The design of new composite materials using extreme biomimetics is of crucial importance for bioinspired materials science. Further progress in research and application of these new materials is impossible without understanding the mechanisms of formation, as well as structural features at the molecular and nano‐level. It presents a challenge to obtain a holistic understanding of the mechanisms underlying the interaction of organic and inorganic phases under conditions of harsh chemical reactions for biopolymers. Yet, an understanding of these mechanisms can lead to the development of unusual—but functional—hybrid materials. In this work, a key way of designing centimeter‐scale macroporous 3D composites, using renewable marine biopolymer spongin and a model industrial solution that simulates the highly toxic copper‐containing waste generated in the production of printed circuit boards worldwide, is proposed. A new spongin–atacamite composite material is developed and its structure is confirmed using neutron diffraction, X‐ray diffraction, high‐resolution transmission electron microscopy/selected‐area electron diffraction, X‐ray photoelectron spectroscopy, near‐edge X‐ray absorption fine structure spectroscopy, and electron paramagnetic resonance spectroscopy. The formation mechanism for this material is also proposed. This study provides experimental evidence suggesting multifunctional applicability of the designed composite in the development of 3D constructed sensors, catalysts, and antibacterial filter systems.
An electrochemical‐assisted leaching process using boron‐doped diamond (BDD) electrodes was developed to recover valuable metals from photovoltaic modules. With BDD electrodes peroxydisulfate is generated from sulfuric acid to oxidatively dissolve copper, tin and silver from solar cell contacts. Since the oxidant is regenerated in the developed process, no additional hazardous and volatile chemicals are required, and the process can be operated solely by electricity. In addition, the dissolved metals can be electrochemically recovered at the cathode of the same cell.
Bei der Produktion von Aluminiumoxid aus dem Na-Aluminiumsilikat Nephelin fallen trotz einer integrierten Prozessführung große Reststoffmengen an, die der Deponierung zugeführt werden müssen. Mithilfe einer Rückgewinnung von Pirssonit, ist es möglich, aus dem anfallenden Nephelinschlamm Calciumcarbonat und Kieselsäurehydrogel zu gewinnen und so das Schlammaufkommen erheblich zu reduzieren. Das zurückgewonnene Calciumcarbonat kann in den Aufbereitungsprozess zurückgeführt und das Kieselsäurehydrogel für die Herstellung von Baustoffen und Geopolymeren eingesetzt werden.In the production of aluminum oxide from the Na-aluminum silicate nepheline, despite integrated process control large quantities of residual material are produced, which must be sent to landfill. With the help of a recovery of pirssonite, it is possible to extract calcium carbonate and silica hydrogel from the nepheline sludge and, thus, considerably reduce the sludge volume. The recovered calcium carbonate can be recycled into the preparation process and the silica hydrogel can be used for the production of building materials and geopolymers.Abbildung 2. Umsatz von Dicalciumsilikat (C 2 S) durch CO 2 im wä ssrigen Medium bei einer Temperatur von 50°C, 75°C und 95°C; s/l = 10, CO 2 -Volumenstrom = 0,6 Á 10 -3 m 3 h -1 mit einer CO 2 -Konzentration von 11 -12 Vol.-%.Abbildung 3. Mikroskopische Aufnahmen der Dicarbonatsalze nach a) 1 h bzw. b) 7 h CO 2 -Behandlung bei 95°C; c) nach 7 h mit gekennzeichneten Reaktionsbereichen.
496ForschungsarbeitChemie Ingenieur TechnikAbbildung 4. Abhä ngigkeit des Dicalciumsilikat (C 2 S)-Umsatzes von der Partikelgrö ße im Kohlensä ure-Verfahren; s/l = 10, CO 2 -Volumenstrom = 0,6 Á 10 -3 m 3 h -1 mit einer CO 2 -Konzentration von 11 -12 Vol.-%.
Forschungsarbeit 497Chemie Ingenieur Technik
Bei der Leiterplattenproduktion nach dem Druckverfahren fallen erhebliche Mengen kupferhaltiger Ätzlösungen an. Die Kupferrückgewinnung aus den ammoniakalischen Ätzbädern erfolgt über eine Zementation mit Aluminiumschrott mit Ausbringungsraten ≥ 99 % Cu. Anstelle der bis dato üblichen Deponierung wird die dabei anfallende aluminiumhaltige Lösung zu einem Koagulationsmittel für die Behandlung von Bergbautailings und Abwasser aufbereitet. Das hergestellte Flockungsmittel wurde eingehend charakterisiert und die Wirksamkeit als Koagulant für feindisperse Systeme im Jar‐Test untersucht und bestätigt.
Sulphuric acid is the chemical with highest production rates in the world. At present, it is mainly synthesized using vanadium pentoxide as catalyst, which determines the applied production process particularly in terms of gas pre‐treatment and heat management. For processes, which cannot be run with vanadium pentoxide, alternative catalysts are required to make different SO2 qualities accessible to sulphuric acid production. Ferric oxides are a very promising alternative, since they combine higher thermal with improved chemical stability. Within this study, various ferric oxides were examined with regard to conversion rates and structural changes during application. Effects of crystal structure, particle size as well as thermal treatment and the influence of precipitation conditions were studied. Although conversion rates are very promising, it has become apparent, though, that these materials cannot compete with vanadium pentoxide in terms of conversion rate as well as long‐time stability, yet. Nevertheless, from the results of this study, it is clear that high potential lies in focused catalyst optimisation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.