Hydrophilic Groups Research Articles

Engineering tribological rehydration of cartilage interfaces: Assessment of potential polyelectrolyte mechanisms

Articular cartilage, primarily composed of water and collagen, is vital for synovial joint function. Traditional hard biomaterials like ceramic or cobalt-chrome used in hemiarthroplasty often result in abnormal contact pressures and premature implant failure. This study investigates the tribological properties of polyelectrolyte functionalised PEEK (SPMK-g-PEEK) in contact with cartilage, proposing a solution to these issues by utilising tribological rehydration and effective aqueous lubrication.We demonstrate a new mode of polyelectrolyte enhanced tribological rehydration where SPMK-g-PEEK achieves low friction and promotes interstitial fluid recovery during sliding, independent of traditional hydrodynamic theories. This results in a rapid stabilisation of the coefficient of friction (CoF) to levels comparable to natural cartilage (CoF ∼ 0.01) and aids in approximately 8% cartilage strain recovery, indicating effective tribological rehydration even under cartilage degradation or altered osmotic conditions.Furthermore, we find that lubrication and rehydration against an SPMK-g-PEEK interface depend minimally on biphasic lubrication but significantly on the hydrophilic sulfonic acid groups of SPMK, which act as a fluid reservoir. Our findings suggest SPMK-g-PEEK as a promising biomaterial for cartilage interfacing implants that offer low friction and modulate cartilage interstitial fluid pressure. This study enhances our understanding of biotribological interactions and contributes to the development of joint replacement materials that support the natural function of cartilage.

Tailoring Waterborne Coating Rheology with Hydrophobically Modified Ethoxylated Urethanes (HEURs): Molecular Architecture Insights Supported by CG-MD Simulations.

A novel investigation of the effects of the hydrophilic and hydrophobic segments of hydrophobically modified ethoxylated urethanes (HEURs) on the rheological properties of their aqueous solutions, latex-based emulsions, and waterborne paints is demonstrated. Different HEUR thickeners were produced by varying the poly(ethylene glycol) (PEG) molecular weight and terminal hydrophobic size. Results reveal that the strength of hydrophobic associations and, consequently, the rheological properties of HEUR formulations can be effectively controlled by modifying the structure of the hydrophobic segment, specifically, the combination of diisocyanate and monoalcohol. This allows for the on-demand attainment of diverse rheological behaviors ranging from predominantly Newtonian profiles exhibiting lower viscosities to markedly pseudoplastic behaviors with significantly higher viscosities. The length of the hydrophilic group appears to affect viscosity only marginally up to a molecular weight of 23,000 g/mol, with more notable effects at 33,000 g/mol. Additionally, it was indicated that the rheological responses observed in water solutions provide a reliable forecast of their behavior in latex-based emulsions and waterborne paints. Coarse-grained molecular dynamics (CG-MD) simulations were also applied to gain insight into HEUR micelle dynamics in aqueous solutions. Guided by the DBSCAN algorithm, the simulations successfully captured the concentration-dependent behavior and the impact of hydrophilic chain length, aligning with the experimental viscosity trends. Various metrics were employed to provide a comprehensive analysis of the micellization process, including the hydrophobic cluster volume, the total micellar volume, the aggregation number, and the number of chains interconnecting with other micelles.

Entanglement Added to Cross-Linked Chains Enables Tough Gelatin-Based Hydrogel for Zn Metal Batteries.

Currently, it is still challenging to develop a hydrogel electrolyte matrix that can successfully achieve a harmonious combination of mechanical strength, ionic conductivity, and interfacial adaptability. Herein, a multi-networked hydrogel electrolyte with a high entanglement effect based on gelatin/oxidized dextran/methacrylic anhydride, denoted as ODGelMA is constructed. Attribute to the Schiff base network formulation of ─RC═N─, oxidized dextran integrated gelatin chains induce a dense hydrophilic conformation group. Furthermore, addition of methacrylic anhydride through a grafting process, the entangled hydrogel achieves impressive mechanical features (6.8MPa tensile strength) and high ionic conductivity (3.68mScm-1 at 20°C). The ODGelMA electrolyte regulates the zinc electrode by circumventing dendrite growth, and showcases an adaptable framework reservoir to accelerate the Zn2+ desolvation process. Benefiting from the entanglement effect, the Zn anode achieves an outstanding average Coulombic efficiency (CE) of 99.8% over 500 cycles and cycling stability of 900h at 5mAcm-2 and 2.5mAhcm-2. The Zn||I2 full cell yields an ultra-long cycling stability of 10000 cycles with a capacity retention of 92.4% at 5C. Furthermore, a 60mAh single-layer pouch cell maintains a stable work of 350 cycles.

