@article{IhlenburgMaiThuenemannetal.2021, author = {Ihlenburg, Ramona and Mai, Tobias and Th{\"u}nemann, Andreas F. and Baerenwald, Ruth and Saalw{\"a}chter, Kay and Koetz, Joachim and Taubert, Andreas}, title = {Sulfobetaine hydrogels with a complex multilength-scale hierarchical structure}, series = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry}, volume = {125}, journal = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry}, number = {13}, publisher = {American Chemical Society}, address = {Washington}, issn = {1520-6106}, doi = {10.1021/acs.jpcb.0c10601}, pages = {3398 -- 3408}, year = {2021}, abstract = {Hydrogels with a hierarchical structure were prepared from a new highly water-soluble crosslinker N,N,N',N'-tetramethyl-N,N'-bis(2-ethylmethacrylate)-propyl-1,3-diammonium dibromide and from the sulfobetaine monomer 2-(N-3-sulfopropyl-N,N-dimethyl ammonium)ethyl methacrylate. The free radical polymerization of the two compounds is rapid and yields near-transparent hydrogels with sizes up to 5 cm in diameter. Rheology shows a clear correlation between the monomer-to-crosslinker ratio and the storage and loss moduli of the hydrogels. Cryo-scanning electron microscopy, low-field nuclear magnetic resonance (NMR) spectroscopy, and small-angle X-ray scattering show that the gels have a hierarchical structure with features spanning the nanometer to the sub-millimeter scale. The NMR study is challenged by the marked inhomogeneity of the gels and the complex chemical structure of the sulfobetaine monomer. NMR spectroscopy shows how these complications can be addressed via a novel fitting approach that considers the mobility gradient along the side chain of methacrylate-based monomers.}, language = {en} } @article{IhlenburgLehnenKoetzetal.2021, author = {Ihlenburg, Ramona and Lehnen, Anne-Catherine and Koetz, Joachim and Taubert, Andreas}, title = {Sulfobetaine Cryogels for Preferential Adsorption of Methyl Orange from Mixed Dye Solutions}, series = {Polymers / Molecular Diversity Preservation International}, volume = {13}, journal = {Polymers / Molecular Diversity Preservation International}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2073-4360}, doi = {10.3390/polym13020208}, pages = {11}, year = {2021}, abstract = {New cryogels for selective dye removal from aqueous solution were prepared by free radical polymerization from the highly water-soluble crosslinker N,N,N',N'-tetramethyl-N,N'-bis(2-ethylmethacrylate)-propyl-1,3-diammonium dibromide and the sulfobetaine monomer 2-(N-3-sulfopropyl-N,N-dimethyl ammonium)ethyl methacrylate. The resulting white and opaque cryogels have micrometer sized pores with a smaller substructure. They adsorb methyl orange (MO) but not methylene blue (MB) from aqueous solution. Mixtures of MO and MB can be separated through selective adsorption of the MO to the cryogels while the MB remains in solution. The resulting cryogels are thus candidates for the removal of hazardous organic substances, as exemplified by MO and MB, from water. Clearly, it is possible that the cryogels are also potentially interesting for removal of other compounds such as pharmaceuticals or pesticides, but this must be investigated further.}, language = {en} } @article{FigueroaCamposPerezBlocketal.2021, author = {Figueroa Campos, Gustavo Adolfo and Perez, Jeffrey Paulo H. and Block, Inga and Sagu Tchewonpi, Sorel and Saravia Celis, Pedro and Taubert, Andreas and Rawel, Harshadrai Manilal}, title = {Preparation of activated carbons from spent coffee and coffee parchment and assessment of their adsorbent efficiency}, series = {Processes : open access journal}, volume = {9}, journal = {Processes : open access journal}, number = {8}, publisher = {MDPI}, address = {Basel}, issn = {2227-9717}, doi = {10.3390/pr9081396}, pages = {18}, year = {2021}, abstract = {The valorization of coffee wastes through modification to activated carbon has been considered as a low-cost adsorbent with prospective to compete with commercial carbons. So far, very few studies have referred to the valorization of coffee parchment into activated carbon. Moreover, low-cost and efficient activation methods need to be more investigated. The aim of this work was to prepare activated carbon from spent coffee grounds and parchment, and to assess their adsorption performance. The co-calcination processing with calcium carbonate was used to prepare the activated carbons, and their adsorption capacity for organic acids, phenolic compounds and proteins was evaluated. Both spent coffee grounds and parchment showed yields after the calcination and washing treatments of around 9.0\%. The adsorption of lactic acid was found to be optimal at pH 2. The maximum adsorption capacity of lactic acid with standard commercial granular activated carbon was 73.78 mg/g, while the values of 32.33 and 14.73 mg/g were registered for the parchment and spent coffee grounds activated carbons, respectively. The Langmuir isotherm showed that lactic acid was adsorbed as a monolayer and distributed homogeneously on the surface. Around 50\% of total phenols and protein content from coffee wastewater were adsorbed after treatment with the prepared activated carbons, while 44, 43, and up to 84\% of hydrophobic compounds were removed using parchment, spent coffee grounds and commercial activated carbon, respectively; the adsorption efficiencies of hydrophilic compounds ranged between 13 and 48\%. Finally, these results illustrate the potential valorization of coffee by-products parchment and spent coffee grounds into activated carbon and their use as low-cost adsorbent for the removal of organic compounds from aqueous solutions.