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- 实验方案
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Selfa??Assembled PMMA Porous Membranes Decorated with In Situ Synthesized ZnO Nanoparticles with UVa??Tunable Wettability
摘要： This study reports a simple approach to fabricate porous poly(methyl methacrylate) (PMMA) membranes homogeneously decorated with exposed zinc oxide (ZnO) nanoparticles (NPs). This fabrication method significantly overcomes the disadvantages of both conventional foaming processes and incorporation of inorganic NPs in polymeric matrices. In particular, the porous structure is simply self-assembled by slowly evaporating a suitable solvent. The ZnO NPs are in situ formed by a thermally activated conversion of the zinc acetate precursor, previously embedded in the polymeric matrix. Scanning and transmission electron microscopy investigations show the formation of the desired self-assembled highly porous structure and ZnO NPs with branched morphology, respectively. The wetting behavior of the membranes surface is studied as a function of the ZnO content and UV irradiation, exploiting the switchable wettability of ZnO. The obtained unexpected results are then tentatively rationalized taking into account the surface chemistry and the roughness that arises from both porous structure and the different NPs dimensions and content.
关键词： porous membranes,nanocomposites,tunable wettability,self-assembly,in situ synthesis
更新于2025-09-23 15:21:01
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Influence of laser texturing on the wettability of PTFE
摘要： Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer showing excellent thermal and electrical insulation properties and a low coefficient of friction. Due to its large stability, and hydrophobic nature, the wettability of PTFE surfaces can be reduced to transform them into superhydrophobic. In this regard, laser texturing is a fast, simple and versatile method to produce superhydrophobic PTFE surfaces in one-step, and over large areas. In this work, we used a CO2 laser to modify the surface of PTFE samples. We studied the effect of the processing parameters (laser power or irradiance, scanning speed, and spacing -overlapping- between scan lines) on the wettability of textured surfaces using water, mineral oil and ethanol/water solutions as test fluids. Laser-treated surfaces showed a hierarchical micro- and nanotopography with a cotton-like appearance. The higher roughness and large quantity of air pockets make these laser-treated surfaces superhydrophobic, and highly oleophobic. Furthermore, they remain unaltered after being in contact with strong alkali and acid solutions or after slight friction. The self-cleaning performance of these surfaces was also demonstrated. The present findings suggest that CO2 laser texturing of PTFE is suitable for the large-scale preparation of surfaces with low-wettability to different liquids.
关键词： Polytetrafluoroethylene (PTFE),self-cleaning,wettability,laser texturing
更新于2025-09-23 15:19:57
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Laser induced graphene printing of spatially controlled super-hydrophobic/hydrophilic surfaces
摘要： Spatial control over the wetting properties of graphene surfaces is a desired feature in numerous applications. Traditionally, this is achieved using time consuming chemical treatment processes that lack spatial tuning. Here, we demonstrate the use of laser induced graphene for the direct, spatial printing of surfaces with either superhydrophilic or superhydrophobic character through simple and convenient control over graphene array morphology, and without the need for chemical surface modification. The wetting properties of the graphene surfaces range from superhydrophilic (0°) for sheet-like structures, to superhydrophobic (>150°) for micro-pillar and hemispherical structures. By varying the induction parameters of the CO2 laser, we demonstrate the ability to write patterns with spatially tailored wettability to enable liquid micro-patterning and channeling of flow. Furthermore, we study solid-liquid interactions for such surfaces using viscosity measurements, where a “petal effect” is observed in the graphene material, thus revealing the parahydrophobicity of the surface.
关键词： Superhydrophobic,Superhydrophilic,Petal effect,Laser induced graphene,Wettability
更新于2025-09-23 15:19:57
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Facile fabrication of multi-scale microgroove textures on Ti-based surface by coupling the re-solidification bulges derived from nanosecond laser irradiation
摘要： A facile method is proposed to fabricate multi-scale microgroove textures (MGT) on Ti-based implant material. The effect of some primary parameters on the morphology of laser-irradiated surface is studied in detail. The results show that at the scanning speed of 42 mm/s, when the laser intensity is ≥4.0 J/cm2 typical microgroove structure with raised edges is produced by single-line scanning irradiation, and various MGT can be easily fabricated by multi-line scanning irradiation through properly adjusting the scanning interval in accordance with the feature size of microgroove structures. Meanwhile, it is firstly found that multi-scale MGT perpendicular to the scanning direction can be achieved by applying suitable high scanning speed with small scanning interval. Using a laser spot with the diameter of 20 μm, multi-scale MGT with various periods ranging from 15 (less than the laser spot diameter) to 35 μm are successfully fabricated on TA2 surfaces, and perpendicular ones with the same period of 21 μm but different ridge widths are also obtained. The aspect ratio of these MGT is > 1.5. Wettability measurements reveal that the water droplet on the produced multi-scale MGT owns anisotropic spreading speeds or spreading lengths. The energy dispersive spectroscopy tests indicate that their ridges are rich in titanium oxides which are good hemo-compatibility materials. The proposed method has a promising application for fabricating multi-scale MGT like those on natural vessel to the stent surface to improve its hemo-compatibility.
