Facile Preparation of Raspberry-Like SiO2@Polyurea Microspheres with Tunable Wettability and Their Application for Oil-Water Separation.

Raspberry-like microspheres have been widely used as superhydrophobic materials, photonic crystals, drug carriers, etc. Nevertheless, their preparation methods, usually consisting of multiple steps, are generally time- and energy-consuming. Herein raspberry-like SiO2@polyurea microspheres (SiO2@PUM) are readily prepared via a one-step precipitation polymerization of isophorone diisocyanate in a H2O/acetone mixture with the presence of SiO2 particles. The sphere size, surface roughness, and SiO2 content of SiO2@PUM are easily adjustable by varying the experimental conditions. TEM and SEM observations reveal that the final SiO2@PUM exhibits a core-shell structure, with polyurea (PU) in the core and SiO2 particles as the shell. In the process, the SiO2 particles were initially located on the PUM surface as a monolayer. With the reaction proceeding, the monolayer of SiO2 particles became thicker, forming a thicker layer of SiO2 particles on PUM due to the accumulation of SiO2 particles, leading to a multilayer structure of SiO2 particles on the shell of SiO2@PUM. The formation mechanism of the raspberry-like SiO2@PUM was thoroughly discussed and ascribed to electrostatic attraction between the positively charged PU and negatively charged SiO2 particles. Once dried, SiO2@PUM was superhydrophobic and turned hydrophilic if water-wetted. Using a layer of SiO2@PUM, effective separation with good reusability for a variety of oil-water mixtures was achieved regardless of the oil density and types of oil-water emulsions. This work presents a novel protocol for the preparation of raspberry-like microspheres with tunable wettability via a rapid and green process, and the resulting microspheres are highly effective for the separation of diverse types of oil-water mixtures.

High-Performance Membranes Based on Spherical-Beaded Nanofibers and Nanoarchitectured Networks for Water-in-Oil Emulsion Separation.

High-performance separation materials for oil-water emulsions are crucial to environmental protection and resource recovery; however, most existing fibrous separation materials are subject to large pore size and low porosity, resulting in limited separation performance. Herein, we create high-performance membranes consisting of spherical-beaded nanofibers and nanoarchitectured networks (nano-nets) using electrostatic spinning/netting technology, for water-in-oil emulsion separation. By manipulating the nonequilibrium stretching of jets, spherical-beaded nanofibers capable of generating a robust microelectric field are fabricated as scaffolds, on which charged droplets are induced to eject and phase separate to self-assemble nano-nets with small pores. Benefiting from 3D undulating networks with cavities originating from 2D nano-nets supported by 1D spherical-beaded nanofibers, the membranes exhibit under-oil superhydrophobicity (>152°), a striking separation performance with an efficiency of >99.2% and a flux of 5775 L m-2 h-1, together with wide pressure applicability, antifouling, and reusability. This work may open up new horizons in developing fibrous materials for separation and purification.

Exploring Wettability: A Key to Optimizing Liquid-Solid Triboelectric Nanogenerators.

Nowadays, the liquid-solid triboelectric nanogenerator (L-S TENG) has gained much attention among researchers because of its ability to be a part of self-powering technology by harvesting ultra-low-frequency vibration in the environment. The L-S TENG works with the principle of contact electrification (CE) and electrostatic induction, in which CE takes place between the solid and liquid. The exact mechanism behind the CE at the L-S interface is still a debatable topic because many physical parameters of both solid and liquid triboelectric layers contribute to this process. In the L-S TENG device, water or solvents are commonly used as liquid triboelectric layers, for which their wettability over the solid triboelectric layer plays a significant role. Hence, this review is extensively focused on the influence of the wettability of solid surfaces on the CE and the corresponding impact on the output performance of L-S TENGs. The present review starts with introducing the L-S TENG, a mechanism that contributes to CE at the L-S interface, the significance of hydrophobic materials/surfaces in TENG devices, and their fabrication methods. Further, the impact of the contact angle over the electron/ion transfer over various surfaces has been extensively analyzed. Finally, the challenges and future prospects of the fabrication and utilization of superhydrophobic surfaces in the context of L-S TENGs have been included. This review serves as a foundation for future research aimed at optimizing the L-S TENG performance and inspiring new approaches in material design and multifunctional energy-harvesting systems.

