Superhydrophilic Surface Research Articles

Antibiofilm and antithrombotic hydrogel coating based on superhydrophilic zwitterionic carboxymethyl chitosan for blood-contacting devices

Blood-contacting devices must be designed to minimize the risk of bloodstream-associated infections, thrombosis, and intimal lesions caused by surface friction. However, achieving effective prevention of both bloodstream-associated infections and thrombosis poses a challenge due to the conflicting nature of antibacterial and antithrombotic activities, specifically regarding electrostatic interactions. This study introduced a novel biocompatible hydrogel of sodium alginate and zwitterionic carboxymethyl chitosan (ZW@CMC) with antibacterial and antithrombotic activities for use in catheters. The ZW@CMC hydrogel demonstrates a superhydrophilic surface and good hygroscopic properties, which facilitate the formation of a stable hydration layer with low friction. The zwitterionic-functionalized CMC incorporates an additional negative sulfone group and increased negative charge density in the carboxyl group. This augmentation enhances electrostatic repulsion and facilitates the formation of hydration layer. This leads to exceptional prevention of blood clotting factor adhesion and inhibition of biofilm formation. Subsequently, the ZW@CMC hydrogel exhibited biocompatibility with tests of in vitro cytotoxicity, hemolysis, and catheter friction. Furthermore, in vivo tests of antithrombotic and systemic inflammation models with catheterization indicated that ZW@CMC has significant advantages for practical applications in cardiovascular-related and sepsis treatment. This study opens a new avenue for the development of chitosan-based multifunctional hydrogel for applications in blood-contacting devices.

Superhydrophilic and Underwater Superoleophobic Copper Mesh Coated with Bamboo Cellulose Hydrogel for Efficient Oil/Water Separation.

Super-wetting interface materials have shown great potential for applications in oil-water separation. Hydrogel-based materials, in particular, have been extensively studied for separating water from oily wastewater due to their unique hydrophilicity and excellent anti-oil effect. In this study, a superhydrophilic and underwater superoleophobic bamboo cellulose hydrogel-coated mesh was fabricated using a feasible and eco-friendly dip-coating method. The process involved dissolving bamboo cellulose in a green alkaline/urea aqueous solvent system, followed by regeneration in ethanol solvent, without the addition of surface modifiers. The resulting membrane exhibited excellent special wettability, with superhydrophilicity and underwater superoleophobicity, enabling oil-water separation through a gravity-driven "water-removing" mode. The super-wetting composite membrane demonstrated a high separation efficiency of higher than 98% and a permeate flux of up to 9168 L·m-2·h-1 for numerous oil/water mixtures. It also maintained a separation efficiency of >95% even after 10 cycles of separation, indicating its long-term stability. This study presents a green, simple, cost-effective, and environmentally friendly approach for fabricating superhydrophilic surfaces to achieve oil-water separation. It also highlights the potential of bamboo-based materials in the field of oil-water separation.

Bionic Surfaces for Fog Collection: A Comprehensive Review of Natural Organisms and Bioinspired Strategies.

Water scarcity has become a critical global threat, particularly in arid and underdeveloped regions. However, certain insects and plants have evolved the capability to obtain water from fog under these arid conditions. Bionic fog collection, characterized by passive harvesting, minimal energy requirements, and low maintenance costs, has proven to be an efficient method for water harvesting, offering a sustainable water source. This review introduces two superwettable surfaces, namely, superhydrophilic and superhydrophobic surfaces, detailing their preparation methods and applications in fog collection. The fog collection mechanisms of three typical natural organisms, Namib Desert beetles, spider silk, and cactus, along with their bionic surfaces for fog collection devices, are discussed. Additionally, other biological surfaces exhibiting fog transport properties are presented. The main challenges regarding the fabrication and application of bionic fog collection are summarized. Furthermore, we firmly believe that environmentally friendly, low-cost, and stable fog collection materials or devices hold promising prospects for future applications.

