Surface Characterization Research Articles

Fabrication, surface characterization and effect of oxygen irradiation on polymeric nanocomposite films

This study addressed the preparation of nanocomposites consisting of polyvinyl alcohol (PVA) and titanium oxide (TiO2) for utilization in optoelectronics technologies. PVA/10%TiO2 nanocomposite samples with a mean thickness of 0.1[Formula: see text]mm were created using the solution casting method. The PVA/TiO2 films are irradiated with oxygen fluences of [Formula: see text], [Formula: see text] and [Formula: see text] ions/cm2. The X-ray diffraction (XRD) and FTIR methodologies were employed to investigate the impact of ion bombardment on the structural characteristics and functional groups of PVA/TiO2 substrates. Diffraction peaks are 20.1° for PVA and 25.4° for TiO2, indicating the successful PVA/TiO2 nanocomposite construction. The absorbance (A) of unirradiated and irradiated samples was measured using UV–Vis spectroscopy within a wavelength range of 200–1100[Formula: see text]nm. Band gaps ([Formula: see text]) were calculated using Tauc’s formula for PVA/TiO2 films, exhibiting a decrease from 4.56[Formula: see text]eV for unirradiated PVA/TiO2 film to 4.16, 3.95 and 3.88[Formula: see text]eV at ion fluences of [Formula: see text], [Formula: see text] and [Formula: see text] ions/cm2, respectively. Furthermore, the Ubrach tail has a rise of 1.23[Formula: see text]eV for unirradiated PVA/TiO2 to 1.28[Formula: see text]eV, 1.4[Formula: see text]eV and 1.77[Formula: see text]eV for irradiated films with ion fluences of [Formula: see text], [Formula: see text] and [Formula: see text] ions/cm2, respectively. Additionally, following ion irradiation, the PVA/TiO2 absorption edge [Formula: see text], which was 3.56[Formula: see text]eV, decreased to 3.48, 3.37 and 3.23[Formula: see text]eV, with increasing ion beam fluences. This study demonstrated that the optical behaviors of the PVA/TiO2 films were altered under bombardment, suggesting their potential applicability in optical devices.

Evaluation of the surface characteristics and antibacterial properties of Titanium dioxide nanotube and methacryloyloxyethylphosphorylcholine (MPC) coated orthodontic brackets-a comparative invitro study.

White spot lesions are the most common iatrogenic effect observed during orthodontic treatment. This study aimed to compare the surface characteristics and antibacterial action of uncoated and coated orthodontic brackets. Sixty commercially available stainless steel brackets were coated with TiO2 nanotubes and methacryloyloxyethylphosphorylcholine. The sample was divided into Group 1: uncoated orthodontic brackets, Group 2: Stainless steel brackets with TiO2 nanotubes coating, Group 3: Stainless steel brackets with methacryloyloxyethylphosphorylcholine coating, and Group 4: Stainless steel brackets with TiO2 nanotubes combined with methacryloyloxyethylphosphorylcholine coating. Surface characterization was assessed using atomic force microscopy and scanning electron microscopy. Streptococcus mutans was selected to test the antibacterial ability of the orthodontic brackets, total bacterial adhesion and bacterial viability were assessed. The brackets were subjected to scanning electron microscopy to detect the presence of biofilm. The surface roughness was the greatest in Group 1 and least in Group 2 followed by Group 4 and Group 3 coated brackets. The optical density values were highest in Group 1 and lowest in Group 4. Comparison of colony counts revealed high counts in Group 1 and low counts in Group 4. A positive correlation between surface roughness and colony counts was obtained, however, was not statistically significant. The coated orthodontic brackets exhibited less surface roughness than the uncoated orthodontic brackets. Group 4 coated orthodontic brackets showed the best antibacterial properties. Coated orthodontic brackets prevent adhesion of streptococcus mutans and reduces plaque accumulation around the brackets thereby preventing formation of white spot lesions during orthodontic treatment.

A Comparative Evaluation of Surface and Elemental Changes in Stainless Steel and Titanium Orthodontic Mini-screw Implants: A Multi-arm Randomized Control Trial.

