BASIC CONCEPTS AND AN OVERVIEW - Foundations of Nanotechnology: Pore Size in Carbon-Based Nano-Adsorbents - page 45

in environmental protection. Some researchers reported that the adsorption iso-
therms of UO 2 2+ adsorbed by calcium alginate beads exhibited Langmuir behavior
and its maximum monomolecular capacity reached 400 mg/g for UO 2 2+ at 25°C.
Others investigated Cu 2+ removal capability of calcium alginate encapsulated
magnetic sorbent and found that the maximum sorption capacity of the mate-
rial can reach 60 mg/g at pH of 5.0 and temperature of 20°Cand too prepared
composite gels of calcium alginate containing iminodiacetic type resin. The bio-
sorption capacity of the composite gels is higher than that of simple alginate gels
and increases with increasing the amounts of resin enclosed in the composite.
The adsorbents were characterized using SEM micrograph, BET surface analysis,
FTIR spectra and Boehm titration method. The CA and CNTs/CA were depos-
ited on a brass hold and sputtered with a thin coat of gold under vacuum, their
morphology and surface CNTs. The results suggest that the higher surface area
and pore volume of CNTs maybe act as microchannels in matrix and benefit for
the improvement of surface area of the CNTs/CA composites. In summary, an ef-
ficient adsorbent of CNTs/CA with exceptional Cu(II) adsorption capability was
prepared. Equilibrium data were fitted to Langmuir and Freundlich isotherms.
Based on Langmuir isotherm, the maximum monolayer adsorption capacity for
CNTs/CA is 84.88 mg/g. The new type of adsorbent of CNTs/CA can resolve the
micropollution problem caused by nano-sized CNTs through immobilizing them
by CA and it will promote the practical applications of CNTs and their composites
in environmental protection.
1.1.7 CARBON NANOFIBER (CNF): PROPERTIES AND APPLICATION
Carbon nanofibers (diameter range, 3-100 nm) have been known for a long time
as a nuisance that often emerges during catalytic conversion of carbon-containing
gases. The recent outburst of interest in these graphitic materials originates from
their potential for unique applications as well as their chemical similarity to fuller-
enes and carbon nanotubes. In this review, focused on the growth of nanofibers
using metallic particles as a catalyst to precipitate the graphitic carbon. First, sum-
marized some of the earlier literature that has contributed greatly to understand the
nucleation and growth of carbon nanofibers and nanotubes. Thereafter, described
in detail recent progress to control the fiber surface structure, texture, and growth
into mechanically strong agglomerates. It is argued that carbon nanofibers are
unique high surface area materials (200 mL/g) that can expose exclusively either
basal graphite planes or edge planes. It is shown that the graphite surface structure
and the lyophilicity play a crucial role during metal emplacement and catalytic
use in liquid phase catalysis. An article by Iijima that showed that carbon nano-
tubes are formed during arc-discharge synthesis of C 60 , and other fullerenes also
triggered an outburst of the interest in carbon nanofibers and nanotubes. These
nanotubes may be even single walled, whereas low temperature, catalytically
grown tubes are multi-walled. It has been realized that the fullerene type materials