Comparison of low and atmospheric pressure air plasma treatment of polyethylene

Abstract

Surface activation of polyethylene (PE) samples has been carried out using low pressure plasmas (at two different operating frequencies, namely, 40 kHz and 13?56 MHz) and dielectric barrier discharge (DBD) (50 Hz frequency and at atmospheric pressure), and the results are compared. The surface of the PE samples has been exposed to these different plasmas for various time durations ranging from 1 to 30 min. The treated samples have also been studied for their aging behaviour by exposing them to the ambient atmosphere for up to 7 days. The plasma induced morphological changes were studied using an scanning electron microscope and an atomic force microscope, while the formation of various functional groups was identified using Fourier transform infrared analysis. The surface energy values were observed to increase from 27?5 dyne cm 21 (of untreated PE) to 73?8 and 52?2 dyne cm 21 after low pressure 40 kHz and 13?56 MHz air plasma treatment respectively and to 35?6 dyne cm 21 after the DBD air plasma treatment. The low pressure plasma treatment at an operating frequency of 40 kHz has produced the best results in the surface activation of PE. During the aging process, the formation of C5C bonds was observed on the surface of PE.

Biodeterioration of plasma pretreated LDPE sheets by Pleurotus ostreatus

“…Similar results were observed by Švorčík et al (2007), who described after argon plasma exposure an increase in 3.02 nm LDPE sheet roughness [ 13 ]. Likewise, Kikani et al (2013) observed an increase in roughness values after submitting PE sheets to air plasma discharge, at low and high atmospheric pressures [ 34 ].…”

“…ostreatus treatment. This rise is attributed to polar group formation, such as carbonyl (C = O), carboxyl (C = O-OH), and hydroxyl (-OH) [ 34 ], responsible for SCA decrease due to changes in superficial hydrophobicity [ 41 , 42 ]. After five-month biodeterioration curve (150 days), LDPE sheet CA for PBBT 150 sequential treatment was 17 ± 4 ° (p < 0.0001).…”

“…To define LDPE hydrophobicity changes static contact angle (SCA) variation at room temperature (RT 14° C) was measured [ 80 , 84 ], between a drop (50 μL) of distilled water and LDPE surface by means of sessile drop method and recording with a videocamara (JVC ™ GZ-EX355 Everio). To this end 50 μL deonized water was placed on top of the sheets and photographs were captured at three points of the sample [ 34 ]. Contact angle was calculated according to Eqs 2 and 3 (mean ± SD) [ 86 ].…”

“…Fourier transformation infrared spectroscopy was used to evaluate LDPE chemical bond modifications and chemical group composition [ 34 , 73 ]. AShimadzu IR Prestige-21 spectrophotometer was employed with the following parameters: Measurement Mode: % transmittance, Apodization: Happ-Genzel, No.…”

Plasma Surface Polymerized and Biomarker Conjugated Boron Nitride Nanoparticles for Cancer-Specific Therapy: Experimental and Theoretical Study

“…Both LP and AP plasmas were used to activate the polyethylene surfaces [20]. The influence of plasma process parameters, such as operating frequencies (40 kHz and 13.56 MHz at LP) and dielectric barrier discharge (50 Hz at AP), on the polymer surface activation were compared.…”