Study On Preparation And Performance Of Extremely Wettable Surface By Argon Cold Plasma

Atmospheric pressure cold plasma jet is a new kind of discharge technology.Compared with the traditional parallel plate discharge,atmospheric pressure cold plasma jet is not limited by the material and size,and has great application value in material processing,polishing and etching,aerospace,biomedical and other fields.Therefore,the study of atmospheric pressure cold plasma jet has great significance and practical value.In this paper,the needle electrode is taken as the positive electrode and the ring electric level as the negative electrode,and a single plasma jet device with needle and ring structure is set up.The single plasma jet device is taken as a unit and extended outward into a large area plasma jet device with array structure.The jet characteristics of a large area and a fine plasma were studied by a micro plasma jet device with a single needle electrode structure.The superhydrophobic wettability surface was prepared by large area plasma system and the superhydrophobic wettability surface was modified by micro plasma.The wettability surface with both superhydrophilic and superhydrophobic regions was prepared to realize the directional transport of liquid.The main research contents of this paper are as follows:Analysis of characteristics of large area cold plasma jet.A 19-tube annular array,9-tube rectangular array and 7-tube annular array plasma jet device were built.The effects of gas flow rate,voltage and ring level distance on plasma jet characteristics are analyzed.It is found that when the gas flow and voltage of the three devices increase,the jet length increases first and then decreases,and the temperature increases first and then decreases.When the voltage is too high,backflow occurs and the temperature drops.With the increase of the distance between the rings,the jet length of the 19 tube and 7 tube device shows a trend of slow increase,the jet length of the 9 tube device fluctuates sharply,and the temperature of the three devices increases first and then decreases.Preparation and wettability analysis of superhydrophobic surface.The superhydrophobic surface was prepared by a 7-tube array device.The experimental methods were divided into two kinds: vertical method and parallel method.The experimental results show that when the voltage,argon gas flow and monomer flow increase,the contact Angle increases first and then decreases in the two schemes.When the processing time and frequency increase,the contact Angle in Scheme 1decreases first and then increases.In scheme 2,the contact Angle increases first and then decreases.When the treatment distance increases,the contact Angle in Scheme 1increases first and then decreases.In the wettability trend analysis of the superphobic surface prepared in scheme 1,the results show that the contact Angle between the edge and the junction is smaller,while the contact Angle between the vertex,center and the region is larger.The superhydrophobic surface was used to verify its self-cleaning performance and anti-staining function.Characteristics of micro cold plasma jet and area analysis of superhydrophilic modification.Micro plasma jet devices with diameters of 100 ?m and 400 ?m were constructed by using single needle electrode structure.The effects of gas flow rate and voltage on the characteristics of micro-plasma jet are analyzed.The experimental results show that the jet length of the two devices increases first and then decreases with the increase of gas flow rate and voltage.When the flow rate changes,the temperature rises first and then decreases;when the voltage increases,the temperature continues to rise.When the superhydrophobic surface is modified with 100 ?m tube,the experimental results show that the increase of the treatment distance will reduce the superhydrophobic modified area.With the increase of voltage,treatment time,frequency and flow rate,the area of superhydrophilic modification will increase.Finally,the optimized process parameters were used to prepare the extremely wettable surface with both superhydrophobic and superhydrophilic regions,and the directional transport of the liquid was realized.