with respect to the adsorption potency as well as the structural integrity up to
20 adsorption/desorption cycles. Alternatively, NC foams with polyethylenimine
(in lieu of aminosilanes) have also been exploited for CO 2 trapping (Sehaqui et al.
2015). Herein, the deposition of urea in the sorbent was counterchecked due to the
presence of water, thereby providing an additional edge to the system in CO 2
adsorption.
In a similar vein, applications as filtration membranes, absorbents, adsorbents,
catalysts, as well as flocculants in the realm of water treatment have garnered
tremendous research impetus in the recent years (Mahfoudhi and Boufi 2017;
Mohammed et al. 2018; Voisin et al. 2017). CNC-based nanocomposite membranes (with a large surface area and wide range of pore size) have been fabricated
using polymer matrices, such as chitosan, gelatin, poly(vinylidene fluoride) (PVDF),
and poly(acrylonitrile) (PAN), for the removal of dyes, heavy metal ions, bacteria,
viruses, and oil (Mohammed et al. 2018). In a similar vein, CNF-nanopaper/
nanocomposite membranes, based on poly(acrylonitrile) (PAN), poly(ether sulfone), poly(vinylidene fluoride) (PVDF), cellulose triacetate, chitosan, and silk
fibroin, find application in ultrafiltration, forward osmosis, as well as nanofiltration
for a wide range of materials, including viruses, oil, heavy metal ions, and organic
solvents (Mohammed et al. 2018). Similarly, silver nanoparticles and chitosan
(an antimicrobial biopolymer) have been adeptly employed to harness NC for
antimicrobial applications, while the applications of CN as catalysts for the degradation of various organic pollutants are noteworthy (Fig. 4.5) (Mohammed et al.
2018). To mention about the application of NC in flocculation, the functionalization
with amines, acidic groups, and pyridinium, on one hand, and specific uses of CNF
for separating solid particles from public wastewater and that of CNC with microbial
cells of bacteria and microalgae as well as surfactants, on the other, merit special
mention (Vandamme et al. 2015; Mohammed et al. 2018).
CNCs have been used in concert with nanoparticles or polymers to develop
efficient adsorbent platforms for dye mitigation in aqueous media (Table 4.2).
Amino-functionalization, carboxylation, imidazolium grafting, and maleic anhydride conjugation are the commonly adopted strategies for chemical modification
of CNCs to facilitate adsorption of various pollutants, under a wide range of pH and,
preferably, at room temperature (Mohammed et al. 2018). Interestingly, reports on
fabrication of CNC nanocomposites based on alginate, dispersion of magnetic beads,
use of hydrolyzed poly(acrylamide) (HPAM), poly(vinyl amine) beads, or
electrospun fibers have widened the scope (Chen et al. 2014; Zhou et al. 2013, Jin
et al. 2015b, Nypelö et al. 2014). In a similar vein, a plethora of chemically
functionalized CNF aerogels (e.g., MnO 2 -coated CNF and GTMAC-grafted CNF)
have been employed as adsorbents besides other polymer nanocomposites, fabricated using high-intensity ultrasonication and TEMPO-mediated oxidation, for
effective dye removal (Wei et al. 2014; Mohammed et al. 2018). The removal of
heavy metal ions (Table 4.2) (e.g., cadmium, copper, iron, lead, nickel, silver, and
vanadium) in the context of water treatment using pristine, acrylamide-grafted,
anhydride-modified, carboxylic acid conjugated, phosphorylated, succinic
bisphosphonate-modified CNCs has been reviewed extensively (Mohammed et al.
4 Harnessing the Sustainable Bioresource, Cellulose at the Nanoscale for. . .
79
20 adsorption/desorption cycles. Alternatively, NC foams with polyethylenimine
(in lieu of aminosilanes) have also been exploited for CO 2 trapping (Sehaqui et al.
2015). Herein, the deposition of urea in the sorbent was counterchecked due to the
presence of water, thereby providing an additional edge to the system in CO 2
adsorption.
In a similar vein, applications as filtration membranes, absorbents, adsorbents,
catalysts, as well as flocculants in the realm of water treatment have garnered
tremendous research impetus in the recent years (Mahfoudhi and Boufi 2017;
Mohammed et al. 2018; Voisin et al. 2017). CNC-based nanocomposite membranes (with a large surface area and wide range of pore size) have been fabricated
using polymer matrices, such as chitosan, gelatin, poly(vinylidene fluoride) (PVDF),
and poly(acrylonitrile) (PAN), for the removal of dyes, heavy metal ions, bacteria,
viruses, and oil (Mohammed et al. 2018). In a similar vein, CNF-nanopaper/
nanocomposite membranes, based on poly(acrylonitrile) (PAN), poly(ether sulfone), poly(vinylidene fluoride) (PVDF), cellulose triacetate, chitosan, and silk
fibroin, find application in ultrafiltration, forward osmosis, as well as nanofiltration
for a wide range of materials, including viruses, oil, heavy metal ions, and organic
solvents (Mohammed et al. 2018). Similarly, silver nanoparticles and chitosan
(an antimicrobial biopolymer) have been adeptly employed to harness NC for
antimicrobial applications, while the applications of CN as catalysts for the degradation of various organic pollutants are noteworthy (Fig. 4.5) (Mohammed et al.
2018). To mention about the application of NC in flocculation, the functionalization
with amines, acidic groups, and pyridinium, on one hand, and specific uses of CNF
for separating solid particles from public wastewater and that of CNC with microbial
cells of bacteria and microalgae as well as surfactants, on the other, merit special
mention (Vandamme et al. 2015; Mohammed et al. 2018).
CNCs have been used in concert with nanoparticles or polymers to develop
efficient adsorbent platforms for dye mitigation in aqueous media (Table 4.2).
Amino-functionalization, carboxylation, imidazolium grafting, and maleic anhydride conjugation are the commonly adopted strategies for chemical modification
of CNCs to facilitate adsorption of various pollutants, under a wide range of pH and,
preferably, at room temperature (Mohammed et al. 2018). Interestingly, reports on
fabrication of CNC nanocomposites based on alginate, dispersion of magnetic beads,
use of hydrolyzed poly(acrylamide) (HPAM), poly(vinyl amine) beads, or
electrospun fibers have widened the scope (Chen et al. 2014; Zhou et al. 2013, Jin
et al. 2015b, Nypelö et al. 2014). In a similar vein, a plethora of chemically
functionalized CNF aerogels (e.g., MnO 2 -coated CNF and GTMAC-grafted CNF)
have been employed as adsorbents besides other polymer nanocomposites, fabricated using high-intensity ultrasonication and TEMPO-mediated oxidation, for
effective dye removal (Wei et al. 2014; Mohammed et al. 2018). The removal of
heavy metal ions (Table 4.2) (e.g., cadmium, copper, iron, lead, nickel, silver, and
vanadium) in the context of water treatment using pristine, acrylamide-grafted,
anhydride-modified, carboxylic acid conjugated, phosphorylated, succinic
bisphosphonate-modified CNCs has been reviewed extensively (Mohammed et al.
4 Harnessing the Sustainable Bioresource, Cellulose at the Nanoscale for. . .
79