Berlin 2024 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 6: Composites and Functional Polymer Hybrids I

CPP 6.5: Talk

Monday, March 18, 2024, 12:45–13:00, H 0106

Non-Systematic Ion-Specific Effects in Aqueous Au Nanoparticle (NP) Suspensions and Polymer-NP Composites — •Philipp Ritzert, Alexandra Striegl, and Regine v. Klitzing — Institute for Condensed Matter Physics, TU Darmstadt, Hochschulstr. 8, 64289 Darmstadt, Germany

Nanocomposites based on inorganic gold nanoparticle (AuNP) inclusions inside an organic matrix (e.g. polymer brushes) are employed in various fields: catalysis, material engineering, and medicine. Despite numerous demonstrations of AuNPs agents for medical and environmental applications, real world environments still present challenges due to a wide variety of interfering stimuli, e.g. ionic contaminations. Therefore, characterisation of AuNPs response to environmental stimuli is key for the usage in real world applications. The most prominent stimulus in medical applications is the presence of salts. The human body and similar environments pose many salty problems that AuNPs composite materials often attack indirectly. To characterise the ion-specific response of different AuNPs in various salt solutions we systematically employ absorption spectroscopy, transmission electron microscopy, atomic force microscopy. Our model system relies on AuNPs of two sizes and two cappings. We monitor the ion-specific response of AuNPs in suspension for various sodium salts along the Hofmeister series (anion: F, Cl, Br, I, SCN) over time. The ion-specific response of the suspensions is highly dependent on the specific anion. In addition, we immobilise the AuNPs in a polymer brush and subsequently characterise the structural rearrangement in salt solutions.

Keywords: polymer brush; gold nanoparticle; NIPAM; ion-specific effects