Laser-textured surfaces enabling reversible wettability switching and improved optical properties are gaining importance in cutting-edge applications, including self-cleaning interfaces, tunable optical lenses, microfluidics, and lab-on-chip systems. Fabrication of such surfaces by combining nanosecond-laser texturing and low-temperature annealing of titanium Ti-6Al-4V alloy was demonstrated by Lian et al. in ACS Appl. Mater. Inter. 2020, 12 (5), 6573–6580. However, it is difficult to agree with (i) their contradictory explanation of the wettability transition due to low-temperature annealing and (ii) their theoretical description of the optical behavior of the laser-textured titanium surface. This comment provides an alternative view—supported by both experimental results and theoretical investigation—on how the results by Lian et al. could be interpreted more correctly. The annealing experiments clarify that controlled contamination is crucial in obtaining consistent surface wettability alterations after low-temperature annealing. Annealing of laser-textured titanium at 100 °C in contaminated and contaminant-free furnaces leads to completely different wettability transitions. Analysis of the surface chemistry by XPS and ToF-SIMS reveals that (usually overlooked) contamination with hydrophobic polydimethylsiloxane (PDMS) may arise from the silicone components of the furnace. In this case, a homogeneous thin PDMS film over the entire surface results in water repellency (contact angle of 161° and roll-off angle of 15°). In contrast, annealing under the same conditions but in a contaminant-free furnace preserves the initial superhydrophilicity, whereas the annealing at 350 °C turns the hydrophobicity “off”. The theoretical calculations of optical properties demonstrate that the laser-induced oxide layer formed during the laser texturing significantly influences the surface optical behavior. Consequently, the interference of light reflected by the air–oxide and the oxide–metal interfaces should not be neglected and enables several advanced approaches to exploit such optical properties.

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评论“在水下超疏油性/超好氧性与亲油性/好氧性之间的生物启发可逆转换以及在纳秒级激光烧蚀的超疏水钛表面上改善的抗反射性能”

激光纹理表面能够实现可逆的润湿性切换并改善光学性能，在包括自清洁界面，可调光学透镜，微流体和芯片实验室系统在内的尖端应用中变得越来越重要。Lian等人证明了通过结合纳秒激光纹理化和Ti-6Al-4V钛合金的低温退火来制造此类表面。在ACS应用中 母校 国米。2020，12（5），6573-6580。但是，很难同意（i）由于低温退火而引起的对润湿性转变的矛盾解释，以及（ii）他们对激光纹理化钛表面光学行为的理论描述。这一评论提供了另一种观点，即Lian等人的结果如何得到实验结果和理论研究的支持。可以更正确地解释。退火实验表明，受控污染物对于低温退火后获得一致的表面润湿性变化至关重要。激光织构的钛在100°C下经污染且无污染的退火熔炉导致完全不同的润湿性转变。通过XPS和ToF-SIMS对表面化学成分的分析表明，（通常被忽略）疏水聚二甲基硅氧烷（PDMS）的污染可能是由熔炉的有机硅成分引起的。在这种情况下，整个表面上均匀的PDMS薄膜会产生疏水性（接触角为161°，滚落角为15°）。相反，在相同条件下但在无污染的炉中进行退火可保留初始的超亲水性，而在350°C下进行的退火可消除疏水性。光学特性的理论计算表明，在激光纹理化过程中形成的激光感应氧化层会显着影响表面光学行为。所以，