飞秒激光制备固体润湿性能微纳结构表面的研究

发布时间：2018-03-17 00:22

本文选题：飞秒激光　切入点：微纳结构　出处：《长春理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：飞秒激光在金属表面可实现多种微纳结构的直接制备,这些微纳结构可使其表面具备优良的润湿性,实现亲水或疏水功能。基于这些功能特性,使其在航天、建筑、医学以及太阳能等诸多领域具有重要的应用价值。本文分别对飞秒激光制备亲水或疏水微纳结构表面进行了研究。在亲水性研究方面,利用聚焦飞秒激光脉冲在金属表面制备了沟槽形微纳结构。研究发现,在激光离焦位置可实现小于焦点烧蚀沟槽区域的微小沟槽制备(焦点光斑处制备沟槽宽度约为120μm,离焦位置处微小沟槽宽度约为70μm),这一发现对于沟槽形微纳结构的制备及优化具有重要的应用意义。进一步通过聚焦激光的光谱监测结果证实了产生这一现象的原因与飞秒激光聚焦过程中击穿空气产生等离子丝的非线性现象有关。通过对亲水性表征发现,所制备沟槽微纳结构表面接触角典型值约为11°,具备超亲水特性。同时吸入的水可逆重力方向沿沟槽定向流动,运动平均速度最快可达21.6mm/s。水的逆重力输运符合扩散定律,产生这一现象的原因可归结于开放腔毛细管效应。在疏水性研究方面,利用聚焦飞秒激光脉冲在金属镍表面进行低于聚焦光斑尺寸扫描间距的聚焦扫描,经过均匀激光辐照,在其表面制备出了柱形双尺度微纳复合结构。研究发现,钢、钛合金及纯铜为样品所制备的微纳结构表面不会出现文献中报道的在空气中可实现从亲水性向疏水性的自然转变。激光制备微纳结构表面经过硅烷化处理后,可展现出疏水特性,其疏水角可达148.28°。这一发现,对于飞秒激光制备金属润湿性微纳结构表面的基材选择具有应用意义。
[Abstract]:Femtosecond lasers can be directly prepared on metal surfaces with a variety of micro and nano structures that allow their surfaces to have excellent wettability, hydrophilic or hydrophobic functions. Many fields such as medicine and solar energy have important application value. In this paper, the surface of hydrophilic or hydrophobic micro-nano structures prepared by femtosecond laser has been studied respectively. Grooves and nanostructures were fabricated on metal surfaces by focusing femtosecond laser pulses. The fabrication of micro-grooves smaller than that of focal ablation grooves can be realized at the laser defocusing position (the width of the prepared grooves at the focal spot is about 120 渭 m, and the width of the micro-grooves at the defocus positions is about 70 渭 m). The preparation and optimization are of great significance in application. The results of spectral monitoring of focusing laser confirm that the cause of this phenomenon and the nonlinear phenomenon of plasma wire produced by air breakdown in the process of femtosecond laser focusing. Through the characterization of hydrophilicity, The surface contact angle of the grooved micro / nano structure is about 11 掳, which has super hydrophilic property. At the same time, the reversibly gravity direction of the inhaled water flows along the trench directional direction, and the average velocity of movement can be as fast as 21.6 mm / s. The reverse gravity transport of water obeys the law of diffusion. In hydrophobicity research, focused femtosecond laser pulses are used to scan the nickel metal surface with a scanning distance below the size of the focal spot, which is irradiated by a uniform laser, the reason of which can be attributed to the open cavity capillary effect. A columnar double scale micro / nano composite structure was prepared on its surface. The surface of micro-nano structure prepared by titanium alloy and pure copper will not change from hydrophilicity to hydrophobicity in air as reported in the literature. The hydrophobic property can be shown, and the hydrophobic angle is up to 148.28 掳. This discovery is of great significance for the selection of substrate for the fabrication of the surface of metal wettable micro-nano structure by femtosecond laser.
【学位授予单位】：长春理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN249

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