The surface properties of bio-fibres change by surface plasma treatment without changing their internal properties. In this study, radio-frequency plasma was used to treat the surface of date palm leaves. Plasma treatment was conducted for different times (1, 5, and 8 min) and at different powers (80, 100, and 120 W), keeping the gas pressure fixed at 0.95 torr. Water-drop contact angles, scanning electron-microscope images, surface free-energy measurements, and X-ray diffraction spectra were recorded for the surfaces of the leaves after plasma treatment. Contact-angle values were found to decrease and the surface energy in decrease. The observed changes in surface properties are attributable to a combination of the increase in polar chemical functional groups.

Electron micrographs show improvement in the sample surface morphology after plasma treatment. The study showed that the surface modification of fibres by plasma could improve interfacial adhesion between the DPF and an epoxy matrix.

生物纤维的表面性质通过表面等离子体处理而改变，而不改变其内部性质。在这项研究中，射频等离子体被用于处理枣椰子叶的表面。在不同的时间（1、5、8分钟）和不同的功率（80、100和120 W）下进行等离子体处理，将气压固定在0.95托。等离子体处理后，记录了叶子表面的水滴接触角，扫描电子显微镜图像，表面自由能测量值和X射线衍射光谱。发现接触角值减小并且表面能减小。观察到的表面性质的变化归因于极性化学官能团增加的组合。

电子显微照片显示等离子处理后样品表面形态得到改善。研究表明，通过等离子体对纤维进行表面改性可以改善DPF与环氧基质之间的界面粘合力。