关键词： Microtexture,Functional surface,Anisotropic wettability,Laser irradiation,Microgroove
更新于2025-09-23 15:19:57
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Investigations in the fabrication of surface patterns for wettability modification on a Zr-based bulk metallic glass by nanosecond laser surface texturing
摘要： Laser texturing has previously been employed to enhance the wettability of metallic alloys. Such studies reported that modifying the wettability of a surface is a result of changes in both its topography and its chemistry. In this paper, an investigation about laser-induced surface wettability modification is also reported but for a less studied type of material in this context. In particular, nanosecond (ns) laser processing was employed to texture two types of surface patterns, i.e. dimples and grooves, on the surface of a Zr-based bulk metallic glass (BMG) known as Vitreloy 105. The specific focus of the research was on understanding the role played by both surface topography and chemistry modifications in changing the wettability of the original surface. Using static contact angle measurements, it was found that groove patterns enhanced the hydrophilicity of the original BMG, while dimple patterns weakened it. Based on the obtained 3D surface measurements and XPS data, it is suggested that the reduced hydrophilicity of dimple-textured surfaces was driven by the decrease of hydrophilic C=O and O=C-O bonds post laser processing. While these bonds were also reduced for groove-textured patterns, the hydrophilicity was still enhanced following laser irradiation as a result of the dominant role that a much larger induced surface roughness should play in this case.
关键词： Surface topography,Bulk metallic glass,Nanosecond laser surface texturing,Surface chemistry.,Wettability
更新于2025-09-23 15:19:57
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Laser-Induced Wettability Gradient Surface of the Aluminum Matrix Used for Directional Transportation and Collection of Underwater Bubbles
摘要： The control of underwater bubble behavior on a solid surface has great research significance. However, the control of the spontaneous directional transport and collection of numerous underwater bubbles remains a challenge. A new technique of a metal mesh with superhydrophobic/hydrophobic properties is demonstrated here, which creates a wettability gradient coupled with a microporous array by means of pulsed fiber laser ablation and chemical modification of the aluminum sheet. The resultant wettability surface effectively achieved the spontaneous movement of bubbles along the directional wettability gradient (superaerophobicity to aerophilicity) and through the metal mesh (aerophilicity to superaerophilicity) in the direction of decreasing free energy. Theoretical analysis accounted first for the spontaneous sliding of bubbles on the wettability gradient surface as a result of the action of an unbalanced surface tension force and second for the spontaneous transition of bubbles from the aerophilic to superaerophilic side as a result of the combined action of Laplace pressure and buoyancy. A device with the capability of directional transportation and collection of underwater bubbles was designed based on the samples with a wettability gradient and a superhydrophobic/hydrophobic microporous array as the core components. The potential application is laser ablation of wettability gradient surfaces and metal mesh with superhydrophobic/hydrophobic properties for directional transportation and collection of underwater bubbles.
关键词： wettability gradient,collection,directional transportation,underwater bubbles,laser ablation
更新于2025-09-23 15:19:57
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Scanning atmospheric-pressure plasma jet treatment of nickel oxide with peak temperature of a??500 ?°C for fabricating pa??ia??n structure perovskite solar cells
摘要： Scanning atmospheric-pressure plasma jet (APPJ) treatment of nickel oxide with a peak temperature of 500 °C was performed for fabricating p–i–n structure perovskite solar cells (PSCs). APPJ post-treatment leading to enhanced light scattering in PSCs that in turn increases the haze of NiO on FTO glass, improves the cell efficiency. APPJ treatment on NiO also improves the wettability to facilitate the follow-up deposition of CH3NH3PbI3. This also leads to better PSC performance. X-ray photoelectron spectroscopy indicates that APPJ treatment results in fewer C–N bonds and reduced NiAc2 content, suggesting more complete conversion of the liquid precursor into NiO. With three APPJ scans, the average PCE improves from 11.91% to 13.47%, with the best-performing PSC achieving an efficiency of 15.67%.
