Precise energy and temperature measurements in dielectric barrier discharges at atmospheric pressure

Gagnon

Plasma Processes & Polymers

et al. 2015

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106

A large reactor for performing dielectric barrier discharges (DBD) experiments at atmospheric pressure (AP) has been built and tested. The area of electrodes is more than 40 times greater than that of a small DBD cell, in which we have perfected a method formeasuring E g , the energy dissipated per cycle of the applied a.c. high voltage, V a (f). This methodology has been successfully applied to plasma polymerization experiments on the larger system, using volatile organic precursors (dopants) at ‰ concentrations in 10 standard liters per minute of argon (Ar). We measured DE g , the energy difference with and without dopant, for V a (f) $ 3 kV rms (20 f 40 kHz). From DE g we then derived E tot /N, the energy per molecule, and observed surprisingly good agreement with data published in the literature relating to lowpressure (LP) plasmas.

Section: Introductionmentioning

confidence: 73%

Energy of Reactions in Atmospheric‐Pressure Plasma Polymerization with Inert Carrier Gas

Gagnon

Plasma Processes & Polymers

et al. 2015

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106

“…Without repeating details, measurements of (a) the absorbed energy difference, Δ E g , and (b) the energy per molecule, E m (in eV/molecule) that obviously play key roles, were carried out. This was possible by using the equivalent circuit model and the MATLAB ® program for computing E g , energy dissipated in the AP plasma during each applied HV cycle …”

Section: Methodsmentioning

confidence: 99%

Energetics of Reactions in a Dielectric Barrier Discharge with Argon Carrier Gas: III Esters

Watson

et al. 2016

Plasma Process. Polym.

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A large research reactor for dielectric barrier discharge (DBD) experiments at atmospheric pressure (AP) has been used with argon (Ar) carrier gas under constant plasma conditions (f = 20 kHz, Va(f) = 8 kVp‐p = 2.8 kVrms). Five esters, acrylates with differing number of unsaturations were used as “monomers”; monomer flows, Fd, were at ‰ concentrations in the F = 10 standard liters per minute (slm) of argon. We earlier perfected and reported a method for measuring Eg, the energy dissipated per cycle of the applied a.c. voltage, and ΔEg, the energy difference with and without monomer in the Ar flow. The latter, combined with Fd enable calculation of Em, the average energy absorbed from the plasma per monomer molecule. Plots of Em versus Fd and 1/Fd yield much valuable information, for example about the role of CC and CC bonds in fragmentation and polymerization reactions. Fourier‐transform infrared (FTIR) spectroscopy, spectroscopic ellipsometry (SE), and scanning electron microscopy (FEG‐SEM) further enhance and complement data interpretation.

“…Without repeating details, measurements of (a) the absorbed energy difference, Δ E g , and (b) the energy per molecule, E m (in eV/molecule) that obviously plays a key role, were carried out. This was possible by using the equivalent circuit model and the MATLAB® program for computing E g , energy dissipated in the AP plasma during each applied HV cycle …”

Section: Experimental Partmentioning

confidence: 99%

Energetics of reactions in a dielectric barrier discharge with argon carrier gas: IV ethyl lactate

Watson

Plasma Processes & Polymers

et al. 2016

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We report dielectric barrier discharge (DBD)‐based atmospheric pressure (AP) plasma enhanced chemical vapor deposition (PECVD) experiments using argon carrier gas and ethyl lactate (EL) as the precursor molecule (“monomer”). As in our preceding research with other monomers, unprecedented precision and reproducibility is again demonstrated, here to create plasma polymerized (PP‐EL) deposits. PP‐EL is thought to be an excellent candidate for bio‐medical applications on account of the non‐toxic nature of resulting PP‐EL deposits. We have shown that a narrow range of energy values absorbed from the plasma, Em, between roughly 21 and 42 eV/molecule, lead to PP‐EL coatings of widely varying structural and physical properties, ones with controlled retention of chemical features of the EL monomer, and a predictable rate of degradation in aqueous media.