TY  - JOUR
A1  - Wintzheimer, Susanne
A1  - Oppmann, Maximilian
A1  - Dold, Martin
A1  - Pannek, Carolin
A1  - Bauersfeld, Marie‐Luise
A1  - Henfling, Michael
A1  - Trupp, Sabine
A1  - Schug, Benedikt
A1  - Mandel, Karl
T1  - Indicator Supraparticles for Smart Gasochromic Sensor Surfaces Reacting Ultrafast and Highly Sensitive
JF  - Particle & Particle Systems Characterization
N2  - The detection of toxic gases, such as NH\(_{3}\) and CO, in the environment is of high interest in chemical, electronic, and automotive industry as even small amounts can display a health risk for workers. Sensors for the real‐time monitoring of these gases should be simple, robust, reversible, highly sensitive, inexpensive and show a fast response. The indicator supraparticles presented herein can fulfill all of these requirements. They consist of silica nanoparticles, which are assembled to supraparticles upon spray‐drying. Sensing molecules such as Reichardt's dye and a binuclear rhodium complex are loaded onto the microparticles to target NH\(_{3}\) and CO detection, respectively. The spray‐drying technique affords high flexibility in primary nanoparticle size selection and thus, easy adjustment of the porosity and specific surface area of the obtained micrometer‐sized supraparticles. This ultimately enables the fine‐tuning of the sensor sensitivity and response. For the application of the indicator supraparticles in a gas detection device, they can be immobilized on a coating. Due to their microscale size, they are large enough to poke out of thin coating layers, thus guaranteeing their gas accessibility, while being small enough to be applicable to flexible substrates.
KW  - CO sensing
KW  - NH\(_{3}\)
KW  - sensor supports
KW  - silica supraparticles
KW  - smart surfaces
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-213671
VL  - 36
IS  - 10
ER  - 
TY  - JOUR
A1  - Szczerba, Wojciech
A1  - Zukrowski, Jan
A1  - Przybylski, Marek
A1  - Sikora, Marcin
A1  - Safonova, Olga
A1  - Shmeliov, Aleksey
A1  - Nicolosi, Valeria
A1  - Schneider, Michael
A1  - Granath, Tim
A1  - Oppmann, Maximilian
A1  - Straßer, Marion
A1  - Mandel, Karl
T1  - Pushing up the magnetisation values for iron oxide nanoparticles via zinc doping: X-ray studies on the particle's sub-nano structure of different synthesis routes
JF  - Physical Chemistry Chemical Physics
N2  - The maximum magnetisation (saturation magnetisation) obtainable for iron oxide nanoparticles can be increased by doping the nanocrystals with non-magnetic elements such as zinc. Herein, we closely study how only slightly different synthesis approaches towards such doped nanoparticles strongly influence the resulting sub-nano/atomic structure. We compare two co-precipitation approaches, where we only vary the base (NaOH versus NH\(_3\)), and a thermal decomposition route. These methods are the most commonly applied ones for synthesising doped iron oxide nanoparticles. The measurable magnetisation change upon zinc doping is about the same for all systems. However, the sub-nano structure, which we studied with Mossbauer and X-ray absorption near edge spectroscopy, differs tremendously. We found evidence that a much more complex picture has to be drawn regarding what happens upon Zn doping compared to what textbooks tell us about the mechanism. Our work demonstrates that it is crucial to study the obtained structures very precisely when "playing'' with the atomic order in iron oxide nanocrystals.
KW  - Ferrite
KW  - FE
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-187390
VL  - 18
IS  - 36
ER  -