Xiaosong Wang | Fluorescence of Aqueous Assemblies Regulated by Integral Water

Xiaosong Wang, University of Waterloo, Canada Title: Fluorescence of Aqueous Assemblies Regulated by Integral Water Abstract: Understanding how water participates in the self-assembly of organic–inorganic hybrid chromophores is essential for advancing aqueous photofunctional materials. Here we show that water plays a dual structural and optical role in colloidal assemblies formed by POSS NDI POSS molecules (POSS = polyhedral oligomeric silsesquioxane; NDI = naphthalene diimide). In aqueous media, these hydrophobic molecules spontaneously form colloids that encapsulate substantial amounts of interstitial water. We attribute its presence to the pronounced steric hindrance imposed by the bulky POSS cages, which prevents tight packing of the NDI cores and creates nanoscale voids that trap water. This confined water is not merely a passive solvent but an integral component of the supramolecular architecture, dissipating excitation energy and leading to substantial fluorescence quenching. Control studies using NDI derivatives with smaller propyl or octyl substituents (C3–NDI–C3 and C8–NDI–C8) show minimal water confinement and correspondingly distinct optical behavior, confirming the mechanistic role of steric bulk in regulating hydration and emission. These findings reveal a previously underappreciated function of water in directing both structure and photophysics, offering new design principles for aqueous luminescent materials and supramolecular systems. Biography: Dr. Xiaosong Wang is a Professor at the Waterloo Institute for Nanotechnology and the Department of Chemistry, University of Waterloo.He expertise spans polymerization, self-assembly, and nanomaterials. He pioneered several notable techniques and concepts, including aqueous APRT (1998), living self-assembly concept (2007), miniemulsion periphery polymerization (MEPP) (2009), and migration insertion polymerization (2013). His current research focuses on uncovering the active roles of water in supramolecular chemistry. #WCCE2026 #chemistry #chemistryconferences #catalysis #analyticalchemistry #organicchemistry #greenchemistry #nanotechnology #environmentalchemistry #inorganicchemistry #organometallics #materialscience #syntheticchemistry #biochemistry #greenchemistry #medicinalchemistry #chemicalresearch #chemicalengineering