Synthesis of Novel Poly(amidoxime) Grafted Multiwall Carbon Nanotube Gel and Uranium Adsorption

Abstract

This is the first report on the synthesis of a new functional nanocomposite gel containing amidoxime functionalized multiwall carbon nanotube (AO-MWNT-FNC GEL). The surface morphology of AO-MWNT-FNC GEL was investigated by field emission scanning electron microscopy. The modification of gel with amidoxine groups was confirmed by Fourier transform infra red spectroscopy. The AO-MWNT-FNC GEL provides effective binding with uranium ions as was ascertained by X-ray photoelectron spectroscopy. The AO-MWNT-FNC GEL was utilized as the new adsorbent for the recovery of uranium ions from aqueous solution. UV-visible spectroscopy was used to monitor the adsorption capacity of the AO-MWNT-FNC GEL toward uranium ions. The influence of initial uranium ion concentration and solution pH on the adsorption capacity of the AO-MWNT-FNC GEL were studied in batch experiments. The new FNC-GEL designed in this study is distinguished by higher adsorption capacity for uranium ions due to the synergistic contributions from high surface area of MWNT and the functional AO groups in FNC-GEL and exhibits potential for efficient recovery of uranium ions.

Synthesis of amidoximated graphene oxide nanoribbons from unzipping of multiwalled carbon nanotubes for selective separation of uranium(vi)

“…12b shows the presence of the characteristic doublets of U 4f 5/2 and U 4f 7/2 at 393.0 and 382.3 eV with a splitting of about 10.7 eV. 23,45 The U 4f spectrum can be resolved into two peaks: the peak at 382.9 eV is assigned to the free uranyl adsorbed on AOGONRs, and the peak at 382.0 eV is attributed to the covalent bond of AO-U(VI). 30,46 The observed spectra of the O 1s and N 1s peaks of AOGONRs and AOGONRs-U(VI) were simulated using two-component Gaussian-Lorentzian sum functions.…”

“…[14][15][16][17] Carbonbased materials with AO groups have been widely used as sorbents for the removal of uranyl ions. [18][19][20][21][22][23] For instance, amidoxime-graed hydrothermal carbon showed a uranium sorption capacity as high as 466 mg g À1 and demonstrated stronger selectivity in acidic medium. 24 Amidoximated magnetite/graphene oxide composites were applied to adsorb uranium from aqueous solutions and a maximum sorption capacity of 284.9 mg g À1 was found.…”

Amidoxime functionalization of mesoporous silica and its high removal of U(vi)

“…27 It is proposed that the lone pairs of electrons of the amino nitrogen atom and the oxime oxygen atom can be donated to the positive metal center to form a stable chelate. 28,29 For uranium sorption, the amidoxime group has been widely used to functionalize many kinds of materials, such as carbon nanotubes, 30 graphene, 31 silica, 32 mesoporous carbon, 26 hydrogel, 33 and various polymers. [34][35][36] However, the interaction between the amidoxime group and uranium has not been fully explored, and the proposed interaction mechanism lacks experimental verification.…”

Uranium(vi) adsorption from aqueous solutions using poly(vinyl alcohol)/carbon nanotube composites

“…21 Polymeric/MWCNTs nanocomposites have been applied extensively in uranium adsorption due to their highly porous and hollow structure, large specic surface area and light mass density. 22,23 However, problems associated with the dispersion of MWCNTs llers and load transfer across the polymer-CNTs interface may limit polymer/CNTs composites usage. The difficulty in preparing well dispersed MWCNTs composite solutions resulted from their high specic surface area which resulted in very strong van der Waals interactions.…”