## 2 Experimental Section
### Power Supply Unit  
The high voltage power supply for the DBD reactor consisted of a function generator (TG 2000 20 MHz DDS, Aim-TTi, Huntingdon, UK), a DC power supply (GPR-11H30D, GW Instek, New Taipei City, Taiwan), an amplifier, and a transformer (AD6170, Amethyst-designs, Cambridge, UK). The maximum settings of the DC power supply are 110 V and 3 A. The amplifier processes the signals from the function generator and the DC power supply and gives an AC signal to the transformer, which transforms the low voltage signal to a high voltage sinusoidal signal, which is then applied to the electrode configuration. A current probe (Pearson current monitor model 4100, Pearson Electronics, Palo Alto, CA, USA) and a voltage probe (PVM-6, 1000:1, North Star High Voltage, Bainbridge Island, WA, USA) were used to measure the applied voltage and the discharge current on the high voltage side of the electrical circuit via an oscilloscope (Tektronix DPO 3014, Beaverton, OR, USA). The plasma is ignited by a high electrical field, where the field strength is defined as voltage divided by electrode separation. After ignition, the output is regulated on current, with the voltage floating up to the level required to deliver the desired current. To be able to calculate the discharge power, a measurement capacitor (TDK Corporation, Tokyo, Japan) with a capacitance of 560 pF is connected in series to the electrode configuration. The voltage drop can be measured across the capacitor with a voltage probe (GE-3121, 100:1, Editest, St Etienne, France). The complete experimental setup, excluding the reel-to-reel web transport mechanism, is shown in Figure 4.  
The discharge power, \(P_{d}\), was calculated using the following equation from the voltage applied to the gas gap, \(V_{gap}\), and the plasma current, \(I_{plasma}\), according to [26]:  
\[P_{d}=\frac{1}{T}\int\limits_{0}^{T}V_{gap}(t)\cdot I_{plasma}(t)dt \tag{1}\]  
The voltage applied to the gas gap, \(V_{gap}\), derives from the subtraction of the voltage drop across the dielectric layer, \(V_{die}\), and of the voltage drop across the measurement capacitor, \(V_{d}\), from the voltage applied to the electrode configuration, \(V_{a}\), as shown by Equation (2):  
Figure 4: Experimental setup of the laboratory scale DBD system with sawtooth electrode configuration.  
\[V_{gap}(t)=V_{a}(t)-V_{die}(t)-V_{d}(t) \tag{2}\]  
The voltage drop across the measurement capacitor, \(V_{d}\), and the voltage applied to the electrode configuration, \(V_{a}\), are directly measured. This is not possible for the voltage drop across the dielectric layer, which needs to be calculated. [PERSON], et al. [27] states that the voltage drop across the dielectric layer is proportional to the voltage drop across the measurement capacitor and can, thus, be calculated by the following equation:  
\[V_{die}(t)=\frac{c_{meas}}{c_{d}}\cdot V_{d}(t) \tag{3}\]  
The capacitance of the measurement capacitor, \(C_{meas}\), is known. The capacitance of the dielectric layer, \(C_{d}\), was estimated manually from [PERSON] figures [5; 28] presented elsewhere [29], which show the charge transferred during the discharge as a function of the applied voltage of the high voltage circuit.