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Speaker : Ahmed Elmeligy Affiliation : Technical University of Kaiserslautern, Germany Region : Europe Year : 2022 Language : English In the last few decades, investigations of nanoparticles (NPs, dimensions below 100 nm) were developing very quickly due to their large applications for different aspects of research and industry. TiO2 NPs are widely consumed not just in sunscreens but also in cosmetics, hygienic products, paints, food additives, energy storage, etc. Even in some medical applications, they are used in drug delivery and skin tissue engineering technology, although they are proven to have potential risks to human health, like lung cancers.1 This high usage of NPs has a significant impact on the environment because the particles are deposited directly onto different environmental surfaces, e.g., nearby seas and river water.2 Despite this fact, there is deficient information about conditions under which NPs could have a negative impact on the environment and health.3 Factors like their aggregation affinity, high surface area, mechanical stability, chemical inertness, corrosion resistance, and attachment to the corresponding surfaces may control the fate and life cycle of TiO2 nanoparticles in the environment.1 A detailed understanding of these effects would allow the prevention of NP aggregation. Scanning Force Microscopy (SFM), especially Scanning Force Spectroscopy (SFS), is a multi-useful technique for studying the forces between the particles at the nanoscale.4 We here use a Fluid-FM addition to the SFM, which gives the opportunity to immobilize particles by applying an underpressure to the hollow tip.5 The first results showed a remarkable difference in adhesion behavior between picked aggregated particles and single ones. In addition, the results showed that the agglomerated particles are more attracted to the surface compared to a few single particles. This indicates their high affinity regarding bonding to themselves or another nearby surface. Ongoing research concerns monitoring the adhesion behavior of TiO2 after being coated with Natural Organic Materials (NOMs) upon exposure to river water and studying how they interact and adhere to nearby particles under deliberated medium information like pH, water ionic conductivity, temperature, etc. References (1) Musial, J.; Krakowiak, R.; Mlynarczyk, D. T.; Goslinski, T.; Stanisz, B. J. Titanium Dioxide Nanoparticles in Food and Personal Care Products-What Do We Know about Their Safety?Nanomaterials (Basel, Switzerland) 2020, 10. (2) Gondikas, A. P.; Kammer, F. von der; Reed, R. B.; Wagner, S.; Ranville, J. F.; Hofmann, T. Release of TiO2 nanoparticles from sunscreens into surface waters: a one-year survey at the old Danube recreational Lake. Environmental science & technology 2014, 48, 5415–5422. (3) Colvin, V. L. The potential environmental impact of engineered nanomaterials. Nature Biotechnology 2003, 21, 1166–1170. (4) Tiede, K.; Boxall, A. B. A.; Tear, S. P.; Lewis, J.; David, H.; Hassellov, M. Detection and characterization of engineered nanoparticles in food and the environment. Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment 2008, 25, 795–821. (5) Meister, A.; Gabi, M.; Behr, P.; Studer, P.; Vörös, J.; Niedermann, P.; Bitterli, J.; Polesel-Maris, J.; Liley, M.; Heinzelmann, H.; et al. FluidFM: combining atomic force microscopy and nanofluidics in a universal liquid delivery system for single cell applications and beyond. Nano Letters 2009, 9, 2501–2507.