Study On Atmospheric Pressure Plasma Jet Discharge And Temperature Sensitive Polymer Materials Polymerization

Atmospheric pressure plasma discharge is usually carried out between parallel plate electrodeswith the short gap, which restricted geometric shape and size for processing materials, and thedischarge stability is also susceptible. The discharge area of atmospheric pressure plasma jet isseparated from the working area and independent of each other. It can treat materials with complexsurfaces and shapes uniformly, while the discharge gas temperature is lower. As a result,atmospheric pressure plasma jet can get a large-scale application in surface modification ofmaterials, thin film deposition and biological medicine, etc.This paper presents a single-electrode dielectric barrier discharge atmospheric pressure argonplasma jet device, and research on different experimental conditions’ effects (voltage, gas flow rate,discharge gap) on the discharge characteristics systematically. The main groups in plasma jet havebeen analyzed by emission spectroscopy. Then selecting three characteristics lines with wavelengthsof696.12nm,706.34nm and714.93nm for line fitting to obtained electronic excitation temperatureby Boltzmann plot method. In addition, the temperature of plasma effluent (plasma jet outside ofthe quartz tube) is observed by using fiber optic temperature sensor.Poly (N-isopropyl acrylamide)(PNIPAm) molecules contains of both hydrophilic amidegroups and isopropyl hydrophobic, so it has a good characteristic of temperature sensing. PNIPAmhas a lower critical solution temperature (LCST) in aqueous solution. When the solution temperatureis lower than LCST, the polymer has a good characteristic of solubility, the solution is transparent;when the temperature rise to higher than LCST, the polymer will be separated from the aqueousphase, and the solution became cloudy. The whole phase transformation process is reversible. Thisunique feature make it has potential applications in drug delivery, physical separation andenvironmental monitoring.The temperature-sensitive characteristic of different concentrations NIPAm monomersolutions were studied for the first time, and the result shows that a high concentration of NIPAmsolution also has a certain temperature sensitive.In this paper, various concentrations of NIPAm monomer is used as reactants, at atmosphericpressure, and working gas (argon) carried with solution was synthesized to a series of differentconcentrations of monomer PNIPAm polymers by means of plasma jet for the first time. Thestructure and properties of the products are characterized by SEM, IR spectroscopy and contactangle. By Fourier transform infrared spectroscopy (FT-IR), we can see C=O stretching vibrationand N-H bending vibration peak’s wave number, indicating that the polymer is PNIPAm.