Material hierarchically organized

Introducing chirality into polymers has distinctive advantages over the use of nonchiral or atactic polymers because it adds a higher level of complexity, allowing for the formation of hierarchically organized materials. This may have benefits in high-end applications such as nanostructured materials, biomaterials, and electronic materials. Synthetically, chiral polymers are typically accessed by two methods. Firstly, optically active monomers - often obtained from natural sources - are polymerized to afford chiral polymers. Secondly, chiral catalysts are applied that induce a preferred helicity or tacticity into the polymer backbone or activate preferably one of the enantiomers [59-64]. 

Brandhuber, D., Peterlik, H. and Husing, N. (2005) Simultaneous drying and chemical modification of hierarchically organized silica monoliths with organofunctional silanes. Journal of Materials Chemistry, 15, 3896-3902. 

Figure 29. Fiuman osteoblast-like MG 63 cells in cultures on material surfaces modified with carbon nanoparticles. A fullerene Cgo layers deposited on carbon fibre-reinforced carbon composites (CFRC), B fullerene C o layers deposited on microscopic glass coverslips, C terpolymer of polytetrafluoroethylene, polyvinyldifluoride and polypropylene, mixed with 4% of single-wall carbon nanohorns, D the same terpolymer with high crystalline electric arc multi-wall nanotubes, E diamond layer with hierarchically organized micro- and nanostmcture deposited on a Si substrate, F nanocrystalline diamond layer on a Si substrate. Standard control cell culture substrates were represented by a PS culture dish (G) and microscopic glass coverslip (FI). Immunofluorescence staining on day 2 (A) or 3 (B-Fl) after seeding, Olympus epifluorescence microscope IX 50, digital camera DP 70, obj. 20x, bar 100 pm (A, C, D, G,H)or 200 pm (B, E, F) [16].

An excellent example that shows the potential of combining various bottom-up techniques is the joint work by Whitesides and Stucky [4]. Hierarchical metallic oxides were produced by combining (i) sol-gel self-assembly of neutral surfactants, (ii) spherical polystyrene templates, and (iii) molds with micrometric cavities (micromolding). Figure 3.12 shows how the described materials are hierarchically organized at several scales ranging from a few nanometers to hundreds of micrometers. 

Supramolecular self-assembly has recently been extensively investigated as a tool to create nanostructured or hierarchically structured optoelectronically active materials from monodisperse, conjugated oligomers because such n-conjugated organic materials are interesting candidates for the fabrication of organic... 

Reznikov, N., Shahar, R., and Weiner, S. (2014a) Three-dimensional structure of human lamellar bone the presence of two different materials and new insight into the hierarchical organization. Bone, 59, 93-104. 

In sediments or soil, a hierarchical sequence of succession of organisms is involved in breakdown of organic materials. Once the altered archaeological wood is removed from the sequence of successions, dried and treated, and placed into a new environment (such as a museum), museum pests such as wood beetles may not infest this wood. 

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