Passivation protein-adhesion platform promoting stent reendothelialization using two-electron-assisted oxidation of polyphenols

Superhydrophilic surfaces play an important role in nature. Inspired by this, scientists have designed various superhydrophilic materials that are widely used in the field of biomaterials, such as PEG molecular brushes and zwitterionic materials. However, superhydrophilic coatings with only anti-fouling properties do not satisfy the requirements for rapid reendothelialization of cardiovascular stent surfaces. Herein, a novel polyphenol superhydrophilic surface with passivated protein-adsorption properties was developed using two-electron oxidation of dopamine and polyphenols. This coating has a multiscale effects: 1) macroscopically: anti-fouling properties of superhydrophilic; 2) microscopically: protein adhesion properties of active groups (quinone-, amino-, hydroxyphenyl groups and aromatic ring). Polyphenols not only enhance the ability of coating to passivate protein-adsorption, but also make the coating have polyphenol-related biological functions. Therefore, the polyphenol and passivated protein-adsorption platform together maintain the stability of the scaffold microenvironment. This, in turn, provides favorable conditions for the growth of endothelial cells on the scaffold surface. In vivo implantation of the coated stents into the abdominal aorta resulted in uniform and dense endothelial cells covering the surface of the neointima. Moreover, new endothelial cells secreted large amounts of functional endothelial nitric oxide synthase like healthy endothelial cells. These results indicate that the polyphenol superhydrophilic coating potentially resists intra-stent restenosis and promotes surface reendothelialization. Hence, polyphenol superhydrophilic coatings with passivated protein-adsorption properties constructed by two-electron-assisted oxidation are a highly effective and versatile surface-modification strategy for implantable cardiovascular devices.

Regulation of fluorescence, morphology, surface wettability and function of naphthalimide-based self-assembly system by metal coordination

Three naphthalimide-based supramolecular gelators (N1, N2 and N3) that contained one, two, or three naphthalimide groups, respectively, were designed and synthesized, and the self-assembly processes of the three gelators were studied using different technique. Their self-assembly behavior could be regulated through the number of terminal branches. More importantly, their self-assembled structure, fluorescence behavior and surface wettability and function could be regulated through metal coordination, and helical nanofibers could be formed by gel N2 with Cd2+, Co2+, Eu3+, Tb3+, Mn2+, Ni2+ and Hg2+. The fluorescence emission intensities of these gels could change with different degrees under the addition of different metal ions, and a super-hydrophilic surface could be obtained from xerogel N3 in the presence of Co2+, Eu3+, Mn2+ and Tb3+. Specifically, gelator N3 could selectively and sensitively respond to Fe2+ in the solution and gel state with a response time of 0.5 s and a low limit of detection of 1.84 nM. This work provided a new regulation method for the supramolecular self-assembly process.

Super-hydrophilic nano-structured surface with antibacterial properties

Adhesion of bacteria to a surface followed by biofilm formation causes many problems in human health care and, in some cases, can even cause human death. Therefore, reducing bacterial attachment to surfaces and antibacterial surface fabrication are two of the most important issues in many applications, including healthcare, medical, food packaging, etc. Polycarbonate (PC) is one of the most widely used polymers in medicine. However, it does not have antibacterial properties. On the other hand, laser treatment is used as a standard method for surface modification of different materials. In this paper, excimer laser irradiation at a fluence below the ablation threshold was used for surface patterning and modification of the polycarbonate sample, aiming to improve its antibacterial properties. The results show that super-hydrophilic nanostructured polycarbonate surfaces have antibacterial properties compared to non-treated PC, which has no antibacterial properties.

Anti-frosting characteristics of superhydrophobic-hydrophilic wettability switchable surfaces

Combining hydrophobicity with hydrophilicity on hybrid surfaces generates unique phenomena in anti-frosting. However, limited attention has been paid to investigate the anti-frosting effects of wettability switchable surfaces in response to temperature changes. Herein, frosting and defrosting characteristics of thermo-responsive, wettability switchable surfaces are investigated. Specifically, the wettability switchable surfaces are successfully fabricated by coating a poly(ε-caprolactone) (PCL) layer onto the microstructured aluminum substrates, resulting in the wettability transition from superhydrophobicity with an apparent contact angle of water droplet as 152° in the surface temperatures under 60 °C to hydrophilicity with an apparent contact angle of water droplet as 63° in the surface temperatures over 60 °C. The wettability transition capabilities of the surfaces not only enable excellent frost retardation comparable to superhydrophobic surfaces in frosting process, but also realize fast full drying capabilities slightly shorter than superhydrophilic surfaces in defrosting process. The unique feature of wettability switchable surfaces represents an effort to combine the distinct advantages of superhydrophobic and superhydrophilic surfaces to realize anti-frosting functionalities.

