In Situ Characterizations of Porous Media for Applications in Biofuel Cells: Issues and Challenges - Porous Media: Applications in Biological Systems and Biotechnology - page 521

Advancements we observed from LB films to LBL polyelectrolyte multistruc-
tures (Lvov et al. 1993; Schmitt et al. 1993; Decher 1997), to composite
inorganic polymer hybrids with periodically organized mesoporous materials
(Sanchez et al. 2008), and to polymer brushes (Whiting et al. 2006; Hollmann
et al. 2007) only indicate the desires and anticipations toward nanobioma-
terial fabrications and optimizations for potential applications in biotechnol-
ogy, biomedicine, bioenergy conversion and storage, and bioremediation of our
polluted environment. To further such advancements, in situ nondestructive
characterizations, syntheses, and controls of the fabrication processes are of
paramount importance to the next generation of biotechnology and nanotech-
nology paradigm.
Emerging imaging capability and instrumentation could expand the hori-
zon of the spectroscopy to provide fine temporal and spatial resolutions as
a nondestructive tool for characterization. For instance, Gustafsson recently
showed that structured illumination can enhance the lateral resolution of
wide-field fluorescence microscopic imaging (Gustafsson 2000). The combined
capability with confocal microscopy and other imaging techniques should be
explored more in the porous media investigations for biofuel cell applications
to help us understand the dynamic nature of the species interaction and trans-
port involved in the system and to provide a vast amount of physical and chem-
ical information about the porous media down to the nanometer scale. Such
ability should be integrated for future applications in the control of porous
media for biofuel cell applications, potentially through self-assembly, nanofab-
rication, smart microstructure, and precise surface modification. It should be
cautioned though that some techniques such as the spectroscopic ones are
more related to molecular and microscopic scale observations, while other tech-
niques such as the electrochemical and microgravimetric ones are providing
microscopic measurements. Therefore, the interpretation of the data and dis-
cussion of their relevance needs to be carefully evaluated to avoid confusions.
13.7 References
Akers, N. L., Moore, C. M., and Minteer, S. D. (2005). Development of
alcohol/O 2 biofuel cells using salt-extracted tetrabutylammonium bro-
mide/Nafion membranes to immobilize dehydrogenase enzymes. Elec-
trochimica Acta, 50 :2521-2525.
Akkermans, R. P., Roberts, S. L., Marken, F., Coles, B. A., Wilkins, S. J.,
Cooper, J. A., Woodhouse, K. E., and Compton, R. G. (1999). Methylene
green voltammetry in aqueous solution: studies using thermal, microwave,
laser, or ultrasonic activation at platinum electrodes. Journal of Physical
Chemistry B, 103 :9987-9995.