The formation of intramolecular micelles in copolymers with periodic sequence, where hydrophobic units (stickers) are periodically placed along the chain, is studied by using multicanonical Monte Carlo computer simulations for an off-lattice bead-rod model in three dimensions. With decreasing the temperature, a transition from random-coil conformations to micelles occurs and flower-type micelles are formed via the transition. The number of stickers forming a micelle core is limited by the excluded-volume effect of loop chains around micelle cores. By this effect, two intramolecular micelles are formed for long polymer chains with 60 bonds via the coil-to-micelle transition. By further decreasing the temperature, we find that another transition, i.e., a micelle-to-micelle transition, takes place. At this transition point, the two intramolecular micelles merge into one micelle. Furthermore, we extend the multicanonical MC method to study elastic properties of single polymer chains with strong attractive interactions under external force fields, and study how the intramolecular micellization affects the elastic property of single polymer chains.
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http://dx.doi.org/10.1140/epje/i2003-10163-x | DOI Listing |
Langmuir
December 2024
Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Dr NW, Calgary T2N 1N4, Canada.
Understanding the mechanism of a CO-responsive surfactant is essential for enhancing its industrial applications. Conventional experimental methods face challenges in pinpointing the exact location of proton transfer within the system and in accurately describing the impact of intermolecular and intramolecular interactions on the CO responsiveness of such substances. To address this gap, this study employs molecular dynamics simulations and free energy perturbation methods to investigate the proton transfer process between a CO-responsive cationic surfactant '-dodecyl-,-dimethylacetamidinium (DMAAH) and its counterion bicarbonate ion at the oil-water interface and micelle surface and in the bulk aqueous phase.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2024
School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia.
Chempluschem
October 2024
Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany.
Native mass spectrometry of membrane proteins relies on non-ionic detergents which protect the protein during transfer from solution into the gas phase. Once in the gas phase, the detergent micelle must be efficiently removed, which is usually achieved by collision-induced dissociation (CID). Recently, infrared multiple photon dissociation (IRMPD) has emerged as an alternative activation method for the analysis of membrane proteins, which has led to a growing interest in detergents that efficiently absorb infrared light.
View Article and Find Full Text PDFLangmuir
June 2024
Department of Chemical & Materials Engineering, National Central University, Jhong-Li, Taoyuan 320, Taiwan.
A biocompatible and antifouling polymeric medical coating was developed through rational design for anchoring pendant groups for the modification of stainless steel. Zwitterionic 2-methacryloyloxyethyl phosphorylcholine (MPC) was copolymerized individually with three anchoring monomers of carboxyl acrylamides with different alkyl spacers, including acryloylglycine (2-AE), 6-acrylamidohexanoic acid (6-AH), and 11-acrylamidoundecanoic acid (11-AU). The carboxylic acid groups are responsible for the stable grafting of copolymers onto stainless steel via a coordinative interaction with metal oxides.
View Article and Find Full Text PDFFood Chem
September 2024
State Key Laboratory of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China. Electronic address:
Excipient selection is crucial to address the oxidation and solubility challenges of bioactive substances, impacting their safety and efficacy. AKPL, a novel ω-3 polyunsaturated fatty acids (PUFAs) esterified phospholipid derived from Antarctic krill, demonstrates unique antioxidant capabilities and synergistic effects. It exhibits pronounced surface activity and electronegativity at physiological pH, as evidenced by a critical micelle concentration (CMC) of 0.
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