Morphological and Chemical Effects of Plasma Treatment with Oxygen (O2) and Sulfur Hexafluoride (SF6) on Cellulose Surface

Cellulose is a polymer widely available in nature, however its applications may be restrict due to its hydrophilic character. The creation of hierarchical structures on the surface is one of the required factors to obtain the hydrophobicity of this material. In order to compare the morphological and chemical effects caused by the action of different gases in the creation of nanostructures on the cellulose surface, samples were exposed to oxygen (O2) and sulfur hexafluoride (SF6) plasma treatments. The changes in morphology after treatment prove that both the gases were able to create similar nanostructures in the material. The analysis of elemental composition and identification of functional groups on the sample surface showed that chemical modifications occurred differently for each treatment. Contact angle measurements revealed that samples treated by O2 plasma remained hydrophilic, whereas low receptivity to polar (θ > 120º) and non-polar (θ > 100º) liquids was observed for samples exposed to SF6 plasma.纤维素（Cellulose）是自然界中广泛存在的聚合物，但其亲水特性会限制其应用范围。在材料表面构建多级结构，是赋予该材料疏水性的必要条件之一。为对比不同气体在纤维素表面制备纳米结构过程中所产生的形貌与化学效应，研究人员将样品分别暴露于氧气（O₂）与六氟化硫（SF₆）等离子体处理环境中。处理后的形貌变化分析证实，两种气体均可在材料表面制备出形貌相似的纳米结构。对样品表面的元素组成进行分析并鉴定官能团后发现，两种处理方式引发的化学改性存在显著差异。接触角测量结果显示，经氧气等离子体处理的样品仍保持亲水特性；而经六氟化硫等离子体处理的样品对极性（接触角θ>120°）与非极性液体（接触角θ>100°）均表现出较低的润湿性。