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Interfacial properties of polymeric materials are significantly influenced by their architectural structures and spatial features, while such a study of topologically interesting macromolecules is rarely reported. In this work, we reported, for the first time, the interfacial behavior of catenated poly(l-lactide) (C-PLA) at the air-water interface and compared it with its linear analogue (L-PLA). The isotherms of surface pressure-area per repeating unit showed significant interfacial behavioral differences between the two polymers with different topologies. Isobaric creep experiments and compression-expansion cycles also showed that C-PLA demonstrated higher stability at the air-water interface. Interestingly, when the films at different surface pressures were transferred via the Langmuir-Blodgett method, successive atomic force microscopy imaging displayed distinct nanomorphologies, in which the surface of C-PLA exhibited nanofibrous structures, while that of the L-PLA revealed a smoother topology with less fiber-like structures.
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http://dx.doi.org/10.1021/acs.langmuir.2c00454 | DOI Listing |
J Colloid Interface Sci
September 2025
Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany. Electronic address:
Glycolipids are key structural and functional components of biological membranes, yet their interfacial hydration behavior remains poorly understood. Here, we use vibrational heterodyne-detected sum-frequency generation (HD-SFG) spectroscopy to probe the molecular structure of the air-water interface formed by monolayers of ohmline, a glycolipid bearing a lactose headgroup and carrying no formal charge. Upon electrolyte addition, we observe a striking reorientation of interfacial water and a reversal of the HD-SFG signal, indicative of apparent surface charging by an otherwise neutral headgroup.
View Article and Find Full Text PDFLangmuir
September 2025
Federal University of São Paulo, Laboratory of Hybrid Materials, Diadema, São Paulo 09913-030, Brazil.
This study demonstrates the successful fabrication of nanostructured Langmuir-Blodgett (LB) films combining the conjugated copolymer poly(9,9-dioctylfluorene--3,4-ethylenedioxythiophene) (PDOF--PEDOT) with spherical and triangular silver nanoparticles (AgNP). The LB technique allowed precise control over the molecular arrangement and distribution of the nanoparticles at the air-water interface, resulting in compact, reproducible and structurally ordered nanocomposite films. The structural and morphological properties of the interfacial monolayers and LB films were investigated using surface pressure-area isotherms, Brewster angle microscopy, polarization modulation infrared reflection-absorption spectroscopy (PM-IRRAS) and quartz crystal microbalance.
View Article and Find Full Text PDFChempluschem
September 2025
HCB Physical Chemistry, Henkel AG & Co. KGaA, Henkelstraße 67, 40589, Düsseldorf, Germany.
Surfactants adsorb at interfaces and reduce the interfacial tension. In technical applications, they are typically used as complex mixtures rather than monodisperse systems. These mixtures often include ionic and non-ionic surfactants, with the non-ionic components comprising various monodisperse species.
View Article and Find Full Text PDFJ Am Chem Soc
September 2025
State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Recently, the atmospheric aerosol surface, which is reported to be quite acidic, is recognized as an important microreactive medium for atmospheric chemistry, profoundly impacting air quality and global climate. Nevertheless, the molecular-level understanding of the effect of surface-bound acids on atmospheric chemical reactions remains limited. Herein, the reactions between CO and NH/amines at the air-water interface with organic acids are investigated using combined molecular dynamic simulations and quantum chemical calculations.
View Article and Find Full Text PDFbioRxiv
August 2025
Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, 10027, USA.
Contact with the air-water interface can bias the orientation of macromolecules during cryo-EM sample preparation, leading to uneven sample distribution, preferred orientation, and damage to the molecules of interest. To prevent this, we describe a method to encapsulate target proteins within highly hydrophilic, structurally homogeneous, and stable protein shells, which we refer to as "nanocrates" for this purpose. Here, we describe packaging, data acquisition, and reconstruction of three proof-of-principle examples, each illuminating a different aspect of the method: apoferritin (ApoF, demonstrating high-resolution), thyroglobulin (Tg, solving a known preferred orientation problem), and 7,8-dihydroneopterin aldolase (DHNA, a structure previously uncharacterized by cryo-EM).
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