A Review of Methods to Modify the PDMS Surface Wettability and Their Applications.

Polydimethylsiloxane (PDMS) has attracted great attention in various fields due to its excellent properties, but its inherent hydrophobicity presents challenges in many applications that require controlled wettability. The purpose of this review is to provide a comprehensive overview of some key strategies for modifying the wettability of PDMS surfaces by providing the main traditional methods for this modification and the results of altering the contact angle and other characteristics associated with this property. Four main technologies are discussed, namely, oxygen plasma treatment, surfactant addition, UV-ozone treatment, and the incorporation of nanomaterials, as these traditional methods are commonly selected due to the greater availability of information, their lower complexity compared to the new techniques, and the lower cost associated with them. Oxygen plasma treatment is a widely used method for improving the hydrophilicity of PDMS surfaces by introducing polar functional groups through oxidation reactions. The addition of surfactants provides a versatile method for altering the wettability of PDMS, where the selection and concentration of the surfactant play an important role in achieving the desired surface properties. UV-ozone treatment is an effective method for increasing the surface energy of PDMS, inducing oxidation, and generating hydrophilic functional groups. Furthermore, the incorporation of nanomaterials into PDMS matrices represents a promising route for modifying wettability, providing adjustable surface properties through controlled dispersion and interfacial interactions. The synergistic effect of nanomaterials, such as nanoparticles and nanotubes, helps to improve wetting behaviour and surface energy. The present review discusses recent advances of each technique and highlights their underlying mechanisms, advantages, and limitations. Additionally, promising trends and future prospects for surface modification of PDMS are discussed, and the importance of tailoring wettability for applications ranging from microfluidics to biomedical devices is highlighted. Traditional methods are often chosen to modify the wettability of the PDMS surface because they have more information available in the literature, are less complex than new techniques, and are also less expensive.

A novel poly(2-hydroxyethyl acrylamide) copolymer for the fabrication of transparent antifogging coatings on polycarbonate substrates

Although polycarbonate (PC) is widely used in various applications, its inherent hydrophobicity limits its potential in applications that require high light transmittance due to surface fog caused by changes in temperature or humidity in the environment. This work presents a facile method to fabricate transparent antifogging coatings on PC substrates based on poly(2-hydroxyethyl acrylamide-co-2-aminoethyl methacrylate) (P(HEAA-co-AEMA)), in which the AEMA segments have an amino functional group that can react with the ester group on the surface of the PC substrate to form covalent urethane bonds during the heat curing process, avoiding the problems of coating susceptibility to mechanical damage, ease of peeling, etc. Moreover, HEAA units are employed as hydrophilic groups, providing antifogging performance. These antifogging coatings can be easily obtained by coating P(HEAA-co-AEMA) copolymers on PC substrates at room temperature and then curing them by thermal treatment. These transparent coatings exhibited excellent antifogging and self-cleaning performance. Furthermore, the coatings exhibited good adhesion in the cross-cut test and thermal stability in the hot water resistance test. Therefore, the present P(HEAA-co-AEMA) copolymer coatings are promising for practical antifogging applications.

Formaldehyde-free bio-composites based on Pleurotus ostreatus substrate and corn straw waste

Corn straw-based board has great potential for the protection of forest resources, waste recycling, and sustainable economic development. However, corn stalk-based board has poor mechanical properties due to its short fiber length and poor water resistance because of the presence of numerous hydrophilic hydroxyl functional groups in its structure. Natural mycelium originating from waste Pleurotus ostreatus substrate is a hydrophobic bio-adhesive. In the present study, formaldehyde-free corn stalk/P. ostreatus substrate bio-composites were prepared using the hot-pressing technique without the addition of any chemical adhesive. The mechanical properties and water resistance of the prepared bio-composites were excellent. The highest internal bonding strength (IBS) of 2.16 MPa and the minimum thickness swelling (TS) of 18.3% were observed, which are beyond the national standards for particleboard in China. These bio-composites were prepared using a simple, green, and convenient manufacturing method to promote their popularization and application. The method may, therefore, be used as a novel technical measure to resolve the problem of overuse of forestry resources and waste disposal.

