title: Structural and water diffusion of poly(acryl amide)/poly(vinyl alcohol) blend films: Experiment and molecular dynamics simulations.
abstract: To study the effects of composition ratios and temperature on the diffusion of water molecules in PVA/PAM blend films, five simulation models of PVA/PAM with ten water molecules at different composition ratios (4/0, 3/1, 2/2, 1/3, 0/4) were constructed and simulated by using a molecular dynamics (MD) simulation. The diffusion behavior of water molecules in blends were investigated from the aspects of the diffusion coefficient, free volume, pair correlation function (PCF) and trajectories of water molecules, respectively. And the hydrophilicity of blend composite was studied based on the contact angle and equilibrium water content (EWC) of the blend films. The simulation results show that the diffusion coefficient of water molecules and fractional free volume (FFV) of blend membranes increase with the addition of PAM, and a higher temperature can also improve the diffusion of water molecules. Additionally, the analysis of PCFs reveals the main reason why the diffusion coefficient of water in blend system increases with the addition of PAM. The measurement results of contact angle and EWC of blend films indicate that the hydrophilicity of blend films decreases with the addition of PAM, but the EWC of blends increases with the addition of PAM.
authors.affiliation: Industry Engineering Department, School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an 710072, PR China.
authors.forename: Yanen
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Industry Engineering Department, School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an 710072, PR China. Electronic address: 598820042@qq.com.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Wei
authors.affiliation: Industry Engineering Department, School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an 710072, PR China.
authors.forename: Shuzhi
authors.initials: S
authors.lastname: Wang
authors.affiliation: Industry Engineering Department, School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an 710072, PR China.
authors.forename: Weihong
authors.initials: W
authors.lastname: Chai
authors.affiliation: Industry Engineering Department, School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an 710072, PR China.
authors.forename: Yingfeng
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D004058:Diffusion; D000431:Ethanol / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D056004:Molecular Dynamics Simulation; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D014867:Water / Q000737:chemistry*; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D000431:Ethanol; D011142:Polyvinyl Alcohol; D014867:Water; D000099166:Polyacrylamides
keywords: Diffusion coefficient; Hydrophilicity; Molecular dynamics; PAM/PVA blend composite