The dynamics of short unentangled tracer chains in the melt of a highly entangled polymer matrix has been investigated using neutron spin echo spectroscopy [Zamponi et al., Phys. Rev. Lett. 126, 187801 (2021)]. Irrespective of the tracer chain length, the center of mass mean square displacement is subdiffusive at short times and crosses over to Fickian diffusion at longer times. The diffusion...
We have investigated the dynamics of polyethylene-oxide (PEO) ring/linear blends of various molecular weight ratios. Both the blend viscosity as well as the microscopic dynamics were studied. The blend viscosity displays a maximum at intermediate ring volume fractions. For symmetric blends the relative viscosity maximum increases with the molecular weight of the polymers, while for...
Vitrimers are redefining the boundaries between thermosets and thermoplastics by combining permanent network integrity with true recyclability enabled by dynamic covalent chemistry. Yet, the key question remains: how does molecular mobility at the smallest length and time scales translate into macroscopic reprocessability? In this work, we unravel this connection through a multiscale dynamics...
The research on Non-Gaussian (NG) dynamics in polymer melts has been largely focused on the decaging of polymer segments near the glass transition and was quantified in terms of the NG parameter. Recently, based on simulations, theoretical investigations led to quantitative determination of the NG parameter for the linear entangled polymers. We present a study on diffusion of short...
Surfactant-free microemulsions (SFME) are an emerging class of self-organized ternary liquids that develop mesoscale structure without conventional surfactants. Understanding their phase behavior and dynamics is crucial for applications in drug delivery, extraction, and chemical engineering.
In ternary mixtures, SFME formation arises from a delicate interplay of molecular architecture,...
Understanding water diffusion in subnanometer pores is essential for designing next-generation proton-conducting materials. Sulfonated porous aromatic frameworks (SPAFs) offer a unique platform for this by combining rigid, permanently microporous carbon scaffolds with adjustable -SO3H densities. Their high proton conductivities, often comparable to fluorinated polymers, indicate that...
Polymeric fluids are one of the most fascinating areas in soft matter physics. Entangled polymer systems exhibit complex, non-Newtonian viscoelastic behaviour arising from topological constraints that restrict chain motion. These entanglements result in characteristic plateau moduli and long relaxation times. To directly access molecular relaxation under shear, we used an updated cone–plate...
In recent years, a great effort has been put to investigate collective relaxations in liquids [1] and polymer systems [2] at mesoscopic scales. This has been experimentally achieved using neutron scattering methods, especially in combination with polarization analysis (PA) capabilities [3] allowing to disentangle incoherent and coherent contributions, or with computational methods [4]. Few...