Formation of Microporous Poly Acrylonitrile-Co-Methyl Acrylate Membrane via Thermally Induced Phase Separation for Immiscible Oil/Water Separation.

An interconnected sponge structure and porous surface poly (acrylonitrile-co-methyl acrylate) (P(AN-MA)) microfiltration membranes (MF) were fabricated via thermally induced phase separation (TIPS) by using caprolactam (CPL), and acetamide (AC) as the mixed diluent. When the ternary system was composed of 15 wt.% P(AN-MA), 90 wt.% CPL, and 10 wt.% AC and formed in a 25 °C air bath, the membrane exhibited the highest water flux of 8107 L/m2·h. The P(AN-MA) membrane contained hydrophobic groups (-COOCH3) and hydrophilic groups (-CN), leading it to exhibit oleophobic properties underwater and hydrophobic properties in oil. The membrane demonstrates efficient separation of immiscible oil/water mixtures. The pure water flux of the petroleum ether/water mixture measured 870 L/m2·h, and the pure oil flux of the petroleum tetrachloride/water mixture measured 1230 L/m2·h under the influence of gravity. Additionally, the recovery efficiency of diluents through recrystallization was 85.3%, significantly reducing potential pollution and production costs.

Rates of air flow in and out of closed atmospheric-pressure plasma jet system affected surface properties of treated polysulfone membrane

The cold plasma jet works in an atmospheric-pressure condition, and is used to modify polymer membranes by creating hydrophilic functional groups on the membrane surface. Since it can be used without a pressure-reducing system, treatment time and cost are reduced. However, the plasma jet has a narrow beam which limits the area of the membrane surface that can be activated. In this study, a plasma jet was generated in a closed system with controllable rates of air flow in and out of the system. The plasma discharge was recorded with a camera and analyzed by optical emission spectroscopy (OES). Polysulfone membrane surfaces were treated with various conditions of plasma discharge, and the induced membrane hydrophilicity was assessed from water contact angle (WCA) and surface energy (SE) measurements. Atomic force microscopy (AFM), Fourier Transform Infrared Spectroscopy (FTIR) and WCA contour mapping were respectively employed to study surface roughness, functional groups, and WCA distribution on the treated membrane surfaces. The airflow had distinctly different effects on the plasma characteristics. The inflow rate condition affected the width of the plasma beam, and the outflow rate condition affected the diffusion of the plasma beam. Water flux was changed according to the plasma characteristic, and an air outflow rate of 6 L/min was the optimum condition for this experiment.

Determination of Acetylamantadine by γ-Cyclodextrin-Assisted α-HL Nanopore for Potential Cancer Prediagnosis.

The high expression of Spermidine/spermine N1-acetyltransferase (SSAT-1) is an important indicator in early cancer diagnosis. Here, we developed a nanopore-based methodology with γ-cyclodextrin as an adaptor to detect and quantify acetylamantadine, the specific SSAT-1-catalyzed product from amantadine, to accordingly reflect the activity of SSAT-1. We employ γ-cyclodextrin and report that amantadine cannot cause any secondary signals in γ-cyclodextrin-assisted α-HL nanopore, while its acetylation product, acetylamantadine, does. This allows γ-cyclodextrin to practically detect acetylamantadine in the interference of excessive amantadine, superior to the previously reported β-cyclodextrin. The quantification of acetylamantadine was not interfered with even a 50-fold amantadine and displayed no interference in artificial urine sample analysis, which indicates the good feasibility of this nanopore-based methodology in painless cancer prediagnosis. In addition, the discrimination mechanism is also explored by 2-D nuclear magnetic resonance (NMR) and nanopore experiments with a series of adamantane derivatives with different hydrophilic and hydrophobic groups. We found that both the hydrophobic region matching effect and hydrophilic interactions play a synergistic effect in forming a host-guest complex to further generate the characteristic signals, which may provide insights for the subsequent design and study of drug-cyclodextrin complexes.

