Surface Wetting Properties Research Articles

Rational design of static wetting on roughness-engineered heterogeneous surfaces

Surface roughness and chemical composition are crucial in controlling the static wetting properties of surfaces. Here, conventional surface structuring methods used in Si microfabrication are used as a reference to analyze the impact of precisely engineered surface roughness. The static wettability of rough chemically heterogeneous surfaces is experimentally studied through contact angle measurements and compared against computational simulations to categorize the wetting behavior of water droplets. Heterogeneous samples are observed to already show significant dependence on the surface fraction covered by each material. Furthermore, owing to the presence of a resist layer on top of the Si pillars, intermediate states between the Wenzel (W) and Cassie–Baxter (CB) models are observed. Consistent with these models, we find that local chemical modifications of microstructured surfaces are crucial for controlling their surface wettability properties. Additionally, a comparison of equivalent microstructures made of Si or polydimethylsiloxane (PDMS) reveals the quantitative impact of the hydrophilic/hydrophobic nature of the material on the evolution of the wetting properties with increasing roughness factors. While Si surfaces behave according to the W model, PDMS surfaces show intermediate wetting states at significantly lower roughness levels. Bubbles trapped beneath water droplets demonstrate the existence of intermediate states that cannot be defined by either the W or CB models. By combining experimental results with finite element simulations, we not only demonstrate wettability control through specific roughness and chemical modifications but also provide insight into how these parameters interact to accurately predict and adjust static wetting properties.

Antibacterial cellulose-based membrane with heat dissipation and liquid transportation for food packaging applications

Food spoilage, caused by fungi and bacteria, has drawn increasing attention due to the lack of suitable temperature and humidity control, resulting in food waste and health risks. It is still a great challenge to develop green packaging materials with excellent antibacterial activities and effective temperature/humidity control for food preservation. Herein, a new strategy is proposed to obtain food packaging material with antibacterial ability, heat dissipation, and liquid transportation functions. In this strategy, Zn-Al layered double hydroxide (LDH)@cellulose was obtained by extracting cellulose from sugarcane husks, followed by in-situ growth of LDH nanosheets on the surface of cellulose. Then, asymmetric structured packaging material, namely cellulose acetate/LDH@cellulose (CALC) membrane, was prepared by the combination of electrospinning and hydrophobic modification. The characterization results confirmed that the CALC membrane exhibits asymmetric surface structure and wettability properties, endowing heat dissipation and liquid transportation for food packaging applications. Due to the asymmetric reflectivity and infrared emissivity, the CALC membrane exhibited excellent heat dissipation properties with a surface temperature of 10.3℃, which is lower than that of commercial food packaging material. Furthermore, the excellent liquid transport properties of the CALC membrane are demonstrated by the fact that water can penetrate from the hydrophobic side to the hydrophilic side within 32s, providing the appropriate storage temperature and dry environment for foods. In addition, compared with PE film, the CALC membrane also has antibacterial properties and UV resistance, which is beneficial to improving the storage conditions for foods. This study shows that the developed CALC membrane and corresponding design strategy can be extended for the preparation of other packaging materials for applications in research and food industrial fields.

Enhancing anti-icing efficacy in hybrid polyurethane coatings: Evaluating the significance of molecular weight, chemical structure, and content of PEG/PDMS

This study investigates the advantages of adding polydimethyl siloxane/polyethylene glycol (PEG/PDMS) copolymers to polyurethane coatings, with a particular focus on optimizing anti-icing efficacy. A range of characterization techniques are applied, including attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) analysis, surface roughness measurements, wettability analysis, tensile testing, and ice adhesion measurements, to elucidate the intricate relationships between copolymer molecular weight, chemical structure, and content and their collective effect on the anti-icing properties of the developed coatings. Tailored PEG/PDMS copolymers significantly reduce ice nucleation temperatures and enhance the anti-icing properties of polyurethane coatings. Adding PEG/PDMS copolymers to polyurethane alters the surface roughness, wettability, and mechanical properties of the coatings to improve anti-icing performance. The presence of copolymers decreases ice adhesion strength (<50 kPa), attributed to the formation of a quasi-liquid layer that acts as a lubricant between the ice and the coatings, and delays ice formation. Furthermore, the enhanced durability of copolymer-containing coatings ensures a long-lasting anti-icing effect after multiple icing/de-icing cycles, although some degradation was observed over time. The tailored PEG/PDMS copolymers demonstrate potential for maximizing the anti-icing properties of polyurethane coatings and advancing anti-icing technologies.

