English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present a neutron spin echo study (NSE) of the nanosecond dynamics ofpolyethylene glycol (PEG) functionalised nanosized gold particles dissolved inD$_2$O at two temperatures and two different PEG molecular weights. Theanalysis of the NSE data was performed by applying a Bayesian approach to thedescription of time correlation function decays in terms of exponential terms,recently proved to be theoretically rigorous. This approach, which addresses ina direct way the fundamental issue of model choice in any dynamical analysis,provides here a guide to the most statistically supported way to follow thedecay of the Intermediate Scattering Functions I(Q, t) by basing on statisticalgrounds the choice of the number of terms required for the description of thenanosecond dynamics of the studied systems. Then, the presented analysis avoidsfrom the start resorting to a pre-selected framework and can be considered asmodel free. By comparing the results of PEG coated nanoparticles with thoseobtained in PEG2000 solutions, we were able to disentangle the translationaldiffusion of the nanoparticles from the internal dynamics of the polymergrafted to them, and to show that the polymer corona relaxation follows a pureexponential decay in agreement with the behavior predicted by coarse grainedmolecular dynamics simulations and theoretical models. This methodology has onefurther advantage: in the presence of a complex dynamical scenario I(Q,t) isoften described in terms of the Kohlrausch-Williams-Watts function that canimplicitly represent a distribution of relaxation times. By choosing todescribe the I(Q,t) as a sum of exponential functions and with the support ofthe Bayesian approach, we can explicitly determine when a finer-structureanalysis of the dynamical complexity of the system exists according to theavailable data without the risk of overparametrisation.

A Bayesian analysis of neutron spin echo data on polymer coated gold nanoparticles in aqueous solutions