Abstract
Low-density polyethylene (LDPE) sheets (3.0 ± 0.1 cm) received sequential treatment, first by the action of direct-current low-pressure plasma (DC-LPP) with a 100% oxygen partial pressure, 3.0 × 10−2 mbar pressure, 600 V DC tension, 5.6 cm distance, 6-min treatment. Then, sheets were submitted to TiO2 photocatalysis at UV radiation at 254 nm (TiO2/UV) with a pH value of 4.5 ± 0.2 and a TiO2 concentration of 1 gL−1. We achieved a complementary effect on the transformation of LDPE films. With the first treatment, ablation was generated, which increased hydrophilicity. With the second treatment, the cavities appeared. The changes in the LDPE sheets’ hydrophobicity were measured using the static contact angle (SCA) technique. The photocatalytic degradation curve at 400 h revealed that the DC-LPP photocatalysis sequential process decreased SCA by 82°. This was achieved by the incorporation of polar groups, which increased hydrophilicity, roughness, and rigidity by 12 and 38%, respectively. These sequential processes could be employed for LDPE and other material biodegradation pretreatment.
Highlights
Plasma Discharge on Low-density polyethylene (LDPE) Sheets–Static Contact AngleIn previous work by Gómez-Méndez et al [29], O2 plasma was used for LDPE pretreatment for consecutive biodeterioration with P. ostreatus
Introduction published maps and institutional affilOn an everyday basis, one of the most employed polymers worldwide is low-density polyethylene (LDPE) with industrial, commercial, and domestic uses
100% O2 plasma treatment bands in the 1180 cm−1 and 975 cm−1 range appeared, associated with alcohol and peroxide groups, respectively [45]. These results suggest Low-density polyethylene (LDPE)’s sheet double bond loss and gain of carbonyl and peroxide groups after O2 plasma treatment
Summary
In previous work by Gómez-Méndez et al [29], O2 plasma was used for LDPE pretreatment for consecutive biodeterioration with P. ostreatus. Likewise, theyremained describedat how Pandiyaraj et al [33] refer to LDPE hydrophobic recoveries of 82% after oxygen discharge scribed SCA as close to 80°, even after 60-days post-treatment with oxygen plasma. Hydrophobic recovery can occur through different mechanisms: (a) the reorganization of the polymer’s surface when low and high molecular weight molecules, not modified by the discharge, diffuse from the material’s core to the outer layers [34]; (b) diffusion of low molecular weight oxidized molecules, and (c) reorientation of chemical polar groups towards the core of the polymer [8,12,42]. Static contact angle (SCA) decrease after 6-min treatment with O2 plasma discharge (ablation (B) Hydrophobic recovery in LDPE sheets after being submitted to O2 plasma discharge and stored curve). The control without discharge remained at (86 ± 3)◦
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
