Influence of cold radiofrequency air and nitrogen plasmas treatment on wetting of polypropylene by the liquid epoxy resin

Investigation of the Impact of Cold Plasma Treatment on the Chemical Composition and Wettability of Medical Grade Polyvinylchloride

The impact of the Corona, dielectric barrier discharge, and low pressure radiofrequency air plasmas on the chemical composition and wettability of medical grade polyvinylchloride was investigated. Corona plasma treatment exerted the most pronounced increase in the hydrophilization of polyvinylchloride. The specific energy of adhesion of the pristine and plasma-treated Polyvinylchloride (PVC) tubing is reported. Plasma treatment increased markedly the specific free surface energy of PVC. The kinetics of hydrophobic recovery following plasma treatment was explored. The time evolution of the apparent contact angle under the hydrophobic recovery is satisfactorily described by the exponential fitting. Energy-dispersive X-ray spectroscopy of the chemical composition of the near-surface layers of the plasma-treated catheters revealed their oxidation. The effect of the hydrophobic recovery hardly correlated with oxidation of the polymer surface, which is irreversible and it is reasonably attributed to the bulk mobility of polymer chains.

Composite Liquid Marbles as a Macroscopic Model System Representing Shedding of Enveloped Viruses

A model macroscopic system imitating the entry of viruses into living cells is suggested. The system represents the contact of a composite (core-shell) liquid marble with hydrophobic/hydrophilic particles. Composite liquid marbles are water droplets coated with silicone oil armored with nanometer-sized hydrophobic particles serving as an interfacial model of a living cell. Composite marbles absorbed hydrophilic polymer particles but prevented hydrophobic particles from entering their core. Swallowing of hydrophilic particles by composite marbles resembles the penetration of viruses into living cells. The interfacial mechanism of absorption is suggested.