Interfacial behavior of selected biologically and technologically relevant ions is studied using molecular dynamics simulations employing polarizable potentials. Propensities of choline, tetraalkylammonium (TAA), and sodium cations, and sulfate and chloride anions for the air/water interface are analyzed by means of density profiles. Affinity of TAA ions for the interface increases with their increasing hydrophobicity. Tetramethylammonium favors bulk solvation, whereas cations with propyl and butyl chains behave as surfactants. The choice of counter-anions has only a weak effect on the behavior of these cations. For choline, sodium, chloride and sulfate, the behavior at the air/water interface was compared to the results of our recent study on the segregation of these ions at protein surfaces. No analogy between these two interfaces in terms of ion segregation is found.
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http://dx.doi.org/10.1016/j.bpc.2006.04.010 | DOI Listing |
Langmuir
January 2025
Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States.
The self-assembly of nanoparticle colloids into large-area monolayers with long-range order is a grand challenge in nanotechnology. Using acoustic energy, i.e.
View Article and Find Full Text PDFLangmuir
January 2025
School of Chemistry, Key Centre for Polymers and Colloids, The University of Sydney, Sydney, New South Wales 2006, Australia.
Polymer Janus nanoparticles with one hard cross-linked polystyrene lobe and one soft film-forming poly(methyl methacrylate--butyl acrylate) lobe were synthesized by reversible addition-fragmentation chain transfer (RAFT)-mediated emulsion polymerization. The Janus nanoparticles adsorbed to oil/water and air/water interfaces, where the soft lobes coalesced, forming films of thickness between 25 and 250 nm; droplets of silicone oil could be stably encapsulated in polymer in this way. When prepared by mechanical mixing without additives, capsules of diameter 5-500 μm could be prepared, and with additives and application of heat, capsules of diameter around 5 μm were achieved, even with highly viscous silicone oil (20,000 cSt).
View Article and Find Full Text PDFJ Pharm Sci
January 2025
Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL, USA, 32310; Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA, 32310. Electronic address:
Monoclonal antibodies (mAb) represent an important class of biologic therapeutics that can treat a variety of diseases including cancer, autoimmune disorders or respiratory conditions (e.g. COVID-19).
View Article and Find Full Text PDFSoft Matter
January 2025
Department of Physics, Central University of Karnataka, Kadaganchi, Kalaburagi, Karnataka-585367, India.
The isomerization kinetics of a liquid crystalline azobenzene dimer, comprising cyanoazobenzene and naphthalene (NAZ6), were investigated at the air-water interface. The Langmuir monolayers of NAZ6 in both its and states were analyzed using surface manometry techniques. The results revealed that NAZ6 molecules in the -state displayed the coexistence of a disordered liquid-expanded phase and an ordered liquid-condensed phase, whereas no such phase transition was observed in the -state.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
Nanoscale Biophotonics Laboratory, University of Galway, University Road, Galway H91 TK33 Ireland. Electronic address:
Poly-N-isopropylacrylamide (PNIPAm), a thermorresponsive polymer, highly soluble in water below its lower critical solution temperature (LCST), is widely used in biomedical applications like drug delivery. Being able to measure PNIPAm size and aggregation state in solution quickly, inexpensively, and accurately below the LCST is critical when stoichiometric particle or molecular ratios are required. Dynamic light scattering (DLS) is probably the most widely available, and inexpensive nanoparticle sizing technique, but there are limitations with respect to sample polydispersity.
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