Platinum pt foil

Argon microplasma was used here as a physical cross-linking tool for the gel-GO composite modification to form hydrogels. The anode is a platinum (Pt) foil (99.95%; Alfa Aesar, Ward Hill, MA, USA), which was immersed into the gel-GO solutions. The cathode is a stainless-steel capillary tube (with an inner diameter of 178 µm), which is also the gas inlet to create direct-current microplasma. Optimization of the argon microplasma process and gelatin and GO concentrations were the key factors in the entire process of gel-GO hydrogel fabrication along with various parameters including current, voltage, gas flow rate, conductivity, time of treatment, etc., were thoroughly investigated periodically to obtain the desired scaffold. The current and voltage are interdependent and affect the ionization of the plasma gas as well as free radical production (Bunshah & Deshpandey, 1985 (link)). It is important to maintain a steady current and voltage for uniform glow plasma discharge. Further, due to the conductive nature of gel-GO solutions, we used a resistor (300 W, 150 KΩ) and copper mesh as a barrier (to avoid surface burning) to stabilize the treatment process for the optimized microplasma conditions (2,500 V, 8.7 mA, 15 min, and a gas flow rate of 100 standard cm³/min). After plasma treatment, the resulting material gel-GO nanocomposite hydrogel was formed.