The present study aimed to compare and quantify the surface changes seen in two most commonly used orthodontic miniscrew implants (MSI) materials; titanium and stainless steel after their clinical use. 40 MSIs (20 titanium and 20 stainless steel) were retrieved from the maxillary arch of 20 subjects (13 females and 7 males) in the age group of 18 - 27 years (mean age=22.4 ± 3.83 years) after their intended use. 40 (20 titanium and 20 stainless steel) asreceived MSIs were used as control. All the MSIs were analyzed under a Scanning Electron Microscope (SEM) for the characterization of their morphological condition (blunting of tip, surface defects and corrosion). Furthermore, Energy Dispersive X-ray (EDX) microanalysis was carried out to study the changes in surface characterization. When imaged using SEM, as-received Titanium and Stainless Steel MSIs demonstrated a relatively smooth surface with no surface defects. However, the retrieved titanium and stainless-steel implants showed increased surface defects (both corrosion and cracks) with the difference being statistically significant. The retrieved Titanium MSIs (115.31±24.38μm) showed 4 times more blunting compared to the retrieved Stainless-steel MSIs (29.74±8.56 μm), with the latter showing 2-3 times more surface corrosion. Clinical usage had pronounced effects on both Titanium and Stainless steel MSI alloys in terms of changes in the surface characteristics. While stainless steel MSIs are more susceptible to surface corrosion, Titanium MSIs exhibit greater alterations in the form of tipblunting and cracks in screw threads.

Effectiveness of luliconazole vs ketoconazole topical formulation in reversing damaged hair cuticle

Azole antifungal agents are effective agents for treating scalp ailments such as seborrheic dermatitis. Luliconazole (LZ) is a new azole with unique effects against clinically important dermatomycotic fungi. This study examines the impact of different topical formulation of Luliconazole vs Ketoconazole (KZ) on damaged hair cuticle repair after 5 and 10 washes, using SEM images and sensory Analysis.In this in-vitro study,twelve damaged hair tresses were divided into two groups, and treated with LZ and KZ formulations. Both groups underwent pretreatment with 20% Sodium Laureth sulfate (SLES) and damage induction using 9% HO and 20% ammonium solution, followed by respective LZ (Lupizol ZS, manufactured by Lupin Ltd, India) and KZ therapies. SEM imaging and expert sensory analysis were conducted at baseline, after 5, and 10 washes to evaluate surface characterization like cuticle upliftment, smoothness, and softness.After five washes, LZ-treated hair exhibited smooth, intact cuticles with no upliftment, improving to grade 1 cuticle damage. In contrast, KZ-treated hair continued to show substantial upliftment without damage grade improvement. After ten washes, LZ maintained grade 1 damage and 0 µm upliftment, while KZ-treated strands persisted in showing considerable cuticular distress. Sensory analysis supported these results, with LZ improving hair smoothness and softness by 2.42x and 2.72x respectively, after ten washes, significantly outperforming KZ. Visually, LZ-treated hair appeared smoother and healthier, indicating its greater effectiveness in enhancing hair integrity post-washing.The botanical conditioner-based formulation of LZ is more efficacious in enhancing hair integrity post-washing compared to the Ketoconazole formulation. Well-controlled human studies are required to further establish the clinical effects on human participants.

A Remarkable Pt Doped CNT Catalyst as a Double Functional Material: Its Application for Hydrogen Production and Supercapacitor

In this study, by producing bifunctional material, hydrolysis, and supercapacitor applications were investigated. The carbon nanotube-supported Pt catalyst was prepared using the sodium borohydride (NaBH<sub>4</sub>) reduction. Surface characterization of the synthesized Pt/CNT catalyst was performed using scanning electron microscopy-energy dıstrıbutıon X-ray spectrometer (SEM-EDX), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Hydrolysis experiments were performed after deciding on the appropriate atomic ratio from the Pt/CNT catalysts synthesized in different nuclear ratios. The parameters affecting the hydrogen production from NaBH<sub>4</sub> were examined. As a result of the kinetic calculations, the initial rates of reaction for 30°C and 60°C were calculated as 21949,69 mlH<sub>2</sub>g<sub>cat</sub>min<sup>-1</sup> and 70018,18 mlH<sub>2</sub>g<sub>cat</sub>min<sup>-1</sup>. Galvastonic charge-discharge (GCD), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were used as characterization techniques for the use of Pt/CNT catalysts as electrodes in supercapacitor applications. The specific capacitance value of 7% Pt/CNT catalyst at 1 A/g current density was calculated as 57,78 F/g. Energy and power density were calculated as 8,025 Wh/kg and 963 W/kg, respectively. Therefore, this catalyst is called a “cap-cat” with capacitor properties. The catalyst used in this study is promising for this recently studied topic.

