Regensburg 2025 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 32: Poster Session II

CPP 32.2: Poster

Thursday, March 20, 2025, 09:30–12:00, P3

Exploring pressure effects on the coil-globule transition of a pH sensitive polymer — •Ved Mahajan, Varun Mandalaparthy, and Nico F. A. van der Vegt — Technical University, Darmstadt

Macromolecules like polymers and proteins are essential to everyday life, with their structure and function influenced by environmental changes. The coil-globule transition is ubiquitous and is influenced by factors like hydrophobic interactions. External conditions, such as pressure, impact this transition differently in proteins and thermoresponsive polymers like PNiPAM[1].

This study investigates the effect of pressure on the coil-globule transition of a pH-sensitive hydrophobic polymer using constant-pH molecular dynamics. Our Results show that both pH and pressure significantly influence the transition. While pressure and charge both cause chain swelling, charge counteracts pressure-induced chain extension at high pressure. We observe distinct water structuring around positively and negatively charged sites with consequence to the polymer’s pressure response. Additionally, we explore zwitterionic polymers under pressure, providing insights into biologically relevant secondary structures.

[1] Papadakis, C. M.; Niebuur, B.-J.; Schulte, A. Thermoresponsive Polymers under Pressure with a Focus on Poly(N-isopropylacrylamide) (PNIPAM). Langmuir 2024, 40 (1), 1* 20, DOI: 10.1021/acs.langmuir.3c02398

Keywords: hydrophobic collapse; coil-globule transition; constant pH molecular dynamics; pressure induced swelling