Kolmangadi, Mohamed AejazMohamed AejazKolmangadiRaab, Aileen RebeccaAileen RebeccaRaabSzymoniak, PaulinaPaulinaSzymoniakLi, ZhuoqingZhuoqingLiHuber, PatrickPatrickHuberLaschat, SabineSabineLaschatSchönhals, AndreasAndreasSchönhals2025-09-252025-09-252025-09-10Physical chemistry, chemical physics 27 (35): 18162-18178 (2025)https://hdl.handle.net/11420/57541This study explores the molecular mobility, phase behavior, and electrical conductivity of dihydroxyphenylalanine-based ionic liquid crystals (DOPAn, with alkyl side chains n = 12, 14, 16) featuring cyclic guanidiniumchloride headgroups, in both bulk and nanoconfined states. Using broadband dielectric spectroscopy, differential scanning calorimetry, and fast scanning calorimetry, the research uncovers a complex interplay between molecular structure, self-assembly, and molecular mobility. In bulk, DOPAn shows a phase sequence from plastic crystalline to hexagonal columnar and isotropic phases, driven by superdisc formation and columnar organization. Multiple relaxation processes are identified: localized side-chain dynamics (γ-relaxation), ionic headgroup or core motions (α<inf>1</inf>-relaxation), and cooperative alkyl domain fluctuations (α<inf>2</inf>-relaxation). Conductivity decreases with increasing side chain length. Under nanoconfinement in anodic aluminum oxide membranes, phase behavior changes: the Col<inf>h</inf>-Iso transition is suppressed, and a new α<inf>3</inf>-relaxation appears, linked to dynamics in an adsorbed interfacial layer. DC conductivity drops by up to four orders of magnitude due to confinement effects, altered molecular orientation, and phase transitions—especially the emergence of a nematic-like state in DOPA16. These findings highlight the importance of molecular design, pore geometry, and surface chemistry in tuning ionic liquid crystal properties for advanced applications in nanofluidics, ion transport, and responsive materials.en1463-90842025351816218178Royal Society of Chemistryhttps://creativecommons.org/licenses/by/3.0/Natural Sciences and Mathematics::541: Physical; Theoretical::541.3: Physical ChemistryTechnology::620: Engineering::620.1: Engineering Mechanics and Materials Science::620.11: Engineering MaterialsJournal Articlehttps://doi.org/10.15480/882.1591610.1039/d5cp02406d10.15480/882.15916Journal Article