Study On Low Temperature Plasma Vapor Treatment Of Thermo-Sensitive Macromolecule

Dielectric bamer discharge (DBD) is an effective way of producing homogeneous plasma. Plasma, a quasi-neutral gas, is referred to as the forth state of matter. Plasma surface treatment consists of plasma surface modification, plasma polymerization and plasma surface grafting. It is very applicable to modern continuous mass production of industry, and has a very broad prospect. Dielectric barrier discharge consists of infinite micro-discharges which distribute irregularly the whole discharge space both in time and in space. Homogeneous dielectric barrier discharge looks like the glow discharge in vacuum and is very necessary to the surface modification of some special materials. And it has become one focus of physics.The paper explains the mechanism of dielectric barrier discharge and favorable conditions for homogenous DBD discharge. The relationship between electrode gap and discharge power has been given. The self-made equipment of atmospheric pressure plasma vapor deposition of poly (N-isopropylacrylamide)(PNIPAAm) was used in the environment of argon and the suitable discharge gap was set to4mm.Firstly, using the self-made equipment modify the surface of glass slide and PS petri dish. The results indicated that the morphology of the discharge is uniform. Both the waveform of the applied voltage and the discharge current are sinusoidal. PNIPAAm is a new type of smart thermo-sensitive macromolecule material that is characterized by a sudden precipitation on heating, switching from a hydrophilic to a hydrophobic state. The samples were characterized by scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS) and water contact angle. It was revealed from the results of SEM analysis that the poly PNIPAAm coatings were formed on the surface of the smooth glass slides, according to XPS, it was found that there exists PNIPAAm and the wettability was significantly modified by changing the temperature above and below the lower critical solution temperature (LCST) from the data of the water contact angle test.The PNIPAAm was enhanced hydrophilcity using crosslink solution2-methyl-2-propenoic acid2-(2-methoxyethoxy) ethyl ester (MEO2MA). The chemical structure of the modified membrane was characterized by FTIR, water contact angle and SEM, the results showed at the temperature of35℃that the membrane has a well property.In this paper, PNIPAAm and MEO2MA-NIPAAm were deposited to Polybutylene Terephthalate (PBT) melt-blown nonwovens and Polyester (PET) fabrics separately. It was found that the wettability and water permeability were significantly modified by changing the temperature above and below the lower critical solution temperature (LCST), according to the data derived from measurements of water contact angle, water permeability time and scanning electron microscopy (SEM) images. Considering human body temperature is close to the LCST, this application to PBT melt-blown nonwovens is quiet valuable.