Novel and superhydrophilic bifunctional NiCuMn@TiN nanosheets supported on iron foam for high-performance supercapacitors and water oxidation

Synthesizing low-cost and highly efficient bifunctional electrocatalysts for hybrid supercapacitors and oxygen evolution reaction (OER) is critically essential for the progress of energy storage and conversion devices. Therefore, a novel, inexpensive and superhydrophilic bifunctional NiCuMn@TiN nanosheet supported on iron foam (NiCuMn@TiN/IF) is successfully designed and fabricated via spent cupronickel (SCN) as Ni and Cu precursor by a facile one-step electrosynthesis routine. With adding nano titanium nitride (TiN), the obtained NiCuMn@TiN/IF composite electrode not only possesses a large superhydrophilic surface that enhances ion/electron transfer efficiency and provides numerous activity sites for the electrochemical reaction but also achieves efficient recovery of metal resources using the secondary resource SCN as soluble anode further reduces the cost of electrode preparation. And since the synergistic effect of large specific surface area and superhydrophilicity, the NiCuMn@TiN/IF delivers a high specific capacity of 22.5 F cm−2 at 10 mA cm−2 in 3 M KOH and also illustrates superior OER activity with an extremely low overpotential (286 mV) and remarkable durability at a high current density of 100 mA cm−2 in 1 M KOH. This research provides a solid foundation for the large-scale preparation of low-cost and high-performance non-precious metal bifunctional electrocatalysts for the commercial development of electrochemical supercapacitors and electrochemical water-to-hydrogen conversion technology.

Direct-coating of cellulose hydrogel on PVDF membranes with superhydrophilic and antifouling properties for high-efficiency oil/water emulsion separation

As a well-known natural and innocuous plant constituent, cellulose consists of abundant hydroxyl groups and can tightly adsorb onto material surfaces hydrogen bonding, resulting in a superhydrophilic surface. In this work, the hydrophobic polyvinylidene fluoride (PVDF) membranes were modified by immersing them in cellulose hydrogel using a simple one-step process. The modified PVDF membrane exhibited excellent resistance to fouling and oil adhesion, making it highly effective in separating various oil-in-water emulsions. The cellulose-modified PVDF membranes achieved a high oil rejection rate (>99 %) and a maximum separation flux of 2675.2 L·m−2·h−1. Furthermore, even an oil-in-water emulsion containing bovine serum albumin maintained a steady permeation flux after four filtration cycles. Additionally, these cellulose-modified PVDF membranes demonstrated excellent underwater superoleophobicity across a wide range of pH levels and high saline conditions. Overall, these cellulose-modified superhydrophilic PVDF membranes are sustainable, environmentally friendly, easily scalable, and hold great promise for practical applications in oily wastewater treatment.

Structure and in-vitro bioactivity study of Nano-DCPD coatings on anodized TiO2 nanotubes deposited on Ti-alloy as scaffold applications

Ti and their alloys are commonly used metallic implants due to their good bio-activity. Post-surgery reflects inferior osseointegration that makes the material unhealthy in the long run after surgery. In this regard, surface characteristic remains one of the most trivial and incurable problems for hard tissue application. In the present study, Nano-Dicalcium Phosphate Dihydrate (DCPD) Coatings were deposited over anodized TiO2 Nanotubes and its structural, surface and in-vitro study has been done. Surface transitions from the contact angle analyser reveal hydrophilic to super-hydrophilic surfaces have been achieved over Ti6Al4V alloy. The highest absorbance value has been observed on TTOAD compared to TD in both 24 h and 48 h. FESEM Mapping and EDS unveil that the distribution of elements is not homogenous entirely. However, the AFM result reveals that the distribution of an ex-situ deposited layer is enriched in Calcium-Phosphorus elements and has distinct irregular topography. Besides more surface roughness value has been revealed in TTOAD surface. Optical density (O.D.) value at 570 nm with ∼ 1.09 O.D. at 24 h and ∼1.3 O.D. at 48 h was obtained on the TTOAD specimen reflecting the best cell proliferation of MG-63 compared to TD. In addition, superhydrophilicity with ∼8.5° contact angle was gained at TTOAD compared to TD and TTOCD specimens.

Collagen membrane functionalized with magnesium oxide via room-temperature atomic layer deposition promotes osteopromotive and antimicrobial properties.

