Low-density polyethylene films treated by an atmospheric Ar-O2 post-discharge

Functionalization, etching, degradation and partial recovery of the native wettability state

S. Abou Rich, T. Dufour, P. Leroy, L. Nittler, J. J. Pireaux, F. Reniers

Résultats de recherche: Contribution à un journal/une revueArticle

Résumé

To optimize the adhesion of layers presenting strong barrier properties on low-density polyethylene (LDPE) surfaces, we investigated the influence of argon and argon-oxygen atmospheric pressure post-discharges. This study was performed using x-ray photoelectron spectroscopy, atomic force microscopy, optical emission spectroscopy (OES) and dynamic water contact angle (WCA) measurements. After the plasma treatment, a slight increase in the roughness was emphasized, more particularly for the samples treated in a post-discharge supplied in oxygen. Measurements of the surface roughness and of the oxygen surface concentration suggested the competition of two processes playing a role on the surface hydrophilicity and occurring during the post-discharge treatment: the etching and the activation of the surface. The etching rate was estimated to about 2.7 nm s-1 and 5.8 nm s-1 for Ar and Ar-O2 post-discharges, respectively. The mechanisms underlying this etching were investigated through experiments, in which we discuss the influence of the O2 flow rate and the distance (gap) separating the plasma torch from the LDPE surface located downstream. O atoms and NO molecules (emitting in the UV range) detected by OES seem to be good candidates to explain the etching process. An ageing study is also presented to evidence the stability of the treated surfaces over 60 days. After 60 days of storage, we showed that whatever the O2 flow rate, the treated films registered a loss of their hydrophilic state since their WCA increased towards a common threshold of 80°. This 'hydrophobic recovery' effect was mostly attributed to the reorientation of induced polar chemical groups into the bulk of the material. Indeed, the relative concentrations of the carbonyl and carboxyl groups at the surface decreased with the storage time and seemed to reach a plateau after 30 days.

langue originaleAnglais
Numéro d'article065203
journalJournal of Physics D: Applied Physics
Volume47
Numéro de publication6
Les DOIs
étatPublié - 12 févr. 2014

Empreinte digitale

Low density polyethylenes
Polyethylene
wettability
Wetting
polyethylenes
Etching
recovery
etching
degradation
Recovery
Degradation
Optical emission spectroscopy
Argon
optical emission spectroscopy
Oxygen
Contact angle
oxygen
flow velocity
Surface roughness
Flow rate

Citer ceci

@article{cdcd778c58664573b1147df7560ae419,
title = "Low-density polyethylene films treated by an atmospheric Ar-O2 post-discharge: Functionalization, etching, degradation and partial recovery of the native wettability state",
abstract = "To optimize the adhesion of layers presenting strong barrier properties on low-density polyethylene (LDPE) surfaces, we investigated the influence of argon and argon-oxygen atmospheric pressure post-discharges. This study was performed using x-ray photoelectron spectroscopy, atomic force microscopy, optical emission spectroscopy (OES) and dynamic water contact angle (WCA) measurements. After the plasma treatment, a slight increase in the roughness was emphasized, more particularly for the samples treated in a post-discharge supplied in oxygen. Measurements of the surface roughness and of the oxygen surface concentration suggested the competition of two processes playing a role on the surface hydrophilicity and occurring during the post-discharge treatment: the etching and the activation of the surface. The etching rate was estimated to about 2.7 nm s-1 and 5.8 nm s-1 for Ar and Ar-O2 post-discharges, respectively. The mechanisms underlying this etching were investigated through experiments, in which we discuss the influence of the O2 flow rate and the distance (gap) separating the plasma torch from the LDPE surface located downstream. O atoms and NO molecules (emitting in the UV range) detected by OES seem to be good candidates to explain the etching process. An ageing study is also presented to evidence the stability of the treated surfaces over 60 days. After 60 days of storage, we showed that whatever the O2 flow rate, the treated films registered a loss of their hydrophilic state since their WCA increased towards a common threshold of 80°. This 'hydrophobic recovery' effect was mostly attributed to the reorientation of induced polar chemical groups into the bulk of the material. Indeed, the relative concentrations of the carbonyl and carboxyl groups at the surface decreased with the storage time and seemed to reach a plateau after 30 days.",
keywords = "ageing, etching rate, LDPE, low molecular weight oxidized material, plasma post-discharge treatment",
author = "Rich, {S. Abou} and T. Dufour and P. Leroy and L. Nittler and Pireaux, {J. J.} and F. Reniers",
year = "2014",
month = "2",
day = "12",
doi = "10.1088/0022-3727/47/6/065203",
language = "English",
volume = "47",
journal = "Journal of Physics D: Applied Physics",
issn = "0022-3727",
publisher = "IOP Publishing Ltd.",
number = "6",

}

TY - JOUR

T1 - Low-density polyethylene films treated by an atmospheric Ar-O2 post-discharge

T2 - Functionalization, etching, degradation and partial recovery of the native wettability state

AU - Rich, S. Abou

AU - Dufour, T.

