| Femtosecond laser has ultra-strong and super-fast characteristics which make it widely used in micro-nano processing field.And the solid/liquid/gas three phase wettability is one of the important branches in surface science.In recent years,the combination of femtosecond laser micromachining and bionic functional surface has attracted people's attention.This dissertation mainly studies the effect of the functional surfaces prepared by femtosecond laser on the control of underwater bubble's wettability and bubble's behaviors.We have succeed in realizing the isotropic and anisotropic sliding of underwater bubbles,as well as the dynamic control of underwater bubble motion,which has important applications in the field of microfluidics and micro-reactions in the future.The full text mainly includes the following three parts:?1?Functional materials with special bubble wettability play an important role in controlling the behavior of underwater bubbles.Inspired by natural Pitcher plants,we prepared and designed a large area lubricated slippery surface?LSS?by femtosecond laser processing.The transportation velocity of the bubbles on the LSS is strongly associated with the surface tension of the lubricants.The lower the surface tension,the higher the sliding velocity.On this basis of it,we prepared LSS tracks to guide the movement of bubbles,achieving bubbles'merging,and realizing the movement of bubbles on three-dimensional LSS.Finally,a gas catcher decorated with large area LSS was manufactured for underwater bubble capture,which maintained a high capture efficiency?more than90%?with an air output of?3.4?8)4)9)-1.This finding reveals a meaningful interaction between the underwater bubbles and the LSS surface,accelerating the applications of bubble slippery surfaces in underwater flammable gas collection.?2?Current researches are mainly concentrated on the isotropic SLIPS,and there are few studies about the behavior of anisotropic bubble sliding.We proposed a periodic microgroove slippery surface?MGSS?,which was fabricated by one-step femtosecond laser scanning.Then the anisotropic sliding of bubbles in liquid phase system was realized by spin-coated with lubricant.The MGSS allows the bubbles to slide along the grooves,but prevents them from sliding along the perpendicular direction to the grooves.The effects of lubricant thickness,laser power,and microgroove period on anisotropy were investigated,and the strongest bubble anisotropy can reach nearly 80°.Finally,the MGSS was successfully used in anisotropic bubble transportation on flat and curved surfaces.We believe that such functional surfaces will be promising candidates for manipulating bubble directional sliding behavior and further underwater gas collection.?3?Dynamically responsive liquid-infused interfacial materials have broad technological implications in manipulating bubble motions.We reported a lubricated elastic groove surface ablated by femtosecond laser,which realized reversible switching between the sliding state and the resting state by one-direction mechanical stretching.The mechanism of reversible conversion mainly contributes to oil film thickness during the stretching process?0 to 60%?.We demonstrated the real-time sliding/static flexible control of an underwater bubble under strain variation.This research has important prospects for future gas phase manipulation and microbiochemical reactions. |
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