Artificial bone grafting materials such as collagen are gaining interest due to the ease of production and implantation. However, collagen must be supplemented with additional coating materials for improved osteointegration. Here, we report room-temperature atomic layer deposition (ALD) of MgO, a novel method to coat collagen membranes with MgO. Characterization techniques such as X-ray photoelectron spectroscopy, Raman spectroscopy, and electron beam dispersion mapping confirm the chemical nature of the film. Scanning electron and atomic force microscopies show the surface topography and morphology of the collagen fibers were not altered during the ALD of MgO. Slow release of magnesium ions promotes bone growth, and we show the deposited MgO film leaches trace amounts of Mg when incubated in phosphate-buffered saline at 37°C. The coated collagen membrane had a superhydrophilic surface immediately after the deposition of MgO. The film was not toxic to human cells and demonstrated antibacterial properties against bacterial biofilms. Furthermore, in vivo studies performed on calvaria rats showed MgO-coated membranes (200 and 500 ALD) elicit a higher inflammatory response, leading to an increase in angiogenesis and a greater bone formation, mainly for Col-MgO500, compared to uncoated collagen. Based on the characterization of the MgO film and in vitro and in vivo data, the MgO-coated collagen membranes are excellent candidates for guided bone regeneration.

Experimental study on frosting and defrosting characteristics for inclined cold plates with surface wettability considered

Frost formation is a ubiquitous phase-change phenomenon, which is a nonlinear and complex physical process involving heat and mass transfer. Most of previous studies focused on frosting and defrosting characteristics of cold surfaces at horizontal or vertical angles, indicating that the inclination angle has a significant effect on the dynamic of frosting and defrosting. However, what happens to the frosting and defrosting process at other different inclination angles have not been clarified. In this study, to explore the effects of inclination angles, surface wettability on frosting and defrosting characteristics, three surfaces with different wettability properties including superhydrophobic, superhydrophilic and hydrophilic surfaces were prepared, and a frosting and defrosting experimental platform with adjustable inclination angle from 0° to 180° was built. Experiment results show that the inclination angle was found to impact both frost quality and thickness. For different wettability surfaces, both frost quality and thickness exhibited a rising trend within the 0°∼90° range, followed by a decrease within the 90°∼180° range. Moreover, the inclination angle has a significant effect on the frost melting process on superhydrophobic and superhydrophilic surfaces. With the increase of the inclination angle, the amount of retained water decreases gradually, and in the interval of 30°∼90°, it does not change much, and the quality is the smallest at 180°.

Janus membrane with asymmetric wettability for efficient oil/water separation

The rapid development of society and industry as well as the frequent occurrence of oil spills cause the shortage of fresh water resources, which not only affects human safety and life, but also impedes the world-wide sustainable development. To address these challenges, novel membrane materials with unique wettability properties have gained significant attention, particularly in the field of oil/water separation. In this research, we modified the hydrophobic PET fabric to achieve superhydrophilic characteristics using impregnation method. Subsequently, we electrospun hydrophobic PVDF fibers onto the superhydrophilic fabric surface, and PVDF/Ca10(PO4)6(OH)2@PET Janus membrane with asymmetric wettability was obtained. The membrane has an excellent unidirectional liquid transport capacity, and can effectively separate heavy oil or light oil, the separation efficiency is more than 90 %. The results also show that the Janus membrane can be used under alkaline conditions and has satisfactory tensile resistance and re-use performance. This work provides a new idea for Janus membrane design and effectively improves the application potential of the Janus membrane in the field of oil/water separation.

Reinforced water hyacinth based biodegradable cutlery: Green alternative to single-use plastics

Water hyacinth (WH) is an invading water plant that severely threatens biodiversity. The aim of this study was to utilize fibres from this underutilized plant to develop binderless biodegradable plates, in combination with different proportions (10%, 20% and 30%) of waste paper (WP), sugarcane leaf (SC), and banana stem fibre (BF), added as reinforcing agents. The properties of these products are compared with WH plates with starch as a binder (ST). The use of an epoxidized castor oil-based coating to enhance hydrophobicity was also studied. Analytical tests including functional group analysis, mechanical property, wettability, surface morphology, thermal stability and biodegradability studies were performed. It was observed that BF samples had the best mechanical properties, followed by SC, WP and ST, with BF-20 showing the maximum tensile strength (6.23 MPa) and elongation (10.09%). The thermogravimetric analysis showed the reinforced samples to be suitable for high-temperature applications, with SC-30 having a T5 value of 269.75 °C. The contact angles indicated that WH could be considered a suitable raw material for manufacturing biodegradable products with low wettability, and the addition of cellulose-rich reinforcing agents can further enhance its water resistance. SC-30 showed the highest hydrophobicity with a contact angle of 124.3°. Coating using an epoxidized castor oil-based solution can reduce the wettability of even super hydrophilic surfaces. All the samples showed good biodegradability, with most samples degrading completely within 20 days. Hence, water hyacinth reinforced with cellulose-rich reinforcing agents can be regarded as a superior raw material for manufacturing biodegradable cutlery.