Bio-inspired magnetically induced self-assembling Janus solar evaporator with antifouling and antiscaling properties

Engineering solar evaporators with Janus structures is crucial for facilitating water transition and heat localization to enhance water evaporation efficiency. However, the fragile discontinuous bilayer structures and unavoidable surface fouling significantly hinder their application. Herein, inspired by the Janus structure of Black Amanita mushrooms, we designed a robust solar evaporator with an integrated wood-like and Janus structure using directional freeze-casting and magnetically induced self-assembly of polypyrrole-coated Fe3O4 particles as a build-in photothermal top layer within a hydrophilic matrix, followed by covering it with an additional hydrophobic fluorine layer to simultaneously regulate surface wettability and antifouling properties. Incorporating the hydrophobic fluorine layer onto the solar evaporator not only enhances its water evaporation efficiency via thermal localization effects, but also prevents fouling, salt, and dust scaling accumulation on its surface, facilitating water transportation, thus achieving a groundbreaking performance with the evaporation rate of 2.13 kg m−2 h−1 under one sun irradiation. Moreover, the mechanical performance of the as-prepared solar evaporator can be further optimized by precisely modulating supramolecular interactions within its structure, achieving Young’s modulus over 4 MPa and maintaining structural integrity after the peel-off tests. The fabricated solar evaporator enables highly efficient water purification from artificial seawater, oil-in-water emulsions, and industrial wastewater, providing a rational strategy for designing high-yield solar evaporation systems for wastewater containing complex contaminants.

The Effect of Wettability on Confinement-Induced Phase Behavior and Storage of Alkane in Nanoporous Media.

The impact of wettability on the confined phase behavior of fluids is paramount for various applications, such as gas storage, carbon dioxide sequestration, and water purification. However, the understanding of the fluid-solid intermolecular interactions in confined systems is still limited and requires further investigation. This work investigates the effect of hydrophilic and hydrophobic nanoporous materials on the adsorption and desorption isotherms of n-butane. The hydrophilic samples in this research are MCM-41 silica powder with two different pore sizes (80 and 100 Å). MCM-41 samples were successfully treated with hexamethyldisilazane (HMDS) to create hydrophobic adsorbents. Isotherms of n-butane in materials with different wetting states were generated at various temperatures using an upgraded gravimetric apparatus. The results demonstrated that n-butane was adsorbed more onto the hydrophilic MCM-41 materials during the initial adsorption process. The lower affinity between n-butane and the modified MCM-41 samples slightly increased the capillary condensation and evaporation pressures in these materials compared to those in the original ones. However, it is noted that wettability's influence on the confined phase transitions of n-butane was not significant in this study. Interestingly, the hysteresis behavior of the vapor-liquid and liquid-vapor phase transitions due to confinement was independent of the surface's wetting properties. Kelvin's equation for a hemispherical meniscus was adopted to evaluate the capillary evaporation pressures of n-butane in nanopores. The calculated pressures showed agreement with experimental data when appropriate pore size and surface tension values were applied. These findings provide valuable insights into the impacts of surface chemistry and wettability on the phase behavior of hydrocarbon gas in nanoporous media. Furthermore, this study enriches the experimental database on confined fluids, which is essential for developing accurate theoretical and modeling tools for numerous industrial and scientific applications.

