Contact Angle Measurements Research Articles

Self-Assembled Monolayers of Triazolylidenes on Gold and Mixed Gold/Dielectric Substrates.

N-Heterocyclic carbenes (NHCs) have emerged as valuable ligands for surface chemistry. They can be used to prepare robust self-assembled monolayers (SAMs) for a variety of applications, including as small-molecule inhibitors (SMIs) for metal surfaces in the fabrication of next-generation integrated circuits with angstrom precision. However, little work has been performed to assess the effect of structural and electronic modifications to the basic NHC structure. Herein, we report the design and deposition of a series of 1,2,3-triazolylidene (Tz)-type carbenes on gold (Au) and Au/SiO2 patterned substrates. Triazolylidenes are an important class of stable carbenes that can be prepared with ease by using click chemistry. In this work, we studied the selective deposition of 1,2,3-triazolium hydrogen carbonate salts. The thermal properties of these precursors were measured and shown to be appropriate for either solution or vapor phase deposition. Tz-SAM stability was studied by time-of-flight secondary-ion mass spectrometry (ToF-SIMS) of Tz SAMs before and after exposure to various conditions, leading to the conclusion that Tz SAMs have thermal stabilities greater than that of NHC SAMs reported to date. Tz SAMs were analyzed by using X-ray and ultraviolet photoelectron spectroscopy (XPS, UPS) and contact angle measurements. High selectivity for deposition on metal regions over dielectric regions on patterned Au/SiO2 substrates enabled the use of Tzs as an entirely new class of SMIs on preventing ZnO deposition, providing considerable potential utility in microelectronics fabrication methods. Structure-property relationships were studied and provided key insight into the effectiveness of the SAM as a blocking agent.

Applicability of the thermodynamic and mechanical route to Young's equation for rigid and flexible solids: A molecular dynamics simulations study of a Lennard-Jones system model.

The wetting properties of a liquid in contact with a solid are commonly described by Young's equation, which defines the relationship between the angle made by a fluid droplet onto the solid surface and the interfacial properties of the different interfaces involved. When modeling such interfacial systems, several assumptions are usually made to determine this angle of contact, such as a completely rigid solid or the use of the tension at the interface instead of the surface free energy. In this work, we perform molecular dynamics simulations of a Lennard-Jones liquid in contact with a Lennard-Jones crystal and compare the contact angles measured from a droplet simulation with those calculated using Young's equation based on surface free energy or surface stress. We analyze cases where the solid atoms are kept frozen in their positions and where they are allowed to relax and simulate surfaces with different wettability and degrees of softness. Our results show that using either surface free energy or surface stress in Young's equation leads to similar contact angles but different interfacial properties. We find that the approximation of keeping the solid atoms frozen must be done carefully, especially if the liquid can efficiently pack at the interface. Finally, we show that to correctly reproduce the measured contact angles when the solid becomes soft, the quantity to be used in Young's equation is the surface free energy only and that the error committed in using the surface stress becomes larger as the softness of the solid increases.

Evaluation of the interaction effect on viscoelastic and moisture behaviour of high-density polyethylene reinforced with multi-walled carbon nanotube and tungsten disulphide hybrid composites

This study examines the influence of varying weight percentages (wt.%) of the solid lubricant, tungsten disulphide (WS2), on the viscoelastic properties and interaction effects of a high-density polyethylene (HDPE) composite that is reinforced with both multi-walled carbon nanotubes (MWCNTs) and WS2. The fabrication of HDPE composites involved the utilisation of a twin screw extruder method to incorporate lubricants and reinforcement. The lubricant was introduced in three different proportions of 2, 4 and 8 wt.% while the MWCNT was reinforced at a constant 1 wt.% for all composite materials. The specimens were fabricated utilising an injection moulding machine. The composite's interaction effects were investigated using the Fourier transform infrared spectroscopy and Raman spectroscopy. The viscoelastic behaviours of the composite were studied using dynamic mechanical analyser (DMA). Composite moister characteristics were analysed using water contact angle measurement and water absorption test. The DMA results indicated that the HC1W2 (HDPE + MWCNT 1 wt.% + WS2 2 wt.%) hybrid composite exhibited enhanced interaction effects and desirable viscoelastic behaviour, as evidenced by loss modulus (G″) and storage modulus (G′) values. HC1W8 (HDPE + MWCNT 1wt.% + WS2 8 wt.%) sample shows less moister absorption, because adding filler improves the sample's hydrophobicity. The composite exhibits significant particle agglomeration when the lubricant content exceeds 2 wt.%. It affects the uniform dispersion of WS2 particles in the matrix, which leads to reduced composite performance.