Hierarchically Multiscale Vertically Oriented NiFeCo Nanoflakes for Efficient Electrochemical Oxygen Evolution at High Current Densities

AbstractCrucial advancements in versatile catalyst systems capable of achieving high current densities under industrial conditions, bridging the gap between fundamental understanding and practical applications, are pivotal to propel the hydrogen economy forward. In this study, vertically oriented hierarchically multiscale nanoflakes of NiFeCo electrocatalysts are presented, developed by surface modification of a porous substrate with nano‐structured nickel. The resulting electrodes achieve remarkably low overpotentials of 139 mV at 10 mAcm−2 and 248 mV at 500 mAcm−2. Further, scaled‐up electrodes are implemented in a water‐splitting electrolyser device exhibiting a stable voltage of 1.82 V to deliver a constant current density of 500 mA cm−2 for over 17 days. Moreover, the role of the unique structures on electrochemical activity is systematically investigated by fractal analysis, involving computation of structure factors such as Minkowski connectivity, fractal dimension, and porosity using scanning electron microscope images. It is found that such structures offer higher surface area than typical layered double hydroxide structures due to morphological coherence that results in a superhydrophilic surface, while the base Ni layer boosts the charge transfer. This study demonstrates a Ni/NiFeCo(OH)x heterostructure with highly porous morphology, a key to unlocking extremely efficient oxygen evolution reaction activity with exceptional stability. Moreover, fractal analysis is presented as a valuable tool to evaluate the electrochemical performance of catalysts for their structured morphology.

Construction of Janus structures on thin silk fabrics via misting for wet–thermal comfort and antimicrobial activity

Owing to their small fiber diameter (10–15 μm), silk fabrics are always thin (32–90 g m−2). Therefore, construction of the Janus surfaces of silk fabrics that possess excellent multifunctionality remains a formidable challenge. Herein, first, silk fabrics were grafted using glycidyltrimethylammonium chloride to form a superhydrophilic surface (G-side). Then, a unilateral hydrophobic surface (O-side) was readily fabricated by mist coating octadecyltrichlorosilane-functionalized SiO2 nanoparticles (NPs) to produce hierarchical surface textures. To prevent NP penetration from the G-side to the O-side, a “fireproof isolation” method was employed. Consequently, Janus silk fabrics (JanSFs) bearing asymmetric wettability were prepared, and their wetting gradient could be conveniently regulated. With the mist time ranging from 4 to 7 min, the unidirectional transport index and efficiency of the unidirectional water transport increased and decreased by 13.2 and 10.4 times, respectively. Sweat could be effectively drained away from human skin to ensure that the skin was dry and comfortable. Compared with the surface temperature of the raw fabric, the raw fabric of JanSFs increased by 2.7 °C. Furthermore, the breathability of JanSF was negligibly affected, and the outer O-side of the JanSF showed substantial antibacterial activity. This study is important for designing JanSFs that exhibit unidirectional water transport.

A biomimetic superwetting Bi2MoO6-dotted PAA/CS@CuC2O4 membrane with self-cleaning and self-healing ability to aggregate oil droplets for enhanced demulsification of O/W emulsion