Molecular-Level Investigation of Binary Fluid Droplets Impacting Surfaces

Droplets impacting with surfaces are commonly encountered processes in the field of protective coatings. The behavior of a colliding binary liquid droplet is sensitive to the impact velocity, surface wetting properties, and the droplet composition. Modeling molecular dynamics and classical density functional theory studies of impacting droplets as well as interfacial-surface free energies was reported on. The presence of two components in the liquid drop makes the surface collision a complicated problem. During the collision the kinetic energy of the drop is converted into heat. Thus, the temperature varies during the collision and throughout the droplet. Two extreme situations were captured by performing both adiabatic and isothermal simulations. Molecular dynamics and classical density functional theory were used to explore the effects of the mixing parameter on the phase diagram of the binary AB mixed droplets. The location of liquid–vapor and liquid–liquid phase separation was determined. In addition, the value of the interfacial tensions of all interfaces was computed. These can be used to predict when an A-rich and B-rich droplet will stay attached and when it will detach.

Enhanced osteogenic potential of spider silk fibroin-based composite scaffolds incorporating carboxymethyl cellulose for bone tissue engineering

This study aimed to investigate the characteristics of composite scaffolds that combine fibroin derived from spider silk and carboxymethyl cellulose (CMC) in the field of bone tissue engineering. Fibroin, obtained from spider silk, serves as a valuable biomaterial and constitutes the primary component of fibrous protein-based spider silk threads. To enhance the binding efficiency in bone formation after scaffold implantation, CMC was integrated into fibroin, aiming to improve the injectability properties of the scaffold in bone substitutes. For bone marrow mesenchymal stem cell (BMSC) tissue engineering, BMSCs isolated from mice were seeded onto the scaffold, and the rate of cell proliferation was assessed. The composite scaffold, with the addition of CMC to fibroin, exhibited superior characteristics compared to scaffolds containing only silks, including porous morphology, porosity, surface wettability, water absorption, and thermal properties. Alkaline phosphatase activity in BMSCs was significantly higher in the CMC-containing scaffold compared to the silk-only scaffold, and the CMC-containing scaffold demonstrated increased expression of osteocyte marker genes and proteins. In conclusion, the biocompatibility and hydrophilicity of CMC-containing scaffolds play essential roles in the growth and proliferation of osteocytes. Furthermore, the CMC-containing scaffold design proposed in this study is expected to have a substantial impact on promoting ossification of BMSCs.

Novel thermally conductive coating for cotton fabrics based on reduced graphene oxide decorated with in situ synthesized silver nanoparticles

The application of thermally conductive materials as coating on fiber surfaces represents an innovative technology solution for conveying heat dissipation capability to IR-opaque textiles. In this work, a sustainable and scalable approach to manufacture a hybrid nanocomposite coating for cotton, formed by Reduced Graphene Oxide (RGO) sheets functionalized by histidine (His) and decorated by Ag nanoparticles (NPs), is reported for increasing thermal conductivity of cotton fabrics. Tens nm in size Ag NPs were synthesized, in situ, at the coordinating sites of the His-RGO modified cotton impregnated by H2O/CH3OH solutions of the AgNO3 precursor, under UV-light exposure, without using chemical reductants. The physical chemical properties of the nanocomposite modified fabrics were comprehensively investigated, integrating chemical, structural and morphological analysis, with characterizations of their thermal, electrical, oxygen permeability, surface wettability and mechanical properties. Thermal conductivity of cotton was measured by Differential Scanning calorimetry (DSC) technique, which was here validated by Transient Plane Source (TPS) method, assessing the effectiveness of DSC in measuring thermal conductivity of textiles. The resulting coating exhibits a thermal conductivity, which was twice as high as untreated cotton, maintaining its breathability, increasing its flexibility, while simultaneously reducing its wettability. This notable enhancement can be attributed to the synergistic effect of the conductive Ag nanostructures formed among the His-RGO sheets within the nanocomposite, and it matches the thermal conductivity achieved by current state-of-the-art methods, while offering additional advantages of being more eco-friendly, scalable, and sustainable. The reported characterization of the structural properties of the achieved coating opens the venue to interesting perspectives towards its application in passive conducting cooling textiles for personal thermal comfort management.