Only-sp2 nanocarbon superhydrophobic materials - Synthesis and mechanisms of high-performance.

Superhydrophobic systems have fascinated the human kind since the earliest observations of the repellence of water droplets by biological systems. Currently, superhydrophobic materials (SHMs), often inspired by nature and engineered as thin coatings, become an important class of complex systems with numerous industrial implementations. The most important applications of SHMs cover waterproof, self-cleaning, anti-/deicing, anti-fogging, and catalytic systems/units, e.g., in textiles, civil and military engineering, automotive and space industry, and water-from-oil separating systems. In a few above areas, SHMs proved also to be tailorable as smart, i.e., reversibly stimuli-responsive and/or recyclable solutions. In all of those emerging fields, carbon - as the 'sixth element' - represents one of the most prospective components, also in the 'only­carbon'-based systems. The versatility of carbon (nano)materials, supported by their surface and morphology/topology tunability at from the nano- to macroscale, is vital in the manufacturing of high-performance SHMs. Here, we review only-sp2-hybridized nanocarbon SHMs, i.e., materials exhibiting water contact angle (WCA) >150°, from molecular design to synthesis and evaluation of their application-oriented properties, including WCA. The nanocarbons - pristine/as-made, (non-)covalently functionalized and in a form of carbon­carbon composites - are analyzed according to their dimensionality: 0D fullerenes, 1D carbon nanotubes (CNTs), 2D graphene, and 3D carbon nanofibers (CNFs). Importantly, this review intends to provide premises toward novel sp2-nanocarbon SHMs, indicating nanowettability and Hansen Solubility Parameters the key ones.

Construction of Durable, Colored, Superhydrophobic Wood-Based Surface Coatings Using the Sand-In Method.

Highly durable color superhydrophobic coatings have attracted much attention in indoor and outdoor decorative applications. In this paper, colorful superhydrophobic coatings with excellent durability were prepared using silane coupling agent-modified iron oxide as the pigment and polydimethylsiloxane-compounded epoxy resin as the base material by the three-step method of "spraying-sanding-spraying". The method is low cost, has a simple preparation process, enables large-area preparation, and has a restorative function. The use of red, yellow, blue, and green four kinds of modified iron oxides through the single color or multicolor into the sand can be obtained by a variety of color coatings, and silica mixed with a variety of colors can be obtained from light to dark coatings. The coating has excellent superhydrophobicity and self-cleaning ability to withstand sandpaper abrasion, water impact, sand impact, UV exposure, and environmental testing. The coating is suitable for interior and exterior decoration and for protection of wooden buildings.

Analysis of time-dependent hydrophobic recovery on plasma-treated superhydrophobic polypropylene using XPS and wettability measurements.

In specific applications like ice-repellent coatings or membrane separation technology, wettability is a key parameter affecting the applicability of commodity polymers. This study presents a technique to fine-control the wetting properties of a hierarchically structured polypropylene surface, enabling the transition between superhydrophobic and superhydrophilic states. To demonstrate the tunability of the wetting properties of polypropylene (PP) substrate, we prepared in a consecutive way superhydrophobic (advancing contact angle (CAadv) of 152°) and superhydrophilic (CAadv of 0°) material by solvent-treatment and mild air plasma treatment. The optimal plasma treatment parameters to achieve superhydrophilic wetting behaviour, which is stable for at least one week of storage in air was also explored. Water contact angle measurement and X-ray photoelectron spectroscopy were used to monitor the time dependency of hydrophobic recovery on a hierarchically structured PP surface. With a simple model considering structural and wetting parameters, we characterized the droplet spreading behaviour of plasma-treated roughened surfaces, which exhibited superhydrophilic wetting behaviour with equilibrium CAadv of nearly 0°. The proposed model, which aligns well with experimental data, can be used to compare the droplet spreading behaviour of plasma-treated roughened surfaces.

