POS4-0625
Water Dynamics Governed by Interfacial Aggregation States in Sequence-Controlled Fluorinated Copolymers
Topic
S4. Colloids, Interfaces, and Molecular Assemblies for Functional Soft Materials
When and Where
Sep 29, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Hae Jung SON
Boseok KANG
Presenter(s)
Kumamoto Kazuma (Kyushu University)
Co-Author(s)
Abstract
Interfacial water dynamics on fluorinated polymers govern macroscopic surface properties such as wetting behavior. In particular, dynamic wetting behavior is highly sensitive to molecular-scale interactions and the mobilities of interfacial water and polymer. Although monomer sequence in copolymers is a promising strategy for controlling the aggregation states, its effects on interfacial water dynamics remain poorly understood. Here, we investigated sequence-dependent interfacial water dynamics using alternating and random copolymers of fluorinated methacrylate and styrene.
Despite exhibiting identical surface roughness and static water contact angles, the alternating copolymer showed a larger sliding angle than the random copolymer. Air bubble contact angle measurement revealed that the alternating copolymer/water interface was more hydrophilic, suggesting that water molecules experience different aggregation states at the water interface. Sum-frequency generation spectroscopy further showed that the broad OH peak of the alternating copolymer remained significantly stronger and was shifted to lower wavenumbers side compared with that of the random copolymer, consistent with a larger population of hydrogen-bonded interfacial water molecules for the alternating copolymer.
Molecular dynamics simulations revealed that fluorinated side chains aggregated in both copolymers. Additionally, the aggregation in the alternating copolymer was predominantly intermolecular, forming dynamic clustering of fluorinated side chains with transient openings generated by side-chain fluctuations. The motions of interfacial water were restricted in the alternating system compared with the random system. This behavior likely originated from the dynamic clustering, which intermittently traps water molecules within the clusters and promotes the exchange between water molecules inside and outside the clusters.
Despite exhibiting identical surface roughness and static water contact angles, the alternating copolymer showed a larger sliding angle than the random copolymer. Air bubble contact angle measurement revealed that the alternating copolymer/water interface was more hydrophilic, suggesting that water molecules experience different aggregation states at the water interface. Sum-frequency generation spectroscopy further showed that the broad OH peak of the alternating copolymer remained significantly stronger and was shifted to lower wavenumbers side compared with that of the random copolymer, consistent with a larger population of hydrogen-bonded interfacial water molecules for the alternating copolymer.
Molecular dynamics simulations revealed that fluorinated side chains aggregated in both copolymers. Additionally, the aggregation in the alternating copolymer was predominantly intermolecular, forming dynamic clustering of fluorinated side chains with transient openings generated by side-chain fluctuations. The motions of interfacial water were restricted in the alternating system compared with the random system. This behavior likely originated from the dynamic clustering, which intermittently traps water molecules within the clusters and promotes the exchange between water molecules inside and outside the clusters.