Bioinspired skin-like in vitro model for investigating catheter-related bloodstream infections

Intravenous (IV) catheter-related bloodstream infections (CRBSIs) cause significant risks in healthcare, necessitating advancements in catheter design and materials. This study investigates the effectiveness of Ecoflex, a silicone-based material, in studying CRBSIs through the development of skin-like replicas that mimic human skin properties for use in wearable sensing devices. We characterized the replica’s bioinspired surface roughness, wettability, bacterial adhesion, and mechanical properties and validated its performance using in vitro IV simulation. The results demonstrated that the bioinspired model replicates human skin textures with less than 7.5% error for surface roughness ranging from 0.05 μm to 6.3 μm. Wettability tests revealed that the artificial sebum application significantly reduced the static contact angles for deionized water and artificial sweat. Comprehensive mechanical testing revealed material high elasticity and resilience, suitable for dynamic biomedical applications. Bacterial adhesion studies using Staphylococcus epidermidis showed varying adhesion patterns influenced by surface roughness, highlighting the potential for material texture to impact infection risk. In IV therapy simulations, we observed bacterial growth dynamics over the incubation period. Our findings suggest that Ecoflex-based skin-like replicas can serve as a valuable tool for developing and testing new catheters, while the potential for use in other medical innovation devices, including wearable sensing devices, ultimately contributes to improved patient outcomes and infection control strategies.

Surface modification and patterning of polymer thin films by plasma and adsorption behavior of proteins

The surface wettability property of hydrophobic polystyrene (PS) and hydrophilic polyethylene glycol (PEG) thin films subjected to modification by direct current plasma glow discharge is studied. The polymer films exhibited change of surface wettability on exposure to air, nitrogen, oxygen or argon plasmas. In PS films a swift modification to hydrophilic surface and subsequent steady recovery following first order kinetics are observed. The rate of modification and recovery are adjustable by adjusting the plasma ambient and parameters, and additional wet-chemical treatment using ionic solutions. In PEG films the hydrophobic wettability evolve with ageing following the first order kinetics, and is stable for long period on exposure to air ambient. Moreover, a vapor deposition like process is possible using the PEG films as source to deposit self-assembled molecular layers with hydrophobic wettability on other surfaces. Using surface modification or molecular deposition processes, the fabrication of wettability patterns in the surface of PS and PEG films, and on other surfaces by vapor transport using PEG films, and also the possibility to produce gradient wettability patterns are demonstrated. Moreover, the adsorption behavior of immuno-specific system of proteins on surface modified hydrophilic PS films is studied.

Surface Activation of Cotton Fabric with Low-Temperature Air Plasma Treatment for Metallic Printing

In this investigation, air plasma treatment was utilised to activate the surfaces of 100% grey and bleached cotton fabrics in preparation for metallic pigment printing. The study delved into the surface morphology, wettability, and surface chemistry properties. Scanning electron microscopy (SEM) revealed roughness and grooves in the treated samples. The contact angle witnessed a 29% and 41% increase for grey and bleached fabrics, respectively, compared to their untreated counterparts. Surface chemistry analysis using FTIR and XPS provided crucial insights into the functional polar groups, such as OH and C=O, along with significantly elevated O1 peaks in both plasma-treated grey and bleached cotton fabrics. These findings contributed to the enhanced surface free energy of the fabrics, preparing them for the subsequent pigment printing process. The study explores the impact of plasma treatment on the colour fastness of grey and bleached cotton fabrics printed with gold and silver metallic pigments. Untreated fabrics exhibited poor durability, with low colour change and staining-resistance ratings, particularly for gold pigments. Plasma treatment significantly improved colour retention, adhesion, and resistance to staining for both metallic pigments, with silver outperforming gold. Rubbing fastness tests revealed that plasma treatment moderately enhanced durability, though gold remained susceptible to friction damage. Light fastness was excellent for both pigments, and plasma treatment further improved performance. Perspiration tests showed that plasma treatment bolstered resistance, particularly for gold. These findings suggest that plasma treatment enhances the stability of metallic pigments, offering potential applications in the textile industry for improved product quality and durability.

