Nanotubes silica

Meegan JE, Aggeli A, Boden N et al (2004) Designed self-assembled beta-sheet peptide fibrils as templates for silica nanotubes. Adv Fund Mater 14 31-37... 

Yuwono VM, Hartgerink JD (2007) Peptide amphiphile nanofibers template and catalyze silica nanotube formation. Langmuir 23 5033-5038... 

Amino functionalized silica nanotube for base catalyzed reaction... 

Keywords Silica nanotubes, amino functionalized, base catalysis 1. Introduction... 

Scheme 2. The synthesis route used in preparation of silica nanotube...

Anisotropy and Dissymmetry Silica Nanotubes and Janus Nanoparticles... 

Template synthesized silica nanotubes (SNTs) provide unique features such as end functionalization to control drug release, inner voids for loading biomolecules, and distinctive inner and outer surfaces that can be differentially functionalized for targeting and biocompatibility.50 A general path to synthesize nanotubes utilizes anisotropic materials as template. They are coated with silica using Si(OR)4 precursors and nanotubes of Si02 are obtained after removal of the template (Figure 1.24). 

Figure 1.24 Silica nanotubes are formed by template synthesis using anisotropic materials (V307 H2Q, in this case.)...

Figure 1.26 Template synthesis using organic gels expands the versatility of the methodology, affording largely different silica nanotubes. (Reproduced from ref. 51, with permission.)...

PDMS nanocomposites with layered mica-type silicates were also reported.374 A two-step sol-gel process of the in situ precipitation of silica led to the development of siloxane-based nanocomposites with particularly high transparencies.3 5 Some unusual nanocomposites prepared by threading polymer chains through zeolites, mesoporous silica, or silica nanotubes were reviewed.3 6 Poly(4-vinylpyridine) nanocross-linked by octa(propylglycidyl ether) polyhedral oligomeric silsesquioxane was reported.377... 

Nakamura and Matsui [71] prepared silica nanotubes as a spin-off product of sol-gel synthesis wherein tetraethylorthosilicate (TEOS) was hydrolyzed in the presence of ammonia and D, L-tartaric acid. Ono et al. [72] showed that certain cholesterol derivatives can gelate tetraethyl orthosilicate (TEOS) to obtain tubular silica structures. Using cholesterol based gelators nanotubes of transition metal (Ti, V and Ta) oxides can also be prepared. The organogelators used in these processes are chiral diamino... 

The advantage of template synthesis is that organo or hydrogelator templates can direct the shape-controlled synthesis of oxide nanotubes. Recent reports describe the use of carbon nanofibers as a template for the shape-controlled synthesis of zirconia, alumina and silica nanotubes [78]. The shape of vapor grown carbon nanofiber... 

Adachi M, Harada T, Harada M (1999) Formation of huge length silica nanotubes by a templating mechanism in the laurylamine/tetraethoxysilane System. Langamuir 15 7097-7100... 

Synthesis of single silica nanotubes in the presence of citric acid J Mater Chem 11 465-468... 

In contrast to chains in zeolites of very small pore diameter, PS chains in amorphous silica nanotubes [241] with diameters between 400 and 16000 A had values of Ts close to that in the bulk [144]. It seems reasonable to conclude that only those geometries corresponding to diameters significantly less than approximately 400 A sufficiently constrain PS chains to the extent of suppressing their glass transition. Nanotubes are certain to be much more intensively investigated in the future, because of the variety of novel properties they might exhibit. They have already been shown, for example, to serve as quantum wires [242]. 

Yang and coworkers also used a surface imprinting approach to prepare nanotube membranes that exhibit selectivity for the molecule estrone.77 In this study, the silica nanotubes with pore diameters of 100 nm were synthesized within the cylindrical pores of nanopore alumina membranes. A covalent assembly approach was used to prepare the imprint.77 Zhang and coworkers have also recently shown how silica nanotubes can be used as an imprinting scaffold.78 In this example, trinitrotoluene (TNT)... 

For example, it will be possible to design peptides that aggregate in well-defined morphology, for example, fibrils of specific and controllable width and twist pitch to act as versatile templates for nanoporous inorganic materials (e.g., silica nanotubes) (Meegan et al., 2004). Another opportunity that opens up will be the ability to produce by precise molecular engineering, a... 

Meegan, J.E., Aggeli, A., Boden, N., Brydson, R., Brown, A.P., Carrick, L., Brough, A.R., Hussain, A., and Ansell, R.J. "Designed self-assembled beta-sheet peptide fibrils as templates for silica nanotubes". Adv. Fund. Mater. 14(1), 31-37 (2004). 

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