Preparation of surface molecularly‐imprinted magnetic kaolin for selective separation and determination of thiabendazole

AbstractIn this study, a selective sorbent was fabricated by combining a surface molecularly‐imprinted polymer and magnetic kaolin for reliable quantification of thiabendazole (TBZ) coupled with spectrofluorimetry. Several surface characterization methods were conducted to confirm the synthesis of TBZ‐imprinted magnetic kaolin with a polymer thickness of ~48 nm. The molecularly‐imprinted magnetic kaolin (MIP@MKLN) showed high adsorption capacity (8.7 mg/g), remarkable selectivity with an imprinting factor of 3.71 and excellent regeneration ability for up to 10 uses without significant change of its initial adsorption capacity for TBZ. The proposed method had linear range from 5 to 500 μg/mL TBZ concentration with a correlation coefficient of 0.995 and the limit of detection was 1.4 μg/mL. MIP@MKLN was used for selective separation and quantification of TBZ in orange and lemon samples. There were high recovery values ranging from 96.4% to 100.2% with lower relative standard deviations (less than 5%) in the spiked samples under optimized conditions. Overall, the proposed method based on MIP@MKLN as an excellent sorbent could produce a feasible, convenient, and promising method for rapid, selective, and sensitive quantification of TBZ in real samples.

Characterization of Bauhinia Variegata natural fiber treated with bleaching, benzoylation, and alkalization

This study describes the physical, chemical, mechanical as well as morphological characterization of surface modified novel Bauhinia Variegata (BVR) stem fibers. Surface modifications for the fiber are accomplished with bleaching, benzoylation, and alkalization treatments. Using standard test methods, the chemical constituents of BVR fiber are evaluated like α- cellulose 62.5%, hemicellulose 10.8%, lignin18.2% and wax 0.8%. Scanning electron microscopy (SEM) was used to see how different the chemical reactions affect the fiber and SEM images confirmed the enhanced rough surface and existence of voids, along with the subtraction of unusual substances from the fiber surface. In both treated as well as untreated BVR, a Fourier-transform infrared spectroscopy (FTIR) analysis established the presence of cellulose, hemicelluloses, and lignin components. X-ray diffraction test evaluated the crystalline index for treated and raw fiber. The thermogravimetric test provides proof of enhanced thermal sustainability in the BVR upon treating chemically. The increased tensile strength and Young’s modulus upon chemical treatment confirm the improvement in the mechanical properties of the BVR fiber. The moisture absorption test revealed that the hydrophilic nature of BVR was reduced after the chemical treatment, promoting greater fiber-matrix adhesion. Presently studied BVR fiber seems to be a good substitute to the harmful man-made fibers for making of bio composites.

Biofunctionalization of dental abutments by a zinc/chitosan/gelatin coating to optimize fibroblast behavior and antibacterial properties.

Tightly sealed peri-implant gingival tissue provides a barrier against oral bacterial invasion, protecting the alveolar bone and maintaining long-term implant survival. To investigate if zinc can enhance the integration between peri-implant gingival tissue and abutment surface, we herein present novel zinc/chitosan/gelatin (Zn/CS/Gel) coatings prepared using the electrophoretic deposition (EPD) technique. The effect of these coatings on human gingival fibroblasts (hGFs) was investigated by culturing these cells on top of the EPD coatings. Surface characterization demonstrated that Zn2+ were released in a sustained and pH-responsive manner. The preclinical cell culture evaluation of these coatings indicated that the zinc-containing coatings enhanced cell migration, adhesion and collagen secretion of hGFs. Moreover, the zinc-containing coatings exhibited antibacterial efficacy by inhibiting the growth of Porphyromonas gingivalis and reducing attachment of Staphylococcus aureus. Notably, zinc-free CS/Gel coatings prevented attachment of P. gingivalis as well. The coatings were also shown to be cytocompatible with epithelial cells and osteoblasts, which are other relevant cell types which surround dental implants after clinical placement. Based on our findings, it can be concluded that Zn-containing coatings hold promise to enhance the adhesion of gingival tissue to the implant surface, which may potentially contribute to the formation of a robust peri-implant soft sealing counteracting bacterial invasion.

