Mar 16 2022
Poly(N-isopropylacrylamide) (PNIPAM) is a synthetic polymer that is widely studied for its thermoresponsive character. However, recent works also reported evidence of a low temperature (protein-like) dynamical transition around 225 K in concentrated PNIPAM suspensions, independently of the polymer architecture, i.e., both for linear chains and for microgels. In this work, we investigate water-polymer interactions by …
Jan 05 2022
Basalts are among the most abundant igneous rocks on Earth. Originated from the rapid cooling of magma erupted by volcanoes, they are increasingly used as raw materials in glass and ceramic technology due to their unique physico-chemical properties. The characteristics of basalts, like the glass transition temperature, are strongly controlled by their structure, which is …
Jun 22 2021
The numerical modelling of magma transport and volcanic eruptions requires accurate knowledge of the viscosity of magmatic liquids as a function of temperature and melt composition. However, there is growing evidence that volcanic melts can be prone to nanoscale modification and crystallization before and during viscosity measurements. This challenges the possibility of being able to …
Feb 26 2021
Combining elastic incoherent neutron scattering experiments at different resolutions with molecular dynamics simulations, we report the observation of a proteinlike dynamical transition in linear chains of poly(N-isopropylacrylamide). We identify the onset of the transition at a temperature Td of about 225 K. Due to a global fit procedure, we find quantitative agreement between measured and …
Feb 11 2021
This study is focused on the vibrational and microstructural aspects of the thermally induced transformation of serpentine-like garnierite into quartz, forsterite, and enstatite occurring at about 620 °C. Powder specimens of garnierite were annealed in static air between room temperature and 1000 °C. The kinetic of the transformation was investigated by means of thermogravimetric and …
Dec 14 2020
Molecular-scale dynamics in sub-to supercritical water is studied with inelastic X-ray scattering and molecular dynamics simulations. The obtained longitudinal current correlation spectra can be decomposed into two main components: A low-frequency (LF), gaslike component and a high-frequency (HF) component arising from the O-O stretching mode between hydrogen-bonded molecules, reminiscent of the longitudinal acoustic mode in …
Sep 15 2020
XV International Workshop on Complex systems Andalo (Trento, Italy) – 17-20 March 2019 Philosophical Magazine, Volume 100, Issue 20 (2020) Contents Foreword Giacomo Baldi, Aldo Fontana, Giulio Monaco & Marco Zanatta Page: 2543 Network dilution and asymmetry in an efficient brain Marco Leonetti, Viola Folli, Edoardo Milanetti, Giancarlo Ruocco & Giorgio Gosti Pages: 2544-2555 Mechanistic …
Aug 10 2020
Local and propagating vibrations occurring in DNA in the terahertz domain are essential for processes at the basis of cellular metabolism. Here we report the results of a study on the B-DNA terahertz dynamics where we combined high-resolution inelastic x-ray experiments and incoherent inelastic neutron scattering. By using two different high-hydration conditions we could study …
May 29 2020
Combining elastic incoherent neutron scattering and differential scanning calorimetry, we investigate the occurrence of the volume phase transition (VPT) in very concentrated poly-(N-isopropyl-acrylamide) (PNIPAM) microgel suspensions, from a polymer weight fraction of 30 wt. % up to dry conditions. Although samples are arrested at the macroscopic scale, atomic degrees of freedom are equilibrated and can …
Mar 20 2020
Residual stresses are well-known companions of all glassy materials. They affect and, in many cases, even strongly modify important material properties like the mechanical response and the optical transparency. The mechanisms through which stresses affect such properties are, in many cases, still under study, and their full understanding can pave the way to a full …