Design and preparation of reticular superabsorbent hydrogel material with nutrient slow-release and high shear strength for ecological remediation of abandoned mines with steep slopes

In order to solve ecological remediation issues for abandoned mines with steep slopes, a kind of hydrogels with high cohesion and water-retaining were designed by inorganic mineral skeleton combining with polymeric organic network cavities. This eco-friendly hydrogel (MFA/HA-g-p(AA-co-AM)) was prepared with acrylic acid (AA)-acrylamide (AM) as network, which was grafted with humic acids (HA) as network binding point reinforcement skeleton and polar functional group donors, KOH-modified fly ash (MFA) as internal supporter. The maximum water absorption capacities were 1960 g/g for distilled water, which followed the pseudo-second-order model. This super water absorption was attributed to the first stage of 62 % fast absorption due to the high specific surface area, pore volume and low osmotic pressure, moreover, the multiple hydrophilic functional groups and network structure swell contributed to 36 % of the second stage slow adsorption. In addition, the pore filling of water in mesoporous channels contributed the additional 2 % water retention on the third stage. The high saline-alkali resistance correlated with the electrostatic attraction with MFA and multiple interactions with oxygen-containing functional groups in organic components. MFA and HA also enhanced the shear strength and fertility retention properties. After 5 cycles of natural dehydration and reabsorption process, these excellent characteristics of reusability and water absorption capacity kept above 97 %. The application of 0.6 wt% MFA/HA-g-p(AA-co-AM) at 15° slope could improve the growth of ryegrass by approximately 45 %. This study provides an efficient and economic superabsorbent material for ecological restoration of abandoned mines with steep slopes.

Effect of biochar on microplastics penetration treatment within soil porous medium under the wetting-drying cycles and optimisation of soil-biochar mixing format

Plant-based biochar was demonstrated promising capability in adsorbing microplastic particles (MPs) within soil porous mediums. However, biochar's function in mitigating MPs' vertical penetration during wetting-drying cycles, typical of seasonal precipitation and evaporation, remains uncertain. Furthermore, few studies have investigated the structures of how biochar combines with soil. This study conducted column tests to assess the MPs retention capabilities of soil-biochar porous media under saturated and wetting-drying conditions. The water retention and hydrophilic properties were investigated to elucidate the impact of wetting-drying cycles. Additionally, different biochar-soil structures were compared to optimise the structural design. Without biochar, wetting-drying cycles resulted in 8.74 % more MPs escaping from samples. However, incorporating 15 % biochar led to only around 2 % more MPs in effluent. Biochar significantly enhanced soil's MP absorption capacity and mitigated the negative effects of wetting-drying cycles. Biochar's alveolate morphology provides ample adsorption sites and creates complex flow paths. The hydrophilic groups of biochar and capillarity by micropores facilitated slower water release during drying, preventing crack propagation and flush on MP particles. This effect was more pronounced with higher biochar content and lower porosity. Moreover, layer structure was found to improve MPs removal, benefiting the long-term performance and management of the biochar functional layer.

Interfacial characteristics and foam stability: A microscopic perspective from molecular dynamics simulation

Foams play a pivotal role in diverse industrial and academic applications, yet their stability, particularly in relation to surfactants, remains inadequately understood at the microscopic level. This study undertakes a comprehensive modeling of water films stabilized by 15 surfactants, spanning 4 ion types of hydrophilic groups. We conducted a systematic comparison and correlation of key interfacial characteristics at different stages of rupture. Our findings reveal that the critical film thickness and interface tension are integral in characterizing foam stabilities near equilibrium (metastable state) and near rupture (critical state), respectively. Furthermore, we observed a positive correlation between the hydrophilicity of surfactant head groups and both the thickness of Gibbs dividing surface and the orderliness of interfacial surfactant molecules. These factors are crucial in maintaining film stability in both metastable and critical states. This work presents a quantitative framework to generalize various interfacial characteristics commonly employed in describing foam stability, which is poised to enhance the data-driven methodology for surfactant selection and design.

Effect of free volume and hydrophilicity on dehumidification performance of 6FDA-Based polyimide membranes

6FDA-based polyimide air-dehumidification membrane has been considered as one of the most advanced technologies for the energy-saving heating, ventilation, and air-conditioning systems due to their excellent solubility and processing. Nevertheless, there are few reports about the effect of free volume and hydrophilic groups on dehumidification performance. Herein, we propose to tune the free volume and hydrophilicity of 6FDA-based polyimides by tuning the hydrophilicity/hydrophobicity of diamines and/or introducing of hydrophilic carboxylic acid groups, and thus to develop a system that would support high H2O/N2 separation performance for dehumidification and retain excellent mechanical properties. It is found that 6FDA/mPDA membrane shows much higher H2O/N2 separation performance (i.e., H2O permeability 12480 Barrer and H2O/N2 separation factor of 13867) than that of the 6FDA/TFDB and 6FDA/DAM membranes even though its lower FFV. It is suggested that the FFV had a negligible effect on the H2O/N2 separation performance. Although the introduction of highly hydrophilic –COOH groups could significantly increase the H2O/N2 separation performance of hydrophobic 6FDA/TFMB and 6FDA/DAM membranes, the performance is still lower than that of 6FDA/mPDA membrane with similar hydrophilicity. In addition, we found that more –COOH groups to polymers can lead to the possible formation of hydrophilic/hydrophobic separation in membrane which will result in the rapid water vapor condensation and thus unstable air-dehumidification. Thus, the excessive hydrophilicity of 6FDA/mPDA-DABA showed a decreased H2O/N2 separation performance compared with 6FDA/mPDA membrane. These results indicated that the excellent H2O/N2 separation performance mainly depends on reasonable hydrophilicity of polyimide membrane without excessive hydrophilic groups and high FFV.

ROS-responsive carboxymethyl chitosan nanoparticles loaded with astaxanthin for alleviating oxidative damage in intestinal cells

The controlled release of antioxidant substances at the intestinal oxidative damage site is crucial for alleviating intestine-related diseases. Herein, the novel ROS-responsive carrier was synthesized through simple amidation reaction between carboxymethyl chitosan (CMC) and methionine (Met), a natural organic compound containing ROS-responsive linkages (thioether). Initially, astaxanthin (AXT) nanoparticles (AXT2@CMT) with excellent stability and drug loading capacity (39.68 ± 0.23 μg/mL) were prepared by optimizing various reaction conditions. In the simulated high-concentration ROS environment of the intestine, CMT achieved a transition from hydrophobic groups (thioether) into hydrophilic groups (sulfone), which was conducive to the controlled release of AXT. In vitro cell experiments revealed that AXT2@CMT could effectively alleviate the oxidative damage in intestinal epithelioid cell line No. 6 (IEC-6 cell) caused by H2O2. This study achieved a straightforward preparation of ROS-responsive nanocarrier through food ingredients, offering a theoretical foundation for the controlled release of AXT at the intestinal oxidative damage site.

Investigation of Surface Modification of Bagasse Fibers: Performance of Asphalt Binders/Mixtures with Bagasse Fibers

The influence of surface modification on the properties of bagasse fibers and asphalt binders/mixtures was investigated. Bagasse fibers were modified by single, binary, and ternary methods with hydrochloric acid, sodium hydroxide, and sodium chlorite, respectively. The physical and chemical properties of bagasse fibers were analyzed by scanning electron microscopy, Fourier transform infrared spectroscopy, and an adsorption test, respectively. The rheological properties of asphalt binders with bagasse fibers or lignin fibers were analyzed by the dynamic shear rheometer test and bending beam rheometer test. In addition, the performance of asphalt mixtures with bagasse fibers or lignin fibers were evaluated by a wheel rutting test, bending test at a low temperature, and water stability test, respectively. In conclusion, the hydrophilic functional groups on the fiber surface were partially eliminated by modification, facilitating the degradation of different fiber components. Furthermore, the degree of fibrillation was improved, and more interfaces with asphalt components were formed, thus enhancing the high-temperature deformation resistance of asphalt binders, but slightly impairing its low-temperature performance. Among all modification methods, the ternary composite modification exerted important influences on fiber structure, oil absorption, and rheological properties of asphalt binders, significantly enhancing the performance of asphalt mixtures. Combined with surface modification methods, bagasse fibers would be promising reinforced pavement materials.

Steering Interfacial Renovation with Highly Electronegative Cl Modulated Trinity Effect for Exceptional Durable Zinc Anode

AbstractThe poor anode/electrolyte interface triggered by abysmal dendritic growth and hydrogen evolution reactions (HER) hinders the development of aqueous zinc‐ion batteries (AZIBs). Here, a highly efficient electrolyte is formulated with sucralose (Sucral) additive to refresh solvated structure and steer interfacial renovation, for building highly electronegative Cl‐modulated trinity effect in the bulk‐interface between electrolyte and electrode. Experiment results and theoretical studies jointly reveal that Sucral with highly zincophilic and hydrophilic hydroxyl groups can remodel primary Zn2+ solvation shell and interrupt strong H‐bond network from H2O molecules, thus boosting fast de‐solvation and restricting undesirable HER. Simultaneously, three highly electronegative chlorides in the adsorbed Sucral possessing hydrophobic features can enable a H2O‐poor electric double‐layer (EDL), thus remodeling the Zn surface against corrosion. Additionally, it realizes preferential exposure of the Zn (002) plane for helping uniform interfacial deposition. The synergy of the above factors achieves a prolonged lifespan of 3000 h (1.0 mA cm−2, 1.0 mAh cm−2), much better than that with Sucrose (Suc) electrolyte. The Zn//V2O5 full cell at 5 A g−1 also maintains enhanced stability of 1500 cycles with 160 mAh g−1.

Flame modified carbon-based electrodes as positive electrode for high performance of hydrogen/iron battery

The electrode is a core component that affects the overall performance of the hydrogen/iron redox flow battery. To address the drawbacks associated with the limited electrochemical activity and fewer active sites of the carbon-based electrode, this study employs a straightforward and effective flame method to synthesize carbon nanotubes (CNTs) on carbon paper and NiO/CNT composite on graphite felt. The CNT on the modified carbon-based electrode contains many hydrophilic and oxygen-containing functional groups, greatly improving the hydrophilicity of the electrode, thereby increasing the electrochemical surface area. The modified carbon-based electrode exhibits better electrochemical activity due to the CNT or NiO/CNT providing more active sites. At 50 mA cm−2, the energy efficiency of pristine carbon paper and graphite felt is 60.8% and 52.4%, respectively, while the energy efficiency of the modified carbon paper and graphite felt reached 75.3% and 80.5%, respectively. The modified carbon-based electrode achieves a 100% coulombic efficiency, with no significant degradation in energy efficiency after running for 300 cycles, demonstrating excellent stability. This study not only investigates the performance of graphite felt electrodes in hydrogen/iron batteries but also proposes a flame method for preparing CNT-modified carbon-based electrodes for high-performance hydrogen/iron batteries.

Novel bioactive petrodispersing agents based on cationic polymeric surfactant: Design, synthesis, and surface indices

Novel bioactive cationic polymeric surfactants based on fatty acid derived from natural wastes were developed with different hydrophilic head groups, which were employed for collecting the thin petroleum film from water surface and dispersing it. The preparation procedures pass through three steps, in first step lauryl methacrylate (LMA) was copolymerized with methacrylic acid (MAA) with different feed from the two monomers to obtain five copolymers of poly(LMA-co-MAA) (P1-5) of different molar ratio. In second step, carboxylic groups in copolymers (P1-5) were esterified with N,N‘-dimethyl-ethanol amine and finally the modified copolymers (PE1-5) were quaternized with Butyl-2-chloroacetate and Hexyl-2-chloroacetate to afford the bioactive PSB1-5 and PSH1-5, respectively. The structure of synthetic compounds was confirmed by FT-IR and 1H NMR. Upon examination, the surface-active characteristics of the bioactive petrodispersing agents that were synthesized exhibited significant defoaming capacity, good wettability, and foaming qualities. The synthesized PSB1-5 and PSH1-5 were applied for petro-collecting and dispersing in solid state and diluted form on three water sources. In sea water and diluted form, the results showed that PSB1-5 showed better effects than PSH1-5. Also, the antimicrobial efficiency of the synthesized PSB(1-5) and PSH(1-5) were tested. The data obtained from FT-IR and 1H NMR spectra proved the esterification of carboxylic group in copolymers due to the appearing of peak at 1738 cm−1 for carbonyl group of formed esters and the disappearing for proton of carboxylic group in 1H NMR. Also, data obtained from antimicrobial studies showed that the highest inhibition zone diameter against C. albicans, L. monocytogenes, S. aureus, Salmonella sp. and E. coli were observed for PSH(1-5). Which PSH-2 gives the highest value of inhibition zone diameter of 3.2 mm against L. monocytogenes. The results exhibited that PSH(1-5) showed the stronger antimicrobial functions than PSB(1-5).

Impact of surfactant groups on the corrosion inhibition properties of superhydrophobic membranes on X80 steel

Fe2O3/Fe3O4 composite films were successfully prepared on the surface of X80 steel through hydrothermal synthesis and annealing treatments. Subsequently, the oxidised films were modified using surfactants such as decanoic acid (DA), decyl silane triol (DS) and perfluorodecyl silane triol (FDS), resulting in the creation of three distinct films exhibiting superhydrophobic properties. The effects of the hydrophilic and hydrophobic groups of surfactants on the superhydrophobic films of X80 steel were analysed using electrochemical methods, surface analysis techniques and theoretical calculations. The results showed that all three superhydrophobic films exhibited excellent corrosion resistance, with the order being DA > FDS > DS after 72 h of immersion in acidic conditions (pH = 6, 60 °C). Theoretical calculations showed that the adsorption performance of carboxyl groups was superior to that of silyl alcohol bonds, whereas fluorination of hydrophobic groups helped to enhance the adsorption capacity of hydrophilic groups. This not only reveals the key role of surfactants in the preparation of superhydrophobic membranes but also provides a theoretical basis for the preparation of superhydrophobic membranes on carbon steel surfaces.

Synthesis and application of dual-functional sorbent SBA-15-Fe3O4-PDA-ODA for removing both water soluble and insoluble pollutants

In this study, inorganic-organic hybrid sorbent SBA-15-Fe3O4-PDA-ODA with functional groups having affinity for both water-soluble and insoluble pollutants was synthesized for treatment of wastewater where Malachite Green (MG) dye and motor oil coexist. In order to enhance the specific interactions between the sorbent and dye via functional groups of polydopamine (PDA), Fe3O4 nanoparticles were encapsulated with SBA-15 and surface functionalization with PDA was accomplished and then the surface of Fe3O4-SBA-15-PDA was modified with octadecylamine (ODA) to remove the oil present in the same environment with dye. While the SBA-15-Fe3O4-PDA-ODA directed to the aqueous phase by magnet provided MG removal thanks to the hydrophilic groups of PDA, it provided motor oil removal thanks to hydrophobicity of ODA when directed to the oil phase. 99.20 % dye removal and 9.24 g/g oil adsorption capacity were achieved from the environment where oil and dye were present together. Besides, the adsorption of MG on Fe3O4-SBA-15-PDA was searched at various pH, dye concentration, adsorbent dosage, and temperature in order to propose optimum experimental conditions for removal of dye and maximum adsorption capacity was determined as 95.83 mg g−1 at optimum conditions (10 mg adsorbent, 10 mg L−1 MG concentration, pH 9). Interaction mechanism between dye and Fe3O4-SBA-15-PDA was explained by studying the adsorption behavior of sorbent derived from the isotherm and kinetic results. The sorbents were characterized by FT-IR, XRD, SEM, N2-adsorption/desorption, water-contact-angle, and VSM measurements. SBA-15-Fe3O4-PDA-ODA sorbent was tested for three successive adsorption cycles for both dye and oil and eventuated insignificant loss in activity when they were recycled. Easy and low-cost fabrication protocol, controllable removal ability of dye and oil will facilitate its versatility in environmental cleanup process for water soluble and insoluble pollutants.