Growth and treatment of hydrogenated amorphous carbon nanoparticles in a low‐pressure plasma. Issue 4 (21st January 2022)

• Record Type: Journal Article
• Authors: Asnaz, Oguz Han; Kohlmann, Niklas; Folger, Hauke; Greiner, Franko; Benedikt, Jan
• Is Part Of: Plasma processes and polymers. Volume 19:Issue 4(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-01-21
• Subjects: FTIR -- infrared absorption spectroscopy (IRAS) -- low‐pressure discharges -- particles -- surface modification; Plasma polymerization -- Periodicals; Plasma-enhanced chemical vapor deposition -- Periodicals; Plasma chemistry -- Periodicals
• DOI: 10.1002/ppap.202100190
• Languages: English
• ISSNs: 1612-8850

Abstract

Abstract: A parallel‐plate, low‐pressure plasma for fundamental nanodusty plasma research is used to grow hydrogenated amorphous carbon nanoparticles using an argon‐acetylene gas mixture. The particles stay confined in the volume of the argon plasma after turning off the C 2 H 2 gas flow and the effects of prolonged treatment with noble gas (Ar) and reactive gas mixtures (Ar/ H 2, Ar/ D 2, or Ar/ O 2 ) are investigated using in situ infrared absorption spectroscopy. Additionally, ex situ scanning electron microscopy imaging of extracted nanoparticles is used to analyze their size and surface morphology. In 45 min of argon treatment, a size increase of about 50% is seen together with a decrease in sp 2 CH x bonds and an increase in C═O bonds, indicating incorporation of oxygen from gas impurities into the particle material. All reactive gas mixtures lead to the expected etching of the nanoparticle material without any exchange reactions between gas‐phase deuterium and surface‐bonded hydrogen atoms. These results are important for in situ studies of nanoparticle clouds such as dust density wave diagnostics, but they also provide fundamental information about plasma interaction with a‐C:H material. Abstract : A parallel‐plate, low‐pressure plasma is used to generate hydrogenated amorphous carbon nanoparticles. The particles are investigated using in situ infrared absorption spectroscopy as well as ex situ scanning electron microscopy imaging, focusing on prolonged treatment with noble gas (Ar) and reactive gas mixture (Ar/ H 2, Ar/ O 2 ) plasmas. Noble gas treatment shows a size increase from impurities together with a decrease of sp 2 CH x bonds and an increase of C═O bonds. Reactive gas treatment shows etching of the nanoparticle material without any exchange reactions.