Silica nanostructured

Coffman, E.A., Melechko, A.V., Allison, D.P., Simpson, M.L. and Doktycz, M.J. (2004) Surface patterning of silica nanostructures using bio-inspired templates and directed synthesis. Langmuir, 20,8431— 8436. 

Lopez, P.J., Gautier, C., Livage, J. and Coradin, T. (2005) Mimicking biogenic silica nanostructures formation. Current Nanoscience, 1, 73—83. 

Zhong, A., Rong, C., and Liu, S. 2007. Structural and dynamic properties of (Si02)6 silica nanostructures A quantum molecular dynamics study. J. Phys. Chem. A 111 3132-3136. 

Red and Near Infrared Photoluminescence Bands in Silica Nanostructures. 83... 

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... 

Recently, living cells were reported to actively direct the assembly of lipid-silica nanostructures 78 extension of this cell-directed assembly (CDA) to hybrid architectures will add another level of organizational control to these materials. 

Potential applications of peptide-polymer conjugates include drug delivery materials, optoelectronics, biosensors, tissue scaffolds, tissue replacement materials, hydrogels, adhesives, biomimetic polymers, lithographic masks, and templates for metallic or silica nanostructures. 

DOX-loaded silica nanostructures exhibiting superb drug release behavior, which is controlled by varying the pH was reported by Tan et al. (2011). Porous hollow silica nanoparticles (HSNS) have been successfully fabricated by a novel combination of stabilizing condensation and dynamic self-assembly. Further, encapsulation of organic molecules into HSNS and their controlled release were... 

Recently, ultrasound imaging has been intensified using a single nanoparticle with double scattering/reflection properties. Zhang et al. developed a rattle-type mesoporous silica nanostructure with two contributing interfaces, that is, incident ultrasound will be scattered and reflected twice between these two interfaces in the nanoparticle [52]. 

In the following sections different families of nanoparticles will be compared to emphasize the unique features of doped luminescent silica nanostructures, and to underline the challenges that these systems are expected to face, mainly in the field of sensing. 

It is proposed that this Si(II) center is present in significant amounts in oxygen-deficient silica. We have to assume, therefore, that the laser ablation of Si in oxygen as described here results in a silica nanostructure with a large concentration of this... 

Baca, H.K., Ashley, C., Carnes, E., Lopez, D., Flemming, J., Dunphy, D., Singh, S., Chen, Z., Liu, N., Fan, H., Lopez, G.P., Brozik, S.M., Werner-Washbume, M., Brinker, C.J., 2006. Cell-directed assembly of hpid-silica nanostructures providing extended cell viability. Science 313, 337-341. http //dx.doi.org/10.1126/science.1126590. 

Halas, N.J. (2008) Nanosdence under glass the versatile chemistry of silica nanostructures. ACS Nano, 2,179-83. 

Jan, J.-S. and Shantz, D.F. (2007) Biomimetic silica formation effect of block copolypeptide chemistry and solution conditions on silica nanostructure. Advanced Materials, 19, 2951-6. 

Helical silica nanostructures Asymmetric No Sol-gel polymerization using chiral cationic gelator to induce formation of helical bundles (many silica nanotubes). Acidic conditions needed for helidty. Straight nanotubes obtained under basic conditions. [23]... 

Helical silica nanostructures Asymmetric No Surfactants used as templates [25]... 

In another investigation, Zhang et al. synthesized nanosilica by reacting polyvinylpyrrolidone (PVP) with water and Au. First, a concentrated gold nanoparticle suspension was diluted with ethanol, after which the solution was mixed with PVP in -pentanol and stirred for 20 min before the addition of aqueous ammonia [29]. The reaction led to the formation of PVP-water-malleable stmctures which acted as a surface where the hydrolysis of TEOS could take place. This gave rise to pure silica nanostructures that were symmetric along an axis, but bent in different ways under various experimental parameters including the amount of PVP, the quantity... 

Yang, Y.G., Suzuki, M., Owa, S., Shirai, H. and Hanabusa, K. (2006) Control of helical silica nanostructures using a chiral surfactant. Journal of Materials Chemistry, 16(17), 1544-50. 

Zhang, J.H., liu, H.Y., Wang, Z.L and Ming, N.B. (2008) Au-induced polyvinylpyrrolidone aggregates with bound water for the highly shape-selective synthesis of silica nanostructures. Chemistry, 14(14), 4374-80. 

The metallization of 1-D silica nanostructures with noble metals provides an alternative method for the attachment of biomolecules. The robust interaction... 

The most common appUcation of 1-D silica nanostructures to date has been in electrical sensors to detect small quantities of biomolecules in solution (71-78). The 1-D nature of these materials provides an enhanced sensitivity to surface charge variations in comparison with bulk 2-D surfaces. The first reported biodetection utilized the weU-characterized interaction between biotin and streptavidin [79]. Here, the streptavidin target was detected in solution by covalently immobilizing biotin on the surface of the silicon nanostructure. A single nanowire was then... 

To date, the appHcations of 1-D silica nanostructures to biological systems have been Hmited to sensor developments for the detection of biomolecules (e.g. DNA,... 

Nguyen, T.P., Hesemann, P., and Moreau, J.J.E. (2011) i-Silica nanostructured silica hybrid materials containing imidazolium groups by hydrolysis-polycondensation of disilylated bis-JVAf-alkyl-imidazolium halides. Microporous Mesoporous Mater., 142 (1), 292-300. 

Figure 12.9 TEM images of the silica nanostructures deposited in 20 nm AAO membranes at (a) -125 V, (b) -1.10V, and (c) -0.95 V versus SCE. Scale bars 100 nm. (Reproduced with permission from Ref [37].)...

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