0000000000303952

AUTHOR

Milos Steinhart

showing 4 related works from this author

SAXS investigation on aggregation phenomena in supercritical CO2.

2004

Synchrotron Small-Angle X-Ray scattering (SAXS) measurements on aggregate formation of a Polyvinyl acetate- b-Perfluoro octyl acrylate (PVAc- b-PFOA) block copolymer in supercritical CO(2) are here reported. Experiments were carried out for a series of different thermodynamic conditions, changing the solvent density by profiling both the pressure at constant temperature and the temperature at constant pressure. This block copolymer and in general fluorocarbon-hydrocarbon di-blocks form aggregates depending on the value of CO(2) density. A sharp transition between monomers dissolved as random coils and micelles characterized by a solvophilic shell and a solvophobic core occurs when the CO(2)…

Polyvinyl acetateMaterials scienceSmall-angle X-ray scatteringBiophysicsThermodynamicsSurfaces and InterfacesGeneral ChemistryCritical valueMicelleSupercritical fluidCondensed Matter::Soft Condensed Matterchemistry.chemical_compoundchemistryCopolymerGeneral Materials ScienceSoft matterSolvophobicBiotechnologyThe European physical journal. E, Soft matter
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Kinetics of block-copolymer aggregation in super critical CO2

2002

Small angle X-ray and neutron scattering (SAXS and SANS) are used to obtain structural information on the aggregation behavior of block-copolymers dissolved in supercritical CO2. The SANS technique is used to provide a detailed structural model for the micellar aggregates, which form below the critical micellization density (CMD), that we defined in our previous work. The SAXS technique (with a synchrotron source) is used to provide the first experimental information concerning the kinetic features of both formation and decomposition of such aggregates as soon as pressure jumps are applied to the solutions across the CMD. 2002 Elsevier Science B.V. All rights reserved.

Work (thermodynamics)Materials scienceSmall-angle X-ray scatteringKineticsThermodynamicsNeutron scatteringCondensed Matter PhysicsKinetic energySynchrotronSupercritical fluidElectronic Optical and Magnetic Materialslaw.inventionlawPolymer chemistryMaterials ChemistryCeramics and CompositesCopolymerJournal of Non-Crystalline Solids
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Pressure effects on α-synuclein amyloid fibrils: An experimental investigation on their dissociation and reversible nature

2017

α–synuclein amyloid fibrils are found in surviving neurons of Parkinson's disease affected patients, but the role they play in the disease development is still under debate. A growing number of evidences points to soluble oligomers as the major cytotoxic species, while insoluble fibrillar aggregates could even play a protection role. In this work, we investigate α–synuclein fibrils dissociation induced at high pressure by means of Small Angle X-ray Scattering and Fourier Transform Infrared Spectroscopy. Fibrils were produced from wild type α–synuclein and two familial mutants, A30P and A53T. Our results enlighten the different reversible nature of α–synuclein fibrils fragmentati…

0301 basic medicineSmall AngleAmyloidHigh-pressureMutantBiophysicsmacromolecular substances010402 general chemistryFibril01 natural sciencesBiochemistryDissociation (chemistry)Scattering03 medical and health scienceschemistry.chemical_compoundX-Ray DiffractionScattering Small AngleSpectroscopy Fourier Transform InfraredPressureHumansPoint MutationFourier transform infrared spectroscopyMolecular BiologySpectroscopyAlpha-synucleinAmyloid; FTIR; High-pressure; SAXS; α-synuclein; Amyloid; Humans; Parkinson Disease; Point Mutation; Pressure; Scattering Small Angle; Solubility; Spectroscopy Fourier Transform Infrared; X-Ray Diffraction; alpha-Synuclein; Biophysics; Biochemistry; Molecular BiologySmall-angle X-ray scatteringWild typeα-synucleinParkinson DiseaseSAXSAmyloid fibril0104 chemical sciences?-synucleinCrystallography030104 developmental biologyBiophysicchemistryFTIRSolubilityFourier Transform InfraredBiophysicsalpha-SynucleinHuman
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A combined small-angle neutron and X-ray scattering study of block copolymers micellisation in supercritical carbon dioxide

2003

Small angle neutron and X-ray scattering (SANS and SAXS) are used to investigate the monomer–aggregate transition of fluorocarbon–hydrocarbon diblock copolymers in supercritical carbon dioxide. SANS data are analyzed using a polydisperse sphere core–shell model. Synchrotron SAXS data have been collected by profiling the pressure at different temperatures, and critical micellization densities have been obtained for a series of diblock solutions. Finally pressure jump experiments, combined with synchrotron SAXS, have revealed two steps in the dynamics of the formation of the aggregates.

Supercritical carbon dioxideScatteringChemistrySmall-angle X-ray scatteringAstrophysics::High Energy Astrophysical PhenomenaAnalytical chemistryX-raySmall-angle neutron scatteringGeneral Biochemistry Genetics and Molecular BiologySynchrotronlaw.inventionCondensed Matter::Soft Condensed MatterlawPolymer chemistryCopolymerNeutronJournal of Applied Crystallography
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