关键词： X-ray photoelectron spectroscopy,light scattering,Scanning atmospheric-pressure plasma jet,perovskite solar cells,wettability,nickel oxide
更新于2025-09-23 15:19:57
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Functionalization of Plastic Parts by Replication of Variable Pitch Laser-Induced Periodic Surface Structures
摘要： Surface functionalization of plastic parts has been studied and developed for several applications. However, demand for the development of reliable and profitable manufacturing strategies is still high. Here we develop and characterize a new process chain for the versatile and cost-effective production of sub-micron textured plastic parts using laser ablation. The study includes the generation of different sub-micron structures on the surface of a mold using femtosecond laser ablation and vario-thermal micro-injection molding. The manufactured parts and their surfaces are characterized in consideration of polymer replication and wetting behavior. The results of the static contact angle measurements show that replicated Laser-Induced Periodic Surface Structures (LIPSSs) always increase the hydrophobicity of plastic parts. A maximum contact angle increase of 20% was found by optimizing the manufacturing thermal boundary conditions. The wetting behavior is linked to the transition from a Wenzel to Cassie–Baxter state, and is crucial in optimizing the injection molding cycle time.
关键词： micro-injection molding,laser-induced periodical surface structures,surface wettability,replication
更新于2025-09-23 15:19:57
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Large-area High-contrast Hydrophobic/Hydrophilic Patterned Surface for Robust Electrowetting Devices
摘要： Hydrophobic/hydrophilic patterned surfaces (HHPS) are found in nature, and highly desired for practical applications as well. Building hydrophilic patterns firmly on low free energy hydrophobic coatings has been a long-term challenge. Conventional process of reactive ion etching combined with a thermal reflow (RIE-reflow) process results in degradation of both the hydrophobicity and dielectric strength of the hydrophobic coatings. In this work, we propose a reconstructive approach by encapsulating the “damaged” hydrophobic Teflon AF 1600 (AF) surface with a fresh one to keep its hydrophobicity the same as a virgin AF surface; and at the same time, enhance the hydrophilicity of patterned microstructures by local plasma etching method with a self-assembled protection mask. In this way, the extremely high wettability contrast with a large oil/water contact angle difference (Δθo/w) of 175o is reached between the hydrophobic and hydrophilic surfaces. Comparing to the conventional RIE-reflow process, the AF films prepared by this reconstruction process show superior dielectric strength and surface hydrophobicity. Electrowetting display devices constructed by this process demonstrate improved optical and electrical performance, presenting a more uniform pixel aperture ratio, higher voltage tolerance, and less leakage current compared to those made using the conventional “RIE-reflow” process.
关键词： electronic devices,large-area fabrication,hydrophobic/hydrophilic pattern,dielectric film,electrowetting,wettability contrast
更新于2025-09-19 17:15:36
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Effect of laser texturing on the surface characteristics and bonding property of 30CrMnSiA steel adhesive joints
摘要： The influence of laser texturing on the bonding property of 30CrMnSiA steel joints were investigated. Three patterns including dimple, groove and grid were laser textured on the 30CrMnSiA steel substrate by nanosecond fiber laser. The processed surface was characterized by surface morphology, surface roughness (Ra and Rz) and wettability. The single lap adhesive joints were fabricated and fracture surfaces were observed. The accelerated hygrothermal aging experiments were performed. The results indicated that surface roughness and wettability were both enhanced after laser texturing. The grid patterned substrate was improved pronouncedly, where Ra increased by 400% and Rz was 13 times higher than as-received specimens, and the contact angle was decreased from 65° to 24°. The shear strength of adhesive joints for dimple pattern was not improved evidently, while it was 14.6 MPa and 23.3 MPa in the groove and grid patterned specimens, which was increased by 219%, 348% compared to as-received ones, respectively. The coverage of adhesive layer on the fracture surface was increased and the fracture mode of dimple and groove patterned specimens was adhesive failure and a cohesive failure was achieved for those joints with grid pattern. The bonding property was decreased after hygrothermal aging, and the residual strength of specimens with grid pattern was the highest. The fracture mode was not changed in all adhesive joints.
关键词： Laser texturing,Wettability,Roughness,Adhesive strength,Hygrothermal aging
更新于2025-09-19 17:13:59