About the deterioration of polyethylene exposed to plasma discharges: A comparison between two models

Buccella, Giacomo; Villa, Andrea; Ceresoli, Davide; Barbieri, Luca; Malgesini, Roberto; Leon-Garzon, Andres R.

doi:10.1016/j.apsusc.2021.150306

Cited by 3 publications

(12 citation statements)

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“…Therefore, let us focus on the mechanism involving the chemisorption of carbon-rich molecules present in the gas. In [10], we also outlined that relatively fast ions (0.1-1.0 eV) can lead to PE surface sputtering, producing a large amount of carbon-rich polymeric fragments which diffuse in the gas phase. In this work we show that, with modest values of electric fields (i.e.…”

Section: Introductionmentioning

confidence: 98%

“…PDs give rise to a plasma inside the defect. Physico-chemical interactions of plasma chemicals with the polymeric surface cause the defect to enlarge [10], forming a cluster of channels and cavities throughout the bulk that compromises the functionality of the material. This process is known as treeing [11][12][13], and the channels are known as treeing branches [14].…”

Section: Introductionmentioning

confidence: 99%

“…In [10], we developed a model of the chemical ageing of a PE surface exposed to air-plasma activity with different values of electric field (E). Our results suggested that H-abstractions are very frequent events.…”

Section: Introductionmentioning

confidence: 99%

“…) is very quickly substituted by an O 2 molecule, forming peroxy radical groups ( ). The model developed in [10] was implemented to match the data obtained from the chemical characterization of corona-treated PE samples, exposed to an oxygen-rich environment [30]. The actual concentrations of plasma species within treeing cavities are not known, but the results described in [10] suggest that the concentration of oxygenated chemicals in the gas is quickly reduced.…”

Section: Introductionmentioning

confidence: 99%

“…The model developed in [10] was implemented to match the data obtained from the chemical characterization of corona-treated PE samples, exposed to an oxygen-rich environment [30]. The actual concentrations of plasma species within treeing cavities are not known, but the results described in [10] suggest that the concentration of oxygenated chemicals in the gas is quickly reduced. In fact, if oxygenated compounds are present, they deposit on the surface during a few discharge events.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

A computational modelling of carbon layer formation on treeing branches

Buccella¹,

Villa²,

Ceresoli³

et al. 2023

Modelling Simul. Mater. Sci. Eng.

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Polymeric insulation employed in electrical power industry undergo irreversible and unpredictable ageing due to partial discharges. In particular, the dielectric properties of polyethylene used in high voltage cables are often compromised by the formation of electrical trees. In this work we assume that the propagation of treeing channels involves the injection of carbonic material into the gas interacting with the surface of the defect. Experimental characterizations proved that, in certain conditions, disordered graphitic carbon can form in some areas of the electrical trees, thus increasing surface conductivity and inhibiting partial discharges. The chemical mechanism involved in this process is yet to be clarified. Here we propose a model for this process. By means of a series of molecular dynamics simulations, we show how the chemisorption of gaseous molecules on a polyethylene surface can lead to a bidimensional carbonic structure. The characterization of the density of states of such systems suggests that the presence of pure carbon adsorbed on the polymer causes an increase in surface conductivity.

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Section: Introductionmentioning

confidence: 98%