Superhydrophobic poly(lactic acid) membrane prepared with the induction of modified carbon dots for efficient separation of water-in-oil emulsions.

Superhydrophobic separation membranes are considered to be one of the most promising technologies for oil-water separation. However, the plastic waste generated from discarded membranes poses a challenge to the preparation of degraded superhydrophobic separation membranes for achieving eco-friendly separation. In this study, superhydrophobic poly(lactic acid) (PLA) membranes were fabricated using a non-solvent induced phase separation method assisted by l-cysteine modified carbon dots (Cys-CDs). The synergistic effect of Cys-CDs-induced crystallization behavior of PLA and the phase separation process results in the evolution of the surface of the PLA-based membrane from a pistil-like structure to a multi-level micro-nano structure composed of dense lamellar nanofibers and microspheres with an increase in Cys-CDs content. At a Cys-CDs content of 5 wt%, the surface roughness of PLA-based separation membrane reached its maximum, and the water contact angle was as high as 159°. Remarkably, the superhydrophobic Cys-CDs/PLA membrane exhibited promising performance in the separation of water-in-oil emulsions, with a rejection rate of 99.98% and a flux of 315.74 L·m-2·h-1·bar-1. Additionally, the superhydrophobic Cys-CDs/PLA separation membrane also demonstrates impressive properties such as acid-alkali resistance and rapid recycling into high-value chemicals. Consequently, this rapidly recoverable superhydrophobic porous Cys-CDs/PLA membrane shows great potential for practical applications in actual oil-water separation.

Green synthesis of multifunctional bamboo-based nonwoven fabrics for medical treatment.

Medical nonwovens fabrics are pivotal materials in modern healthcare systems, and find extensively application in surgical gowns, masks, nursing pads, and surgical instrument packaging. As healthcare requirements evolve and medical technology advances, the demand for functional nonwoven medical devices is continuously increasing. In addition, numerous environmental challenges and the need to transition to a sustainable society have increased the popularity of studies on environmentally friendly multifunctional nonwoven materials prepared from biomass fibers. Therefore, in this study, ecofriendly bamboo fibers were used to fabricate multifunctional medical nonwoven materials with superhydrophobic, antibacterial, flame-retardant, and biocompatible properties. Specifically, ZIF-67 was grown in situ on natural bamboo cellulose fibers (BCFs) extracted from natural bamboo and coated with polydimethylsiloxane to construct an environmentally friendly and versatile nonwoven fabric. The treated nonwoven fabric exhibited superhydrophobicity with contact angle of 163° and possess excellent self-cleaning properties. The antibacterial activity of the samples was investigated by the plate-counting method; the results showed that the untreated BCFs did not exhibit antibacterial activity, whereas the treated bamboo nonwoven fabrics demonstrated significant antibacterial activity (p < 0.001), with an antibacterial rate of >99 % against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, and Candida albicans. In addition, when the samples were exposed to different temperatures (-4 and 50 °C) and humidities (0 % and 95 %), they demonstrated an antibacterial activity of >99 % against E. coli (F5,10 = 0.602; p = 0.670) and S. aureus (F4,10 = 0.289; p = 0.879). The heat release rate and smoke production rate of the nonwoven fabric decreased by 54.64 % and 93.18 %, respectively, compared to those of the BCFs, indicating excellent flame retardancy. The nonwoven fabric also exhibited satisfactory biocompatibility and breathability, ensuring user comfortability. This research not only has significant implications for producing low-cost, environmentally friendly, sustainable, and multifunctional medical products and openi up new pathways for the diversified utilization of bamboo, thereby expanding its applicability.

Droplet Friction on Superhydrophobic Surfaces Scales With Liquid-Solid Contact Fraction.

