engleski

Optical emission spectroscopy of plasma during treatment of polymers

Several widely used polymers (HDPE, LDPE, PMMA, PS and PVC) were treated by low pressure cold plasmas. Each polymer was treated with oxygen plasma (at the pressures of 35 and 70 Pa), hydrogen plasma (pressure of 35 Pa) and argon plasma (pressure of 35 Pa). Inductively coupled RF plasma was created by an 8 turn coil with an EM field oscillating at 13.56 MHz. Discharge powers from 200 to 270 W were used. Main plasma characterization technique is optical emission spectroscopy (OES). For OES measurements CCD spectrometers were used (LIBS2000+ with nominal optical resolution of 0.1 nm in the spectral range from 200 to 980 nm and Ocean Optics USB2000 with a nominal optical resolution of 1 nm in the spectral range from 200 to 980 nm). These spectrometers offer the possibility of real time collection of spectra and the measurements were temporally resolved (during the whole treatment time of 300 to 400 s). Temperature of the polymer samples was continually monitored by an infrared sensor MI from Cole-Palmer with spectral response from 8 to 14 μm and D/S ratio 10:1. All these plasmas lead to the rise in temperature of the polymer samples during treatment and different temperature profiles were observed. Temperature profiles were related to spectroscopic features and their temporal evolution. Namely, during plasma treatment the polymers are intensively etched, leading to formation of various volatile species which are easily detected by OES.

Optical emission spectroscopy; polymers

nije evidentirano