Decoding Macromolecular Compactness by Light Scattering: From Measurement to Chemical Insight in the Teaching Laboratory

Abstract A critical pedagogical challenge in polymer science is bridging the gap between theoretical concepts and their experimental validation. Herein, we present an integrated laboratory course designed to address this challenge by immersing students in a complete model construction-validation cycle. This course centers on experimentally determining the ρ-value (ρ = Rh/Rg), one of the key quantitative descriptors of macromolecular compactness, using light scattering techniques. Using a series of architecturally defined samples, including linear chain and single-chain nanoparticles (SCNPs) with varying cross-linking densities, students performed static and dynamic light scattering (SLS/DLS) to measure their radius of gyration (Rg) and hydrodynamic radius (Rh). Through guided data analysis, including constructing Zimm plots, fitting correlation functions, and evaluating the appropriateness of analytical models, students actively engaged in the iterative process of scientific inquiry─operating instruments, processing raw data, and comparing results to theoretical predictions. This approach transforms the laboratory from a routine characterization exercise into a coherent investigative experience that connects measurement, model-based analysis, and chemical insights of the structure–property relationship.