Sulfonation Treatment of Polyether-Ether-Ketone for Dental Implant Uses

There has been a recent uptake in the use of polyether-ether-ketone (PEEK), which is an organic thermoplastic polymer, in the manufacturing of various medical devices, implants, and equipment. Finding the best time and procedure for PEEK after sulfonation is the goal of this research. A total of 30 PEEK discs were sulfonated in this study by immersing them in concentrated (H2SO4) sulfuric acid for various durations and subsequently treated using various post-treatment techniques. Five experiments were carried out, aimed studying the effect of immersion time (5 s–2 min). The methods used as post-treatment were hydrothermal treatment, immersion in NaOH, and washing with acetone. The sulfonation time was measured, and the post-treatment techniques, surface characterizations, were conducted using scanning electron microscopy (SEM) (Electron Optics Instruments, LLC., West Orange, NJ, USA), atomic force microscopy (AFM) (AFM, Vía Burton, CA, USA), and hydrophilic properties. The results were confirmed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The findings of this study demonstrate that sulfonating PEEK caused a structure with a porous network to form in every sample. As the sulfonation time increased, the porous structure became more noticeable and the concentration increased. As a consequence, the roughness of the surface increased notably, and the modified PEEK surface’s wettability improved noticeably. Hydrothermal treatment was determined to be the most successful way for eliminating the leftover sulfuric acid, and sulfonation for 2 min was determined to be ideal. By understanding the best post-treatment procedures and ideal sulfonation duration, a theoretical foundation for the production of sulfonated PEEK for orthopedic uses may be laid.

Development and experimental evaluation of surface enhancement methods for laser powder directed energy deposition microchannels

ABSTRACT This research evaluates Laser Powder Directed Energy Deposition (LP-DED) for producing fine feature internal microchannels. This study is focused on enhancing and characterising the surfaces of microchannels produced using techniques such as abrasive flow machining, chemical milling, chemical mechanical polishing, electrochemical machining, and thermal energy method to modify internal surfaces of microchannels made from NASA HR-1 Fe-Ni-Cr alloy. Flow testing for discharge coefficient measurement is conducted on processed microchannel samples, followed by characterisation through optical microscopy, Scanning Electron Microscopy (SEM), and Computed Tomography. Findings reveal variations in surfaces due to powder adherence, melt pool undulations, and polishing mechanisms. The study emphasises the significance of removing material equivalent to the mean powder diameter to reduce surface roughness and impact the discharge coefficient. The research proposes a ratio for planarising roughness and waviness peak height and density, offering insights for tailored surface adjustments in specific applications requiring reduced flow resistance. Highlights Internal microchannels with thin-walls were fabricated using the laser powder directed energy deposition process. Various surface enhancements and polishing processes were developed to modify the surface texture of the LP-DED channels. Flow testing was conducted to determine the discharge coefficient. Post-test characterisation was completed to obtain cross sectional area, perimeter, surface texture, and general surface condition to analyse results. Ratio of roughness and waviness peak and density (Spk/Spd and Wp/WPc) is proposed as a relevant surface characterisation parameter. Tailored surface modifications for specific end-use applications.

First-principles study of CO2 hydrogenation to methanol on In-Ru alloys: Revealing the influence of surface In/Ru ratio on reaction mechanism and catalyst performance

Designing high-performance catalyst is vital in the field of CO2 methanolization. In this study, two In3Ru surfaces (In3Ru_i and In3Ru_r) were employed as computational models and the density functional theory was applied to study the influence of surface In/Ru ratio on their surface morphologies, reaction mechanisms and catalysis performance for methanol synthesis. Surface characterization reveals that In3Ru_i is higher in surface In/Ru ratio than In3Ru_r, and such difference facilitates CO2 adsorption on In3Ru_r. Being different in surface In/Ru ratio, two surfaces exhibit distinct variations in the reaction mechanism of methanol formation. For In3Ru_i, the “Formate” pathway dominates the first CO2 activation step which leads to methanol production. On the other hand, In3Ru_r prefers the “reverse water-gas shift” pathway (RWGS) in the initial step of CO2 activation, but this mechanism is unable to generate CH3OH due to the kinetic limitation of CO* hydrogenation. Based on the microkinetic modeling, In3Ru_i is superior in both CO2 production rate and CH3OH selectivity than the other one, suggesting higher surface In/Ru ratio benefits methanol formation, which complies well with the experiment. Overall, our study offers a new perspective with respect to how surface morphology of the bimetallic catalyst influences the reaction mechanisms of CO2 hydrogenation.

Evaluation of vateria indicia leaves extract as a green source of potential corrosion inhibitor against mild steel corrosion in 1M HCl solution: electrochemical, and surface characterisation studies

Evaluation of vateria indicia leaves extract as a green source of potential corrosion inhibitor against mild steel corrosion in 1M HCl solution: electrochemical, and surface characterisation studies

The preparation and characterization of lubricant-infused silicone rubber surface based on laser-splicing-scan microstructure

Slippery surface, as the most cutting-edge function surface, has aroused the extensive attention ascribed to excellent hydrophobicity and self-cleaning property. Micro/nanostructure (functional carrier) and lubricant fluid (functional layer) collectively constitute slippery bi-phase surface. To our best knowledge, we firstly validate the preparation feasibility of lubricant-infused silicone rubber surface (LISRS) based on nanosecond laser splicing scan. Comprehensive characterizations demonstrate that laser splicing traces will break the uniformity of microstructures resulting in droplet pinning. However, the lubricant infusion can significantly endow the whole microstructure surfaces with droplet depinning effect, which directly improves the process compatibility of the laser splicing machining. The capillary infiltration and unstable loss of the lubricant on the microstructure surfaces not only confirm the stable lubricant layer of LISRS conformal with microstructures, but also reveal capillary stabilization mechanism of microgroove structures under gravity environment. Then, after being subjected to comprehensive stability tests (including mechanical abrasion, water droplet and jet impacts), the water droplet sliding behaviors of impacted surfaces show that the lubricant-infused microstructure surface has a certain degree of resistance to external impacts. These results show that it is extremely feasible to create large-scale LISRS using a laser splicing scan. With the rapid development of laser micro/nanofabrication, it is promising to break through the tough issue of large-scale and high-efficiency preparation of slippery silicone rubber surfaces, and bring slippery surfaces to the practical applications of anti-corrosion, anti-fouling and anti-icing materials or products.

Evaluation of plasma parameters’ impact on MRR and surface roughness in plasma polishing of fused silica: An investigation of surface characterization

Advanced fabrication methods with high efficiency are needed to meet the rising demand for precision optical components. This study proposes a plasma-based isotropic polishing method to remove fused silica's surface defects and subsurface damaged layers. Hence, a medium-pressure plasma process is developed to serve this purpose. The qualitative analysis of the plasma and atom emission spectrum explores the plasma generation and scattering of the activated fluorine (F*) radicals inside the plasma chamber. Material removal rate (MRR) and surface roughness variations with different total pressures of 5–30 mbar and substrate dimensions (i.e., varying length between 5 and 45 mm with fixed width and thickness of 5 and 2 mm) at fixed process parameters, i.e., radio-frequency power of 80 W, pressure ratio of 1:1, gas composition of 90:10, have been investigated. The highest and lowest MRR, i.e., 0.039 mm3/min and 0.0061 mm3/min, are achieved at 5 and 30 mbar total pressures on substrates having lengths 45 and 5 mm, respectively. The highest and lowest percentage change in surface roughness observed are 86.4 % and 17.1 % at 5 mbar and 30 mbar for substrates with 5 and 45 mm lengths, respectively. Surface morphology analysis shows the micro-cracks are reduced after plasma processing. The presence of elements, i.e., F and C, through EDX analysis, confirms the reactions on the plasma processed surface. Moreover, The XPS findings demonstrated that minimal radicals could be incorporated onto the fused silica surface during He/O2/SF6 plasma processing. At lower pressure, the surface roughness value increases due to the increased excitation and ionization rate caused by more interaction between the fluorine and surface atoms. The MRR increases with substrate dimension with constant pressure. Larger substrate dimensions result in increased MRR at lower pressure.