Effects of Incorporating TiO2 Aggregates on the Growth, Anticorrosion, and Antibacterial Properties of Electrodeposited Multifunctional Coatings Based on Sn-Ni Materials

Multifunctional coatings based on Sn-Ni materials with and without titanium oxide nanoparticles (TiO2NPs) incorporation were prepared using the electrochemical deposition technique at 70 °C. TiO2NPs were dispersed in the electrolyte bath, and their influence on the surface texture, crystalline phase, and properties was investigated. Various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray microanalysis (EDX) were used to characterize the prepared coatings. The formation mechanism of the deposited coatings has been demonstrated to be consistent with the electrochemical behavior of instantaneous growth, and the three-dimensional growth is controlled by diffusion phenomena. The anticorrosion effectiveness of the coatings was assessed using potentiodynamic polarization curves and electrochemical impedance spectroscopy in an artificial sweat medium, while the bactericidal activity of the composite coatings (the ability to induce cell death) was evaluated in accordance with the ISO 27447:2019 test. The influence of TiO2NPs at a low concentration of 1 g/L on the composition, structure, and properties of the deposited coatings was demonstrated. Particular attention was paid to the relationship between the anticorrosive and bactericidal properties of the coatings and their structure composition and wetting properties. The synergistic effect of chemical composition and surface-wetting properties has been demonstrated to enhance the anticorrosive and bactericidal properties of the prepared coatings.

Hydrophobic surface texture air-liquid phase composite assisted laser processing and tribological properties

In order to improve the surface hydrophobicity and tribological properties of 304 stainless steel, this study used laser processing technology to prepare three types of surface textures (CSA, CM2, CM5) in an air and air–liquid composite environment. By testing the surface quality, wettability and tribological properties of the texture, it was found that the surface quality and interfacial friction control ability of CSA were poor due to the influence of the processing environment. However, due to the air–liquid composite assisted laser preparation, while using the air medium laser processing technology to ensure the texture depth, the scattering effect of bubbles and the influence of negative pressure on the solid–liquid interface during the liquid phase assisted laser processing remove the oxide recast layer and burr on the surface of the sample, and improve the surface quality of the texture, thereby improving the surface friction behavior of the sample. This study promotes the development of surface texture laser processing technology and broadens the application field of 304 stainless steel.

Preparation and Properties Improvement of Decynediol-Ethoxylate-Modified Trisiloxane Surfactant.

Silicone surfactants are increasingly used in the industrial field due to their advantages such as low surface energy, stable performance, and good biocompatibility. However, many polyether-modified silicone surfactants' foam stability and easy hydrolysis in non-neutral aqueous systems limit their application in many fields. In this article, the decynediol-ethoxylate chain segment was grafted onto heptamethyltrisiloxane to synthesize a modified trisiloxane surfactant (G2). FT-IR and 1H NMR characterized its structure. Its surface activity, aggregation behavior, and wetting and spreading properties in water were studied by using instruments such as a surface tension meter, transmission electron microscope (TEM), dynamic light scattering (DLS), and contact angle tester. G2 can reduce the surface tension of water to 19.24 mN/m at a lower CMC (40.44 mg/L), and the foaming properties and hydrolysis stability of decynediol-ethoxylate-modified trisiloxane (G2) in water are significantly improved compared with allyl-polyoxyethylene-ether-modified trisiloxane (X5).

