TY - GEN A1 - Saloga, Patrick E. J. T1 - What’s for eats? – Zinc phosphate nanoparticle mass fractals form during the artificial digestion of zinc chloride N2 - Zinc is an essential trace element and is ingested daily by humans, partly in dissolved form. The first contact is with saliva, in which many ions are dissolved whose solubility product with zinc can be low. This could result in compounds forming, possibly in nanoparticular form, which could have different effects on the organism than pure zinc ions. In this study, we report on the saliva stage of the artificial digestion of zinc chloride as a model substance for zinc ions. To facilitate in situ measurements, the sample is continuously passed through a small-angle x-ray scattering (SAXS) system. This custom-made machine is capable of measuring over a wide q-range and thereby able to resolve structures from around 250 nm down to the crystal structure. It is thus an excellent tool for investigating both the particle size distribution and the atomic structure of the sample. By curve fitting, we found that shortly after addition of zinc chloride to saliva, small particles with a mean radius of 1.9 ± 0.1 nm and a distribution width of 0.6 ± 0.1 nm formed. These particles are aggregated to compact mass fractals with a fractal aggregate size of 14.7 ± 0.1 nm and a fractal dimension of 2.96 ± 0.02. Approximately 7200 single particles form each mass fractal, whose radius of gyration was found to be 36 ± 1 nm. The growth of these structures continues over the course of several weeks. To determine the compound that was formed, infrared spectroscopy was used in addition to the SAXS measurements, and zinc phosphate was identified as the product. T2 - 6th Nano Today Conference CY - Lisbon, Portugal DA - 16.06.2019 KW - SAXS KW - digestion KW - nanoparticles PY - 2019 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/48342 AN - OPUS4-48342 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany