Nano-templates

The template method for synthesizing nanostructures involves the synthesis of the desired material within the pores of a nanoporous membrane or other solid. This approach has been used in several experiments [224—229] for the preparation of Ti02 nanotubes and nanorods typically, porous aluminum oxide (PAO) nano-templates were used. 

Compact, continuous, and uniform anatase nanotubules with diameters in the range 50-70 nm were produced inside PAO nano-templates by pressure impregnating the PAO pores with titanium isopropoxide and then oxidatively decomposing the reagent at 500 °C [230], Cleaning the surface of the template and repeating the process several times produced titania nanotubules with a wall thickness of 3 nm per impregnation. The tube exteriors appeared to be faithful replicas of the pores in which they were formed. 

Core-shell cylindrical brushes have gained increasing interest due to their unique properties and applications as nano-templates. Thus, Matyjaszewski et al. and our group first prepared core-shell brushes [30, 134], We have been studying core-shell brushes containing ionic blocks [30, 31], Amphiphilic and double hydrophilic coreshell brushes were prepared and studied for their solution properties. 

Kitaura R, Imazu N, Kobayashi K, Shinohara H. Fabrication of metal nanowires in carbon nanotubes via versatile nano-template reaction. Nano Lett 2008 8 693-9. 

Very recently, a novel and versatile method has been reported for the construction of stable, zero-valent metal quantum dots, using dendrimers as well-defined nano-template/containers. The concept involves the use of dendrimers as hosts to preorganize small molecules or metal ions, followed by a simple in situ reaction, which immobilizes and incarcerates these nanodomains (Figure 17) [89]. The size, shape, size distribution, and surface functionality of the dendritic nanocomposites are determined and controlled by the architecture. Dendrimer-based nanocomposites display unique physical and chemical properties as a consequence of the atomic/molecular level interactions between the guest and host components within the dendrimer as well as the dendrimer interaction with various solvents and media. 

Nature demonstrated the use of regular 2dimensional protein grids in bacterial surface S-layers (5 nm to 15 nm thick). These layers are protein crystals forming the outermost cell envelope of many prokaryotes. A variety of lattice symmetries from pi, p2, p3, p4 to p6 is found in bacterial strains. Sometimes even a single strain is able to switch from one type of S-layer to another induced via a change in the microenvironment. The pores and spacing in between the units varies from 3-30 nm. S-layer proteins are handled dissolved or suspended in a buffer at a concentration of up to 2 mg/ml. Their stability and unique property to coat two-dimensional arrays with perfect uniformity makes them an ideal nano-template. 

Abstract Molecular self-assembly is a powerful approach being explored for novel supra-molecular nanostructures and bio-inspired nanomaterials. In this article, we focus on recent research concerning the self-assembly of de novo designed artificial peptides and peptidomimetics into nanofiber structures, specifically towards developing a new class of soft-materials. These nanofiber architectures have potential use not only in biomedical applications, such as 3D-matrix scaffolds for tissue engineering and biomineralization, but also in nanotechnology such as nano-templates and dimension-regulated functional nano-objects. 

Peptide nanofibers were also utihzed as nano-template for the synthesis of metal nanowires and for the spatial control of inorganic nanoparticles [73,74]. Wang et aL prepared -sheet-based peptide nanofiber with... 

Anton, N., Benoit, J. P. Saulnier, P. (2008). Design and production of nanopartides formulated from nano-emulsion templates - A review. Journal of Controlled Release, Vol. 128, 3, (June 2008), pp. (185-199), ISSN 0168-3659... 

Although random and irregular type GaN nanorods have been prepared by using transition metal nanoparticles, such as Ni, Co, and Fe as catalysts and carbon nanotubes as the template, the preparation of controllable regular array of strai t GaN nanorods has not yet been reported. Fabrication of well-ordered nano-structures with high density is very important for the application of nano-structures to practical devices. 

Keywords. Nano-sized space. Porphyrin, Cyclic oligomer. Multi-detectable molecule. Inverse-template effect... 

Electrochemical template-controlled sjmthesis of metallic nanoparticles consists of two steps (i) preparation of template and (ii) electrochemical reduction of metals. The template is prepared as a nano structured insulating mono-layer with homogeneously distributed planar molecules. This is a crucial step in the whole technology. The insulating monolayer has to possess perfect insulating properties while the template has to provide electron transfer between electrode and solution. Probably, the mixed nano-structured monolayer consisting of alkylthiol with cavities which are stabilized by the spreader-bar approach [19] is the only known system which meets these requirements. 

Bhattacharyya S, Gedanken A (2008) A template-free, sonochemical route to porous ZnO nano-disks. Microp Mesop Mater 110 553-559... 

Use of Nano-emulsions as Templates for the Preparation of Polymeric Nanoparticles 167... 

Traditional methods for fabricating nano-scaled arrays are usually based on lithographic techniques. Alternative new approaches rely on the use of self-organizing templates. Due to their intrinsic ability to adopt complex and flexible conformations, proteins have been used to control the size and shape, and also to form ordered two-dimensional arrays of nanopartides. The following examples focus on the use of helical protein templates, such as gelatin and collagen, and protein cages such as ferritin-based molecules. 

Kao, C.C. and Dragnea, B. (2006) Nanopartide-templated assembly of viral protein cages. Nano Letters, 6, 611-615. 

Fig. 7.9 SEM images of HSA nanotubes pre- (C) The length of the resulting nanotubes is pared by self-assembly in AAO membranes. about 60pm. (D) Highlyflexible HSA nanotubes. (A) HSA nanotube arrays afterthe removal ofthe (Reproduced from [93] with permission of the AAO template. (B) Highly ordered HSA nano- American Chemical Society, Copyright 2005 tubes with a wall thickness of around 30 nm. American Chemical Society).

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