Low Surface Energy Research Articles

Preparation of composite superhydrophobic coatings for mortar utilizing polydimethylsiloxane as a hydrophobic interconnection

Cement-based materials are prone to various contamination problems in aqueous environments, and superhydrophobic coatings are an effective solution to solve this problem. Polydimethylsiloxane (PDMS) is a low surface energy polymer with good mechanical properties, which has a wide range of applications in the field of superhydrophobic coatings. In this study, isobutyltriethoxysilane (IBTES) was employed to hydrophobically modify nano- SiO2, resulting in the modified particles with a core-shell structure to enhance the interfacial effect between the inorganic particles and organosilanes. Simultaneously, the organic-inorganic composite superhydrophobic coatings were prepared using PDMS as a hydrophobic interconnection. The waterproofing performance, self-cleaning performance, aging resistance, mechanical stability, and chemical durability of the coatings were investigated. The results indicate that the water contact angle of the IBTES@SiO2/PDMS composite coating can reach 163°, showing good resistant to contamination, self-cleaning, and mechanical stability. The IBTES@SiO2/PDMS composite coating can maintain the superhydrophobicity after the UV-accelerated aging and immersion in different pH values solutions.

AgNP Composite Silicone-Based Polymer Self-Healing Antifouling Coatings.

Biofouling poses a significant challenge to the marine industry, and silicone anti-biofouling coatings have garnered extensive attention owing to their environmental friendliness and low surface energy. However, their widespread application is hindered by their low substrate adhesion and weak static antifouling capabilities. In this study, a novel silicone polymer polydimethylsiloxane (PDMS)-based poly(urea-thiourea-imine) (PDMS-PUTI) was synthesized via stepwise reactions of aminopropyl-terminated polydimethylsiloxane (APT-PDMS) with isophorone diisocyanate (IPDI), isophthalaldehyde (IPAL), and carbon disulfide (CS2). Subsequently, a nanocomposite coating (AgNPs-x/PDMS-PUTI) was prepared by adding silver nanoparticles (AgNPs) to the polymer PDMS-PUTI. The dynamic multiple hydrogen bonds formed between urea and thiourea linkages, along with dynamic imine bonds in the polymer network, endowed the coating with outstanding self-healing properties, enabling complete scratch healing within 10 min at room temperature. Moreover, uniformly dispersed AgNPs not only reduced the surface energy of the coating but also significantly enhanced its antifouling performance. The antibacterial efficiency against common marine bacteria Pseudomonas aeruginosa (P.sp) and Staphylococcus aureus (S.sp) was reduced by 97.08% and 96.71%, respectively, whilst the diatom settlement density on the coating surface was as low as approximately 59 ± 3 diatom cells/mm2. This study presents a novel approach to developing high-performance silicone antifouling coatings.

Octadecylamine modified gelatin-based biodegradable packaging film with good water repellency and improved moisture service reliability

Industrial gelatin is a good candidate for fabricating biodegradable packaging film, but the strong hydrophilicity of gelatin-based film lowers its moisture service reliability. Herein, we demonstrated a low surface energy water repellency surface design combined with covalent cross-linking for decreasing the water absorption and improving the moisture service reliability. Biodegradable octadecylamine (ODA) was chosen as the low surface energy providing material to fabricate the water repellency surface through a dehydration condensation reaction between the amine groups of ODA and gelatin chains via tetra-hydroxymethyl phosphonium chloride (THPC) in an aqueous phase. THPC also was employed as the cross-linking agent to form covalent bonding between the gelatin chains. The results determined that ODA modification and covalent cross-linking endowed the gelatin-based film with good water repellency and improved moisture service reliability. But high dose of ODA would result in phase separation and mechanical strength loss of the fabricated film. Additionally, ODA modification did not change the biodegradability of gelatin-based film, all the modified films were completely biodegradable in natural soil. Considering the sustainable modification process and abundant raw materials, the proposed strategy facilitates the effective utilization of low value industrial gelatin and provides a facile way for gelatin-based film as biodegradable packaging film.

Self-growing composite photocatalytic materials for surface self-renewal of marine antifouling coatings

The attachment of marine organisms leads to the problem of marine biofouling. Biofouling can be prevented by using antifouling coatings this provided a low surface energy surface to inhibit the attachment of marine organisms. However, microorganisms inevitably attach during their use, leading to failure of the fouling release coating. To address this problem, we report an innovative strategy of doping photocatalytic materials into silicone coatings. This approach enables the degradation of bacterial carcasses and their secretions, leading to surface self-renewal and extended fouling protection. In this work, we report the controlled crystallisation of Ag-TiO2 nanomaterials (APTES-Ag@TiO2) using various methods influenced by aminopropylsilane. This strategy ensures the full utilisation of sunlight and strong interfacial adhesion, thereby preventing the degradation of photocatalytic performance. APTES-Ag@TiO2 not only has a self-growth effect and excellent photocatalytic performance but also facilitates the degradation of bacterial carcasses, thereby renewing the surface in organosilicon coatings.

The development of a porous nickel/polysiloxane superhydrophobic coating with long-time corrosion resistance properties

Superhydrophobic (SH) coatings have great potential to protect metals by reducing the contact area between metals and corrosive media. However, the poor mechanical stability of SH coatings restricts their potential applications. In this study, a nickel underlayer with a multi-hierarchical structure was deposited on the substrate using two-step electroplating in a nickel-plating bath. Finally, the SH coating was obtained by electrodeposition in an octamethyltrisiloxane solution. The morphology, composition, hydrophobicity, and corrosion resistance of SH coating were characterized using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), contact angle measurement, and electrochemical workstation. The prepared coating, with a water contact angle (WCA) of 157.5 ± 0.5° and a sliding angle (SA) of 4.3 ± 0.4°, exhibited excellent hydrophobicity due to the multi-hierarchical rough structure and low surface energy of the coating. The porous structure of the coating allowed its hydrophobic properties to be maintained even after 240 cm of sandpaper abrasion testing. After 20 days of immersion in 3.5 wt% NaCl solution, the coating still exhibited excellent corrosion resistance (icorr ∼ 1.01 × 10−8 A⋅cm−2) and hydrophobic properties (∼ 148.5 ± 0.5°), providing long-lasting protection to the substrate and prolonging its lifespan. This study introduces a strategy for preparing long-term corrosion-resistant SH coating on metallic surfaces.

Interfacial stability and electronic properties of YBCO/ABO3 heterostructures: A comparative DFT study

In this study, we utilized density functional theory (DFT) to analyze the interfacial properties of YBa2Cu3O7 (YBCO) with perovskite metal oxides LaAlO3 (LAO), KTaO3 (KTO), and SrTiO3 (STO). We focused on surface energies, lattice mismatches, strain energies, and adhesion energies to gauge the stability and compatibility of these interfaces. Our findings indicate that KTO exhibits the highest surface preference due to its lowest surface energy (0.054 eV/Å 2), suggesting superior surface stability. Moreover, LAO and STO show minor lattice mismatches with YBCO, implying effective interface integration, while YBCO/KTO interfaces experience significant strain due to extensive lattice mismatches. STO is distinguished by the lowest strain energy (0.07 eV), indicating minimal energy requirement for lattice mismatch accommodation, unlike KTO, which demonstrates high strain energy (0.42 eV) and potential structural distortions. The strongest interfacial bond, as indicated by an adhesion energy of −2.16 eV, was observed at YBCO/LAO, while the weakest was found at the YBCO/KTO interface, with an adhesion energy of −0.56 eV. Additionally, charge density difference (CDD) analysis highlighted electron density redistribution at the interfaces, predominantly around interfacial oxygen atoms, indicating a mix of ionic and covalent bonding. This study provides comparative insights into the interfacial characteristics of YBCO/ABO3 heterostructures, suggesting pathways for optimizing their design and performance.

Development of flexible nanocellulose-based composites with enhanced hydrophobicity and improved haze for efficient light management in solar cells

The proliferation of flexible electronic products derived from petroleum substrates in the market has exacerbated environmental pollution stemming from electronic waste generation. As a result, there is an increasing demand for cellulose nanofiber substrates that are green and degradable. However, substantial challenges remain in addressing the hydrophilicity of nanocellulose substrates and optimizing their optical properties for commercial viability. In this study, we propose a multifunctional composite film material through the use of amidation modification and biomineralization technology. We successfully grafted highly carboxylated transparent oxide nanocellulose (TCNF) and octadecylamine (ODA) using carefully designed amidation conditions. Through the carboxyl group after amination, we were able to generate amorphous calcium carbonate (ACC) in situ, resulting in the creation of a flexible, sustainable, and transparent TCNF/ODA/CaCO3 composite film with high hydrophobicity and haze. This was confirmed by a water contact angle value of 138.21° and a haze value of 84.8%. The composite film exhibits low surface energy and high dual-scale surface roughness, while its internal structure is relatively porous and loose, but still possesses multi-scale interface interactions. We demonstrate a strong correlation between the multifunctional properties and structural properties of the composite films in this work, thereby achieving effective light management applications in solar cells. Our findings are expected to provide new insights and ideas for the design of multifunctional green flexible solar cell device substrate materials.

A multifunctional coating with switchable wettability for efficient oil-water and emulsions separation

Superwettable materials with switchable wettability have been attracting tremendous attention in the field of oil-water separation. In this work, a multifunctional coating with switchable wettability was designed for efficient oil-water and emulsions separation. Fe3O4 was combined with TiO2 nanoparticles and hydrophobically modified by low surface energy stearic acid (SA) to form the Fe3O4/TiO2@SA coating with uniform micro-nanostructures. The introduction or removal of amino group via ammonia treatment or heating treatment endowed the coating with reversible conversion between hydrophilicity and hydrophobicity. By switching hydrophilicity and hydrophobicity, the coating could separate oil/water/oil ternary mixtures in sequence with high separation efficiency of more than 99.9 %. More importantly, it displayed excellent separation efficiency with oil rejection above 99.5 % for oil-in-water (O/W) emulsions and water rejection above 98.7 % for water-in-oil (W/O) emulsions. Moreover, this coating showed reliable reusability and mechanical stability after 10 cycles of O/W and W/O emulsions separation and 20 cycles of sandpaper abrasion. Fe3O4 and TiO2 imparted magnetic and photocatalytic properties to the coating, allowing it to be used for magnetic navigation of oil absorption and photocatalytic degradation of organic dyes. The unique features of multifunctional coating with switchable wettability provide the blueprint for treating oily wastewater and marine oil spills.

Superhydrophobic Stainless Steel Mesh through Chemical Vapour Deposition of TMCS for Effective Oil-Water Separation

Aim: To Fabricate the superhydrophobic Stainless Steel (SS) mesh using Trimethylchlorosilane (TMCS) through a Chemical Vapor Deposition (CVD) method for the oil-water mixture separation Background: The frequent oil spills have a devastating impact on marine ecosystems and the environment. The porous materials with superhydrophobic properties have been created to separate oil and water effectively. Due to their ability to effectively separate oil and water, superhydrophobic coatings have gained significant attention. Methods: The cleaned stainless-steel mesh was put on a stand and covered with a glass container. Within the container, 50 mL of hexane, which contained 1 mL of TMCS, was added. The mesh was then left for 3 h to undergo the CVD process Results: The silane content with low surface energy creates a highly rough structure on the mesh surface. The optimal mesh coating is superhydrophobic, having a strong affinity to oil and a water contact angle of 162 ± 2°. The coated mesh has shown a separation efficiency of over 97.8% for different oil-water mixtures. The coatings sustain their superhydrophobicity up to 30 tape peels and 40 times sandpaper abrasion, indicating good mechanical durability. Conclusion: The study concludes that the S-3 sample is mechanically stable and can withstand various tests such as adhesive tape peeling, sandpaper abrasion, bending, folding, and twisting. It efficiently separates oil and water mixtures on a large scale with high efficacy

Method for controlling the polypropylene wettability using surfactants

This paper describes a novel approach to imaging polypropylene PP using digital inkjet printing techniques. The low surface energy of PP, and significant hydrophobic properties prevent it from being used for direct coloration by available methods. A number of surfactants (surfactants) have been proposed as pre-coatings to improve the adhesion between the polymer surface and the ink. Due to the amphiphilicity of surfactants, improved coloration and enhanced color rendering are provided. The polymer/surfactants interactions were evaluated by IR spectroscopy. The amount of surfactants was evaluated using TGA analysis. The effect of modifying agent concentration was evaluated using wetting edge angle measurement. The surface morphology was evaluated using scanning electron microscopy. The test scales were printed and their colorimetric performance was investigated. The study demonstrates the high potential of surfactants for tuning the properties of nonwoven polymeric materials.

Fabrication and tribological behavior of laser cladding Cu/Ti3SiC2 reinforced CoCrW matrix composite coatings on Inconel718 surface

To satisfy the need for high wear resistance of Inconel718 alloy under harsh working conditions, laser cladding technique was adopted to fabricate the Cu/Ti3SiC2-CoCrW metal matrix composite coatings on that surface. The phase composition, microstructure, microhardness, surface energy, and tribological properties of the composite coatings were systematically analyzed by characterization methods such as XRD/ SEM/ EDS/ XPS and performance test methods such as high-temperature friction and wear test, and the wear mechanism at different temperatures was deeply discussed. The research results indicate that the microhardness of coatings is increased by 2.2–2.9 times compared to the substrate, which is mainly owing to the solid solution strengthening effect and the diffusely distributed hard reinforcing phases such as Cr7C3, WCx, and TiC. Regarding the wear resistance, the wear rate of coatings is significantly reduced by 1–2 orders of magnitude over the substrate. Among them, the Co-based coating adding 10 wt% Cu - 10 wt% Ti3SiC2 exhibited the lowest wear rates at room and high temperatures, which were 0.22 and 3.23 × 10−5 mm3/ N·m, respectively, with 98.22 % and 88.19 % reductions in comparison with the substrate. The low surface energy (27.94 mN/m) was one of the main reasons for the good tribological properties. When the friction environment changes from room temperature to 600 °C, the primary wear mechanism of coatings changes from abrasive and adhesive wear to oxidative wear.

Assembled Wood-Polyester Fabric-Hydrogel Janus Evaporator for Sustainable Seawater Desalination.

Solar-driven interfacial evaporation technology is a novel and efficient desalination process that helps alleviate the global shortage of freshwater resources. We developed a Janus evaporator assembled from cotton hydrogel, hydrophilic polyester fabric (PF), and Hydrophobic Wood (PW). By doping graphene oxide and TiO2 as light-absorbing materials within the hydrogel, we achieved a high absorptivity of over 90% across the entire solar spectrum. The hydrophilically modified PF, combined with the PW substrate, provided robust water transport and reduced thermal losses. Subsequent optical path simulations using TracePro74 software verified that the sawtooth light-trapping design of the wood substrate increased multiple light reflections and absorption (compared to a flat structure), enhancing light absorption capabilities. The sawtooth interface also enlarged the evaporation area, further boosting evaporation performance. The cleverly designed evaporator exhibited an evaporation rate of 1.722 kg m-2 h-1 and an efficiency of 83.1% under 1 sun irradiation. Additionally, after applying polydimethylsiloxane to the single surface of the photothermal hydrogel for low surface energy treatment, the resulting Janus structure demonstrated asymmetric wettability that prevented salt ions from accumulating on the irradiated interface. After 8 h of continuous evaporation in saline water (10 wt %), only slight salt crystallization occurred at the edges. The evaporator maintained long-term stability during a 15 day cyclic test, and the produced freshwater fully met the relevant drinking water standards. The components of the evaporator are characterized by simple fabrication, low cost, and eco-friendliness, offering significant application potential in the global context of energy conservation and emission reduction initiatives.

Transparent, robust, and anti-fingerprint silicone coating with a three-dimensional cross-linked network enabled by hydrosilylation reaction

Silicone coatings with anti-smudge, anti-fingerprint, abrasion resistance, and ultraviolet (UV) resistance properties are increasingly demanded for touch screens as the development of artificial intelligence and human-computer interaction interfaces. Herein, a transparent, robust, and self-cleaning silicone coating was developed by incorporating cage-like structures and long carbon chains into a 3D cross-linked network via the rational combination of polymethylhydrosiloxane (PMHS), PSS-Octavinyl substituted (VPOSS), lauryl acrylate (LA), and 1,2-epoxy-4-vinylcyclohexane (EVCH) through hydrosilylation reaction with the presence of Karstedt catalysts. After introducing sealed diphenyliodonium phosphate (I-200), the silicone coating (PVLE-I-200) demonstrated excellent pencil hardness, anti-smudge, and abrasion resistance, and its average transmittance of visible light reached about 92 %. Owing to the low surface energy carbon chains, the coating showed amphiphobic properties and excellent anti-fingerprint property. The binding between cyclohexyl epoxy and glass substrate contributed to the high adhesion of the coating, which remained nearly intact and slightly reduced surface wettability after 500 friction cycles of sandpaper. In addition, the PVLE-I-200 coating demonstrated UV resistance which could withstand 200 h of UV irradiation attributed to the cage-like structure of VPOSS. The functional silicone coating provides insights into the development of environmentally friendly coatings for touch screens with high transparency, abrasion resistance, anti-smudge, and anti-fingerprint properties.

Cellulose nanofiber powered interface engineering strategy to manufacture mechanically stable, moldable, recyclable, and biodegradable cellulose foam

In this work, an ingenious and energy-efficient interface engineering strategy is developed to manufacture pulp cellulose foam via incorporating cellulose nanofiber/alkyl ketene dimer (CNF/AKD) Pickering emulsions. In this strategy, CNF/AKD emulsion can uniformly anchor onto pulp microfiber surface, not only achieving interfacial exoskeleton reinforcement, but also enabling low energy surface, which facilitates the direct and large-scale production of lightweight pulp/CNF/AKD (PCA) foam by oven drying without requiring any harmful crosslinking chemistries. By simply regulating the mass fractions of CNF and AKD in emulsion, the prepared PCA foams can achieve excellent and tunable 3D porous structure, mechanical performance, water resistance and wet stability. The dry compressive modulus and wet compressive modulus underwater of PCA foams with low density of 0.09 g/cm3 can reach 0.67 and 0.57 MPa, respectively. Even 1 week in water, the compressive modulus still retains 76.2 % of initial modulus. Notably, the proposed interface engineering strategy provides remarkable formability, moldability and structural designability, enabling cellulose foam to be customized into complex and delicate 3D macroscopic structures for different scenarios. Furthermore, the PCA foam displays economically feasible closed-loop recyclability by easy hot-water disintegration and natural biodegradability in soil. Therefore, this work proves a cost-effective and viable interface engineering strategy for scalable production of lightweight, mechanically stable, recyclable, biodegradable cellulose foams with high environmental benefits and low petrochemical consumption.

Composite coatings from polycarbosilane derived SiC and Al/SiC cermet active fillers as protective barriers against steel corrosion

Stainless steel is used throughout the world as a structural material. However, it undergoes corrosion damage when exposed to extremely corrosive media, such as the marine environment. An alternative to solve this problem lies in the development of coatings that can withstand extreme conditions but also be easily deposited with inherently corrosion-resistant materials such as silicon carbide (SiC). The present study shows a simple method to produce Al/SiC cermet powders by attrition milling. The resulting cermet powders with a metallic matrix and hemispherical morphology, were employed as fillers in polycarbosilane (PCS) solutions that were sprayed on A304 stainless steel substrates. Al/SiC composite coatings were produced after heating the sprayed suspensions at 700 °C for 1 h in Ar atmosphere. The resulting composite coatings exhibited low surface energies (< 35 mN/m), water contact angles of 53°, and adhesion strength of up to 30 MPa. Finally, corrosion tests were performed in a cyclic corrosion test chamber, showing that these coatings effectively reduced the corrosion rate of stainless steel by 87%, reaching corrosion rate values of 0.007 g/cm2 year.

Efficient oil spill cleanup from water: Investigating the effectiveness of a sustainable anti-swelling hydrogel for rapid water repellency and oil absorption

Considering the significant harm caused to aquatic ecosystems and marine life by oil spills and the discharge of oily wastewater, there is a pressing need to address this issue to protect our environment and prevent the wastage of valuable resources. We introduced a two-step approach to create an anti-swelling, water-repellent sorbent using a green polysaccharide called gum gellan, functionalized with Octadecyl trichlorosilane (OTS) through dip coating method. Natural gums like gellan have high absorption capability due to their large surface area. However, they are hydrophilic, which means they can only absorb water. This property makes them unsuitable for oil spill applications. To make gum gellan suitable for oil spill applications, we have modified it in this study. We have introduced a material called octadecyltrichlorosilane, which has low surface energy and hierarchical roughness. This modification changes the wettability of gellan from hydrophilic to hydrophobic/oleophilic, allowing it to absorb oil and repel water. The sorbent is analyzed using several techniques, such as FTIR, XRD, TGA, FE-SEM, BET, Raman, EDX, and H1-NMR. The hydrophobic sorbent obtained demonstrates low density, high surface area, and high porosity. These characteristics give it excellent floatability and immediate and exceptional selectivity for absorbing oil from water. Additionally, it does not absorb any detectable amount of water. The sorbent exhibited a water contact angle (WCA) of 140 ± 3 ° and an oil contact angle (OCA) of 0° for various oils and organic solvents. It has rapid oil absorption capacity of 3.72 g/g for diesel, and can be easily recovered after use. The BET analysis revealed that after the modification with OTS, the sorbent's total surface area increased from 0.579 m2/g to 4.713 m2/g. This indicates that the OTS modification greatly enhances the surface area and pore volume of the, thus improving its ability to absorb oil. This sorbent efficiently separates oil-in-water emulsions, both surfactant-stabilized and surfactant-free, achieving over 90% separation through gravity alone. Moreover, the sorbent can sustain its wettability even under harsh environmental conditions, including exposure to acids, alkalis, and salts. The absorption data predominantly aligned with the pseudo-2nd-order model. Thus, this sorbent provides a cost-effective alternative for efficiently absorbing and separating oil-water emulsions in households and industries.

First-principles calculations of cubic boron arsenide surfaces

The properties of cubic boron arsenide (c-BAs) (100), (110), and (111) surfaces are investigated by performing first-principles calculations using the slab and Green's function surface models with different terminals. The (111) surface with As-termination is found to be the most stable structure among the studied surfaces, with its lowest surface energy (1.70–1.92 J m−2) and largest surface density (20.24 nm−2). The electronic affinity of these surfaces lie in the range 4.62–6.17 eV, which is higher than that of common semiconductor materials, such as silicon (4.05 eV) and germanium (4.13 eV), implying that the electrons at the bottom of the conduction band require more energy to escape. The surface states of the structures with As-termination in the surface band structures are generally more numerous and extended than those with B-termination. The absorption peak of the bulk c-BAs is located in the ultraviolet region, and the light absorption ranges of the surfaces are significantly extended compared with the bulk c-BAs, due to the surface states inside the bandgap.

One-step hydrothermal fabrication of Co-MOFs/LDH superhydrophobic composite coating with corrosion resistance and wear resistance on anodic aluminum oxide

In recent years, metal–organic framework materials (MOFs) have garnered significant attention in the field of metal corrosion protection. In this study, novel Co-MOFs were synthesized using cobalt nitrate as the metal source and 4,4′-bipyridine as the organic ligand. A one-step solvothermal method was employed to synthesize a black MOFs/LDH composite coating, integrating corrosion resistance, friction reduction, and hydrophobicity into a single coating. The successful reaction between metal ions and organic ligands was confirmed through FTIR, FE-SEM, EDX, XRD, and XPS characterization tests. Cross-sectional SEM and EDX analyses demonstrated the successful synthesis of the coating. Electrochemical tests indicated that after 14 days of immersion in 3.5 wt% NaCl, the composite coating exhibited the lowest corrosion current of 2.23 × 10−9 A∙cm−2, outperforming the aluminum substrate (5.99 × 10−6 A∙cm−2) and anodized aluminum (7.08 × 10−7 A∙cm−2). Hydrophobicity tests showed that without additional modification with low surface energy substances, the composite coating had a contact angle of 154.7°, demonstrating excellent hydrophobicity. Tribological tests revealed that the composite coating exhibited superior tribological performance, with a friction coefficient of 0.3.

In-situ deposition modification of hydrophilic polytetrafluoroethylene (PTFE) membranes using surfactants as anchoring points for long-term stability

Polytetrafluoroethylene (PTFE) membranes are renowned for their excellent thermal stability, resistance to strong acids and alkalis, and superior mechanical stability. However, its inherent strong hydrophobicity significantly limits its use in water treatment. In this study, a SiO2 coating was successfully deposited in-situ on the surface of PTFE membranes using a hydrolyzed solution of tetraethyl orthosilicate (TEOS) compounded with the commercial fluorinated polyoxyethylene ether surfactant FS-31 (C6F13CH2CH2O(CH2CH2O)nH). The modification mechanism involves using the low surface energy nonionic fluorocarbon surfactant FS-31, which interacts hydrophobically with the PTFE substrate, serving as an “anchor” point around which the TEOS hydrolyzes and condenses around the fibers and nodes of the PTFE membrane, forming a complete and stable chemical network structure. The results show that the initial water contact angle of the modified membrane dropped to 36.5°, and the water flux reached 537.9 L m−2 h−1. After being continuously immersed in strong acid (5 wt% HCl), strong alkali (4 wt% NaOH), and oxidizing agent (5 wt% NaClO) for one week, the membrane maintained excellent hydrophilicity and stability. This study proposes a mild and efficient modification method to prepare durable hydrophilic PTFE membranes, portending great potential for applications in harsh environments.

Plasma/Ozone Induced PolyNaSS Graft-Polymerization onto PEEK Biomaterial for Bio-integrated Orthopedic Implants

Owing to its superior bulk mechanical properties, poly (ether ether ketone) (PEEK) has gained popularity over the past 15 years as a metal substitute in biomedical implants. Low surface energy is a fundamental issue with PEEK implants. This low surface energy caused by a moderately hydrophobic surface may be able to inhibit cellular adherence and result in the development of an inflammatory response, which may result in cell necrosis and apoptosis. In this work, plasma and ozone treatments have been utilized to surface activate PEEK and graft ionic bioactive polymer polyNaSS (poly (sodium styrene sulfonate)) successfully on the surface to promote cellular attachment and biomineralization. The main goal of our research has been to find a stable green process for surface modification of PEEK by plasma/ozone approaches to increase PolyNaSS grafting efficiency and biomineralization. To further the field of bioactive orthopedic and dental implant technology, this research attempts to address a significant constraint of PEEK implants while preserving their favorable mechanical properties.