<p><strong><u>Title</u> :</strong></p><h3>Heterogeneous transport dynamics at soft polymer interfaces</h3><p><strong><u>Abstract</u> :</strong></p><p style="text-align:justify;">Mass transport is an important physical process with crucial implications in several biophysical, materials, and engineering applications. Molecular transport at soft material interfaces determines material functions that range from how nano- and microplastics disrupt biological membranes and how photoacid diffusion in photoresist polymers impacts semiconductor manufacturing. It is crucial to obtain a mechanistic understanding of the structure and dynamics occurring in these materials, but the inherent heterogeneity in material structure and chemistry makes characterization by ensemble measurements difficult. Single-particle techniques analyze one particle at a time providing nanoscale molecular information uncovering crucial materials processes. I aim to study the nanoscale transport of single particles to reveal material heterogeneity and its implications in biological and material sciences using single-particle techniques. I will develop novel optical microscopy and spectroscopy techniques and apply single-molecule methods for biophysical understanding of particle transport at the nanoscale, and solve real-life problems related to materials, environment, and human health. In this talk, I will present two main areas of research in my laboratory focused on understanding heterogeneous transport processes on soft material surfaces. First, I will talk about understanding the transport processes of plastic nanoparticles (PNP or nanoplastic). PNPs have an immense impact on the environment and can pose a significant health risk due to their interactions with biological membranes. Mechanistic understanding of PNP transport dynamics on model biomimetic systems is limited and single-particle methods with high spatio-temporal resolution are required to uncover nanoscale effects. Using novel optical microscopy techniques, single-particle tracking (SPT), and super-localization analysis I aim to understand the basic mechanism of PNP interaction, uptake, and fate on model membranes, vesicles, and live biological systems. The second part of my talk will be focused on understanding nanoscale molecular diffusion of photoacid in resist materials using single-particle methods to understand the limiting factors of resolution enhancement in the Extreme Ultraviolet (EUV) photolithography used in nanomanufacturing.</p>