Study On Surface Modification Of Polystyrene Micro Plate By Low Temperature Plasma Treatment

Polystyrene (PS) has been commonly used due to strong rigidity, excellent durability, optical transparency invisible range and non-toxicity. However, the hydrophobicity of the PS surface limits its applied effects on biological medical field. Plasma processing of materials has been developed fast in recent years for its advantages that only affect the chemical and physical properties of the substrate’s outmost layer without altering the bulk properties. In this paper. The surface of the PS micro plate was modified using low-temperature plasma technology by different methods, the changes of the surface properties of the PS micro plate before and after modification were studied with contact angle measurement, X-ray photoelectron spectroscopy (XPS), scanned electron microscopy (SEM), atomic force microscopy (AFM), Fourier Transform infrared-Attenuated Total Reflectance (FTIR-ATR), etc.Setting various process parameters (different irradiation time and power), the surface of the PS micro plate were treated with low temperature air plasma. The studying results show that:the roughness of PS has been increased obviously resulting the advance of the hydrophily after modification, and the best result has been acquired at60s and60w.The maleic anhydride was grafted to the surface of PS by irradiation at the same time using Ar low temperature plasma. The studying results show that:The studying results show that:a large amount of oxygen groups were introduced to the surface of the PS micro plate that lead to the hydrophily of the PS surface has been improved, the properties of the PS surface rebound rapidly at began few days and slowly after7days.The acrylic was grafted to the surface of PS by irradiation at the same time using air low temperature plasma. The studying results show that:a large amount of oxygen groups and carboxyl were introduced to the surface of the PS micro plate that lead to the hydrophily of the PS surface has been improved.We modified the PS surface using amino sulfonic acid by air low temperature plasma though two different methods. The studying results show that:it got excellent effect by the method of irradiation at the same time, the sulfo group and oxygen groups were introduced to the PS surface, the hydrophily was improved leading to the contact angle has been increased, and the aging evolution property was better than the result of directly irradiation by air plasma.