It is generally assumed that contact angle hysteresis of superhydrophobic surfaces scales with liquid-solid contact fraction, however, its experimental verification has been problematic due to the limited accuracy of contact angle and sliding angle goniometry. Advances in cantilever-based friction probes enable accurate droplet friction measurements down to the nanonewton regime, thus suiting much better for characterizing the wetting of superhydrophobic surfaces than contact angle hysteresis measurements. This work quantifies the relationship between droplet friction and liquid-solid contact fraction, through theory and experimental validation. Well-defined micropillar and microcone structures are used as model surfaces to provide a wide range of different liquid-solid contact fractions. Micropillars are known to be able to hold the water on top of them, and a theoretical analysis together with confocal laser scanning microscopy shows that despite the spiky nature of the microcones droplets do not sink into the conical structure either, rendering a diminishingly small liquid-solid contact fraction. Droplet friction characterization with a micropipette force sensor technique reveals a strong dependence of the droplet friction on the contact fraction, and the dependency is described with a simple physical equation, despite the nearly three-orders-of-magnitude difference in liquid-solid contact fraction between the sparsest cone surface and the densest pillar surface.

Superhydrophobic and environmentally friendly bovine bone biomass based cellulose membrane for oil-water separation.

With the development of superhydrophobic materials for oil-water separation, there is an urgent need to develop environmentally friendly, low-cost, and novel hydrophobic materials. In this paper, based on bovine bone biomass raw materials, bone ash particles are obtained by calcination and grinding, and then bovine bone ash/cotton fabric cellulose membranes are prepared by vacuum filtration and impregnation methods. The pore size of the membrane is regulated and the hydrophobicity of the material is enhanced by constructing the surface microstructures. Results indicate that the membranes possess good hydrophobicity with a contact angle of 161° and the flux can reach 53,635.2 L/m2h for light oil. The separation efficiencies for petroleum ether, cyclohexane, kerosene, and dichloromethane all reach >99 %. In addition, the separation efficiency of the cellulose membrane is still >99 % in the 40-day separation test and always exceeds 90 % for 30 cycling test, indicating that it has good stability and recoverability. Interestingly, the cellulose membrane is prepared from biodegradable and renewable raw materials, which reduces environmental pollution and effectively utilize natural resources.

Construction and characterization of pickering emulsion stabilized by amphoteric microgel and its application in cotton fabric.

Studies with regard to how to obtain superhydrophobic properties by directly coating emulsified silicone oil onto the surface of cotton fabric have always been a hot topic in the field of textiles. In this paper, an amphoteric microgel with thermo- and pH-responsive ability was synthesized. Subsequently, a series of Poly(methylhydrosiloxane) (PMHS) /water emulsions were prepared by using these amphoteric microgels as a Pickering emulsifier. When the PMHS/water system's mass ratio was 5/5 and the microgel content was kept at 2.0 wt%, this emulsion showed good stability allowing the PMHS parts to be dispersed uniformly in aqueous solution. The optical microscopy showed the emulsion's particle size was in a range from 5 to 20 µm and the stability test confirmed that no stratification occurred when this emulsion was subjected to 3000 rpm for 30 min. By using this emulsion as a post-treatment reagent, cotton fabrics with different yarn counts can obtain a water contact angle as high as 150o, which is about 25 % higher than commercial emulsifiers. Furthermore, this cotton fabric can hold superhydrophobicity after 50 rubbing cycles and 10 peel-off cycles. The development of this work provides a new direction for the study of the application of microgels.

UiO-66 Inspired Superhydrophobic Coatings Fabricated from Discarded Polyester/Spandex Textiles.

