Binary diblock copolymers and corresponding ternary miktoarm stars are studied at oil-water interfaces. All polymers contain oil-soluble poly(propylene oxide) PPO, water-soluble poly(dimethylaminoethyl methacrylate) PDMAEMA and/or poly(ethylene oxide) PEO. The features of their Langmuir compression isotherms are well related to the ones of the corresponding homopolymers. Within the Langmuir-trough, PEO-b-PPO acts as the most effective amphiphile compared to the other PPO-containing copolymers. In contrast, the compression isotherms show a complexation of PPO and PDMAEMA for PPO-b-PDMAEMA and the star, reducing their overall amphiphilicity. Such complex formation between the blocks of PPO-b-PDMAEMA is prevented in bulk water but facilitated at the interface. The weakly-interacting blocks of PPO-b-PDMAEMA form a complex due to their enhanced proximity in such confined environments. Scanning force microscopy and Monte Carlo simulations with varying confinement support our results, which are regarded as compliant with the mathematical random walk theorem by Pólya. Finally, the results are expected to be of relevance for e.g. emulsion formulation and macromolecular engineering.
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Polymers (Basel)
January 2025
Department of Mechanical Engineering, University of Massachusetts Lowell, Lowell, MA 01854, USA.
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Department of Polymer Engineering and Science, Polymer Processing, Montanuniversitaet Leoben, Franz-Josef Strasse 18, 8700 Leoben, Austria.
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View Article and Find Full Text PDFMaterials (Basel)
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Instituto Universitario de Investigación de Ciencia y Tecnología del Hormigón (ICITECH), Universitat Politècnica de València, 46022 Valencia, Spain.
LC3 (limestone calcined clay cement) is poised to become the construction industry's future as a so-called low-carbon-footprint cement. Research into this subject has determined the minimum kaolinite content in calcined clays to guarantee good mechanical performance. This study examines the use of clay from the Valencian Community (Spain), which has a lower kaolinite content than the recommended amount (around 30%) for use in LC3 and how its performance can be enhanced by replacing part of that clay with metakaolin.
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Department of Robotics Engineering, Hanyang University, 55 Hanyangdaehak-ro, Ansan, Gyeonggi-do 15588, Republic of Korea.
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View Article and Find Full Text PDFJ Phys Chem B
January 2025
Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg 79104, Germany.
The selective insertion of membrane-impermeant amphiphiles such as detergents, (lipo)peptides, drugs, etc. into the leaflet of a membrane causes an imbalance between the intrinsic areas of the and leaflet, referred to as asymmetry stress or differential stress. The literature provides individual mechanisms of how membranes respond to such stress, which are relevant to membrane remodeling processes and leakage phenomena.
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