Quasielastic neutron scattering in soft matter

Sakai, Victoria García; Arbe, Arantxa

doi:10.1016/j.cocis.2009.04.002

Cited by 100 publications

(70 citation statements)

References 123 publications

(71 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…25,26 Polymer dynamics includes vibrational motions, rotations of side groups, the segmental α-process as well as the overall chain dynamics, thus covering a very broad time regime of more than ten decades from the pico-second (ps) to the second (s) regime. 27 This necessitates the use of different experimental techniques with complementary spatial and temporal capabilities, like, for example, light and neutron scattering 28 and/or dielectric relaxation spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

Dynamics of Hyperbranched Polymers under Confinement: A Dielectric Relaxation Study

Androulaki

Chrissopoulou

Prevosto

et al. 2015

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

The effect of severe confinement on the dynamics of three different generations of hyperbranched polyesters of the Boltorn family is investigated by dielectric relaxation spectroscopy (DRS). The polymer chains are intercalated within the galleries of natural montmorillonite (Na+-MMT), thus forming 1 nm polymer films confined between solid walls. The structure of the nanocomposites is studied with X-ray diffraction and the thermal behavior of the polymers in bulk and under confinement is determined by differential scanning calorimetry. The glass transition temperatures of the polymers show a clear dependence on the generation whereas the transition is completely suppressed when all the polymer chains are intercalated. The dynamic investigation of the bulk polymers reveals two sub-Tg processes, with similar behavior for the three polymers with the segmental relaxation observed above the Tg of each polymer. For the nanocomposites, where all the polymer chains are severely confined, the dynamics show significant differences compared to that of the bulk polymers. The sub-Tg processes are similar for the three generations but significantly faster and with weaker temperature dependence than those in the bulk. The segmental process appears at temperatures below the bulk polymer Tg, it exhibits an Arrhenius temperature dependence and shows differences for the three generations. A slow process that appears at higher temperatures is due to interfacial polarization.

show abstract

Section: Introductionmentioning

confidence: 99%

Dynamics of Hyperbranched Polymers under Confinement: A Dielectric Relaxation Study

Androulaki

Chrissopoulou

Prevosto

et al. 2015

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

show abstract

“…QENS is a unique way of probing dynamics of polymer molecules [25][26][27] and soft matter 28,29 in general, local as well as segmental relaxations as a function of length scale. Furthermore, the mobility of different parts of a polymer molecule can be identified by selective deuteration.…”

Section: Quasi Elastic Neutron Scattering (Qens)mentioning

confidence: 99%

Multihydroxyl End Functional Polyethylenes: Synthesis, Bulk and Interfacial Properties of Polymer Surfactants

et al. 2014

Self Cite

View full text Add to dashboard Cite

(2014) 'Multihydroxyl end functional polyethylenes : synthesis, bulk and interfacial properties of polymer surfactants. ', Macromolecules., 47 (6). pp. 2062', Macromolecules., 47 (6). pp. -2071 Further information on publisher's website:http://dx.doi.org/10.1021/ma402158bPublisher's copyright statement:This document is the Accepted Manuscript version of a Published Work that appeared in nal form in Macromolecules, copyright c American Chemical Society after peer review and technical editing by the publisher. To access the nal edited and published work see http://dx.doi.org/10.1021/ma402158bAdditional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. for polar interfaces, are thermally stable up to ~ 250 °C, and to have similar crystallinity and dynamics to their unfunctionalised homopolymers analogues. The polymers segregated strongly to silicon oxide interfaces, with adsorbed layers forming spontaneously at annealed polymer interfaces, having surface excess concentrations approaching 2 R g , and a maximum areal density of approximately 0.6 adsorbed chains per nm 2 . This interfacial activity is achieved almost without detriment to the bulk physical properties of the polymer as evidenced by thermal analysis, quasi-elastic neutron scattering and smallangle neutron scattering (SANS). SANS experiments show little evidence for aggregation of the dihydroxyl functionalized polymers in blends with PE homopolymers, which is thought to explain why these additives have particularly strong interfacial adsorption, even at relatively high concentrations. A modest level of segregation of the additives to exposed blend surfaces was also seen, particularly when the additive molecular weight was significantly lower than that of the matrix. We attribute this to a combination of the relatively low molecular weight of the additives and the marginally lower surface energy associated with deuterated polymers.3

show abstract

“…The r 2 in Figs. (6) and (7) are barely distinguishable. This shows that intrinsic r 2 obtained is not sensitive to the form of C(t) and R(ω) used in the model at the present level of precision of the data.…”

Section: A the Msdmentioning

confidence: 99%

“…Following pioneering experiments and subsequent developments, the mean square displacement (MSD) of hydrogen in proteins can now be readily observed in neutron scattering experiments [1][2][3][4][5][6][7][8][9][10][11]. Specifically, the global average MSD of H throughout the protein is typically determined from the elastic component of the incoherent dynamic structure factor (DSF).…”

Section: Introductionmentioning

confidence: 99%

Intrinsic mean-square displacements in proteins

Vural

Glyde

2012

Phys. Rev. E

View full text Add to dashboard Cite

The thermal mean square displacement (MSD) of hydrogen in proteins and its associated hydration water is measured by neutron scattering experiments and used an indicator of protein function. The observed MSD as currently determined depends on the energy resolution width of the neutron scattering instrument employed. We propose a method for obtaining the intrinsic MSD of H in the proteins, one that is independent of the instrument resolution width. The intrinsic MSD is defined as the infinite time value of r 2 that appears in the Debye-Waller factor. The method consists of fitting a model to the resolution broadened elastic incoherent structure factor or to the resolution dependent MSD. The model contains the intrinsic MSD, the instrument resolution width and a rate constant characterizing the motions of H in the protein. The method is illustrated by obtaining the intrinsic MSD r 2 of heparan sulphate (HS-0.4), Ribonuclease A and Staphysloccal Nuclase (SNase) from data in the literature.

show abstract

Quasielastic neutron scattering in soft matter

Cited by 100 publications

References 123 publications

Dynamics of Hyperbranched Polymers under Confinement: A Dielectric Relaxation Study

Dynamics of Hyperbranched Polymers under Confinement: A Dielectric Relaxation Study

Multihydroxyl End Functional Polyethylenes: Synthesis, Bulk and Interfacial Properties of Polymer Surfactants

Intrinsic mean-square displacements in proteins

Contact Info

Product

Resources

About