AU - Leroy, P.

AU - Nittler, L.

AU - Pireaux, J. J.

AU - Reniers, F.

PY - 2014/2/12

Y1 - 2014/2/12

N2 - To optimize the adhesion of layers presenting strong barrier properties on low-density polyethylene (LDPE) surfaces, we investigated the influence of argon and argon-oxygen atmospheric pressure post-discharges. This study was performed using x-ray photoelectron spectroscopy, atomic force microscopy, optical emission spectroscopy (OES) and dynamic water contact angle (WCA) measurements. After the plasma treatment, a slight increase in the roughness was emphasized, more particularly for the samples treated in a post-discharge supplied in oxygen. Measurements of the surface roughness and of the oxygen surface concentration suggested the competition of two processes playing a role on the surface hydrophilicity and occurring during the post-discharge treatment: the etching and the activation of the surface. The etching rate was estimated to about 2.7 nm s-1 and 5.8 nm s-1 for Ar and Ar-O2 post-discharges, respectively. The mechanisms underlying this etching were investigated through experiments, in which we discuss the influence of the O2 flow rate and the distance (gap) separating the plasma torch from the LDPE surface located downstream. O atoms and NO molecules (emitting in the UV range) detected by OES seem to be good candidates to explain the etching process. An ageing study is also presented to evidence the stability of the treated surfaces over 60 days. After 60 days of storage, we showed that whatever the O2 flow rate, the treated films registered a loss of their hydrophilic state since their WCA increased towards a common threshold of 80°. This 'hydrophobic recovery' effect was mostly attributed to the reorientation of induced polar chemical groups into the bulk of the material. Indeed, the relative concentrations of the carbonyl and carboxyl groups at the surface decreased with the storage time and seemed to reach a plateau after 30 days.

AB - To optimize the adhesion of layers presenting strong barrier properties on low-density polyethylene (LDPE) surfaces, we investigated the influence of argon and argon-oxygen atmospheric pressure post-discharges. This study was performed using x-ray photoelectron spectroscopy, atomic force microscopy, optical emission spectroscopy (OES) and dynamic water contact angle (WCA) measurements. After the plasma treatment, a slight increase in the roughness was emphasized, more particularly for the samples treated in a post-discharge supplied in oxygen. Measurements of the surface roughness and of the oxygen surface concentration suggested the competition of two processes playing a role on the surface hydrophilicity and occurring during the post-discharge treatment: the etching and the activation of the surface. The etching rate was estimated to about 2.7 nm s-1 and 5.8 nm s-1 for Ar and Ar-O2 post-discharges, respectively. The mechanisms underlying this etching were investigated through experiments, in which we discuss the influence of the O2 flow rate and the distance (gap) separating the plasma torch from the LDPE surface located downstream. O atoms and NO molecules (emitting in the UV range) detected by OES seem to be good candidates to explain the etching process. An ageing study is also presented to evidence the stability of the treated surfaces over 60 days. After 60 days of storage, we showed that whatever the O2 flow rate, the treated films registered a loss of their hydrophilic state since their WCA increased towards a common threshold of 80°. This 'hydrophobic recovery' effect was mostly attributed to the reorientation of induced polar chemical groups into the bulk of the material. Indeed, the relative concentrations of the carbonyl and carboxyl groups at the surface decreased with the storage time and seemed to reach a plateau after 30 days.

KW - ageing

KW - etching rate

KW - LDPE

KW - low molecular weight oxidized material

KW - plasma post-discharge treatment

UR - http://www.scopus.com/inward/record.url?scp=84893201057&partnerID=8YFLogxK

U2 - 10.1088/0022-3727/47/6/065203

DO - 10.1088/0022-3727/47/6/065203

M3 - Article

VL - 47

JO - Journal of Physics D: Applied Physics

JF - Journal of Physics D: Applied Physics

SN - 0022-3727

IS - 6

M1 - 065203

ER -