Nanoporous hard templates

The disadvantages of the nanoporous hard-template method are the generally tedious post-synthetic processes, which are required in order to remove the templates, and the destruction of nanostructures during die post-synthetic process, i.e. the formation of undesirable aggregated structures after removal of the templates. 

Nanoporous Hard-Template Methods PANI-NTs have been prepared by the chemical oxidative polymerization of aniline within the pores of PC nanoporous membranes... 

Supramolecular Organization of Polymeric Materials in Nanoporous Hard Templates... 

Despite these still-challenging issues, the fabrication of nanotubes using nanoporous hard templates is associated with several advantages beyond the possibility to align them. Readily available porous hosts such as self-ordered porous AAO have a narrow pore diameter (Dp) distribution and pores with Dp-values ranging from about 20 nm up to a few lOOnm. The pore depths (Tp) can be adjusted to values between about 1 im and several 100 xm. Therefore, it is easily possible to tailor the diameter and the aspect ratio of the nanotubes. However, the most important advantage is the possibility to control mesoscopic structure formation processes inside the pores. There are relatively few limitations regarding the materials that can be formed into nanotubes via hard templates. Mixtures, sols, semicrys-... 

Only few attempts have been made to rationally design the mesoscopic fine structure of nanotubes fabricated by wetting nanoporous hard templates with polymeric solutions. Chen et al. infiltrated solutions of PS-fo-PAN in DMF into AAO. As described above, the PAN was at first crosslinked and then carbonized. However, the PS domains were converted into holes, and porous amorphous carbon nanotubes could be fabricated [89]. hi a similar approach, Rodriguez et al. used a solution of PS-fo-PVP and carbohydrates associated with the PVP blocks via hydrogen bonds in DMF into AAO and obtained mesoporous amorphous carbon nanotubes with the positions of the mesopores determined by the positions of the PS domains. Solvent annealing of the BCP/hydrocarbon films in DMF/benzene vapor led to a significantly... 

Little is known about the natiure of disordered, amorphous interphases covering the pore walls of nanoporous hard templates, but a hmited body of literature deals with ordered supramolecular architectures in singlecomponent nanotubes and nanorods confined to hard templates. Mesoscopic morphologies characterized by a crystaUine or liquid-crystalline degree... 

BCPs [117-121], The concepts discussed above may help to understand the crystallization behavior of bulk polymers as well as that of non-polymeric materials such as pharmaceuticals [122] and inorganic semiconductors [123] confined to nanoporous hard templates. 

In the case of diblock copolymer melts, which are the simplest model system for the elucidation of structure formation processes involving BCPs in nanoporous hard templates, only the two immiscible blocks have to be considered as components. Self-consistent field methods were applied to study the morphologies of liquid diblock copolymer/homopolymer mixtures that were considered as a model system for triblock copolymers in sol solutions [182], of pure diblock copolymer melts [200-202], and of order-disorder transitions in diblock copolymer melts [203]. For example, Li et al. found for a model diblock copolymer that forms cylinders in the bulk... 

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