Influence of Dielectric Barrier Discharge Treatment on Surface Structure of Polyoxymethylene Fiber and Interfacial Interaction with Cement

Polyoxymethylene (POM) fiber was treated with atmospheric dielectric barrier discharge (DBD) plasma to enhance the surface activity of the fiber and interfacial interaction with cement. The physical and chemical properties of samples with different DBD plasma treatment durations were tested and analyzed. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed that the surface roughness of the sample increased significantly as a result of the DBD plasma treatment. Fourier transform infrared spectrophotometer (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis showed that a large number of –COH and –COOH groups were formed on the surface of the sample after DBD plasma treatment. The hydrophilicity of the POM fiber was greatly improved with the increase in the treatment duration. When the treatment duration was longer than 120 s, the fiber surface contact angle decreased from 90° to 43°. The DBD plasma treatment resulted in a decrease in the tensile strength of the POM fiber, but the increase in the amount of –COH and –COOH on the surface of the POM fiber and the increase in the roughness resulted in an increase in the fiber pull-out bonding strength in cement from 2.15 N to 4.68 N.