Temperature-dependent structure and dynamics of highly-branched poly( N -isopropylacrylamide) in aqueous solution
| Autor: | Johann P. de Silva, Steven R. Carter, Stephen Rimmer, Bela Farago, Mark Geoghegan, Stephen M. King, Ateyyah M. Al-Baradi, Marco Maccarini, Laurence Noirez |
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| Přispěvatelé: | Department of Physics and Astronomy [Sheffield], University of Sheffield [Sheffield], Department of Chemistry [Sheffield], Laboratoire de Physique des Solides (LPS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), ISIS Neutron and Muon Source (ISIS), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC)-Science and Technology Facilities Council (STFC), Institut Laue-Langevin (ILL), ILL, Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Aqueous solution Thermodynamics 02 engineering and technology General Chemistry Neutron scattering 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Branching (polymer chemistry) 01 natural sciences Lower critical solution temperature 0104 chemical sciences Condensed Matter::Soft Condensed Matter Solvent chemistry.chemical_compound chemistry Poly(N-isopropylacrylamide) Neutron Small-angle scattering 0210 nano-technology [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft] |
| Zdroj: | Soft Matter Soft Matter, Royal Society of Chemistry, 2018, 14 (8), pp.1482-1491. ⟨10.1039/C7SM02330H⟩ Soft Matter, 2018, 14 (8), pp.1482-1491. ⟨10.1039/C7SM02330H⟩ |
| ISSN: | 1744-683X 1744-6848 |
| DOI: | 10.1039/C7SM02330H⟩ |
| Popis: | International audience; Small-angle neutron scattering (SANS) and neutron spin-echo (NSE) have been used to investigate the temperature-dependent solution behaviour of highly-branched poly(N-isopropylacrylamide) (HB-PNIPAM). SANS experiments have shown that water is a good solvent for both HB-PNIPAM and a linear PNIPAM control at low temperatures where the small angle scattering is described by a single correlation length model. Increasing the temperature leads to a gradual collapse of HB-PNIPAM until above the lower critical solution temperature (LCST), at which point aggregation occurs, forming disperse spherical particles of up to 60 nm in diameter, independent of the degree of branching. However, SANS from linear PNIPAM above the LCST is described by a model that combines particulate structure and a contribution from solvated chains. NSE was used to study the internal and translational solution dynamics of HB-PNIPAM chains below the LCST. Internal HB-PNIPAM dynamics is described well by the Rouse model for non-entangled chains. |
| Databáze: | OpenAIRE |
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