S.S.S. Uygan, D. Yablon, C. Kielar, E. Vogelsberg, D. Erb, P. Müller, T. Heine, K. Monakhov, B. Abel, C. Fischer
Leibniz Institute of Polymer Research,
Germany
Keywords: nanoparticles, critical minerals, elasticity, intermolecular forces
Summary:
SiO2 nanoparticles are one of the most abundant nanoparticles on Earth and are released from the industries into the environment. In the following, they have attached with minerals, microorganisms, and other materials, which have been found in soil. In particular, the mobility of SiO2 nanoparticles with biotite and muscovite influences the environmental remediation and contributes the nanotechnological innovations. On the other hand, muscovite and biotite are also crucial and critical minerals on Earth. Therefore, we need to investigate the interfacial interactions between SiO2 nanoparticles and minerals with a focus on mechanical and physiochemical properties. Furthermore, the formation of etch pits on biotite and muscovite are quite variable at specific time frame and not well-known in terms of their nanomechanical mapping under the environmental conditions particularly at environmental relevant pH in soil. On the other hand, the formation of etch pits on biotite and muscovite with morphological alterations has also an effect at interfaces for the stability mechanisms of SiO2 nanoparticles. Atomic Force Microscopy is a versatile tool that investigates particle-mineral interactions with high resolution. Furthermore, nanomechanical mapping has particularly given the structural information about intermolecular forces in terms of the colloidal stability, which has been based on DLVO theory for particle-mineral interactions. Moreover, we introduce Force Spectroscopy Measurements with Machine Learning Assessment to understand the viscoelasticity and elasticity properties of SiO2 nanoparticles on etched biotite and muscovite surfaces. Adhesion and repulsive forces have been quantified by Force Spectroscopy Measurements under different environmental conditions. qb Bio AC, -COOH and -NH2 functionalized, RTESPA-300-30 AFM tips have been used during the measurements to understand the viscoelasticity and elasticity of SiO2 nanoparticles on etched pits and pristine biotite and muscovite surfaces at environmental relevant pH range. In addition, machine learning assessment has been performed to classify, and predict large nano-indentation data sets. The etch pits of biotite and muscovite compared to pristine biotite and muscovite have provided different adsorption sites for SiO2 nanoparticles due to cations with aluminium and silicates, which consist the nature of biotite and muscovite surfaces. Furthermore, the different geometries have influenced the nanomechanical forces with different nanotopography configurations. Overall, the mobility of SiO2 nanoparticles on etched muscovite and biotite is playing an important role for the environment and the utilisation for applications in manufacturing, waste water treatment, semiconductor technology, biomedicine, catalysis, supercapacitors/batteries, and digital technology.