Series of fluorinated amphiphilic diblock copolymers poly(ethylene oxide)-b-poly(heptafluorobutyl methacrylate) (PEO-b-PHFBMA) and nonfluorinated analogue copolymers poly(ethylene oxide)-b-poly(n-butyl methacrylate) (PEO-b-PBMA) with different lengths of hydrophobic blocks were synthesized. Their interface properties at the air-water interface were investigated using surface pressure and X-ray reflectivity (XR) measurements on the Langmuir trough. The fluorinated species have shown a distinct transition from flat-lying to standing side chains, whereas the nonfluorinated ones have no indication for a significant amount of flat-lying side chains. The water surface is covered by a single layer, which is proved by XR measurements of PEO-b-PHFBMA. The obtained thickness and electron density can be related to the hydrophobic part of the copolymer by a simple consistency check: The total numbers of electrons from the fit of the XR curve should agree with the numbers of electrons in the corresponding block.
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http://dx.doi.org/10.1021/jp905016s | DOI Listing |
Membranes (Basel)
December 2024
Department of Physical Chemistry, Faculty of Chemistry and Pharmacy, Sofia University St. Kliment Ohridski, 1 "James Bourchier" Blvd., 1164 Sofia, Bulgaria.
Poly(butyl cyanoacrylate) (PBCA) nanoparticles have numerous applications, including drug and gene delivery, molecular imaging, and cancer therapy. To uncover the molecular mechanisms underlying their interactions with cell membranes, we utilized a Langmuir monolayer as a model membrane system. This approach enabled us to investigate the processes of penetration and reorganization of PBCA nanoparticles when deposited in a phospholipid monolayer subphase.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China.
Artificial photosynthesis of hydrogen peroxide (HO) from ambient air, water, and sunlight has attracted considerable attention recently. Despite being extremely challenging to synthesis, sp carbon-conjugated covalent organic frameworks (COFs) can be powerful and efficient materials for the photosynthesis of HO due to desirable properties. Herein, we report the designed synthesis of an sp carbon-conjugated COF, BTD-spc-COF, from benzothiadiazole and triazine units with high crystallinity and ultralarge mesopores (∼4 nm).
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
University of Pennsylvania, Department of Earth and Environmental Science and Department of Chemistry, 251 Hayden Hall, 240 South 33rd Street, 19104-6316, Philadelphia, UNITED STATES OF AMERICA.
Nitrogen (N2) has long been considered as stable atmospheric reservoir for N element and has a persistence time of hundreds of years. This study reveals that oxygen (O2) at typical tropospheric concentrations can rapidly activate N2, leading to substantial production of nitrous oxide (N2O), the third most impactful greenhouse gas, at rates approaching 2.83 ± 0.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2024
Institute of Physical Chemistry, Rheinisch-Westfälische Technische Hochschule Aachen University, Aachen 52074, Germany.
The adsorption of ellipsoidal colloidal particles on liquid interfaces induces interfacial deformation, resulting in anisotropic interface-mediated interactions and the formation of superstructures. Soft prolate-shaped microgels at the air-water interface offer an ideal model for studying spontaneous capillary-driven self-assembly due to their tunable aspect ratio, controlled functionality, and softness. These microgels consist of a polystyrene core surrounded by a cross-linked, fluorescently labeled poly([Formula: see text]-isopropylmethylacrylamide) shell.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
National Research and Development Center for Egg Processing, College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China. Electronic address:
Storage of shell eggs converts natural ovalbumin (N-OVA) into its more thermostable forms (S-OVA). This conversion may be associated with deterioration in the foaming properties of the stored shell egg. Thus, the foaming behavior of N-OVA and S-OVA, especially their performance at different pH conditions, was conducted.
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