We report on a method for synthesizing superhydrophobic coatings using a UiO-66 metal-organic framework (MOF) with discarded polyester/Spandex fabrics as raw materials. Unlike traditional recycling techniques that involve separating non-poly(ethylene terephthalate) (PET) components, our approach directly uses blended polyester/Spandex fibers. Discarded polyester/Spandex fabrics were exposed to an alkaline depolymerization process to produce disodium terephthalate (Na2BDC), which is a known linker for UiO-66 synthesis. We conducted experiments under two different conditions involving different amounts of ethanol. We found that with a small amount of ethanol, the resulting UiO-66 structure, when assembled on top of a polyester/Spandex substrate, exhibited a water contact angle of ≥150°â”€a superhydrophobic behavior. When using larger amounts of ethanol, we noted a hydrophobic behavior with a water contact angle of ∼139°. As a control, we performed the same experiments but using discarded 100% polyester fabrics as raw materials, which resulted in a superhydrophilic behavior. We attribute the superhydrophobic behavior of the UiO-66 coatings, produced from the polyester/Spandex fabrics, to the presence of hydrophobic compounds generated by the chemical degradation of Spandex. Our approach introduces a pathway for upcycling discarded textiles into superhydrophobic coatings.

Fabrication of versatile and durable superhydrophobic cotton fabrics using PTA-Ala adhesive.

In recent years, the preparation of functional textiles based on polyphenols adhesion has received extensive attention and research. However, polyphenols are prone to peroxidation during oxidative polymerization, which can compromise the interfacial adhesion of their monomers. Reintroducing reactive functional groups after oxidative polymerization of polyphenols may potentially compensate for the lost interfacial adhesion while increasing cohesion. In this paper, L-alanine (Ala) is introduced into poly (tannic acid) (PTA) solution to generate the PTA-Ala via Michael addition and Schiff base reaction. Original cotton fabrics are modified with PTA-Ala solution to enhance adhesion strength between the fabrics and subsequent functional modifiers. A silver nanowire network is then incorporated to increase the surface roughness through tannic acid reduction. Finally, polydimethylsiloxane is applied to reduce fabric surface energy, resulting in superhydrophobic multifunctional OH-PDMS/Ag/PTA-Ala/cotton fabrics. The finished cotton fabric exhibits a water contact angle of 166.7 ± 1.9° and a rolling angle of 5 ± 0.5°. Moreover, the fabric features diverse functionalities such as oil-water separation, photothermal conversion, antimicrobial properties, water collection, and anti-icing capabilities, alongside excellent durability and self-healing properties that extend its service life. This finished cotton fabric demonstrates promising applications in oil pollution control, outdoor clothing and medical protection, highlighting its broad across various industries.

Formation of Armored Silicon Nanowires Array via High-Repetition-Rate Femtosecond Laser Oxidation for Robust Surface-Enhanced Raman Scattering Detection.

Superhydrophobic nanostructures with dense hotspots and high concentration efficiency are of paramount importance for highly sensitive surface-enhanced Raman scattering (SERS) detection. However, their low mechanical strength makes them susceptible to damage from external interferences, leading to hotspot loss and superhydrophobicity failure. In this study, robust SERS detection is achieved using an armored superhydrophobic silicon nanowires array. A micro/nanocross-scale oxide mask is created through high-repetition-rate femtosecond laser oxidation to fabricate the armored nanowires array. The underlying mechanisms of the nanoparticle layer serving as a mask in deep reactive ion etching (DRIE) are analyzed to elucidate the formation of the silicon nanowires. The armored nanowires array SERS substrate exhibits a high contact angle of 158°, demonstrating exceptional analyte enrichment capability. Combined with the dense hotspots provided by the high aspect ratio nanostructures, the detection limit for Rhodamine 6G is 10-13 M, and the enhancement factor (EF) is 4.35 × 109. After undergoing various mechanical tests, the substrate maintains its superhydrophobicity along with a stable Raman signal enhancement, demonstrating its resistance to potential external interference in SERS detection. The sensitive detection of various analytes highlights the promising applications of the armored nanowires substrate in diverse SERS scenarios.

Functionalized flattened bamboo board: In-situ immersion assembly of flame-retardant, waterproof and anti-mold composite coatings.

