平行场刷形等离子体羽的放电特性及其聚合物表面改性

Discharge characteristics of a linear-field brush-shaped plasma plume and surface modification of polymer

大气压等离子体射流可以在开放空间产生富含活性粒子的等离子体羽,在材料生长、表面改性、生物医疗等领域具有广泛的应用前景.由于通常等离子体羽的截面尺度很小,造成等离子体射流应用时效率较低,因此,急需产生大尺度的等离子体羽.目前报道的大尺度的等离子体羽多是交叉场等离子体羽,相比于平行场等离子体羽而言其化学活性较低.针对于此,本文利用双电极结构的平行场氩气射流,通过交流激励产生了大尺度的刷形等离子体羽.利用电学、光学和光谱学手段对刷形等离子体羽的放电特性进行了表征.在此基础上,利用该平行场刷形等离子体羽对聚合物(聚对苯二甲酸乙二醇酯(PET))进行了改性研究.通过研究PET表面的水接触角(WCA)、拉曼光谱、X线光电子能谱(XPS)和原子力显微镜(AFM)照片,发现刷形等离子体羽能实现PET表面的大尺度均匀改性.改性后的PET表面含氧极性官能团数量显著增加,并且PET表面的粗糙度增加,因此亲水性得到改善,此种亲水性改良对不同的聚合物具有普适性.这些研究结果对于大尺度等离子体射流的深入研究及等离子体表面改性的应用均具有一定参考价值.

Atmospheric pressure plasma jets have the ability to generate a plasma plume with a large number of active species in open space,and have been extensively used for material growth,surface modification,biomedicine and et al.However,the small cross section size of plasma plume have limited the efficiency for plasma jet application.Therefore,it is needed to develop a plasma plume with large-scale.At present,the large-scale plasma plumes reported are mostly cross-field plasma jets,which are less chemically active than the linear-field plasma jets.Excited by an alternate-current voltage,an argon linear-field jet with two electrodes has been developed to generate a large-scale brush-shaped plasma plume.The discharge characteristics of brush-shaped plasma plume are characterized by electrical,optical and spectral methods.Besides,the linear-field brush-shaped plasma plume is used to modify surface of a polymer(polyethylene terephthalate(PET)).By studying the water contact angle(WCA),Raman spectrum,X-ray photoelectron spectrum(XPS)and atomic force microscopy(AFM)image of PET surface,it is found that the brush-shaped plasma plume can achieve large-scale uniform modification.After plasma modification,the amount of oxygen-containing groups on the surface of PET significantly increases,and the roughness of PET surface also increases.Hence,the hydrophilicity of plasma treated PET surface has been improved.This hydrophilic modification is universal to different polymers.These results are of great significance for the development of large-scale plasma jet and the application of plasma modification.