Multifunctional Novel Lanthanide Complexes Based on Chromone Moiety for Corrosion Inhibition, Molecular Docking, and Anticancer and Antimicrobial Applications

ABSTRACTTwo novel multifunctional complexes [M(CCAM)2(NO3)](NO3)2·C2H5OH (M = Dy (III)/Er (III); CCAM = 2‐cyano‐N′‐((4‐oxo‐4H‐chromen‐3‐yl)methylene)acetohydrazide) were synthesized and characterized via elemental and thermal analyses, molar conductivity, UV–vis., and FT‐IR spectroscopy, revealing a 1:2 metal‐to‐ligand stoichiometry. The CCAM ligand coordinated with Dy(III) or Er(III) ions through nitrogen of azomethine and oxygen of the carbonyl and γ‐pyran groups. Corrosion inhibition studies for Dy(CCAM), Er(CCAM), and CCAM on carbon steel (C‐steel) in 1‐M HCl showed Dy(CCAM) and Er(CCAM) as highly efficient, with Er(CCAM) offering the best protection. In a 1‐M HCl solution, Fe2+ at the C‐steel surface interacts with the CCAM, Dy(CCAM), and Er(CCAM) compounds, as demonstrated by UV–vis spectroscopy. At a concentration of 10−3 M, the Dy(CCAM) and Er(CCAM) compounds showed greater performance efficiency in the weight loss test in 1‐M HCl solution, reaching 93.34% and 95.67%, respectively. The Langmuir adsorption isotherm pronounced the mixed adsorption mechanisms. The surface characteristics SEM, EDX, AFM, and contact angle measurements confirmed surface shielding. In vitro antibacterial and antifungal activity of the prepared compounds against organisms, including Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis as bacteria, and Candida albicans and Aspergillus fumigatus as fungi is carried out. Er(CCAM) inhibitor exhibits the greatest action against different tested antimicrobials. Additionally, the in vitro cytotoxicity of the produced complexes as growth inhibitory effects against Erlish Acities Carcinoma was ascertained. Er(CCAM) and Dy(CCAM) were found to have cytotoxic levels with (IC50 of 64 and 65 μM), respectively. As a result, Er(CCAM) inhibitor is a more effective therapeutic approach for the creation of novel antimicrobial and antitumor agents. For Er(CCAM) superior corrosion protection, the theoretical studies of molecular docking and DFT and MD simulations validated the experimental results.

Development and Characterization of Silibinin-Loaded Nanoemulsions: A Promising Mucoadhesive Platform for Enhanced Mucosal Drug Delivery

Background: Silibinin (SLB), a flavonoid derived from milk thistle, exhibits promising therapeutic properties but faces significant clinical limitations due to poor solubility and bioavailability. Objectives: This study focuses on the development and characterization of SLB-loaded nanoemulsions designed for mucosal delivery. Methods: Nanoemulsions were prepared using the spontaneous emulsification method, guided by pseudoternary phase diagrams to determine selected component ratios. Comprehensive characterization included particle size, polydispersity index (PDI), zeta potential, encapsulation efficiency, rheological properties, and surface tension. Mucoadhesive properties were evaluated using quartz crystal microbalance with dissipation (QCM-D) to quantify interactions with mucin layers. Results: The combination of Capryol 90, Tween 80, and Transcutol in selected proportions yielded nanoemulsions with excellent stability and solubilization capacity, enhancing the solubility of silibinin by 625 times compared to its intrinsic solubility in water. The ternary phase diagram indicated that achieving nanoemulsions with particle sizes between 100 and 300 nm required higher concentrations of surfactants (60%), relative to oil (20%) and water (20%), with formulations predominantly composed of Smix (surfactant and cosurfactant mixture in a 1:1 ratio). Rheological analysis revealed Newtonian behavior, characterized by constant viscosity across varying shear rates and a linear torque response, ensuring ease of application and mechanical stability. QCM-D analysis confirmed strong mucoadhesive interactions, with significant frequency and dissipation shifts, indicative of prolonged retention and enhanced mucosal drug delivery. Furthermore, contact angle measurements showed a marked reduction in surface tension upon interaction with mucin, with the SLB-loaded nanoemulsion demonstrating superior wettability and strong mucoadhesive potential. Conclusions: These findings underscore the suitability of SLB-loaded nanoemulsions as a robust platform for effective mucosal drug delivery, addressing solubility and bioavailability challenges while enabling prolonged retention and controlled therapeutic release.

Cold-Drawn Wood-Filled Polybutylene Succinate Macro-Fibers as a Reinforcing Material for Concrete

The corrosive behavior of steel reinforcements causes issues in the concrete industry. To overcome this issue, alternative noncorrosive reinforcements such as polymer fibers could be used. However, as environmental protection becomes more important, sustainability must also be considered in the solution. An alternative to polymers based on raw oil is bio-based polymers. This study investigates the suitability of polymer fibers produced from polybutylene succinate together with cellulose and wood fillers as concrete reinforcements. Different mixtures of polybutylene succinate, cellulose, and wood fillers were created, and fibers were produced using a multiple drawing process. The fibers were tested using tensile tests, a single-fiber pull-out test, contact angle measurements, reflected light microscopy, density measurements, and thermogravimetric analysis. The fillers were shown to decrease the mechanical properties as the particle size and filler amount increased, resulting in a reduction in Young’s modulus and tensile strength of 55% and 70%, respectively, while adhesion to concrete increased with particle size from 0.31 ± 0.02 N/mm2 without filler to 0.90 ± 0.10 N/mm2 for the best-performing material combination. Reflected light microscopy images show changes in the fiber surface before and after pull-out. The fiber density decreased from 1.26 ± 0.05 g/cm3 to 0.91 ± 0.04 g/cm3 with an increasing filler amount and particle size for a compound with 10 weight percent of wood filler 1. The fiber thermal stability decreased slightly with the addition of filler. The greatest effect was a reduction in the temperature to ≈58 °C at 1% weight loss when 10 weight percent of wood was added. This study proves the possibility of using bio-based materials as concrete reinforcements.

Protein Orientation and Polymer Phase Separation Induced by Poly(methyl methacrylate) Tacticity.

Stereochemistry may affect the physicochemical and biological properties of polymer films that are important for their applications, including substrates for the fabrication of protein microarrays. In this study, we investigated the effect of poly(methyl methacrylate) (PMMA) tacticity on the interaction of polymer thin films with proteins and on the phase separation process in blends with poly(tert-butyl methacrylate) (PtBMA). Thin films of isotactic, atactic, and syndiotactic PMMA were studied for topography, surface chemistry, and protein adsorption. Secondary ion mass spectrometry and contact angle measurements revealed a lower surface exposure of polar ester functional groups for iso-PMMA, resulting in the reduced adsorption of albumin and fibrinogen proteins. We also showed that changes in surface chemistry alter the orientation of proteins adsorbed on iso-PMMA through hydrophobic and electrostatic interactions. In addition, blends composed of PMMA and PtBMA, both of different tacticities, were investigated in terms of protein microarray fabrication. The two-dimensional domain structure was obtained by a phase separation process for at-PtBMA blends prepared on silicon substrates modified with amino-silane. Finally, for an isotropic and regular polymer pattern of iso-PMMA/at-PtBMA, the possibility of protein microarray formation on this blend was demonstrated, showing selective adsorption to PtBMA domains and perfect mirroring of the polymer patterns.

