Environmental Engineering Reference
In-Depth Information
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figure 6.10 UV−vis spectra of Cr(VI) aqueous solution (a) treated with the Pd NP-immobilized PEI/PVA nanofibrous mat in the presence
of formic acid, (b) treated with the PEI/PVA nanofibrous mat without Pd NPs in the presence of formic acid, and (c) treated with only formic
acid. reprinted with permission from ref. [72]. © 2012, American Chemical Society.
be solely attributed to the immobilized Pd NPs. reusability results show that more than 99% of Cr(VI) can be transformed to
Cr(III) after 12, 15, and 15 min in the first, second, and third reaction cycles, respectively, confirming the superior reusability
of the Pd NP-immobilized PEI/PVA nanofibrous mats.
6.6
coNclusioNs aNd outlook
In summary, this chapter has described the fabrication of different metal NP-immobilized polymer nanofibers for environ-
mental remediation applications. In particular, ZVI NP-immobilized PAA/PVA nanofibers have been fabricated via different
approaches. To further improve mechanical durability, MWCNTs have been incorporated within the nanofibers prior to the in
situ formation of ZVI NPs. Furthermore, to enhance the reactivity of immobilized ZVI NPs, bimetallic Fe/Pd NPs were formed
within PAA/PVA nanofibers. These ZVI NP-based nanofibers are able to decolorize dying contaminants, to remove toxic heavy
metal ions, and to dechlorinate chlorinated organic solvents (e.g., TCE). For the catalytic remediation of heavy metal ions, Pd
NP-immobilized polymer nanofibers have been fabricated, and the hybrid fibers are able to efficiently transform Cr(VI) to
Cr(III) in aqueous solution. The formed metal NP-containing polymer nanofibers are stable, and no leakage of the metal NPs
are observed during storage and remediation processes.
There is no doubt that electrospun polymer nanofibrous mats have exhibited great advantages over other conventional
media as an ideal substrate to immobilize active metal NPs for environmental remediation applications. The electrospinning
technology has received increasing attention in the fabrication of various metal NP-immobilized polymer nanofibers, owing
to their high porosity, huge specific surface area, and flexibility in surface functionalization. However, there still remain some
challenges for practical environmental applications. For example, the lack of mass production of high-quality electrospun
nanofibers quite restricts its application in practice. The selection of suitable polymer materials with improved mechanical
durability and the surface modification of preformed nanofibers with new functionalities for selective remediation of environ-
mental pollutants are additional issues to be addressed. These challenges will drive the development of a variety of metal
NP-incorporated hybrid polymer nanofibers for various environmental applications.
refereNces
[1] Kreuter J. Nanoparticlebased drug delivery systems. J Control release 1991;16:169.
[2] Paciotti gF, Myer l, Weinreich d, goia d, Pavel N, Mclaughlin rE, Tamarkin l. Colloidal gold: a novel nanoparticle vector for tumor
directed drug delivery. drug deliv 2004;11:169.
[3] Shi X, Wang S, Meshinchi S, Van Antwerp ME, bi X, lee I, baker Jr. dendrimer-entrapped gold nanoparticles as a platform for cancer
cell targeting and imaging. Small 2007;3:1245.
[4] Trewyn bg, giri S, Slowing II, lin VSY. Mesoporous silica nanoparticle based controlled release, drug delivery, and biosensor systems.
Chem Commun 2007:3236.
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