Search Results (148)

The interaction between carbon nanoparticles (CNs) and Langmuir monolayers of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) as a model pulmonary surfactant (PS) film was studied to shed light on the physicochemical bases underlying the potential adverse effects associated with pollutant inhalation. The results indicated that the surface pressure–area isotherms of the DPPC monolayers shifted toward lower molecular areas, and the compression modulus was reduced in the presence of CNs, hindering the ability of the DPPC monolayers to reduce the surface tension. The relaxation process of the DPPC monolayers were influenced, and the surface morphology and the continuity of the monolayers were destroyed by the penetration of CNs into the DPPC monolayers. The molecular dynamics simulation revealed that particle incorporation into the DPPC monolayers reduced the packing density of the DPPC molecules, worsening the mechanical performance of the monolayers. This effect was attributed to the strong binding trend between the CNs and the DPPC molecules. These results demonstrated that CNs could alter the relaxation mechanisms of the PS film, and this may cause a modification of the inhaled particle transport at the PS film and contribute to adverse health effects in the respiratory system of workers involved in the CN production process. Full article

Pulsed laser annealing (PLA) was performed on a 0.3 μm thick hydrogenated amorphous carbon (a-C:H) film deposited on silicon substrate by plasma-enhanced chemical vapor deposition (PECVD). The 532 nm, 32 ns PLA ranged in fluence from 0.2 to 0.94 J cm⁻². There were no visible signs of film delamination over the entire fluence range for a single pulse. As the fluence increased, graphitization of the amorphous film bulk was observed. However, at the near surface of the film, there was a concomitant increase in sp³ content. The sp³ bonding observed is the result of the formation of a thin diamond-like layer on the surface of the carbon film. Along with increasing laser fluence, the film swelled by 75% up to 0.6 J cm⁻². In addition, carbon fiber formation was observed at 0.6 J cm⁻², increasing in size and depth up through 0.94 J cm⁻². The origin of this transformation may be associated with a rapid outgassing of hydrogen from the amorphous carbon during the PLA step. Additionally, there was a dramatic increase in the visible light absorption of these thin films with increasing laser fluence, despite the films being less than a micron thick. These results suggest that PLA of a-C:H film is a useful method for modifying the surface structure for optical or electrochemical applications without film ablation. Full article

The growing scarcity of freshwater worldwide has increased interest in forward osmosis (FO) membranes as a promising solution for water desalination and wastewater treatment. This study investigates the enhancement of thin-film composite (TFC) FO membranes via the incorporation of carboxyl-functionalized multiwalled carbon nanotubes (COOH-MWCNTs) into the polyethersulfone (PES) support layer. The membranes were fabricated using a combination of phase inversion and interfacial polymerization techniques, with COOH-MWCNTs incorporated into the membrane support layers at different concentrations (0–0.75 wt.%). Comprehensive characterization was carried out using various analytical methods and mechanical testing to evaluate the physicochemical and structural properties of the membranes. The modified membranes demonstrated improved hydrophilicity, enhanced mechanical and thermal stability, and improved surface charge properties. Performance tests using a 1 M NaCl draw solution showed that the optimized membrane (0.5 wt.% COOH-MWCNTs) attained a 161% enhancement in water flux (7.48 LMH) compared to the unmodified membrane (2.86 LMH), while also reducing internal concentration polarization (ICP). The antifouling properties were also significantly improved, with a flux recovery rate of 91.92%, attributed to enhanced electrostatic repulsion as well as surface and microstructural modifications. Despite a moderate rise in reverse solute flux, the specific reverse solute flux (J_s/J_w) remained within acceptable limits. These findings highlight the potential of COOH-MWCNT-modified membranes in enhancing FO desalination performance, offering a promising option for next-generation water purification technologies. Full article

Background/Objectives: A nanostructured membrane of polycaprolactone (a synthetic polymer) was synthesized using an electrospinning technique aiming to enhance its hydrophilicity and rate of degradation by surface modification via aminolysis. Since polycaprolactone nanofibrous films are naturally hydrophobic and with slow degradation, which restricts their use in biological systems, amino groups were added to the fiber surface using the aminolysis technique, greatly increasing the wettability of the membranes. Methods: Polycaprolactone nanofibrous membranes were synthesized via the electrospinning technique and surface modification by aminolysis. Trypsin, pepsin, and pancreatin were conjugated onto the aminolyzed PNF surface to further strengthen biocompatibility by enhancing the hydrophilicity, porosity, and biodegradation rate. SEM, FTIR, EDX, and liquid displacement method were performed to investigate proteolytic efficiency and morphological and physical characteristics such as hydrophilicity, porosity, and degradation rates. Results: Enzyme activity tests, which showed a zone of clearance, validated the successful enzyme conjugation and stability over a wide range of pH and temperatures. Scanning electron microscopy (SEM) confirms the smooth morphology of nanofibers with diameters ranging from 150 to 950 nm. Fourier transform infrared spectroscopy (FTIR) revealed the presence of O–H, C–O, C=O, C–N, C–H, and O–H functional groups. Energy-dispersive X-ray (EDX) elemental analysis indicates the presence of carbon, oxygen, and nitrogen atoms owing to the presence of peptide and amide bonds. The liquid displacement technique and contact angle proved that Pepsin-PNFs possess notably increased porosity (88.50% ± 0.31%) and hydrophilicity (57.6° ± 2.3 (L), 57.9° ± 2.5 (R)), respectively. Pancreatin-PNFs demonstrated enhanced enzyme activity and degradation rate on day 28 (34.61%). Conclusions: These enzyme-conjugated PNFs thus show improvements in physicochemical properties, making them ideal candidates for various biomedical applications. Future studies must aim for optimization of enzyme conjugation and in vitro and in vivo performance to investigate the versatility of these scaffolds. Full article

Biochemical monomer upcycling of plastic waste and its conversion into value-added products is deemed necessary, as it provides a greener and more sustainable solution to plastic waste management. In the current study, the polystyrene (PS) biodegradation potential of the fungus Phanerochaete chrysosporium NA3 was evaluated using various analytical techniques, such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), gel permeation chromatography (GPC), and high-performance liquid chromatography (HPLC). The biodegradation capacity of the fungal strain was further evaluated using a carbon dioxide (CO₂) evolution test, which showed that the PS films treated with NA3 produced more CO₂, indicating the strain’s ability to successfully utilize PS as a carbon source. The FTIR analysis of the PS films treated with NA3 showed modifications in the polymer chemical structure, including the formation of carbonyl and hydroxyl groups, which suggests the enzymatic dissociation of the polymer and the associated biodegradation mechanism. Pretreatments were found to be effective in modifying the polymer’s properties, making it more susceptible to microbial degradation, thus further accelerating the biodegradation process. The current study strongly advocates that P. chrysosporium (NA3) can be effectively used for the biochemical monomer recovery of PS waste and could be further utilized in the upcycling of plastic waste for its conversion into value-added products under the concept of circular economy. Full article

This study systematically investigates the effects of repeated Kurome treatment—a physical modification method combining mechanical stirring and oxidative regulation—on the processing characteristics and film properties of Chinese lacquer (urushi). By subjecting raw lacquer to 1–4 cycles of hydration–dehydration (KL1–KL4), the researchers observed a significant increase in viscosity (from 12,688 to 16,468 mPa·s) and a dramatic reduction in curing time (from 74 h to just 3.6 h), driven by deep oxidation of urushiol and quinone-mediated crosslinking, as confirmed by FTIR spectroscopy. The Kurome treatment enabled controlled darkening (L* value decreased from 29.31 to 26.89) while maintaining stable hue and gloss (88.96–90.96 GU), with no adverse effects on abrasion resistance (mass loss of 0.126–0.150 g/100 r) or adhesion (9.58–9.75 MPa). The reduced transparency of the KL3/KL4 films is associated with a densified polymer network, a feature that may benefit protective coatings. Scanning electron microscopy (SEM) analysis confirmed the formation of uniform, defect-free surfaces across all treatment groups. Among them, the KL2 group (viscosity of 14,630 mPa·s, curing time of 9.2 h) exhibited the most favorable balance for industrial applications. This study establishes Kurome technology as a low-carbon, additive-free strategy that enhances the processability of Chinese lacquer while preserving its traditional craftsmanship standards, offering scientific support for its sustainable use in modern coatings and cultural heritage conservation. Full article

In this study, carbon nanosheets were deposited on the surface of graphite films for surface modification using radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) method. The effects of catalyst addition and concentration, growth gas flow rate, and hydrogen plasma pretreatment on the size, morphology, and density of the deposited carbon nanosheets were investigated. These factors influence the deposition results by affecting the nucleation and growth processes of the carbon nanosheets, while the growth process affects their size. The surface morphology and distribution of the carbon nanosheets were characterized using scanning electron microscopy (SEM). Graphite film/aluminum composites were prepared using graphite films modified under different process conditions as reinforcements. The composite prepared with graphite films modified without catalysts showed significant improvement in thermal conductivity, achieving an xy-direction thermal conductivity of 705 W/(m·K) and a z-direction thermal conductivity of 14.8 W/(m·K), both of which are higher than those of unmodified graphite film/aluminum composites. X-ray diffraction (XRD) analysis was conducted to identify the phase composition of the resulting composites and confirm the structural integrity of the reinforcement after processing. Full article

Diblock copolymers (BCP) consisting of poly(methyl methacrylate) (PMMA) and poly(1H,1H,2H,2H-perfluorodecyl methacrylate) (PsfMA) blocks are employed as templates for controlled dispersion and localization of multi-walled carbon nanotubes (MWCNT). Short MWCNT are modified with perfluoroalkyl groups to increase the compatibility between MWCNT and the semifluorinated (PsfMA) phase and to promote a defined arrangement of MWCNT in the BCP morphology. Thin BCP and BCP/MWCNT composite films are prepared by dip-coating using tetrahydrofuran as solvent with dispersed MWCNT. Atomic force microscopy, scanning and transmission electron microscopy reveal a strong tendency of the BCP to form micelle-like domains consisting of a PMMA shell and a semifluorinated PsfMA core, embedded in a soft phase, containing also semifluorinated blocks. MWCNT preferentially localized in the embedding phase outside the micelles. Perfluoroalkyl-modification leads to significant improvement in the dispersion of MWCNT, both in the polymer solution and the resulting nanocomposite film due to increased interaction of MWCNT with the semifluorinated side chains in the soft phase outside the micelle domains. As a result, reliable electrical conductivity is observed in contrast to films with non-modified MWCNT. Thus, well-dispersed, modified MWCNT provide a defined electrical conduction path at the micrometer level, which is interesting for applications in electronics and vapor sensing. Full article

This study examines the intrinsic optical enhancements of carbon fiber-reinforced polymers (CFRPs) achieved through the integration of magnesium oxide (MgO) nanoparticles, as well as Mg/MgO and titanium dioxide (TiO₂) thin films onto carbon fibers. Integration was performed by quasi-continuous electrophoretic deposition (EPD) and physical vapor deposition (PVD), respectively. Employing a customized electrophoretic cell, EPD facilitated uniform MgO nanoparticle deposition onto unsized carbon fibers, ensuring stable nanoparticle dispersion and precise fiber coating. As a result, the fibers exhibited increased ultraviolet (UV) reflectance, largely attributed to the optical properties of the protective MgO layer. In parallel, PVD enabled the deposition of Mg/MgO and TiO₂ thin films with tailored thicknesses, providing precise control over key optical parameters such as reflectivity and interference effects. Mg/MgO coatings demonstrated high UV reflectivity, while TiO₂ layers, with their varying refractive indices, generated vibrant colors in the visible (Vis) range through thickness-dependent light interference. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) assessed the quality, thickness, and uniformity of these thin films, and UV/Vis spectroscopy confirmed the influence of deposition parameters on the resulting optical performance. Post-lamination analyses revealed that both EPD and PVD modifications significantly enhanced UV reflectivity and allowed for customizable color effects. This dual strategy underscores the potential of combining EPD and PVD to develop advanced CFRPs with superior UV resistance, decorative optical features, and improved environmental stability. Full article

Aluminum solid-state batteries are emerging as one of the most promising energy storage systems, offering advantages such as low cost and high safety. This study adopts a safe and cost-effective approach by alloying and doping the all-solid-state aluminum-ion battery to enhance its electrochemical performance. This research further explores the electrochemical impacts of these modifications on the performance of solid-state aluminum batteries. In this experiment, aluminum-based anodes were deposited onto nickel foil using the thermal evaporation (TE) method. At the same time, the graphite film (GF) cathode material was enriched with sodium (GFN) through a solution-based process. The system was combined with magnesium silicate solid electrolytes to investigate the all-solid-state aluminum-carbon battery′s structural characteristics and charge–discharge mechanisms. The experimental results demonstrate that the aluminum-coated electrode alloying effects and the graphite film modification significantly improve battery performance. The system achieved a maximum specific capacity of approximately 700 mAh g⁻¹, with a cycle life exceeding 100 cycles. Furthermore, the microstructural characteristics and phase structure of the aluminum evaporation film were confirmed. Analysis of ion transport pathways during the charge–discharge cycles of the all-solid-state aluminum-carbon battery revealed that both aluminum and magnesium ions play critical roles in the electrode processes. Full article

We studied the influence of different supporting electrolytes (TBAPF₆, TMAPF₆, TEAPF₆, TBAClO₄, and LiClO₄) on the morphology of PEDOT films electrochemically polymerized on screen-printed carbon electrodes, as part of which the synthesis of gold nanoparticles was tested for the subsequent modification of Ki-67 antibodies. Electrochemical deposition of the polymer was carried out using cyclic voltammetry and was characterized in the same way in solutions without the monomer. The nanoparticles were obtained using chronoamperometry at a constant potential for 3 s. The processes of p- and n-doping/undoping of both deposits (with and without gold) were studied, as was their characterization using SEM and ESEM-EDS. It was found that the supporting electrolytes intervened in the morphology and conductivity of the polymer films. In all films, it was possible to electrosynthesize gold nanoparticles, but the type of supporting electrolyte also influenced their distribution, showing that for this study, the most suitable were those obtained using TBAPF6, giving the most promising results for the covalent modification of antibodies to obtain future biosensors. Full article

Background/Objectives: The increasing demand for total hip arthroplasty (THA), due to aging populations and active lifestyles, necessitates advancements in implant materials and design. This review evaluates the role of surface coatings in enhancing the performance, biocompatibility, and longevity of hip implants. It addresses challenges like wear, corrosion, and infection, focusing on innovative surface engineering solutions. Methods: The review analyzes various surface modification techniques, including physical vapor deposition (PVD), chemical vapor deposition (CVD), electrophoretic deposition (EPD), plasma spraying, and ion implantation. It also examines their effectiveness in improving tribological properties, biocompatibility, and resistance to infection. Computational methods such as finite element analysis (FEA) are discussed for predicting potential coating failures. Results: The findings underscore the challenges posed by wear debris and corrosion in common configurations, like metal-on-metal (MoM) and metal-on-polyethylene (MoP). Innovative coatings, such as diamond-like carbon (DLC) films and hydroxyapatite (HA) layers, demonstrate enhanced performance by reducing friction, wear, and bacterial adhesion, while promoting osteogenic cell attachment. Surface textures and optimized tribological properties further improve implant functionality. Multifunctional coatings exhibit potential in balancing biocompatibility and infection resistance. Conclusions: Surface engineering plays a critical role in advancing next-generation hip implants. The integration of advanced coatings and surface modifications enhances implant durability, reduces complications, and improves patient outcomes. Future research should focus on combining innovative materials and computational modeling to refine coating strategies for long-term success in THA. Full article

Polymer corrosion inhibitors are reported to form dense films on carbon steel surfaces, and their thermostability enables survival in harsh downhole environments. In this paper, PEG-OTs was synthesized by mechanochemistry using ball mill by grafting tosyl on PEG. Using this solvent-free green chemistry, non-toxic PEG and PEG-OTs with various molecular weights (600, 2000, and 10,000 g/mol) were prepared and used as corrosion inhibitors. The corrosion inhibition performance of 5 × 10⁻³ mol/L inhibitors on Q235 carbon steel in 0.5 M HCl solution was investigated using static weight-loss, electrochemical impedance spectroscopy, polarization curves, SEM, and contact angle measurements. The results show that, after modification, PEG-OTs has an elevated corrosion inhibition effect compared to PEG. A maximum of 90% corrosion inhibition efficiency was achieved using static weight-loss. The morphology study shows that a dense film formed to protect carbon steel. Thanks to their polymeric structure, a higher molecular weight leads to better corrosion inhibition. Full article

This research explored the formation and effects of carbon layers on Grade 5 titanium alloy (Ti–6Al–4V) surfaces during a microfinishing process using both traditional abrasive films and graphite-coated abrasive films. The study tried to appraise the effect of using graphite-coated films in the microfinishing process concerning surface roughness. Microfinishing with an abrasive film impregnated with diamond particles and an additional coating of graphite was performed to minimize surface roughness and enhance the overall performance of the surface. As a result, it was shown that after processing, the uniform carbon texture formed by the graphite-coated film significantly improved the lubricating and thermal properties. Energy dispersive spectroscopy (EDS) analysis confirmed the homogeneity of carbon distribution over the whole treated surface. Moreover, the graphite-coated films enabled us to obtain smoother surfaces with improved tribological properties. The study therefore concluded that the inclusion of graphite in the abrasive films is necessary for effecting surface modification in light of considerable improvements in surface quality and performance, especially where the wear needs to be reduced and the integrity of the surface maximized. Full article

There are limited studies in the literature on the surface characterization of modified graphene and graphene oxide and the impact of these modified adsorbents on adsorption performance. In addition, the amine group essentially has a promising affinity for carbon dioxide (CO₂). Therefore, chitosan was used in this study to be grafted onto graphene and graphene oxide respectively. This study examines the effects of graphene, graphene oxide, and chitosan-modified graphene oxide thin films on the removal of carbon dioxide (CO₂). Thin films of graphene, graphene oxide, and their chitosan-modified counterparts were prepared via the methods of precipitation and grafting. The differences in the chemical structure, surface properties, and surface morphology of the films were evaluated, and their effect on the adsorption performance of CO₂ is discussed herein. The micrographs from a scanning electron microscope (SEM) show that the surface of graphene oxide appeared to be more porous than graphene, and the amount of grafted chitosan on graphene oxide is higher than that on graphene. An analysis of atomic force microscope (AFM) finds that the surface of chitosan-modified graphene oxide is rougher than that of chitosan-modified graphene. The results of energy-dispersive X-ray spectroscopy (EDS) spectra reveal that the composition of oxygen in graphene oxide is greater than that in graphene and confirm that the oxygen and nitrogen contents of chitosan-modified adsorbents are greater than those of the pristine materials. An analysis of Fourier-transform infrared spectroscopy (FTIR) shows that most of the oxygen-containing groups are reacted or covered by amide or amine groups due to modification with chitosan. The adsorption isotherms for CO₂ adsorbed by the prepared graphene and graphene oxide presented as type I, indicating great adsorption performance under low pressure. The appropriate amount of chitosan for modifying graphene oxide could be found based on the change in surface area. Although the breakthrough times and the thicknesses of the mass transfer regions for graphene oxide modified with 0.9% and 1.2% chitosan were similar, the modification of graphene oxide with 0.9% chitosan was appropriate in this study due to a significant decrease in surface area with 1.2% chitosan dosage. The adsorption uptake difference between chitosan-modified graphene oxide and graphene was greater than that without modification with chitosan due to more chitosan grafted on graphene oxide. The Toth adsorption isotherm model was used to fit the adsorption uptake, and the average deviation was about 1.36%. Full article