![]() ![]() Moreover, SEM and TEM are limited to small sample volumes, which are not necessarily representative of the entire batch. In both cases, sample preparation is laborious and costly and not well suited for quality control or process development, where sample processing and analysis have to be continuously iterated. For small nanoparticles, this requires high-resolution techniques such as scanning-electron microscopy (SEM) of specially prepared sample surfaces 10, or transmission electron microscopy (TEM) of microtome slices 11. In solid media, dispersion-state characterization mainly relies on microscopic imaging. In order to ensure consistent product quality, the dispersion state must be continuously monitored during fabrication, which has been identified a key challenge both in nanomaterial development and industrial production 9. The dispersion state is governed by the nanoparticle properties, by the composition and the physical parameters of the host material, as well as by the processing route adopted for dispersing the nanoparticles in the host material. Properties of nanocomposites depend not only on the size and shape of the particles but also on their dispersion state, characterized by the degree of agglomeration when immersed into a liquid or solid host material. These applications mostly rely on the unique properties of nanosize particles, namely huge surface-to-volume ratios, enhanced tensile strengths and superior electrical conductivities as shown by carbon nanotubes (CNT) or other nanofibres 7, or outstanding barrier properties of nanoplatelets 8. Examples comprise nanocomposite polymers with enhanced mechanical or electronic properties 1, 2, functional coatings 3, flame-retardant materials 4, advanced drug-delivery systems 5, and anode materials for Li-ion batteries 6. Nanomaterials represent an emerging multi-billion dollar market driven by a vast variety of applications that range from mechanical and civil engineering to energy storage and life sciences. These experiments represent the first demonstration of multiscale nanomaterial characterization using OCT. The technique is perfectly suited for in-line metrology in a production environment, which is demonstrated using a state-of-the-art compounding extruder. We further prove the viability of the approach by characterizing highly relevant material systems based on nanoclays or carbon nanotubes. Using a model system of polystyrene nanoparticles, we demonstrate nanoparticle sizing with high accuracy. Large particle agglomerates can be directly found by OCT imaging, whereas dispersed nanoparticles are detected by model-based analysis of depth-dependent backscattering. The technique does not require sample preparation and is applicable to a wide range of solid and liquid material systems. ![]() Here we show that optical coherence tomography (OCT) represents a versatile tool for nanomaterial characterization, both in a laboratory and in a production environment. Conventional methods like optical or electron microscopy need laborious, costly sample preparation and do not permit fast extraction of nanoscale structural information from statistically relevant sample volumes. ![]() In particular, achieving and maintaining well-dispersed particle distributions is a key challenge, both in material development and industrial production. However, development of nanomaterial fabrication still suffers from the lack of adequate analysis tools. Nanocomposite materials represent a success story of nanotechnology. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |