High Contact Angle Research Articles

Rapid identification of pathogenic bacteria using data preprocessing and machine learning-augmented label-free surface-enhanced Raman scattering

Despite the advantages of label-free surface-enhanced Raman scattering (SERS) for bacterial detection, the effective implementation of this approach is hindered by several intrinsic limitations, such as the uniformity and spectral similarity of bacterial SERS spectra. In this study, we developed a machine learning (ML)-integrated hydrophobic SERS platform for sensitive bacterial detection and classification. The hydrophobic Si wafer was successfully fabricated through treatment with dimethyldichlorosilane (DMDCS), resulting in a high contact angle (> 100°). To achieve the highest SERS signals for bacteria, the density of gold core–silver shell nanoparticles (Au@AgNPs) was adjusted. Subsequently, the SERS activity of the Au@AgNPs under the coffee-ring effect on normal Si substrates was compared with that under the local concentration effect on hydrophobic Si substrates. Notably, the SERS signal for bacteria detected from the hydrophobic SERS platform, which enabled local enrichment of bacteria and Au@AgNPs, was approximately 33 times higher than that obtained from the normal Si substrates. Moreover, this hydrophobic SERS platform was integrated with ML algorithms to enhance the accuracy of bacterial detection. By applying three data preprocessing techniques, including baseline correction, smoothing, and normalization, we achieved 100 % accuracy in classifying SERS signals for four bacterial species. Our simple and versatile hydrophobic SERS platform, combined with ML models, exhibits immense potential for label-free detection and classification of pathogenic bacteria.

Patterned durable superhydrophobic and UV protective cotton fabric prepared through inkjet printing of Zn-based MOFs and long alkyl chain siloxane.

In order to solve the problems of high energy consumption, high raw material consumption and poor air permeability of fabrics in the dip-baking method, a simple low-liquid inkjet printing method was used to prepare superhydrophobic cotton fabrics. Inkjet printing technology enables precise control over the printing position and droplet amount, allowing for the creation of superhydrophobic patterns on the fabric surface. ZIF-8 precursor solution and long alkyl chain siloxane were formulated as suitable inks and printed on the surface of the fabric, forming a rough interface with low surface energy. The surface micromorphology and chemical structure of the fabric samples were characterized in detail. The prepared ZIF-HDTMS-cotton fabric exhibited superhydrophobic property with a high water contact angle of 158° and self-cleaning property against liquid and solid contaminants. Importantly, after undergoing a variety of harsh damage tests, the modified fabric still exhibited good superhydrophobicity, indicating its favorable chemical stability and mechanical durability. Compared to raw cotton fabric, the treated fabric exhibited an air permeability rate of 311.6L/m2/s, proving its excellent breathability. Due to the high absorption capacity of ZIF-8 to ultraviolet rays, the prepared cotton fabric has obtained a certain ultraviolet protection effect. In addition, through infrared camera observation, it is found that the ZIF-HDTMS-cotton fabric also has a good anti-permeation effect on hot water, which can play a role in preventing scalding. These findings pave the way for the development of patterned multifunctional textiles through precise inkjet printing technology.

Optimizing oil-water separation using fractal surfaces.

Oil has become a prevalent global pollutant, stimulating the research to improve the techniques to separate oil from water. Materials with special wetting properties-primarily those that repel water while attracting oil-have been proposed as suitable candidates for this task. However, one limitation in developing efficient substrates is the limited available volume for oil absorption. In this study, we investigate the efficacy of disordered fractal materials in addressing this challenge, leveraging their unique wetting properties. Using a combination of a continuous model and Monte Carlo simulations, we characterize the hydrophobicity and oleophilicity of substrates created through ballistic deposition (BD). Our results demonstrate that these materials exhibit high contact angles for water, confirming their hydrophobic nature while allowing significant oil penetration, indicative of oleophilic behavior. The available free volume within the substrates varies from 60% to 90% of the total volume of the substrate depending on some parameters of the BD. By combining their water and oil wetting properties with a high availability of volume, the fractal substrates analyzed in this work achieve an efficiency in separating oil from water of nearly 98%, which is significantly higher compared to micro-pillared surfaces made from the same material but lacking a fractal design.

Single-Step Production of Doubly Re-entrant Microstructures Through Reaction-Diffusion Photolithography for Omniphobic Surfaces.

Omniphobic surfaces, which repel virtually any liquid regardless of its wettability, have been developed using doubly re-entrant microstructures. Although various microfabrication techniques have been explored, these often require multiple complex steps. In this study, reaction-diffusion photolithography (RDP) is used to fabricate micropost arrays with doubly re-entrant geometries through a single-step ultraviolet (UV) exposure process. To create a doubly re-entrant structure consisting of a central, elongated micropost topped with a short ridge, a photomask featuring a circular window surrounded by a narrow ring-shaped window is employed. This configuration is utilized in the RDP process, which relies on radical polymerization. Vertical growth of the structure from the photomask is achieved by introducing strong UV attenuation along the vertical axis, enabled by increasing the photoinitiator concentration. Concurrently, the growth of the ridge is slowed down by designing the ring window with minimal dimensions. This promotes rapid oxygen diffusion into the ring region, where the radicals generated by UV exposure are consumed through reactions with oxygen, thereby delaying the polymerization. This approach enables precise fabrication of full-length central microposts with short ridges in a single step. The resulting doubly re-entrant structures show high contact angles across various liquids and exhibit robust omniphobic performance.

Superhydrophobic Nanocoatings Fabricated by Materials with Low Young's Contact Angle.

To achieve superhydrophobicity with an apparent contact angle (θ*) greater than 150° on rough surfaces, materials with a high Young's contact angle (θY > 90°) are commonly utilized. However, achieving superhydrophobicity with θY < 90° materials without specific auxiliary designs faces unknown challenges. Here, we develop a novel superhydrophobic nanocoating with θ* of ∼155° sprayed by an ethanol suspension only composed of bisphenol A epoxy resin (EPA) with a low θY of ∼70° and hydrophilic SiO2 nanoparticles. Additionally, we also show more superhydrophobic nanocoatings created by low θY resins that even down to 58°. This superhydrophobicity results from sustained three-dimensional hydrogen bonding equilibrium on the droplet surface postcontact with the rough surface, despite low θY. We also constructed a wetting transition model to quantify the impact of surface energy on the stability of droplet surface structures and revealed how the concentration of EPA can regulate the wetting behavior of the coating.

The effects of anodization and instrumentation on titanium abutment surface characteristics and biofilm formation.

To assess the impact of anodization and instrumentation on titanium abutment surface characteristics (surface roughness and wettability) and biofilm formation (viability and mass). Titanium discs were obtained from pre-milled abutment blanks made of titanium-6aluminum-7niobium alloy. Polished samples were divided into three groups: un-anodized, gold-anodized, and pink-anodized. Instrumentation methods included no-instrumentation, air polishing, and titanium scaling treatment. Surface roughness was measured using an optical profilometer, and wettability was determined by measuring the contact angles using the sessile drop method with an optical tensiometer. Biofilm formation by Streptococcus sanguinis was evaluated based on the biofilm viability and mass. The biofilm viability was evaluated through colony-forming unit counting (CFU/mL), and biofilm mass was assessed with crystal violet staining (mean absorbance measured at 490nm, in optical density values). Sample surfaces before and after biofilm formation were also examined by scanning electron microscope (SEM). Two-way ANOVA was performed to determine the group differences, and Spearman's correlation (ρ) was used to analyze the correlation among surface roughness, wettability, and CFU/mL (α=0.05). Pink anodization significantly increased surface roughness (0.38±0.07µm, p<0.001) compared to un-anodized samples (0.25±0.01µm), while gold anodization did not (0.24±0.03µm, p=0.301). Among pink-anodized groups, air polishing resulted in significantly lower surface roughness (0.33±0.08µm) compared to titanium scaling (0.51±0.11µm, p<0.001) and no instrument treatment (0.38±0.07µm, p=0.050). Anodization significantly increased wettability (p<0.001), while instrumentation with a titanium scaling decreased it (p<0.001). The combination of un-anodized samples and titanium scaling treatment showed the lowest wettability with the highest contact angle (70.72±2.63°). The biofilm viability, measured by CFU/mL, was significantly inhibited by anodization (p<0.001) and air polishing (p<0.001) while promoted by titanium scaling (p<0.001). Gold-anodized titanium discs subjected to air polishing exhibited the lowest CFU/mL (279,420±16,300), while un-anodized samples instrumented with a titanium scaler had the highest CFU/mL (945,580±13,580). Biofilm mass, quantified by optical density values, was significantly inhibited by anodization (p<0.001) as well as air polishing (p=0.001). A moderate negative correlation was observed between CFU and wettability (ρ=-0.55, p<0.001). Gold- and pink-anodized titanium surfaces were more hydrophilic, leading to less biofilm formation than un-anodized ones. Biofilm formation was inhibited by air polishing while promoted by titanium scaling. Gold anodization combined with air polishing had the least biofilm formation and can be considered the preferred abutment anodization/instrumentation combination.

Imidazolium-Based Ionic Liquid Exhibiting Dual Hydrophilic and Oleophobic Properties without Polar End Groups.

Simultaneously hydrophilic and oleophobic surfaces offer substantial advantages for applications such as antifogging, self-cleaning, and oil-water separation. It remains challenging to engineer such surfaces without requiring polar functional groups. This study introduces HFIL, a novel ionic liquid (IL) coating that achieves simultaneous hydrophilic and oleophobic properties via a one-step dip-coating process without relying on polar functional groups. Key findings show that, despite the bulk form of HFIL having a high hexadecane contact angle (HCA) of 74.1° and an even higher water contact angle (WCA) of 87.6°, the IL forms a stable monolayer on high-energy surfaces exhibiting a much lower WCA of approximately 40° with minimal change to the HCA. Washing tests demonstrate that, even without the polar functional groups, there is a non-zero bonded thickness upon which the oleophobicity is comparable to polytetrafluorethylene (PTFE). These properties highlight HFIL's potential for durable applications in antifouling, antifogging, and environmental separation technologies, where selective liquid interactions are essential. This work contributes to a broader understanding of IL-based surface modifications, advancing the development of high-performance coatings.

Adaptable, Dynamic, and Superhydrophobic Standing‐Fiber Surface with Muti‐Level Energy Barrier for Anti‐Icing

AbstractPassive deicing technologies achieved by dynamic superhydrophobic surfaces and slippery substances contribute to widely used anti‐icing. However, the constant status of microstructures cannot cater to the changing environment, meanwhile, the energy barrier needs to be improved. Here, a dynamic superhydrophobic standing‐fiber surface with a three‐level energy barrier is fabricated by electrical flocking technology, which directly utilizes the wind field to assist anti‐icing. The standing‐fiber surface has low ice adhesion of 2.7 kPa, a high water contact angle of 171.1°, and a long icing delay time of 859 s under −30 °C. The superhydrophobicity contributes to excellent water repellency with a droplet retracting and bouncing distance of 3.53 and 3.75 mm. In the wind field at 9 ms−1, the inclined standing‐fiber surface theoretically accelerates the motion of the water droplet by 1.5 times compared with the lying‐fiber surface. The difference in thermal conductivity between the front and back sides of the standing‐fiber surface makes it an ideal candidate for designing anti‐icing, deicing, and thermal insulation clothes.

Advancements in Superhydrophobic Paper-Based Materials: A Comprehensive Review of Modification Methods and Applications.

Superhydrophobic paper-based functional materials have emerged as a sustainable solution with a wide range of applications due to their unique water-repelling properties. Inspired by natural examples like the lotus leaf, these materials combine low surface energy with micro/nanostructures to create air pockets that maintain a high contact angle. This review provides an in-depth analysis of recent advancements in the development of superhydrophobic paper-based materials, focusing on methodologies for modification, underlying mechanisms, and performance in various applications. The paper-based materials, leveraging their porous structure and flexibility, are modified to achieve superhydrophobicity, which broadens their application in oil-water separation, anti-corrosion, and self-cleaning. The review describes the use of these superhydrophobic paper-based materials in diagnostics, environmental management, energy generation, food testing, and smart packaging. It also discusses various superhydrophobic modification techniques, including surface chemical modification, coating technology, physical composite technology, laser etching, and other innovative methods. The applications and development prospects of these materials are explored, emphasizing their potential in self-cleaning materials, oil-water separation, droplet manipulation, and paper-based sensors for wearable electronics and environmental monitoring.

Thermoformed, thermostable, waterproof and mechanically robust cellulose-based bioplastics enabled by dynamically reversible thia-Michael reaction.

Cellulose is a renewable biodegradable polymer derived from abundant natural resources. Substituting petroleum-based polymers with cellulose-based bioplastics is an effective way to alleviate environmental issues like resource depletion and white pollution. However, challenges such as poor thermostability, difficulty in thermoforming and water sensitivity seriously hinder the fabrication and use of cellulose-based bioplastics. Herein, a thermoformed, thermostable, waterproof and mechanically robust cellulose-based bioplastic (H-HEC) is fabricated by introducing thia-Michael-based reversible crosslinked structure into hydroxyethyl cellulose. This is the first instance of integrating thia-Michael-based crosslinked structure into cellulose derivatives. The resulting H-HEC can be thermoformed and remolded without adding any plasticizers. Besides, the obtained H-HEC exhibit excellent overall properties, such as a high thermal decomposition temperature of 366°C, a high water contact angle of 108°, a high transmittance of 90% and good mechanical properties. Additionally, H-HEC combines impressive transparency with effective UV-shielding properties. We envision that this work provides a novel method to prepare thermoformable cellulose-based bioplastics with good water resistance, thermostability, transparency and mechanical properties. The combined thermoformability and superior overall performances will promote the practical application of cellulose-based bioplastics and contribute to the replacement of petroleum-based polymer by cellulose-based bioplastics.

Increasing the waterproof performance of fatliquored leather by silane modification: a simple and feasible green treatment method.

Waterproof fatliquoring agents can transform leather from a hydrophilic state to a hydrophobic state in the wet process of leather production. However, traditional waterproof fatliquoring agents may cause environmental pollution. Fluorocarbons in fluorinated fatliquoring agents are difficult to degrade, and polyacrylic acid fatliquoring agents require chromium powder fixation. In this work, we proposed a simple and green leather waterproofing strategy through the wet process. The strategy used silane coupling agents, water, and ethanol to waterproof the fatliquored leather. The results indicated that leather exhibited excellent waterproof performance when treated with 20% hexadecyltrimethoxysilane (TMS16), 20% water and 300% ethanol at 30 °C for 6 hours. The water contact angle (WCA) of leather was greater than 120° and maintained lasting hydrophobicity, which can still sustain a high contact angle after 30 minutes. In addition, the physical properties of the leather were significantly improved. After the TMS16 treatment, the tensile strength of the leather increased from 4.82 MPa to 12.45 MPa, the tear strength increased from 77.07 N mm-1 to 125.01 N mm-1, and the elongation at break increased from 47.03% to 66.71%. This leather waterproofing strategy is environmentally friendly, and the process is simple.

Studying a droplet impaction on a vibrating porous medium

This study investigates the influence of vibration on droplet dynamics when a droplet impacts a three-dimensional (3D) structured porous medium, focusing on intrinsic properties such as porosity and wettability, along with the effect of vibration phase angle. Using an Allen-Cahn equation-based lattice Boltzmann method (A-C LBM), the research analyzes multiphase flow dynamics. The results compare droplet spreading and penetration on vibrating versus non-vibrating porous media. Without vibration, droplets get trapped within the pores, reaching equilibrium due to adhesive, viscous, and capillary forces. However, sufficient vibrational forces can overcome surface adhesion, allowing droplets to pass through the porous medium. This phenomenon is influenced by the droplet's contact angle and initial impact inertia. The study finds that hydrophobic surfaces, characterised by higher contact angles, significantly reduce liquid infiltration into the medium under both vibrational and non-vibrational conditions. This reduction is due to dominant surface tension and repellent forces, which, in combination with vibrational forces, minimise droplet spreading and penetration, even in highly porous media. Conversely, on hydrophilic surfaces, adhesive and capillary forces enhance the droplet's inertia, causing sudden penetration into the porous medium. Further, the study reveals that the phase angle of vibration critically affects the droplet's behaviour. With sinusoidal vibration, lower phase angles cause the porous medium to move in the opposite direction to the droplet, enhancing the synergy between vibration and inertia forces, leading to rapid infiltration. Higher phase angles, aligning the medium's movement with the droplet's impact path, result in reduced infiltration. Overall, this research provides crucial insights into how porosity, wettability, and vibration phase angle collectively influence droplet dynamics on structured porous media, offering valuable implications for applications involving fluid transport and filtration in porous structures.

Cellulose-based encapsulation for all-printed flexible thermoelectric touch detectors

Printed and flexible electronics have gained considerable scientific attention in recent years, driving the demand for low-energy production techniques, eco-friendly materials and flexible substrates. However, effective encapsulation is essential to protect these devices in harsh environmental conditions. Thus, sustainable encapsulant materials are critical for advancing flexible electronics. In this work, we studied three encapsulant materials—commercial plastic, polyvinyl alcohol and ethyl cellulose—applied to thermoelectric touch sensors printed on paper and fabric substrates. Ethyl cellulose demonstrated promising properties in terms of flexibility, water resistance and transparency, along with a low carbon footprint. Encapsulated substrates with ethyl cellulose exhibited high contact angles (121° on fabric and 116° on paper), indicating robust water repellency. Thermal stability tests showed minimal mass loss (10%) at 315 °C, confirming its temperature resilience. Furthermore, sensors encapsulated with ethyl cellulose retained their electric performance after water submersion for 1 min and withstood 100 bending cycles, maintaining response times below 1 s and signal output around 100 µV. These findings highlight ethyl cellulose as a viable green encapsulant material compatible with large-scale sustainable electronics manufacturing.

In Vitro Comparison of Surface Characteristics and Bacterial Adhesion in Composite Resin-Based Materials for Additive, Subtractive, and Conventional Manufacturing.

This study aims to compare the surface roughness (SR), contact angle (CA), surface free energy (SFE), and bacterial adhesion of resin-based materials used in additive, subtractive, and conventional manufacturing techniques. This study involved four groups of 23 specimens: Indirect conventional resin composite (ICRC), subtractively manufactured resin composite (SMRC), additively manufactured resin composite (AMRC), and soda-lime-silica glass (SLSG). One specimen per group was analyzed by Energy Dispersive X-ray Spectroscopy (EDS) before polishing. Following the polishing procedure, SR, CA, and SFE were measured. The sterilized specimens were divided into two subgroups for Streptococcus mutans and Streptococcus mitis adhesion. One randomly selected specimen from each group was also reserved for visualization of bacterial adhesion using Scanning Electron Microscopy (SEM), and bacterial adhesion was quantified in the remaining specimens (n=10). Data for SR, CA, SFE, and bacterial adhesion were analyzed using one-way ANOVA, Tukey post-hoc tests, and Pearson correlation (α = .05). Among the resin groups, the ICRC group had the lowest SR values (P < .001). The higher CA was observed in the SMRC group than AMRC (P = .016). AMRC displayed significantly lower S. mitis adhesion compared to ICRC and SMRC (P < .001 and P = .003, respectively). A positive correlation was found between SR and S.mutans adhesion (R = .455, P < .003). Resin materials designed for different manufacturing techniques exhibited diverse surface characteristics. Nevertheless, the 3D printable permanent resin demonstrated comparable S. mutans adhesion to that of ICRC and SMRC.

One-Step Fabrication Process of Silica-Titania Superhydrophobic UV-Blocking Thin Coatings onto Polymeric Films.

Developing a durable multifunctional superhydrophobic coating on polymeric films that can be industrially scalable is a challenge in the field of surface engineering. This article presents a novel method for a scalable technology using a simple single-step fabrication of a superhydrophobic coating on polymeric films that exhibits excellent water-repelling and UV-blocking properties, along with impressive wear resistance and chemical robustness. A mixture of titanium precursors, tetraethylorthosilicate (TEOS), hydrophobic silanes and silica nano/micro-particles is polymerized directly on a corona-treated polymeric film which reacts with the surface via siloxane chemistry. The mixture is then spread on polymeric films using a Mayer rod, which eliminates the need for expensive equipment or multistep processes. The incorporation of silica nanoparticles along with titanium precursor and TEOS results in the formation of a silica-titania network around the silica nanoparticles. This chemically binds them to the activated surface, forming a unique dual-scale surface morphology depending on the size of the silica nanoparticles used in the coating mixture. The coated films were shown to be superhydrophobic with a high water contact angle of over 180° and a rolling angle of 0°. This is due to the combination of dual-scale micro/nano roughness with fluorinated hydrocarbons that lowered the surface free energy. The coatings exhibited excellent chemical and mechanical durability, as well as UV-blocking capabilities. The results show that the coatings remain superhydrophobic even after a sandpaper abrasion test under a pressure of 2.5 kPa for a distance of 30 m.

Control of the Wetting Ability of a Material by Local Vibration on the Interfacial Layer

The possibility of controlling the wetting ability of a material synthesized in the interfacial layer of a heterogeneous liquid/liquid system by local vibration has been shown. The influence of the nature of the organic acid, metal and solvent on the contact angle of the interfacial layer material adhering to various substrates was studied. It has been established that with local vibration, a material with a more ordered structure, with higher roughness and lower water content, and, as a consequence, with a higher contact angle, is synthesized. On the studied substrates, hydrophobic coatings with contact angles of 100–163° were obtained, which retained their water-repellent properties under atmospheric conditions for a long time.

Dynamic covalent bonds enabled robust and self-healing superhydrophobic coatings with multifunctions

Inspired by plants and animals in nature, durable superhydrophobic surfaces have been successfully developed in the past decades. However, the practical application of these superhydrophobic surfaces suffers from poor mechanical and chemical stability after damage or longtime usage. Thus, effective silicone-based polymers are developed to prepare the intelligent self-healing and durable superhydrophobic coatings with multifunctions. The superhydrophobic coatings are composed of dynamic silicone polymers and silica nanoparticles, which can be applicable in various substrates with enhanced water repellency. The abundant hydrogen bonds and reversible B-O covalent bonds in the dynamic silicone polymers enable a strong binding force with the substrate and self-healing nature. Thus, the superhydrophobic coatings exhibit a high contact angle up to 159.3°, and a low sliding angle of 6.9°. Meanwhile, it displays mechanical stability against washing and abrasion damage, and chemical stability in acid and alkaline environment. Especially, it is capable of repairing the superhydrophobicity after damage due to the reversible association/dissociation of dynamic B-O covalent bonds in silicone polymers. In addition, the superhydrophobic cotton fabric shows excellent anti-fouling, self-cleaning, antibacterial property, and can be applied in oil–water separation with high efficiency. This robust and versatile superhydrophobic coatings without containing perfluoro-compounds are promising in commercial textile fishing treatment with low cost.

Effect of Bio‐Based Plasticizers From Modified Vegetable Oils in a New Formulation of PVC Materials

ABSTRACTThis study investigates the performance of polyvinyl chloride (PVC) plasticized with diisononyl phthalate (DINP), rapeseed oil epoxidized ester (ROE), and rapeseed oil carbonated ester (ROC). The formulations were evaluated for surface resistance, wettability, migration, mechanical properties, and resistance to aging and thermal degradation. PVC/ROC exhibited the highest surface resistance of 1.5 × 1016 Ω, indicating superior electrical insulation. Wettability tests showed PVC/ROE with the highest contact angle at 63°, while PVC/ROC and PVC/DINP demonstrated lower contact angles of 44° and 43°, respectively. Migration tests revealed that PVC/ROC had the lowest migration rates: 0.1% in distilled water and 1.5% in 95% ethanol. Mechanical testing under algae exposure demonstrated that PVC/ROC achieved the highest tensile strength of 43 MPa and a strain at break of 200%. After 1008 h of thermo‐oxidative aging, PVC/ROC retained superior tensile strength and hardness, while PVC/ROE showed a slight decrease. PVC/ROC also demonstrated improved thermal stability at 255°C compared with DINP (245°C). These results confirm that ROC is an effective bio‐based plasticizer, providing enhanced mechanical properties, reduced migration, and greater durability compared to conventional DINP, offering a sustainable alternative for diverse PVC applications in medical, automotive, and packaging industries.

Fluorinated waterborne polyurethane/SiO₂ nanoparticle dispersions for superhydrophobic foam fabrication: Physicochemical properties and oil/water separation studies

The rapid development of chemical industries and oil spills during extraction and transportation have caused severe environmental pollution. Polyurethane foams “PUF” are widely used to remove oil from water due to their three-dimensional porous networks, which provide high absorption capacity. However, their effectiveness in oil/water separation applications, may decrease with repeated use as a result of structural and chemical degradation, and loss of hydrophobicity. In this research, to address this limitation and increase in their long-term stability and durability, fluorinated waterborne polyurethanes containing Fluorolink E10-H-modified nano-silica (WPU/Fl@SiO2) were synthesized and applied to coat PUFs by the dip-coating technique. This strategy offers several advantages, including low VOC emissions, a one-stage and scalable modification method, minimal material usage, and reduced time and energy consumption. The prepared nanostructures, WPU nanocomposites, and modified foams were analyzed by FTIR, XRD, TGA, DLS, FE-SEM, contact angle, and oil/solvents removal tests. The findings confirmed that the PUF/W10 sample, coated with WPU-Fl@SiO2 containing 10 wt% of nanostructures, in addition to the high surface roughness, has the highest contact angle (164.9°) and superior adsorption capacity for Xylene (42 g/g) and ethyl acetate (52 g/g). Moreover PUF/W10 sample showed an acceptable oil/water performance after 50 absorption cycles compared to unmodified and other modified foam samples The PUF/W10 sample performed well in different temperature ranges and corrosive environments, including acidic, alkaline, and strong salt solutions. Moreover, this foam displayed a continuous, efficient, and selective oil/water separation capability under a simple vacuum system. This research highlights the potential of PUFs coated with WPU-Fl@SiO2 aqueous dispersion as effective and durable materials for oil/solvent separation from water.

Surface properties and biofilm formation on resins for subtractively and additively manufactured fixed dental prostheses aged in artificial saliva: Effect of material type and surface finishing

Statement of problemAdditive manufacturing (AM) and subtractive manufacturing (SM) have been widely used for fabricating resin-based fixed dental prostheses. However, studies on the effects of material type (AM or SM resin) and surface finishing (polishing or glazing) on the surface properties and biofilm formation are lacking. PurposeThe purpose of this in vitro study was to investigate the effects of material type and surface finishing on the surface roughness, wettability, protein adsorption, and microbial adhesion of the AM and SM resins marketed for fixed restorations under artificial saliva-aged conditions. Material and methodsDisk-shaped specimens (∅10×2 mm) were fabricated using 3 types of resins: AM composite resin with fillers (AMC), AM resin without fillers (AMU), and SM composite resin with fillers (SMC). Each resin group was divided into 2 subgroups based on surface finishing: polished (P) and glazed (G). Therefore, 3 polished surface groups (AMCP, AMUP, and SMCP) and 3 glazed surface groups (AMCG, AMUG, and SMCG) were prepared. Specimens were then categorized according to aging condition in artificial saliva. Surface roughness (Ra and Sa), contact angle, surface free energy (SFE), protein adsorption, and microbial adhesion were measured. The data were analyzed using a nonparametric factorial analysis of variances and post hoc tests with Bonferroni correction (α=.05). ResultsWhen nonaged, significant interactions between material type and surface finishing were detected for Ra, contact angle, SFE, protein adsorption, and microbial adhesion (P≤.008). AMCP showed higher Ra and microbial adhesion than AMUP and SMCP, and higher contact angle and protein adsorption than SMCP (P<.001). AMCG had lower SFE than AMUG (P=.005) and higher bacterial adhesion than SMCG (P<.001). AMC had higher Sa than AMU and SMC (P≤.006). When aged, significant interactions between material type and surface finishing were detected for Ra, Sa, protein adsorption, and microbial adhesion (P≤.026). The contact angle and SFE were significantly affected only by the material type (P≤.001), as AMC exhibited higher wettability than SMC (P≤.004). AMCP had higher Ra and microbial adhesion than AMUP and SMCP (P≤.003). AMCP had higher Sa and protein adsorption than SMCP (P≤.004). AMCG showed lower Ra and higher protein adsorption than AMUG (P≤.001). ConclusionsBoth material type and surface finishing significantly affected surface properties and biofilm formation. AMCP exhibited higher surface roughness, protein adsorption, and microbial adhesion compared with SMCP. Glazing may reduce the differences in surface-biofilm interactions between AMC and SMC.