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- Molla, Shimelis, et al.
(författare)
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Extracting metal ions from water with redox active biopolymer electrodes
- 2015
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Ingår i: Environmental Science. - : ROYAL SOC CHEMISTRY. - 2053-1400 .- 2053-1419. ; 1:3, s. 326-331
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Tidskriftsartikel (refereegranskat)abstract
- Renewable, environmentally friendly and cheap materials like lignin and cellulose have been considered as promising materials for use in energy storage technologies. Here, we report a new application for biopolymer electrodes where they can also be simultaneously used as ion pumps to purify industrial wastewater and drinking water contaminated with toxic metals. A ternary composite film consisting of a conducting polymer polypyrrole (PPy), biopolymer lignin (LG) and anthraquinonesulfonate (AQS) was synthesized by one-step galvanostatic polymerization from an aqueous electrolyte solution. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) techniques revealed that lead ions can be extracted from a neutral aqueous solution containing lead ions by applying a potential, and can be released into another solution by reversing the polarity of the applied potential. Electrochemical quartz crystal microbalance was used to quantify the amount of metal ions that can be extracted and released.
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| 2. |
- Romagnoli, Priscila, et al.
(författare)
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Making graphene visible in transparent dielectric substrates : Brewster angle imaging
- 2015
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Ingår i: Current Opinion in Chemical Engineering. - : Institute of Physics (IOP). - 2211-3398. ; 2:3
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Tidskriftsartikel (refereegranskat)abstract
- The visibility of graphene is greatly increased by illuminating samples deposited on transparent dielectrics at the substrates’ Brewster angle. Using a commercial ellipsometer, the reflectivity of monolayers of CVD graphene is found to be up to 33 times higher than that of the substrate, i.e., an optical contrast as high as 3200% is obtained, more than 380 times higher than with standard optical microscopy. Also, with a simpler, homemade, experimental setup, a 1400% optical contrast was measured for a monolayer of CVD graphene and linear features as small as ~20 μm were visible in a monolayer, while ~6×17 μm2 trilayers could still be imaged in exfoliated samples. It is also shown that the reflectance/transmittance ratio increases quadratically with the number of graphene layers, which may allow for counting layer numbers and identifying wrinkles and folds in transferred samples.
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