Microwave-Assisted In-Situ Synthesis of Polyethersulfone–ZnO Nanocomposite Membranes for Dye Removal: Enhanced Antifouling, Self-Cleaning, and Antibacterial Properties

Microwave-assisted synthesis presents a promising method for enhancing the formation of nanocomposites due to its rapid heating and uniform energy distribution. In this study, we successfully fabricated polyethersulfone–zinc-oxide (PES-ZnO) nanocomposite membranes by exposing PES/ZnCl2/DMF dope solutions to microwave radiation. Before synthesizing the membranes, zinc-oxide nanoparticles (ZnO-NPs) were optimized in an organic phase using microwave radiation to ensure effective nanoparticle formation. The synthesis of ZnO-NPs in DMF solvent was validated through UV–Vis spectroscopy, X-ray diffraction (XRD), and Dynamic Light Scattering (DLS). We examined the surface morphology and roughness of the PES-ZnO membranes through Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). Moreover, we assessed the membranes’ hydrophilicity, permeability, and physicochemical properties through contact-angle measurements, pure water flux tests, water uptake assessments, and porosity tests. Energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) verified the successful integration of ZnO nanoparticles (ZnO-NPs) into the membrane matrix. The results indicate that including ZnO-NPs significantly improves the membrane’s permeability and hydrophilicity. The nanocomposite membranes exhibited high dye rejection efficiency, with ZnO-NPs facilitating photocatalytic self-cleaning properties. Antibacterial tests also demonstrated a substantial inhibition of common bacteria, suggesting enhanced resistance to biofouling. This research highlights the potential of microwave-assisted PES-ZnO nanocomposite membranes as effective and sustainable solutions for wastewater treatment, offering scalable applications along with added benefits of antifouling, self-cleaning, and antibacterial properties.

Poly(vinyl alcohol) Nanocomposites Reinforced with CuO Nanoparticles Extracted by Ocimum sanctum: Evaluation of Wound-Healing Applications

This study focused on the synthesis of plant-mediated copper-oxide nanoparticles (OsCuONPs) via the sol–gel technique and the fabrication of OsCuONP-infused PVA composite films (POsCuONPs) utilizing the solvent casting method for wound-healing applications. The prepared OsCuONPs and nanocomposite films were characterized using UV–visible spectra, FTIR, SEM, XRD, TGA, water contact-angle (WCA) measurements, and a Universal testing machine (UTM) for mechanical property measurements. The UV and FTIR tests showed that OsCuONPs were formed and were present in the PVA composite film. Moreover, the mechanical study confirmed that there is an increase in the tensile strength (TS) and Young’s modulus (Ym) with 21.75 MPa to 32.50 MPa for TS and 24.80 MPa to 1128.36 MPa for Ym, and a decrease in the % elongation at break (Eb) (394.32 to 75.6). The TGA and WCA study results demonstrated that PVA films containing OsCuONPs are more stable when subjected to high temperatures and demonstrate a decreased hydrophilicity (60.89° to 89.62°). The cytotoxicity and hemolysis tests showed that the CuONPs-3 containing composite films (PVA/OsCuONPs with a wt. ratio of 1.94/0.06) are safe to use, have a good level of cell viability, and do not break down blood. This is true even at high concentrations. The study also discovered that cells moved considerably in 12 and 24 h (13.12 to 19.26 for OsCuONPs and 312.53 to 20.60 for POsCuONPs), suggesting that 60% of the gaps were filled. Therefore, the fabricated POsCuONP nanocomposites may serve as a promising option for applications in wound healing.

Fully printed field-effect transistor humidity sensor with chitosan/polyvinyl alcohol/nano carbon powder for enhanced moisture sensitivity.

With the advancement of flexible electronics, the demand for low-cost, high-performance flexible humidity sensors for wearable devices has increased significantly. However, commercial humidity sensors require complex preparation methods and are expensive. Therefore, we report polyvinyl alcohol/chitosan/nano carbon powder (PVA/CS/NCP) humidity-sensitive composite materials, which were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and contact angle measurements. A resistive humidity sensor was fabricated using screen printing, and the device showed a good response at 33%RH-98%RH humidity, and at 98% RH, the sensor achieved a response of 1.74. A fully printed field-effect transistor (FET) humidity sensor was prepared by integrating an ion gel transistor with a CS/PVA/NCP humidity-sensitive resistor to improve the response. The comparison reveals a significant improvement in the FET humidity sensor's response, reaching 6.27at 98% RH. In addition, both types of sensors exhibit less hysteresis and good repeatability. Lastly, we tested the constructed humidity sensors under non-contact and variable breathing conditions, laying the groundwork for future wearable applications.

Advanced characterization of fish skin gelatin-proanthocyanidins covalent and non-covalent composite emulsions for benzyl isothiocyanate delivery.

This research endeavored to engineer robust delivery matrices for bioactives, specifically benzyl isothiocyanate (BITC), by harnessing the synergistic covalent and non-covalent interactions between fish skin gelatin (FSG) and proanthocyanidins (PC) to synthesize novel composite emulsions. The objective was to delineate the influence of these molecular interactions on the emulsion's structural integrity and stability, which are pivotal for the efficacious encapsulation and controlled release of BITC. Employing a suite of analytical techniques, including Fourier transform infrared spectroscopy (FTIR), fluorescence spectroscopy, and contact angle measurements, the study delineated the predominant molecular forces at play within the FSG-PC complex, identifying electrostatic and hydrophobic interactions as the cornerstones of this interaction. An assessment of the emulsions' physicochemical properties, encompassing chromaticity, antioxidant efficacy, microstructural attributes, particle dimensions, zeta potential, and BITC retention, was undertaken to discern the optimal encapsulation strategy. The data unequivocally indicated that emulsions enriched with 0.06wt% PC, in non-covalent synergy with FSG, afforded the most pronounced stability and retention of BITC. This work paves the way for future studies and the translational application of FSG-PC composite emulsions in the realm of bioactive substance delivery, offering a promising avenue for innovation in pharmaceutical and nutraceutical formulations.

Degradable mesoporous organosilicon nanoparticles coated with chitosan-Cu2+ complexes with dual stimulus-response for efficient prochloraz delivery.

Accurate pesticide application enhances efficiency, reduces usage and minimizes environmental risks. This study employed amino-functionalized degradable mesoporous organosilicon nanoparticles (DMON-N) as a carrier, with chitosan (CS) acting as a capping agent. Chemical cross-linking of CS with Cu2+ through chelation promotes the formation of Cu2+-CS complexes. A pH/redox dual-responsive prochloraz (PRO) delivery system (Cu-CS@PRO-DMON, CCPD) was constructed and evaluated for its potential application in controlling rice sheath blight. The successful preparation of CCPD was confirmed through a series of physicochemical characterizations. The findings demonstrated that CCPD exhibited a high PRO loading capacity (29.09%) and that PRO could be released from CCPD for an extended duration (up to 144h) under the influence of acidity and glutathione promotion. Furthermore, CCPD demonstrated excellent wettability (measured contact angle: 63.52±0.42°), adhesion (23.83±2.59mg/cm2) and resistance to rainfall washout on rice leaves. CCPD demonstrated superior antimicrobial efficacy to prochloraz technical (PRO TC) material and prochloraz emulsion in water (PRO EW). The biosafety assessment revealed that CCPD exhibited minimal acute toxicity to zebrafish, no discernible toxicological effects on human bronchial epithelial cells and no notable impact on rice.

Ultrasound assisted complexation of soybean peptide aggregates and soluble soybean polysaccharide: pH optimization, structure characterization, and emulsifying behavior.

This study aims to enhance the emulsifying properties of soybean peptide aggregates (SPA) by preparing SPA-soluble soybean polysaccharide (SSPS) composite particles at the assistance of ultrasound technique. The optimal pH for SPA and SSPS complexation was determined by measuring the charge and particle size of the composites. The effects of ultrasound power and duration on the physicochemical properties of the composite particles were assessed through measurements of particle size, zeta potential, contact angle, FTIR, and SEM. The influence of ultrasound duration on the emulsifying properties of the composite particles was evaluated by particle size, zeta potential, microstructure, rheology, and in vitro digestibility. The optimal pH for SPA and SSPS complexation was determined to be 4.0. Zeta potential and FTIR analyses indicated that ultrasound enhanced the electrostatic interactions and hydrogen bonding between SPA and SSPS. Emulsions stabilized with ultrasonicated composite particles exhibited reduced particle sizes, increased viscosity, improved viscoelastic properties, and better in vitro digestibility. The results suggest that moderate ultrasound treatment can strengthen the interactions between SPA and SSPS, thereby enhancing their emulsifying properties. This study offers valuable insights into enhancing the emulsifying performance of highly hydrophobic protein particles.

Advanced chitosan hybrid dye labels for dynamic monitoring of shrimp and milk freshness.

This study presents the development of intelligent screen-printed labels for real-time food freshness monitoring. Using chitosan grafted with rosolic acid (RA) and immobilized on montmorillonite (MMT) through cationic exchange, a hybrid dye was synthesized and applied in screen-printing inks. The hybrid structure was characterized by XRD, TGA, and UV-vis, confirming improved thermal stability and maintained halochromic properties. SEM analysis showed consistent ink deposition on filter paper, while water contact angle (WCA) measurements demonstrated enhanced surface hydrophobicity due to the MMT. The labels exhibited clear pH-sensitive color transitions from yellow to purplish red (pH 2.0-12.0) and rapid ammonia sensitivity, with ΔE values exceeding 45.0 within 10 min. The labels also demonstrated excellent reversibility, storage stability, leaching resistance, and cytocompatibility. Practical tests on shrimp and milk confirmed the labels' ability to accurately monitor freshness through visible color changes. These findings highlight the potential of hybrid labels as effective, scalable freshness indicators for intelligent food packaging.

Electrospun Collagen-Coated Nanofiber Membranes Functionalized with Silver Nanoparticles for Advanced Wound Healing Applications

Complex wounds pose a significant healthcare challenge due to their susceptibility to infections and delayed healing. This study focuses on developing electrospun polycaprolactone (PCL) nanofiber membranes coated with Type I collagen derived from bovine skin and functionalized with silver nanoparticles (AgNPs) to address these issues. The collagen coating enhances biocompatibility, while AgNPs synthesized through chemical reduction with sodium citrate provide broad-spectrum antimicrobial properties. The physical properties of the membranes were characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Results showed the formation of nanofibers without defects and the uniform distribution of AgNPs. A swelling test and contact angle measurements confirmed that the membranes provided an optimal environment for wound healing. In vitro biological assays with murine 3T3 fibroblasts revealed statistically significant (p ≤ 0.05) differences in cell viability among the membranes at 24 h (p = 0.0002) and 72 h (p = 0.022), demonstrating the biocompatibility of collagen-coated membranes and the minimal cytotoxicity of AgNPs. Antibacterial efficacy was evaluated against Staphylococcus aureus (SA), Pseudomonas aeruginosa (PA), and Vancomycin-resistant Enterococcus (VRE), with the significant inhibition of biofilm formation observed for VRE (p = 0.006). Overall, this novel combination of collagen-coated electrospun PCL nanofibers with AgNPs offers a promising strategy for advanced wound dressings, providing antimicrobial benefits. Future in vivo studies are warranted to further validate its clinical and regenerative potential.

Comparative study of polymeric nanoparticles and traditional agents in dental implant decontamination.

Peri-implant diseases, such as peri-implantitis, affect up to 47% of dental implant recipients, primarily due to biofilm formation. Current decontamination methods vary in efficacy, prompting interest in polymeric nanoparticles (NPs) for their antimicrobial and protein-specific cleaning properties. This study evaluated the efficacy of polymeric nanoparticles (NPs) in decontaminating titanium dental implants by removing proteinaceous pellicle layers and resisting recontamination. Titanium discs were treated with saline water, PrefGel®, hydrogen peroxide (H2O2), GUM® Paroex®, or polymeric NPs, and analysed using SEM, EDX, XPS, and contact angle measurements to assess changes in surface composition, morphology, and hydrophilicity. Polymeric NPs significantly reduced nitrogen levels compared to PrefGel® (mean reduction: 2.6%, p < 0.05), indicating effective protein removal. However, their carbon reduction efficacy was similar to that of other agents. SEM images revealed that polymeric NPs disaggregated larger protein aggregates but did not fully decontaminate the surface. Contact angle analysis showed changes in hydrophilicity consistent with other treatments. Hydrogen peroxide performed best overall, achieving the lowest carbon levels post-recontamination (mean reduction: 13%, p < 0.01). While polymeric NPs exhibited unique protein-specific cleaning potential, their overall performance was comparable to traditional agents. Residual contaminants, including carbon and oxygen, persisted on all treated surfaces, indicating enhanced cleaning strategies were needed. These findings highlight the potential of polymeric NPs as an innovative approach to implant decontamination, particularly for protein-specific biofilm control. However, their efficacy in broader applications remains like that of conventional methods. This research contributes to developing targeted decontamination protocols to manage peri-implant diseases and improve long-term implant outcomes.

D-Histidine modulated chiral metal-organic frameworks for discriminating 3,4-Dihydroxyphenylalanine enantiomers based on a chemiluminescence quenching mode.

Drug enantiomers often display distinguishable or even opposite pharmacological and toxicologic activities. Therefore it is of great necessity to discriminate enantiomers for guaranteeing safetyness and effectiveness of chiral drugs. Facile chiral discrimination has long been a noticeable challenge because of the minimal differences in physicochemical properties of enantiomers. As one of high-performance chirality selection components, chiral metal-organic frameworks (CMOFs) are bringing new opportunities for the establishment of chiral discrimination platform with merits of high enantioselectivity, low cost, and facile operation. By introducing D-Histidine as a modulator, a CMOFs material termed as D-Histidine-ZIF-8 was prepared on chitosan (CS) with an in-situ growth protocol. The positively charged CMOFs/CS hybrids were adsorbed onto negatively charged polystyrene microplate via electrostatic interaction to form a chiral discrimination interface. This interface can effectively adsorb 3,4-Dihydroxyphenylalanine (DOPA) enantiomers, and the adsorbed molecules can be quantitated based on their quenching behavior on the chemiluminescent (CL) signal of Co2+-catalyzed luminol-H2O2 reaction. The results of contact angle measurements and density functional theory calculations imply that CMOFs/CS have stronger affinity towards D-isomer than L-isomer. Thus the sensitivity for quantifying D-isomer is 2.93 times of that for L-isomer, demonstrating the enantioselectivity of the CMOFs/CS hybrids. The content of D-isomer in nonracemic mixtures of DOPA enantiomers and real samples were assayed with satisfactory results, showing the practicality of this method. The strategy also exhibited discrimination capacity for many other chiral molecules. The CMOFs/CS hybrids prepared with in-situ growth protocol display satisfactory selectivity for discriminating enantiomers. Due to usage of multi-well microplate platform, the method is anticipated to achieve high-throughput assay in the future work. This study paves a pathway for facile chiral discrimination based on a chemiluminescence quenching mode to meet the demand of drug development and manufacture.

Enhanced carbon fiber interface with thermoplastics via nanostructure surface modification: failure, morphology and wettability analysis

Improving the fiber-matrix adhesion in thermoplastic composites remains a significant challenge due to the lack of chemical bonding between thermoplastics and common reinforcing fibers. This study investigates the effectiveness of carbon fibers enhanced with nanostructure surface modification for strengthening the interfacial adhesion to thermoplastic matrices. The fiber surface was modified with graphene nanoplatelets (GNP) through the facile coating method, and the apparent interfacial shear strength (IFSS) was determined by the single-fiber pullout test. GNP-coated fiber improved IFSS by 74% with neat high-density polyethylene (HDPE-Neat) and 28% with maleic anhydride-grafted HDPE (HDPE-8MA), while reduced by 27% with polyamide 6 (PA6) due to different failure mechanisms. Morphology, chemical, and wettability analysis were conducted on the nano-enhanced carbon fibers to quantitatively elucidate these findings on micro/nanoscale, combining machine learning-based image segmentation, X-ray photoelectron spectroscopy (XPS), and contact-angle measurements of intermittent beading on fibers.

Investigation of Amphiphilic PDMS-Hyperbranched Polyglycerol Copolymers to Tune the Fouling-Release Properties in a Moisture Curable Coating System.

Hyperbranched polyglycerol (HBPG) has been proven to be effective as a hydrophilic material when incorporated into amphiphilic copolymers, enhancing fouling-release properties. These amphiphilic polymers not only increase the effectiveness of coatings across a wide range of organisms but also impart antifouling characteristics without resorting to toxic chemicals. HBPGs exhibit high resistance to proteins and lead to the effective removal of marine organisms under low impact pressures. To enhance the effectiveness of HBPGs and facilitate polymer stratification onto the coating surface, copolymers with polydimethylsiloxane (PDMS) were synthesized through a ring-opening multibranching polymerization reaction. These amphiphilic polymers, with varying molecular weights of the PDMS block and different degrees of branching in the HBPG blocks, were incorporated into a urea-siloxane moisture-cure coating system at a concentration of 5 wt %. This study aimed to identify the optimal molecular weight of PDMS and the degree of branching in HBPG that provides the most improved fouling-release (FR) properties to the base coating. The amphiphilic copolymers underwent thorough characterization using Fourier transform infrared (FTIR), NMR, and surface tension measurements. Coatings were extensively characterized for their surface properties by using atomic force microscopy (AFM), photoinduced force microscopy (PiFM), X-ray photoelectron spectroscopy (XPS), moisture adsorption measurements, and contact angle measurements. To assess fouling-release and antifouling properties, laboratory biological assays were conducted with five common marine fouling organisms: Navicula incerta, Celluphaga lytica, Ulva linza, Chlorella vulgaris, and Amphibalanus amphitrite. Notably, 1k or 5k PDMS with a polyglycerol branching ratio of 10:1 or 15:1 emerged as the best performers across a diverse array of laboratory biological assays.

Synthetic Receptors Decorated on Nanoparticles for Selective and Sensitive Glyphosate Detection

Herein, an innovative glyphosate imprinted poly(hydroxyethyl methacrylate-N-methacroyl-(L)-phenylalanine methyl ester nanoparticles (MIP@NPs) based plasmonic nanosensor featured with high sensitivity and selectivity was constructed by using the molecular imprinting technique and used for real-time glyphosate detection. The characterization of nanoparticles was performed by the nano Zetasizer and scanning electron microscopy (SEM), while nanosensors were characterized by the Fourier transform infrared-attenuated total reflection (FTIR-ATR) and contact angle measurement. Control experiments were conducted to evaluate the imprinting efficiency on the signal response using a non-imprinted surface plasmon resonance (NIP SPR) nanosensor prepared without adding glyphosate pesticide into the polymerization mixture. The MIP@NPs integrated molecularly imprinted surface plasmon resonance (MIP SPR) nanosensor having synthetic molecular recognition elements yielded a novel biosensing platform for label-free detection and real-time monitoring of glyphosate pesticide. The MIP SPR nanosensor detected the target glyphosate molecule 4.950 times more selectively than the competitor molecule malathion while 3.918 times more selectively than the competitor molecule malaoxon. In addition, the imprinting efficiency factor was found to be 6.76, indicating that the molecular imprinting process was successful. In addition, the imprinting factor was found to be 6.76. Kinetic studies and adsorption characteristics of glycosate adsorption were carried out to assess adsorption dynamics. The linear concentration range for glyphosate detection was 0.001 ppm–10.000 ppm of pesticide, and the detection limit was found to be 0.120 ppb. Studies on the repeatability of the MIP SPR nanosensor revealed that even after five cycles, the signal response for glyphosate detection did not change significantly with relative standard deviation, RSD<1.5 value. The artificial urine selected as the real sample was spiked with glyphosate at a final concentration of 10.000 ppm to evaluate the matrix effect, and the glyphosate amount was reported.