Site nanoscale surface morphology

Nanoscale Surface Morphological Change of PS-b-P4VP Block Copolymer Films Induced by Site-Selective Doping of a Photoactive Chromophore... 

Site-Selective Modification of the Nanoscale Surface Morphology of Dye-Doped Copolymer Films Using Dopant-Induced Laser Ablation... 

Site-Selective Modification of the Nanoscale Surface Morphology 213... 

As aforementioned, diblock copolymer films have a wide variety of nanosized microphase separation structures such as spheres, cylinders, and lamellae. As described in the above subsection, photofunctional chromophores were able to be doped site-selectively into the nanoscale microdomain structures of the diblock copolymer films, resulting in nanoscale surface morphological change of the doped films. The further modification of the nanostructures is useful for obtaining new functional materials. Hence, in order to create further surface morphological change of the nanoscale microdomain structures, dopant-induced laser ablation is applied to the site-selectively doped diblock polymer films. 

It is believed that the nanoscale surface morphology of PS has advantages for the growth of nanostructures like nanowires by increasing the number of nuclei sites and reducing strain (Hsu et al. 2005 Lee et al. 2003 Yang and Lieber 1997). 

Laser ablation of polymer films has been extensively investigated, both for application to their surface modification and thin-film deposition and for elucidation of the mechanism [15]. Dopant-induced laser ablation of polymer films has also been investigated [16]. In this technique ablation is induced by excitation not of the target polymer film itself but of a small amount of the photosensitizer doped in the polymer film. When dye molecules are doped site-selectively into the nanoscale microdomain structures of diblock copolymer films, dopant-induced laser ablation is expected to create a change in the morphology of nanoscale structures on the polymer surface. 

Due to the nanoscale confinement in the system, the interaction via interfacial bonding is considered to play an essential role in the impacts. Morphologically, the interfacial interaction sites on the CNT surface are (a) defeet sites at the tube ends and side-walls (b) covalent side-wall bindings (c) non-eovalent exohedral side-wall bindings and (d) endohedral filling (Figure 1.6). Three routes have been commonly used for preparation of... 

The electrochemical insulation of the enzyme-active site by its protein or glycoprotein shell usually precludes the possibility of any direct electron-transfer with bulk electrodes [15]. However, under carefully controlled conditions, some enzymes can exhibit direct, nonmediated electrical communication with electrode supports, and biocatalytic transformations can be driven by these processes [16, 17]. For example, the direct electroreduction of O2 and H2O2 biocatalyzed by laccase [18] and horseradish peroxidase (HRP) [19], respectively, have been demonstrated. This unusually facile electronic contacting is believed to be the consequence of incompletely encapsulated redox centers. When these enzymes are properly orientated at the electrode surface, the electrodeactive site distance is short enough for the electron-transfer to proceed relatively unencumbered. Direct electron communication between enzyme-active sites and electrodes may also be facilitated by the nanoscale morphology of the electrode. The modification of electrodes with metal nanoparticles allows the tailoring of surfaces with features that can penetrate close enough to the enzyme active site to make direct electron-transfer possible [20, 21]. 

Beside the appropriate design of their chemical composition, the control of morphology and size of PCP crystals at the nanoscale provides an additional mean to modulate their physicochemical properties, in particular their sorption capacity. Recent studies showed that when PCP crystals are downsized to the nanometer scale and for peculiar morphologies, the external surface of the crystal starts to influence the sorption kinetics and sorption type. This phenomenon was explained by the decrease of the diffusion length toward the adsorption sites and by the enhanced accessibility of speciflc pore entrances. Contribution of the size and shape of the crystals upon the sorption properties is an inherent feature of porous materials, which was exploited for facilitating their integration into catalysis, separation, or sensing systems. 

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