly shows promise in advanced lithography and a variety of other applications that have less complex requirements. For example, directed self-assembly could be used for enhancing etch selectivity, placing dopants in ordered arrays, or generating high-density, close-packed electrodes in capacitor arrays [6]. Additionally, the assembled nanostructures could be used for fabricating densely packed porous templates [12-14] or membranes [15, 16] at the nanoscale. Other potential applications of assembled block copolymer thin films include the fabrication of MOSFETs (metal-oxide-semiconductor field-effect transistors) [17], quantum dots [18], high surface area devices [19, 20], photovoltaic devices [21], and bit patterned media [22-24]. 

Nanoparticles or nanostructured materials can be prepared by evaporation, sol-gel processing, directed self-assembly, oxidation or reduction of suitable precursors, or electrochemical S5mthesis. 

The aforementioned processes lead to organic-inorganic hybrid materials with ordered structures at the nanoscale. Controlled structural characteristics have been achieved by seeking an equilibrium state of BCP-directed self-assembled nanostructures. The achievable structural diversity can be expanded by kinetic... 

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... 

Preparation of flnorescent molecular probes Rational design of mnitifnnctional drug systems and drug carriers Self-assembly DNA directed self-assembly Shape-targeted nanostructures... 

The observation that a repeating, relatively short sequence of amino acids directs the spontaneous self-assembly of a large protein is shared by other structural proteins from mammalian systems [6] as well as of plant origin [16], Hence, such sequences may inspire the construction of nanostructures made of polypeptides and small proteins, as discussed later. 

Due to the ability of adamantane and its derivatives to attach to DNA, it is possible to construct well-defined nanostructures consisting of DNA fragments as linkers between adamantane cores. This could be a powerful tool to design DNA-directed nanostructured self-assemblies [149]. 

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