The flattened bamboo board (FB) represents a promising innovation in the bamboo industry. To address the challenges of flammability and hygroscopicity, composite coatings consisting of melamine (MEL), phytic acid (PA), cerium ions (Ce3+), and sodium laurate (La) are assembled on the FB surface through an in-situ impregnation strategy. The resulting MEL/PA-Ce3+@La FB exhibits exceptional flame retardancy. It achieves a V-0 rating in the vertical burning test (UL-94) and boasts a high limiting oxygen index (LOI) value of 38.5 %. The coated FB exhibits superhydrophobicity, evidenced by a water contact angle of 156.5°, which can be attributed to the in-situ growth of PA-Ce3+ complexes (for constructing micro/nanoscale coarse structures) and the modification with La (for reducing surface energy).This superhydrophobic surface imparts both self-cleaning and anti-mold properties to the coated FB. Moreover, the coated FB exhibits excellent mechanical stability, withstanding 36 cycles of sandpaper abrasion and tape peeling without losing its hydrophobicity. In summary, this work provides an innovative strategy for the bamboo processing industry to produce flattened bamboo boards with combined flame retardancy, superhydrophobic and anti-mold properties. Such versatility holds significant potential to facilitate the utilization of flattened bamboo boards in the construction and decorative materials industries.

A Flexible and High-Efficient Anti-Icing/Deicing Coating Based on Carbon Nanomaterials.

Anti-icing/deicing coatings with low energy consumption and superior flexibility could better fit application requirements in practical engineering. In this paper, an active-passive-integrated anti-icing/deicing coating based on carbon nanomaterials is prepared, which not only possesses various functions of electrothermal conversion, photothermal conversion, and superhydrophobicity but also shows a large deformability to accommodate curved surfaces. The coating consists of a sandwich-structured bottom part and top layer, the former of which includes a core conductive layer made of densely mixed carbon nanotubes (CNTs) and graphene and two polydimethylsiloxane (PDMS) wrapping layers, while the latter is a polymeric composite filled with TiN and SiO2 nanoparticles. Experimental studies show that, when the present coating works under an electric field alone, a 90% conversion of electric energy to thermal energy can be realized, only a 2 V voltage is enough to unfreeze the surface at minus 20 degrees within 400 s, and a slightly larger voltage of 2.5 V leads to a significant temperature increase of more than 100 °C within 200 s. Such required voltages are significantly smaller than their counterparts in existing electrothermal-based methods to achieve the same heating effects, which could be further diminished with the auxiliary action of sunlight illumination. A fast and complete deicing/defrosting can be consequently achieved with a small energy input. Furthermore, the water repellency function, electric property, and electrothermal conversion performance of the coating remain almost unchanged after either a large bending deformation or many bending cycles, thus ensuring an outstanding anti-icing/deicing effect on both flat and curved surfaces. All of the results demonstrate apparent advantages of the present coating including high efficiency, low energy consumption, all-weather adaptability, and excellent flexibility, which should be of great practical value for the freeze protection of differently shaped industrial equipment.

Polyurethane Nanocomposite Coatings Coupled with Titanium-Based Conversion Layers for Enhanced Anticorrosion, Icephobic Properties, and Surface Protection.

This study examines the efficacy of icephobic polyurethane nanocomposite coatings in mitigating corrosion on an aluminum substrate. A titanium-based conversion coating is applied to modify the substrate, and the research focuses on optimizing the dual functionalities of icephobicity and anticorrosion within the polyurethane coatings while ensuring strong substrate adhesion. The coatings are formulated using fluoropolyol, isocyanate, and silica nanoparticles treated with polydimethylsiloxane. Surface properties are analyzed using contact angles, contact angle hysteresis measurements, and atomic force microscopy, and the coatings' icephobicity is evaluated through differential scanning calorimetry, freezing time delay, ice adhesion under impact and non-impact conditions, and ice accretion tests. The corrosion resistance and adhesive strength of the coatings are assessed using electrochemical impedance spectroscopy and cross-cut tests, respectively. Increasing the concentration of silica nanoparticles to 10 wt.% increases contact angles to 167°, although the 4 wt.% coating produces the lowest contact angle hysteresis (3° ± 0.5°) and ice nucleation temperature (-23 °C). The latter coating is then applied to a substrate pretreated with a titanium/cerium-based conversion coating. This prepared surface maintains an ice adhesion of about 15 kPa after 15 icing/de-icing cycles and provides approximately 90 days of surface protection (|Z|lf = 1.6 × 109 Ω·cm2). Notably, the impedance value exceeds that of untreated substrates, underscoring the effectiveness of the titanium/cerium-based conversion coating in enhancing both corrosion resistance and coating adhesion to the substrate.

