2 research outputs found
Recovery of Au(III), Pt(IV), and Pd(II) Using Pyridylethyl-Containing Polymers: Chitosan Derivatives vs Synthetic Polymers
The
sorption properties of <i>N</i>-2-(2-pyridyl)Âethylpolyethylenimine
(PEPEI), <i>N</i>-2-(2-pyridylethylpolyallylamine (PEPAA),
and <i>N</i>-2-(2-pyridyl)Âethylchitosan (PEC), synthesized
via the aza-Michael reaction with 2-vinylpyridine and cross-linked
with epichlorohydrin, have been investigated. It was shown that sorption
capacities toward PdÂ(II) and
PtÂ(IV) changed in the order PEPEI > PEC > PEPAA, with the maximal
capacity of 4.6 mmol Pd/g for PEPEI. All the derivatives showed comparable
efficiencies in PtÂ(IV) uptake, with sorption capacities within the
range 2.4–2.7 mmol/g. PEC was found to be the most efficient
sorbent for AuÂ(III) recovery, with the sorption capacity equal to
4.9 mmol/g. XPS investigations have revealed that sorption of AuÂ(III)
and PtÂ(IV) by polymer precursors and all pyridylethyl derivatives
is accompanied by changes in metal oxidation states. No direct correlation
between sorption capacities and total ion-exchange capacities of the
polymers was found, showing that noble-metal ions were recovered by
pyridylethyl derivatives via chelation and/or redox sorption mechanisms
rather than ion exchange. Pyridylethylation was beneficial to increase
the efficiency of platinum and palladium elution after the sorption
on PAA and PEI derivatives and of gold elution after sorption on the
chitosan derivative, which enhances the potential of the application
of these polymers in sorption/regeneration cycles
Data
The Data.zip consists of the data of Figures (from Figure 1 to Figure 9). The files can be opened by specific software such as Diffrac Plus 1.01 for XRD, SpecsLab 2.23 for XPS, SigmaPlot Workbook 12.0 for Raman, TA60 2.01 for TGA, ZView 3.4c and Origin 8.0 for electrochemical data