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Nanoporous Templates

Block Copolymer Lithography Employing Nanoporous Templates. 145... [Pg.149]

Figure 10 FE-SEM images of polyp5rrole/C104 nanotubes obtained by electropolymerization in the pores of supported nanoporous template with thickness of 350 nm (a, b, c) and 1.3 pm (d). Figure 10 FE-SEM images of polyp5rrole/C104 nanotubes obtained by electropolymerization in the pores of supported nanoporous template with thickness of 350 nm (a, b, c) and 1.3 pm (d).
Fig. 2.7 Schematic representation of the preparation of gyroid metallic nanofoam, a Chemical structure of the supramolecular complex PS-h-P4VP(PDP). b Bicontinuous gyroid morphology of PS-h-P4VP(PDP). c Nanoporous template after PDP was removed, d By electroless deposition, the pores between PS struts are filled with nickel, e Gyroid nickel nanofoam after the polymer template was removed by pyrolysis. Adapted with the permission from Ref. [48]. Copyright 2011 American Chemical Society... Fig. 2.7 Schematic representation of the preparation of gyroid metallic nanofoam, a Chemical structure of the supramolecular complex PS-h-P4VP(PDP). b Bicontinuous gyroid morphology of PS-h-P4VP(PDP). c Nanoporous template after PDP was removed, d By electroless deposition, the pores between PS struts are filled with nickel, e Gyroid nickel nanofoam after the polymer template was removed by pyrolysis. Adapted with the permission from Ref. [48]. Copyright 2011 American Chemical Society...
Alumina nanoporous templates have also been used in gas-phase growth of CPNTs. It has been reported that isolated nanotubes consisting of poly(p-phenylenevinylene) (PPV) and carbonized-PPV bilayers can be synthesized in an alumina template by chemical-vapor deposition (CVD) polymerization. In a smdy done by Kim and colleagues, CVD polymerization of PPV was carried out by passing monomer vapor through a pyrolysis zone at 625 °C to form precursor polymer nanotubes on the inner surface of the alumina nanochannels. The nanotubes were further thermally treated in vacuum at 270 °C for an extended time (14 h) to be converted into PPV nanotubes. In order to create PPV/ carbonized PPV bilayer nanotubes, the PPV nanotubes were then carbonized at 850 °C... [Pg.429]

Figure 10.23 Fabrication of ultrahigh density array of conducting polymer nanorods with block-copolymer nanoporous templates. (Reprinted with permission from Nano Letters, Highly Aligned Ultrahigh Density Arrays of Conducting Polymer Nanorods using Block Copolymer Templates by j. I. Lee et ai., 8, 8. Copyright (2008) American Chemical Society)... Figure 10.23 Fabrication of ultrahigh density array of conducting polymer nanorods with block-copolymer nanoporous templates. (Reprinted with permission from Nano Letters, Highly Aligned Ultrahigh Density Arrays of Conducting Polymer Nanorods using Block Copolymer Templates by j. I. Lee et ai., 8, 8. Copyright (2008) American Chemical Society)...
S. H. Lee, and K.S. Ryu, Conducting polymer nanotube and nanowire synthesized by using nanoporous template Synthesis, characteristics, and applications, Synth. Met., 135, 7-9 (2003). [Pg.462]

In a template synthesis, CP is polymerized within the pores or channels of a nanoporous template to obtain the controlled structure and morphology upon removal of the template. Templates can be either a masking of a confined area that CP can grow in or a structured surface that CP is deposited upon. Masking type templates, namely nanoporous anodic aluminium oxide (AAO also commonly known as AI2O3, alumina, or anodise ) [113-118], hydrogels [119,120] and latex particles [121-130], have been used to prepare nanoscale fibrils, particles, and tubules of CPs. [Pg.723]

While the previously mentioned processes require complex instruments and high voltages up to 20 kV with limited scale, an alternative fabrication process is realized through a template wetting. Dissolved or molten PVDF is soaked into a nanoporous template (Fig. 5.7D) (Bhavanasi et al., 2014 Whiter et al., 2014). During the formation of nanowires, the PVDF is subjected to substantial stresses which result in preferential formation of a ferroelectric p-phase. Suitable templates include anodized aluminum oxide that is available commercially with a range of sizes, pore diameters, and pore densities. Furthermore, it is possible to free the nanowire from the template via a selective etch in phosphoric acid... [Pg.179]

After polymerization, an add (e.g., HF or H3PO4), base (e.g., NaOH or KOH), or organic solvent can be used to dissolve the nanoporous template and isolate the synthesized NTs or NWs. The intrinsic optical properties of the electrochemically synthesized light-emitting polymer NTs or NWs can be controlled by the synthetic conditions such as molar ratio of monomer to dopant, applied current or voltage, synthetic temperature, and type of solvent used for the dissolution of the nanoporous template. [Pg.205]

By changing the doping level, dopant, and template-dissolving solvents, the electrical and optical properties of the nanotubes and nanowires can be controlled. The diameters of the conducting polymer nanotubes and nanowires are in the range 100-200 nm, depending on the diameter of the nanoporous template used, it was found that the polymerization was initiated from the wall-side of the AAO template. The synthesized nanotubes have an open end at the top with the filled end at the bottom. As polymerization time increases, the nanotubes will be filled and nanowires will be formed with the length increased. For example,... [Pg.33]

One-dimensional conducting polymer nanomaterials have been utilized as the field emission electron sources for flat panel displays [365-367]. Conducting polymer nanotubes or nanowires were mostly prepared by the electrochemical polymerization within the cylindrical pores of alumina membranes, and the field emission characteristics were evaluated. As a typical example, a field emission cell was composed of PEDOT nanowire (conductivity, 3.4 x 10 S cm ) tips (cathode) and ITO (anode). The turn-on field of PEDOT nanowire was 3.5-4.0 jiAcm at 10V jim , and the current density increased up to 100 xAcm at 4.5 V jim . The field enhancement factor of the PEDOT nanowire tips was 1200 and this value was comparable to that of CNT. PPy nanowire and PANI nanotube was also prepared using nanoporous template, and their field emission characteristics were investigated [365]. PPy nanowire and PANI nanotubes showed the turn-on fields of 3.5-4.0 and 5.0 jjlA cm at 6 and 8 V im . These studies offered a great feasibility of conducting polymers as the building blocks for all-polymer field emission displays. [Pg.244]

The formation of nanostructured arrays of conjugated polymers by the utilization of nanoporous templates has been reported. The deposition of the polymer inside the pores can be achieved by filling the pores with a solution of polymer and evaporation of the solvent or by the direct synthesis of conjugated polymer inside the pores by chemical or electrochemical approaches. Porous templates were based on track-etched polycarbonate membranes [106-108] or alumina that is obtained by anodic aluminum oxidation (AAO) [109-lllj. Thus, periodic vertical channels with diameters between 20 and 120 nm are formed by first electrochemical oxidation and etching and then subsequent etching for pore widening (Figure 13.16). [Pg.387]

Template-based synthesis involves the fabrication of the desired material within the pores or channels of a nanoporous template. A template may be defined as a central structure within which a network forms in such a way that removal of the template creates a filled cavity with morphological and/or stereochemical features related to those of the template. Track-etch membranes, porous alumina, and other nanoporous structures have been characterized as templates. Electrochemical and electroless depositions, chemical polymerization, sol-gel deposition, and chemical vapor deposition have been presented as major template synthetic strategies. Template-based synthesis can be used to prepare nanostructures of conductive polymers, metals, metal oxides, semiconductors, carbons, and other solid matter... [Pg.397]


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