Superhydrophobicity Effects on Spheroid Formation and Polarization of Macrophages.

The interaction of biomaterials with the immune system is ruled by the action of macrophages. The surface features of these biomaterials, like wettability, which is an expression of chemical composition, texture, and geometry, can affect macrophages response. Such surface parameters can be then efficiently exploited to improve biocompatibility by lowering undesired immunological reactions and at the same time creating the substrate for positive interactions. In this work, the preparation and physicochemical characterization of highly water-repellent surfaces to develop and characterize 3D spheroids derived from monocyte-macrophages (RAW 264.7 cell line) has been carried out. As a measure of cell viability over time, the obtained aggregates have been transferred under standard 2D cell culture conditions. Significant changes on the morphology-associated polarization of the derived cellular entities have been evaluated at the nanoscale through 3D profilometry. The results suggested that the spheroid formation using highly repellent substrates induced the activation of M2-type cells. This simple and cost-effective approach can be used for preparing M2-based macrophages for regenerative purposes.

Locomotion behavior of air bubbles on solid surfaces.

Air bubbles are a common occurrence in both natural and industrial settings and are a significant topic in the fields of physics, chemistry, engineering, and medicine. The physical phenomena of the contact between bubbles and submerged solid surfaces, as well as the locomotion behavior of bubbles, are worth exploring. Bubbles are generated in an unbounded liquid environment and rise due to unbalanced external forces. Bubbles of different diameters follow different ascending paths, after which they approach, touch, collide, bounce, and finally adsorb to the solid surface, forming a stable three-phase contact line (TPCL). The bubbles are in an unstable state due to the unbalanced external forces on the solid surface and the effects generated by the two-phase contact surface, resulting in different locomotion behaviors on the solid surface. Studying the formation, transport, aggregation, and rupture behaviors of bubbles on solid surfaces can enable the controllable operation of bubbles. This, in turn, can effectively reduce the loss of mechanical apparatus in agro-industrial production activities and improve corresponding production efficiency. Recent research has shown that the degree of bubble wetting on a solid surface is a crucial factor in the locomotion behavior of bubbles on that surface. This has led to significant progress in the study of bubble wetting, which has in turn greatly advanced our understanding of bubble behavior. Based on this, exploring the manipulation process of the directional motion of bubbles is a promising research direction. The locomotion behavior of bubbles on solid surfaces can be controlled by changing external conditions, leading to the integration of bubble behavior in various scientific and technological fields. Studying the dynamics of bubbles in liquids with infinite boundaries is worthwhile. Additionally, the manipulation process and mode of these bubbles is a popular research direction.

Superhydrophobic Array Devices for the Enhanced Formation of 3D Cancer Models.

During the metastatic cascade, cancer cells travel through the bloodstream as circulating tumor cells (CTCs) to a secondary site. Clustered CTCs have greater shear stress and treatment resistance, yet their biology remains poorly understood. We therefore engineered a tunable superhydrophobic array device (SHArD). The SHArD-C was applied to culture a clinically relevant model of CTC clusters. Using our device, we cultured a model of cancer cell aggregates of various sizes with immortalized cancer cell lines. These exhibited higher E-cadherin expression and are significantly more capable of surviving high fluid shear stress-related forces compared to single cells and model clusters grown using the control method, helping to explain why clustering may provide a metastatic advantage. Additionally, the SHArD-S, when compared with the AggreWell 800 method, provides a more consistent spheroid-forming device culturing reproducible sizes of spheroids for multiple cancer cell lines. Overall, we designed, fabricated, and validated an easily tunable engineered device which grows physiologically relevant three-dimensional (3D) cancer models containing tens to thousands of cells.