Biomimetic super-wetting membranes via in-situ growth and synchronous integration of ZIF nanoleaves (ZIF-Ls) for emulsified oily wastewater purification and catalytic Knoevenagel condensation

To address the increasingly severe oil spill accidents and water contamination, the development of super-wetting membranes with high oil/water separation efficiency is in great demand but remains challenging. The critical challenge lies in the rational design and fabrication of robust rough surface with hierarchical micro/nano-structure. In this study, biomimetic super-wetting polyacrylonitrile composite membrane was developed through in-situ synthesis and synchronous integration of zeolitic imidazolate framework nanoleaves (ZIF-Ls). Thorough investigation was conducted to assess the effect of the ZIF-Ls growth time on membrane morphology and surface wetting property. Incorporating the nanoleaf-like ZIF-Ls onto the surface of the membrane provided the surface with micro/nano rough structure and superamphiphilic/superlyophobic features. The prepared membrane showed great separation capability toward various O/W and W/O emulsions, and could be easily regenerated by employing a simple rinsing and drying procedure with high separation efficiency sustained even after multiple separation cycles. Moreover, the membrane with ZIF-Ls demonstrated outstanding catalytic performance in the Knoevenagel condensation. This study achieves advancements in the development of super-wettable membranes with outstanding performance in separating emulsions and the as-prepared membranes have the potential to serve as promising candidates for practical oily mixture treatment.

Effects of chemical etching on surface structure and tribological behavior of silicate substrates

Abstract This study investigated the effect of chemical etching on the surface structure and tribological behavior of silicate substrates. Silicate surfaces were etched using a mixture of nitric acid (HNO3) and ammonium bifluoride (NH4HF2) for durations ranging from 1 to 60 min. The etched surfaces were characterized using optical microscopy, scanning electron microscopy, surface profilometry, water contact angle measurements, and UV–vis spectroscopy to evaluate the changes in surface morphology, roughness, wettability, and optical properties. Tribological performance was assessed using reciprocating ball-on-plate friction tests. The results showed that increasing the etching time resulted in the formation of microscale surface features, increased surface roughness, enhanced hydrophilicity, and reduced optical transmittance. The average friction coefficient decreased with an increase in the etching time up to 30 min, beyond which a slight increase was observed. The 1-minute etched specimen exhibited the best wear resistance with the narrowest wear track and the least material removal. The improved tribological performance was attributed to the formation of a stable transfer film, reduced real contact area, and entrapment of wear debris. This study highlights the potential of chemical etching as a technique to tailor the surface structure and tribological properties of silicate materials for various applications.

Adsorption, Adhesion, and Wettability of Commercially Available Cleansers at Dental Polymer (PMMA) Surfaces.

This study aims to evaluate the adsorptive, adhesive, and wetting energetic properties of five commercially available cleansers in contact with model dental polymer (PMMA). It was assumed that the selected parameters allow for determining the optimal concentration and place of key component accumulation for antibacterial activity in the bulk liquid phase and prevention of oral plaque formation at the prosthetic material surface. The adsorptive (Gibbs' excesses ΓLV, critical micellar concentration) and thermal (entropy and enthalpy) surface characteristics originated from surface tension γLV(T) and γLV(C) dependences. The surface wetting properties were quantified upon the contact angle hysteresis formalism on the advancing ΘA, receding ΘR contact angles, and γLV as the input data, which yield a set of wettability parameters: 2D adsorptive film pressure, surface free energy with its dispersive and polar components, work of adhesion, and adhesional tension, considered as interfacial interaction indicators. In particular, molecular partitioning Kp and ΓLV are indicators of the efficiency of particular active substance accumulation in the volume phase, while γSV, a = ΓSL/ΓLV, and WA point to the degree of its accumulation at the immersed polymer surface. Finally, the liquid penetration coefficient PC and the Marangoni temperature gradient-driven liquid flow speed were estimated.

Customized surface adhesive and wettability properties of conformal electronic devices.