Separation of thermodynamically-stable emulsions is of great significance, yet challenging due to the low efficiency and membrane fouling associated with existing methods. Inspired by the water-collection functionality of the hierarchically-structured back of desert beetles, we fabricated a novel inversely beetle-back-like copper mesh membrane, featuring superhydrophobic bumps on a superhydrophilic surface to facilitate the capture-aggregation of tiny oil droplets in oil-in-water (O/W) emulsions. Such membrane was composed of superhydrophobic (SH) Bi2MoO6 microparticles-dotted superhydrophilic polyacrylic acid/chitosan-coated CuC2O4 nanosheet arrays on copper mesh membranes. A cross-flow asymmetric filtration (CAF) device was constructed using the as-prepared membrane to continuously and efficiently separate O/W emulsions. The dispersed oil droplets were captured and coalesced by SH Bi2MoO6 on the superhydrophilic nanoarrays, then detached from the mesh membrane. Simultaneously, the continuous water phase could permeate freely through the mesh pores. The combination of the SH Bi2MoO6-dotted superhydrophilic membrane and CAF device ensured an excellent separation efficiency with an average water permeation flux of 2.7 kL m−2 h−1 for different surfactant-stabilized O/W emulsions and oil residual contents in the filtrate being less than 40 mg L−1. Moreover, the cross-flow of the feed solution in the CAF system strengthened the separation of the coalesced oil phase on the membrane surface, thus preventing the formation of a filter cake caused by the aggregation of emulsified oil droplets.

Numerical Investigations on Enhancement of Pool Boiling Heat Transfer on a Mixed Wettability Surface Employing Lattice Boltzmann Method

Abstract In this paper, a systematic numerical study of pool boiling heat transfer on a mixed wettability heated surface is done using the lattice Boltzmann method (LBM) with a multiple relaxation time (MRT)-based collision operator. The effect of the design parameters, viz, size of the hydrophobic patch (D), spacing between hydrophobic patches (L), number of hydrophobic patches (N), and uneven-sized patches, on pool boiling was studied and results are explained through detailed analysis of bubble nucleation, growth, coalescence, and departure from the heated surface. The results show that mixed wettability surfaces with strategically sized and positioned hydrophobic patches on a hydrophilic surface can result in high heat flux for pool boiling across the entire range of surface superheat or Jacob number (Ja) by combining the advantages of hydrophobic surface in nucleate boiling and hydrophilic surface in transition and film boiling. Further, the mixed wettability surface can delay the onset of film boiling compared to a pure or superhydrophilic surface thereby resulting in higher critical heat flux (CHF). A hydrophobic to total surface area ratio of 30–40% was found to be optimal for all ranges of surface superheat or Jacob number (Ja), which agrees well with the experimental result of 38.46% reported by Motezakker et al. (2019, “Optimum Ratio of Hydrophobic to Hydrophilic Areas of Biphilic Surfaces in Thermal Fluid Systems Involving Boiling,” Int. J. Heat Mass Transfer, 135, pp. 164–174).

Pumping and sliding of droplets steered by a hydrogel pattern for atmospheric water harvesting.

Atmospheric water harvesting is an emerging strategy for decentralized and potable water supplies. However, water nucleation and microdroplet coalescence on condensing surfaces often result in surface flooding owing to the lack of a sufficient directional driving force for shedding. Herein, inspired by the fascinating properties of lizards and catfish, we present a condensing surface with engineered hydrogel patterns that enable rapid and sustainable water harvesting through the directional pumping and drag-reduced sliding of water droplets. The movement of microscale condensed droplets is synergistically driven by the surface energy gradient and difference in Laplace pressure induced by the arch hydrogel patterns. Meanwhile, the superhydrophilic hydrogel surface can strongly bond inner-layer water molecules to form a lubricant film that reduces drag and facilitates the sliding of droplets off the condensing surface. Thus, this strategy is promising for various water purification techniques based on liquid-vapor phase-change processes.

Enhancing wettability of sapphire (Al2O3) substrate through laser surface texturing

Sapphire (Al2O3) has emerged as an incredibly versatile ceramic material, attracting significant interest across various fields due to its superior properties. The potential to control its wettability offers opportunities for enhancing the functionalities of sapphire-based devices. This study focuses on achieving superhydrophilic surfaces on sapphire substrates using a 355 nm nanosecond laser. The effects of the Laser Surface Texturing (LST) parameters on the morphology and wettability of the samples were examined through a Taguchi L16 experimental design. The results showed that the repetition rate and scanning speed influenced the Contact Angle (CA) and Surface Roughness (Ra) of the laser-textured sapphire. Lower repetition rates and higher scanning speeds resulted in rougher surfaces and smaller contact angles. The minimum CA of 4.5° was obtained at a repetition rate of 50 kHz and a scanning speed of 1100 mm/s. The study highlights the importance of controlling processing parameters to achieve desired wetting properties for superhydrophilic surfaces. The findings of this research provide insights into the application of LST for achieving superhydrophilic surfaces on sapphire substrates.