406
11 Templated Systems
reduction), the deposition mechanism is not fully clear. The difficulty of the process
is indicated by the experimental constraint that the anode and the cathode had to be
aligned in a closely facing position with a gap of 0.5–1.0 mm in order to ensure a
high enough electrical field for the good phase ordering. With this method, cuprite
nanowires of high aspect ratio could be obtained with a good crystallinity.
11.4.4 Electrodeposited Polymers by Using Various Lyotropic
Templates
The electrodeposition of polymers into H 1 -type mesoporous templates is in some
cases analogous to metal and semiconductor deposition in the sense that the polymer
is formed in the aqueous phase [217, 353]. Although the porosity of the resulting
polymer films can be well evidenced with electrochemical measurements, the inverse
H 1 structure of the resulting polymer coating is difficult to image due to the soft
nature of the polymer. Nevertheless, the low-angle X-ray diffraction indicates the
same periodicity of the resulting film as that observed for the template.
However, a deposition mechanism dissimilar to the above detailed pattern has
been described, too [354]. In this case, the polymerization of aniline was reported
to take place in the apolar phase whose components may also catalyse the polymerization process. Since both the monomers to be polymerized and the amphiphilic
component(s) of the lyotropic systems were different in the works cited above, the
difference in the mechanisms can be explained with the different properties of the
systems studied. At the time being, it cannot be unambiguously categorized which
deposition mode is relevant to a specific system.
Another synthesis strategy is the polymerization of a monomer in a lyotropic
liquid crystal template and the use of the resulting composite without removing the
template. An example is the polymerization of 3,4-ethylenedioxythiophene in the
hydroxypropyl cellulose/water system [355]. The additional benefit of this template
is the chiral nematic nature of the liquid crystal that is transferred to the polymer
embedded. The result shows that the electrodeposited polymer remains electrochemically switchable even in the template, and the electrochemical and optical properties
are strongly interrelated.
11.4.5 Dual Template Methods Involving Lyotropic Liquid
Crystals
Dual template methods apply two fundamentally different template methods in the
same deposition system in parallel. For the successful merge of two templating
methods, the characteristic pore size of the two template methods must differ by
at least about an order of magnitude. This condition is easily fulfilled if a lyotropic
11 Templated Systems
reduction), the deposition mechanism is not fully clear. The difficulty of the process
is indicated by the experimental constraint that the anode and the cathode had to be
aligned in a closely facing position with a gap of 0.5–1.0 mm in order to ensure a
high enough electrical field for the good phase ordering. With this method, cuprite
nanowires of high aspect ratio could be obtained with a good crystallinity.
11.4.4 Electrodeposited Polymers by Using Various Lyotropic
Templates
The electrodeposition of polymers into H 1 -type mesoporous templates is in some
cases analogous to metal and semiconductor deposition in the sense that the polymer
is formed in the aqueous phase [217, 353]. Although the porosity of the resulting
polymer films can be well evidenced with electrochemical measurements, the inverse
H 1 structure of the resulting polymer coating is difficult to image due to the soft
nature of the polymer. Nevertheless, the low-angle X-ray diffraction indicates the
same periodicity of the resulting film as that observed for the template.
However, a deposition mechanism dissimilar to the above detailed pattern has
been described, too [354]. In this case, the polymerization of aniline was reported
to take place in the apolar phase whose components may also catalyse the polymerization process. Since both the monomers to be polymerized and the amphiphilic
component(s) of the lyotropic systems were different in the works cited above, the
difference in the mechanisms can be explained with the different properties of the
systems studied. At the time being, it cannot be unambiguously categorized which
deposition mode is relevant to a specific system.
Another synthesis strategy is the polymerization of a monomer in a lyotropic
liquid crystal template and the use of the resulting composite without removing the
template. An example is the polymerization of 3,4-ethylenedioxythiophene in the
hydroxypropyl cellulose/water system [355]. The additional benefit of this template
is the chiral nematic nature of the liquid crystal that is transferred to the polymer
embedded. The result shows that the electrodeposited polymer remains electrochemically switchable even in the template, and the electrochemical and optical properties
are strongly interrelated.
11.4.5 Dual Template Methods Involving Lyotropic Liquid
Crystals
Dual template methods apply two fundamentally different template methods in the
same deposition system in parallel. For the successful merge of two templating
methods, the characteristic pore size of the two template methods must differ by
at least about an order of magnitude. This condition is easily fulfilled if a lyotropic