Modification of stearic acid in Ar and Ar-O2 pulsed DC discharge

Materials Research

Euclides Alexandre Bernardelli²  Thiago Souza²  Márcio Mafra¹  Ana Maria Maliska²  Thierry Belmonte¹  Aloisio Nelmo Klein² 

[1] ,Federal University of Santa CatarinaFlorianópolis SC ,Brazil

关键词: stearic acid;    grafting;    etching;    cleaning by plasma;   

DOI  :  10.1590/S1516-14392011005000068

来源: SciELO

【 摘 要 】

Stearic acid (CH3(CH2)16COOH) was treated with Ar and Ar-O2 (10%) pulsed DC discharges created by a cathode-anode confined system to elucidate the role of oxygen in plasma cleaning. The treatment time (5 to 120 minutes) and plasma gas mixture (Ar and Ar-O2) were varied, and the results showed that the mass variation of stearic acid after Ar-O2 plasma exposure was greater than that of pure Ar plasma treatment. Thus, compared to Ar*, active oxygen species (O and O2, in all states) enhance the etching process, regardless of their concentration. During the treatments, a liquid phase developed at the melting temperature of stearic acid, and differential thermal analyses showed that the formation of a liquid phase was associated with the breakage of bonds due to treatment with an Ar or Ar-O2 plasma. After treatment with Ar and Ar-O2 plasmas, the sample surface was significantly modified, especially when Ar-O2 was utilized. The role of oxygen in the treatment process is to break carbonaceous chains by forming oxidized products and/or to act as a barrier again ramification, which accelerates the etching of stearic acid.

【 授权许可】

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