Environmental Engineering Reference
In-Depth Information
mesopores is essential for have been many researchers aiming to control micro or
mesoporosity. The present review attempted to give a general view of the recent
activities on the study of pore structure control, with application novel simulation
and modeling methods and necessity and important of this controlling. The aim
of this review is to provide a brief overview of the methodology and modeling
beside simulation methods for characterization of nanoporous carbons by using
adsorption isotherm parameters. Our final goal is reported an agreed well between
results as obtained by DFT and other modeling methods and our experimental
works that determined from analysis of N 2 adsorption data on samples and molec-
ular dynamic simulation or Monte Carlo simulation, that predicted optimum con-
dition before any experimental works. The techniques the researchers employed
for this purpose are unique and effective. A brief summary of these techniques is
given by the carbonization of metal cation exchanged resin and the benzene CVD
over ACF gave MSC with uniform microporosity or other application. For the
production of mesoporous carbon, catalytic activation, polymer blend carboniza-
tion, organic gel carbonization and template carbonization methods turn out to
be useful. Some of these novel methods were also applied to the formation of
controlled macropores [1, 2].
All the methods introduced in this review have advantages and disadvantages.
Some of them look quite unique but still far from future industrial application
and some others seem to be close to practical use. However, further improve-
ment of these methods and much effort to create a new idea for pore structure
control simulation methods must be necessary to achieve the ultimate aim, that
is, to prepare porous carbon with tailored pore structure. It was apparent from the
literature survey that the beneficial effects of specific modification techniques on
activated carbon adsorption of targeted contaminant species from aqueous so-
lutions were profound, with some studies reported increase of contaminant up-
take factors more. Concurrently, considerable decreases associated with certain
contaminant uptakes can also occur depending on the technique used. The slit
pore model that is currently widely used in simulating activated carbons is in part
supported by physical evidence from electron microscopy, X-ray diffraction and
other techniques. An alternative geometry for modeling activated carbon micro-
pores might involve non- parallel walls. Such a wedge shaped pore model could
reduce packing effects if the assumed wedge angle were large enough to blur the
transitions between small integer numbers of layers of adsorbate as pore size is
changed. It would be important to find independent physical evidence to support
such a model [121].
A second possibility is that the explicit modeling assumption concerning the
inertness of the adsorbent may not be valid. If the in vacuo pore structure of a car-
bon is relaxed by the relatively large quantity of adsorbate uptake at low pressure,
one would expect a dilation or swelling of the structure, which in turn would re-
duce observable packing effects. An estimate of the driving force for pore dilation
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