TY - JOUR A1 - Flegler, Andreas A1 - Schneider, Michael A1 - Prieschl, Johannes A1 - Stevens, Ralph A1 - Vinnay, Thomas A1 - Mandel, Karl T1 - Continuous flow synthesis and cleaning of nano layered double hydroxides and the potential of the route to adjust round or platelet nanoparticle morphology JF - RSC Advances N2 - Here, we report a continuous flow synthesis of nano LDH, comprising a continuous precipitation process using static mixers and followed by an immediate cleaning process via a semi-continuous centrifuge to obtain the final product in one-go. Via this synthesis setup, it is possible to independently vary the concentrations of the reactants during precipitation and at the same time ensure constant reaction conditions and an immediate "quenching" of the precipitate due to "on the flow"-washing. We found that this paves the way to adjust the synthesis parameters in a way that the final morphology of the nano-LDH particles can be controlled to be either round or platelet-like. KW - MgAl LDH KW - nano LDH KW - static mixer KW - synthesis process Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-191305 VL - 6 IS - 62 ER - TY - THES A1 - Schneider, Michael T1 - Entwicklung magnetischer Kompositpartikel zur Fluidbehandlung und Wertstoffrückgewinnung T1 - Developement of magnetic composite particles for the treatment of fluids and resource recovery N2 - In der vorliegenden Arbeit wurden magnetische Kompositpartikel für den Einsatz in Flüssigkeiten entwickelt. Der Aufbau der Partikel erfolgte dabei modular, sodass eine Anpassung an verschiedene Einsatzmöglichkeiten realisierbar sein sollte. Die gezeigten Arbeiten bauen auf Partikeln bestehend aus magnetischen Nanopartikeln eingebettet in eine Silica-Matrix als Trägerpartikel auf, welche im Rahmen der vorliegenden Arbeit weiterentwickelt wurden. Der Schwerpunkt lag dabei auf der Entwicklung eines Adsorbermaterials für Phosphat als Funktionalisierung für die magnetischen Trägerpartikel, welches für den Einsatz der Entfernung von Phosphat aus kommunalem Abwasser geeignet sein sollte, sowie dessen Einsatz im Labor- und Technikumsmaßstab. Besonderes Augenmerk lag auf der umfassenden Charakterisierung des entwickelten Matrerials sowie der Aufklärung des Wirkmechanismus bei der Phosphatadsorption. Ein weiterer Teil der Arbeit beschäftigte sich mit der Steigerung der Magnetisierung des magnetischen Anteils der Partikel für eine verbesserte magnetische Abtrennung. Um die vielseitige Einsetzbarkeit der magnetischen Trägerpartikel zu demonstrieren, wurden abschließend weitere Funktionalisierungen für diese entwickelt und deren Anwendbarkeit grundlegend getestet. So wurde zum einen eine Modifizierung mit Komplexverbindungen und Metal-Organic Frameworks (MOF) realisiert mit dem möglichen Einsatzgebiet der Wasserdetektion in organischen Lösemitteln. Zum anderen wurde eine Beschichtung mit Kohlenstoff durchgeführt und die Entfernung von organischen Farbstoffmolekülen aus Wasser untersucht. N2 - In this work, magnetic composite particles were developed for the application in fluids. The particle structure was designed modular to enable its modification for different applications. The work presented in this thesis builds on earlier research and advances further the synthesis of composite particles consisting of magnetic nanoparticles embedded in a silica matrix used as magnetic carriers. The focus of this work was on the development of a phosphate adsorbent material suitable for the functionalization of the magnetic carrier particles, which were then successfully used at laboratory and pilot scale to remove and recover phosphate from municipal wastewater. Particular attention was paid to the elaborate characterization of the developed adsorbent material, as well as the elucidation of the adsorption mechanism during phosphate removal. Another part of the work was to enhance the magnetization of the magnetic fraction of the particles to improve their magnetic separation. In order to demonstrate the versatility of the magnetic carrier particles, additional functionalizations were developed and their applicability was fundamentally tested. Thus, on the one hand, a functionalization with complex compounds and metal-organic frameworks (MOF) was realized for the possible detection of water in organic solvents. On the other hand, a carbon coating was carried out to investigate the removal of organic substances from water. KW - Magnetisches Trennverfahren KW - Superparamagnetismus KW - Wasserreinigung KW - Eisenoxide KW - Adsorption KW - Wertstoffrückgewinnung KW - Phosphatentfernung KW - Recycling KW - Nano KW - Materialentwicklung KW - magnetic separation KW - resources recovery KW - water purification KW - nano KW - superparamagnetism Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199681 ER - TY - JOUR A1 - Schneider, Michael A1 - Tschöpe, André A1 - Hanselmann, Doris A1 - Ballweg, Thomas A1 - Gellermann, Carsten A1 - Franzreb, Matthias A1 - Mandel, Karl T1 - Adsorber Particles with Magnetically‐Supported Improved Electrochemical Conversion Behavior for Waste Water Treatment Processes JF - Particle & Particle Systems Characterization N2 - Micron‐sized supraparticles, consisting of a plurality of discrete nano‐ and microscale functional units, are assembled and fused by means of a droplet extrusion process. By combining nano magnetite, activated carbon, and conductive carbon with a polymeric binder matrix, particles are obtained which unite good magnetic properties, electrical conductivity, and adsorber activity through the high accessible surface area of the incorporated activated carbon of about 570 m\(^{2}\) g\(^{-1}\), thereby enabling a new approach toward sustainable water treatment processes. Due to the interplay of the components, it is possible to adsorb target substances, dissolved in the water which is demonstrated by the adsorption of the model dye methylene blue. A very fast adsorption kinetic and an adsorption capacity of about 400 mg g\(^{-1}\) is determined. By using the developed composite particles, it is also possible to electrochemically alter substances flowing through a magnetically‐stabilized fluidized‐bed reactor by electrochemically charging/discharging, significantly supported by the magnetic field enabling alternatingly optimum mobility/adsorption phases with contact/charging intervals. The electrochemical conversion can be increased up to 151% depending on the applied flow‐rate and electrical voltage. By applying an external magnetic field, a further increase of electrochemical conversion of up to 70% can be observed. KW - composite supraparticles KW - dye adsorption KW - electrochemical conversion KW - magnetic particles KW - water purification Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-214738 VL - 37 IS - 2 ER -