Abstract
Chemically cross-linked polymer networks of poly(vinyl alcohol)/poly(methacrylate) form monolitic hydrogels and microgels suitable for biomedical applications, such as in situ tissue replacement and drug delivery. In this work, molecular dynamics (MD) simulation and incoherent neutron scattering methods are used to study the local polymer dynamics and the polymer induced modification of water properties in poly(vinyl alcohol)/poly(methacrylate) hydrogels. This information is particularly relevant when the diffusion of metabolites and drugs is a requirement for the polymer microgel functionality. MD simulations of an atomic detailed model of the junction domain at the experimental hydration degree were carried out at 283, 293 and 313 K. The polymer-water interaction, the polymer connectivity and the water dynamics were investigated as a function of temperature. Simulation results are compared with findings of elastic and quasi-elastic incoherent neutron scattering measurements, experimental approaches which sample the same space-time window of MD simulations. This combined analysis shows a supercooled water component and an increase of hydrophilicity and mobility with temperature of these amphiphilic polymer networks.
Highlights
Cross-linked polymer hydrogels form an important class of soft materials [1,2,3,4,5,6] which finds application in the agricultural, cosmetic, pharmaceutical and food industries
We report firstly the simulation results and the findings of the neutron scattering measurements
A preliminary consideration has to be made about the solvent difference between neutron scattering experiments and molecular dynamics (MD) simulations
Summary
Cross-linked polymer hydrogels form an important class of soft materials [1,2,3,4,5,6] which finds application in the agricultural, cosmetic, pharmaceutical and food industries. In PVAMA hydrogels the hydrophobic poly(methacrylate) chains are incorporated in the network to cross-link the PVA chains, imparting an amphiphilic character to the polymer matrix The characterization of these systems pertains to both structural and dynamical features of polymer and water. In this work we use the combined approach of neutron scattering experiments and MD simulations for the investigation of a PVAMA hydrogel with low content of poly(methacrylate), hereafter named. MD simulation technique was chosen to highlight at a molecular level the relationship between structural features and dynamical behavior of the network and to study the water properties in the hydrogel. MD simulation study allows to analyze the network dynamics by separating the different polymer components, i.e., PVA and PMA chains, and to investigate the water behavior. A more detailed description of the polymer network and of the permeating solvent is obtained by coupling MD simulations and neutron scattering measurements
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
