TY - CONF A1 - Heinrich, Thomas A1 - Schneider, Markus A1 - Schäpe, Kaija A1 - Unger, Wolfgang A1 - Stockmann, Jörg M. T1 - Classification of engineered Titania nanomaterials via surface analysis using principal component analysis (PCA) assisted Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) N2 - Due to the growing number of engineered nanomaterials (NM) the need for a reliable risk assessment for these materials is today bigger than ever before. Especially the nanomaterial’s surface or shell directly interacts with its environment and therefore is a crucial factor for NM’ toxicity or functionality. Especially, titania is one of the NM with the greatest technological importance. It is used for a large number of applications and can be found in food, cosmetics, glasses, mirrors, paints to mention only a few. In 2012, experts estimate[d] the annual European nano-titania production or utilization at an amount of more than 10,000 t. Great progress has been achieved in the area of NM investigation and characterization during the past decade. A variety of publications provide information about technological innovation as well as hazard potential, which means the potential risk on human health and ecosystems. However, enhanced data harmonization and well-defined standards for nanomaterial analysis, could significantly improve the reliability of such studies which often suffers from varying methods, parameters and sample preparations. To develop a suitable approach for the NM’s risk assessment, the ACEnano project aims at establishing a toolbox of verified methods. The size of this well-structured European project allows to handle even those big challenges like data harmonization and standardization. Due to its powerful combination of superior surface sensitivity and lateral resolution down to the Nano regime, ToF-SIMS could become one of these toolbox methods. Supported by multivariate data analysis such as principal component analysis (PCA), the method can be used for sub-classification of nanomaterial families using slight differences in surface chemistry. Here, we show a PCA supported classification of titania nanoparticles from various sources (NIST, JRC, BAM) with ToF-SIMS. Parameters like size, shell, pre-preparation and crystal system cause variance in the data and allow us to distinguish the species from each other. Moreover, this variance in the data also occurs and can be used for investigation when we compare our measurements of particle ensembles with those of grown titania films. The carefully selected and refined peaks allow a reasonable particle categorization and further a reliable allocation of blank feeds, which introduces a promising approach for NM characterization in the context of NM risk assessment. T2 - SIMS-Europe CY - Münster, Germany DA - 16.09.2018 KW - Nanoparticles KW - ToF-SIMS KW - XPS KW - PCA KW - Titania PY - 2018 AN - OPUS4-46250 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heinrich, Thomas A1 - Sparnacci, K. A1 - Unger, Wolfgang A1 - Schneider, Markus A1 - Müller, Anja T1 - Chemical Analysis of Core-Shell Nanoparticles using ToF-SIMS and XPS N2 - The analysis of nanomaterials is current an important task - especially in case of risk assessment, as the properties of these material class are not well understood currently. The rather high surface area of these objects renders their interactions significantly different to their corresponding bulk. Thus, the surfaces chemical composition has to be investigated to get a better understanding and prediction of the nanomaterials' behavior. ToF-SIMS has proven as a powerful tool to determine said chemical composition. Its superior surface sensitivity allows us to study mainly the utmost atomic layer and therefore gives us an idea of the interactions involved. Here, we show first result from the validation of the method for the analysis of polystyrene and gold nanoparticles. ToF-SIMS will be compared to other methods like XPS, T-SEM or REM. Furthermore, principle component analysis (PCA) will be used to detect the influence of different sample preparation performed by an innovative microfluidic device. ToF-SIMS imaging is desired to be implemented for single particle detection as well. T2 - DPG-Frühjahrstagung der Sektion Kondensierte Materie gemeinsam mit der EPS CY - Berlin, Germany DA - 11.03.2018 KW - XPS KW - ToF-SIMS KW - Nanoparticles PY - 2018 N1 - Geburtsname von Müller, Anja: Hermanns, A. - Birth name of Müller, Anja: Hermanns, A. AN - OPUS4-44790 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heinrich, Thomas A1 - Müller, Anja A1 - Schneider, Markus A1 - Sparnacci, K. A1 - Unger, Wolfgang T1 - Chemical Analysis of Core-Shell Nanoparticles using ToF-SIMS and XPS N2 - The analysis of nanomaterials is currently an important task - especially in case of risk assessment – as the properties of these material class are not well understood. The rather high surface area of these objects renders their interactions significantly different to their corresponding bulk. Thus, the surface’s chemical composition must be investigated to get a better understanding and prediction of the nanomaterials’ behavior. ToF-SIMS and XPS have proven to be powerful tools to determine the general chemical composition. The superior surface sensitivity of ToF-SIMS furthermore allows us to study mainly the utmost atomic layer and thus gives us an idea of the interactions involved. Here, we present initial data on the analysis of Hyflon®-polystyrene core-shell nanoparticles which can be used as a model system due to the known preparation and a rather good chemical as well as physical separation of core and shell. Furthermore, principle component analysis (PCA) will be used to detect the influence of sample preparation and for a better separation of different samples. ToF-SIMS imaging is desired to be implemented for single particle detection as well. T2 - RSC-NPL Symposium: Nanoparticle concentration – critical needs and state-of-the-art measurement CY - London, UK DA - 24.04.2018 KW - XPS KW - ToF-SIMS KW - Nanoparticles PY - 2018 AN - OPUS4-44795 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heinrich, Thomas A1 - Traulsen, Christoph A1 - Holzweber, Markus A1 - Richter, S. A1 - Kastner, S. K. A1 - Unger, Wolfgang A1 - Schalley, C. A. T1 - Coupled molecular switching processes in ordered mono- and multilayers of stimuli-responsive rotaxanes on gold surfaces N2 - Interfaces provide the structural basis for function as, for example, encountered in nature in the membrane-embedded photosystem or in technology in solar cells. Synthetic functional multilayers of molecules cooperating in a coupled manner can be fabricated on surfaces through layer-by-layer self-assembly. Ordered arrays of stimuli-responsive rotaxanes undergoing well-controlled axle shuttling are excellent candidates for coupled mechanical motion. Such stimuli-responsive surfaces may help integrating synthetic molecular machines in larger systems exhibiting even macroscopic effects or generating mechanical work from chemical energy through cooperative action. The present work demonstrates the successful deposition of ordered mono- and multilayers of chemically switchable rotaxanes on gold surfaces. For the first time, rotaxane mono- and multilayers are shown to reversibly switch in a coupled manner between two ordered states as revealed by linear dichroism effects in angle-resolved NEXAFS spectra. Such a concerted switching process is observed only when the surfaces are well packed, while less densely packed surfaces lacking lateral order do not exhibit such effects. T2 - SupraChem 2015 CY - Berlin, Germany DA - 22.02.2015 KW - NEXAFS KW - Rotaxanes KW - Molecular machines KW - XPS KW - ToF-SIMS KW - AFM PY - 2015 AN - OPUS4-42800 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -