Noncovalent intrinsic properties

Badaire et al. reported the formation of liquid crystalline phase of CNTs by noncovalent functionalization with single strand DNA in water [74]. The nonco-valent functionalization in water is simpler and does not affect the intrinsic properties of the CNTs. They observed that a nematic-isotropic coexistence is observed for nanombes concentrations between 2 and 4 wt%. Above 4 wt%, the system forms a single nematic phase of unmodified and freely dispersed nanotubes. They investigated the boundaries of the phase diagram with respect to the aspect ratios of the nanombes determined by dynamic depolarized light scattering. Poulin et al. uniformly aligned the nematic aqueous suspensions of nanombes in... 

Noncovalent functionalization offers the advantage of preserving the intrinsic properties of CNTs, and, consequently, their original electronic and optical properties. In this case, the adsorption of functional molecules does not occur with disruption of the extended 3t-conjugated system (sp sp rehybridization) but via van der Waals-type or electrostatic interactions. As a consequence, the original electronic and optical properties of the CNTs are preserved almost completely. However, the main drawback of this functionalization type is the problem of the possible reaggregation of the nanotubes due to the inherently weak interactions [48]. 

MS can be used to study several intrinsic physicochemical properties of ILs, for example, the acidity of components of ILs or the determination of wafer miscibilities. Furthermore, MS delivers valuable information about noncovalent interactions, for example, responsible for the formation of quasi-molecular structures [23] formed by three-dimensional supramolecular polymeric networks within the IL. 

Figure 4.20. Strategies for optical detection of intrinsic DNA bends and kinks. (Top) The FRET approach. The energy transfer donor dye (open circle) is covalently attached to the 5 end of a DNA strand. The complementary strand is labeled on its 5 end with an energy transfer acceptor dye (closed circle). The measured energy transfer is a function of the dye-to-dye distance R and should be different for the double helical straight DNA compared with the double helical bent DNA. (Bottom) The noncovalent probe approach. A probe molecule (shaded circle) is allowed to bind to either straight or bent duplex DNA. Equilibrium binding constants or kinetics of association may be monitored via the spectroscopic properties of the probe.

Taking into accoimt the large specific surface area, unique intrinsic optical properties and easy noncovalent interactions with aromatic drug molecules, GO is a potential material for biomedical applications. Further, GO is photoluminescent in the visible and near-infrared (NIR)... 

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