Conformal and body-adaptive electronics have revolutionized the way we interact with technology, ushering in a new era of wearable devices that can seamlessly integrate with our daily lives. However, the inherent mismatch between artificially synthesized materials and biological tissues (caused by irregular skin fold, skin hair, sweat, and skin grease) needs to be addressed, which can be realized using body-adaptive electronics by rational design of their surface adhesive and wettability properties. Over the past few decades, various approaches have been developed to enhance the conformability and adaptability of bioelectronics by (i) increasing flexibility and reducing device thickness, (ii) improving the adhesion and wettability between bioelectronics and biological interfaces, and (iii) refining the integration process with biological systems. Successful development of a conformal and body-adaptive electronic device requires comprehensive consideration of all three aspects. This review starts with the design strategies of conformal electronics with different surface adhesive and wettability properties. A series of conformal and body-adaptive electronics used in the human body under both dry and wet conditions are systematically discussed. Finally, the current challenges and critical perspectives are summarized, focusing on promising directions such as telemedicine, mobile health, point-of-care diagnostics, and human-machine interface applications.

Modeling bacterial transport and fate: Insight into the cascading consequences of soil water repellency and contrasting hydraulic conditions

The mechanisms governing bacteria transport and fate rely on their hydrophobicity and the wettability of porous media across a wide range of soil moisture conditions, extending from extreme dryness to highly saturated states. However, it largely remains unknown how transport, retention, and release mechanisms change in natural soil systems in such conditions. We thus optimized our previously published unique transport data for hydrophilic Escherichia coli (E. coli) and hydrophobic Rhodococcus erythropolis (R. erythropolis) bacteria, and bromide (Br−) in two distinct wettable and water-repellent soils at column scale. The soils were initially dry, followed by injecting influents in two pulses followed by a flushing step under saturated flow conditions for six pore volumes. We conducted simulations for each pulse separately and simultaneously for soils. There were differences in hydraulic properties of the soils due to their contrasting wetting characteristic in separate and simultaneously modeling of each pulse affecting Br− and bacteria transport fate. Bacteria attachment was the dominant retention mechanism in both soils in these conditions. Notably, the 82.4 min−1 attachment rate in wettable soil was almost 10× greater than in the water-repellent soil and it governed optimization of bacteria die-off. Physicochemical detachment and physical release unraveled the effect of bacteria size and hydrophobicity interacting with soil wettability. The smaller and hydrophobic R. erythropolis detached more easily while hydrophilic E. coli released; the rates were enhanced by soil water repellency. Further research is needed to reveal the effects of surface wettability properties on bacteria survival especially at the nanoscale.

Omniphobic Photoresist‐Assisted Patterning of Porous Polymethacrylate Films

AbstractPatterning of various surface properties, including roughness, wettability, adhesiveness, and mechanical properties, can markedly enhance the functionality of test systems. Thus, porous polymethacrylates prepared by polymerization‐induced phase separation (PIPS) represent a promising class of functional materials for the construction of miniaturized test systems. Different porosity, surface chemistry, and wettability are achieved in porous polymethacrylates with different precursor compositions. Nevertheless, only wettability microstructuring has been highlighted for these materials thus far. Here, the study presents a novel method for the direct and selective deposition of porous polymethacrylate films with different surface chemistry and porosity. The selective adhesion of omniphobic–omniphilic wettability patterns is used to facilitate the polymer pattern formation. The feasibility of patterning with different monomers and porogenic solvents is demonstrated. The topological study confirms the selective application of polymer structures with different thickness and roughness. The wettability characterization of the omniphobic material shows no significant changes caused by the operations performed. Thus, a new pattern with a greater difference in the wettability of the areas is produced in the process. Discontinuous dewetting of different liquids is performed. The use of poly(2‐hydroxyethyl methacrylate‐co‐ethylene dimethacrylate) (HEMA‐EDMA) modified patterns for precise living cell patterning is also demonstrated.