}, language = {en} } @article{BalischewskiChoiBehrensetal.2021, author = {Balischewski, Christian and Choi, Hyung-Seok and Behrens, Karsten and Beqiraj, Alkit and K{\"o}rzd{\"o}rfer, Thomas and Gessner, Andre and Wedel, Armin and Taubert, Andreas}, title = {Metal sulfide nanoparticle synthesis with ionic liquids state of the art and future perspectives}, series = {ChemistryOpen}, volume = {10}, journal = {ChemistryOpen}, number = {2}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {2191-1363}, doi = {10.1002/open.202000357}, pages = {272 -- 295}, year = {2021}, abstract = {Metal sulfides are among the most promising materials for a wide variety of technologically relevant applications ranging from energy to environment and beyond. Incidentally, ionic liquids (ILs) have been among the top research subjects for the same applications and also for inorganic materials synthesis. As a result, the exploitation of the peculiar properties of ILs for metal sulfide synthesis could provide attractive new avenues for the generation of new, highly specific metal sulfides for numerous applications. This article therefore describes current developments in metal sulfide nano-particle synthesis as exemplified by a number of highlight examples. Moreover, the article demonstrates how ILs have been used in metal sulfide synthesis and discusses the benefits of using ILs over more traditional approaches. Finally, the article demonstrates some technological challenges and how ILs could be used to further advance the production and specific property engineering of metal sulfide nanomaterials, again based on a number of selected examples.}, language = {en} } @article{WojnarowskaLangeTaubertetal.2021, author = {Wojnarowska, Zaneta and Lange, Alyna and Taubert, Andreas and Paluch, Marian}, title = {Ion and proton transport in aqueous/nonaqueous acidic tonic liquids for fuel-cell applications-insight from high-pressure dielectric studies}, series = {ACS applied materials \& interfaces / American Chemical Society}, volume = {13}, journal = {ACS applied materials \& interfaces / American Chemical Society}, number = {26}, publisher = {American Chemical Society}, address = {Washington}, issn = {1944-8244}, doi = {10.1021/acsami.1c06260}, pages = {30614 -- 30624}, year = {2021}, abstract = {The use of acidic ionic liquids and solids as electrolytes in fuel cells is an emerging field due to their efficient proton conductivity and good thermal stability. Despite multiple reports describing conducting properties of acidic ILs, little is known on the charge-transport mechanism in the vicinity of liquid-glass transition and the structural factors governing the proton hopping. To address these issues, we studied two acidic imidazolium-based ILs with the same cation, however, different anions-bulk tosylate vs small methanesulfonate. High-pressure dielectric studies of anhydrous and water-saturated materials performed in the close vicinity of T-g have revealed significant differences in the charge-transport mechanism in these two systems being undetectable at ambient conditions. Thereby, we demonstrated the effect of molecular architecture on proton hopping, being crucial in the potential electrochemical applications of acidic ILs.}, language = {en} } @article{BlockGuenterRodriguesetal.2021, author = {Block, Inga and G{\"u}nter, Christina and Rodrigues, Alysson Duarte and Paasch, Silvia and Hesemann, Peter and Taubert, Andreas}, title = {Carbon Adsorbents from Spent Coffee for Removal of Methylene Blue and Methyl Orange from Water}, series = {Materials}, volume = {14}, journal = {Materials}, number = {14}, publisher = {MDPI}, address = {Basel}, issn = {1996-1944}, doi = {10.3390/ma14143996}, pages = {18}, year = {2021}, abstract = {Activated carbons (ACs) were prepared from dried spent coffee (SCD), a biological waste product, to produce adsorbents for methylene blue (MB) and methyl orange (MO) from aqueous solution. Pre-pyrolysis activation of SCD was achieved via treatment of the SCD with aqueous sodium hydroxide solutions at 90 °C. Pyrolysis of the pretreated SCD at 500 °C for 1 h produced powders with typical characteristics of AC suitable and effective for dye adsorption. As an alternative to the rather harsh base treatment, calcium carbonate powder, a very common and abundant resource, was also studied as an activator. Mixtures of SCD and CaCO3 (1:1 w/w) yielded effective ACs for MO and MB removal upon pyrolysis needing only small amounts of AC to clear the solutions. A selectivity of the adsorption process toward anionic (MO) or cationic (MB) dyes was not observed.}, language = {en} }