Characterization of Surface and Bulk Properties of α-Tocopherol Blended and γ Irradiated UHMWPE Sandwich Nanocomposites

In the present study, an unconventional approach in compression molding is chosen to fabricate Ultra High Molecular Weight Polyethylene (UHMWPE) sandwich composites with Graphene (Gr) and Nano-diamond (ND) as fillers. A unique comparison is done between the surface and bulk properties of UHMWPE nano-composites and UHMWPE sandwich composites. Influence of gamma irradiation at doses of 50, 100 kGy doses and vitamin E (vit-E) on crystal structure, mechanical, thermal and tribological characteristics of UHMWPE composites were studied through x-ray diffraction (XRD), raman spectroscopy, dynamic mechanical analysis (DMA), rheology, differential scanning calorimetry (DSC), tensile, nano-indentation and wear characterization techniques. Fracture regions and surface wear of the samples were analyzed through scanning electron microscopy (SEM) to understand the dispersion behavior of fillers in matrix. The concentration of vit-E content in UHMWPE greatly influenced the crosslinks and surface properties in gamma irradiated composites. Gamma irradiation have shown significant improvement in crystallinity, viscous behavior and bulk properties of UHMWPE composites. Irradiated UHMWPE nano-composites have shown better tensile results when compared with sandwich composites, with 22 % increase in young’s modulus and 16 % increase in yield stress. Wear rate has been reduced by 25 % for irradiated sandwich UHMWPE composites when compared with UHMWPE nano-composites.

Siderite with chelator as high-efficiency Fenton reagent to degrade naphthalene via ferrous liberation and carbon dioxide radical anion-mediated iron redox cycle

Siderite (FeCO3) has been verified to be an effective iron material in Fenton-like process, but large dose of FeCO3 and oxidants limits its application. Here, chelators were successfully used to enhance the degradation of naphthalene (NAP). When 1.0 mM of hydrogen peroxide (H2O2) and 1.0 g L−1 of FeCO3 were applied, in the presence of 0.2 mM oxalic acid (OA), 0.1 mM nitrilotriacetic acid (NTA), or 0.1 mM DL-tartaric acid (DL-TA), 99.3 %, 100 %, or 96.7 % of NAP was degraded within 24 h, respectively. The different roles of chelators were confirmed. For OA and DL-TA, due to weak complexation with iron ions, acid effect and generation of carbon dioxide radical anion (CO2−) contributed to high concentration of Fe2+, while for NTA, chelation and CO2− were two major factors. In addition, the excellent potential application of H2O2/FeCO3/chelator was determined because of (1) lower environmental risk of chemicals; (2) strong tolerance to water matrixes; (3) the excellent stability of FeCO3 confirmed by surface characterizations and cyclic experiment, as NAP was completely degraded after the 6th cycle. At last, H2O2/FeCO3/chelator had superiority over other reduced iron minerals due to lower running cost in lab study, better reusability, and environmental friendliness. Therefore, it is expected that H2O2/FeCO3/chelator technique can provide an effective alternative to Fenton-like process in remediation of NAP contaminated sites.

Exploring chitosan-plant extract bilayer coatings: Advancements in active food packaging via polypropylene modification

UV-ozone activated polypropylene (PP) food films were subjected to a novel bilayer coating process involving primary or quaternary chitosan (CH/QCH) as the first layer and natural extracts from juniper needles (Juniperus oxycedrus; JUN) or blackberry leaves (Rubus fruticosus; BBL) as the second layer. This innovative approach aims to redefine active packaging (AP) development. Through a detailed analysis by surface characterization and bioactivity assessments (i.e., antioxidant and antimicrobial functionalities), we evaluated different coating combinations. Furthermore, we investigated the stability and barrier characteristics inherent in these coatings. The confirmed deposition, coupled with a comprehensive characterization of their composition and morphology, underscored the efficacy of the coatings. Our investigation included wettability assessment via contact angle (CA) measurements, X-ray photoelectron spectroscopy (XPS), and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), which revealed substantial enhancements in surface concentrations of elements and functional groups of CH, QCH, JUN, and BBL. Scanning electron microscopy (SEM) unveiled the coatings' heterogeneity, while time-of-flight secondary ion mass spectrometry (ToF-SIMS) and CA profiling showed moderately compact bilayers on PP, providing active species on the hydrophilic surface, respectively. The coatings significantly reduced the oxygen permeability. Additionally, single-layer depositions of CH and QCH remained below the overall migration limit (OML). Remarkably, the coatings exhibited robust antioxidative properties due to plant extracts and exceptional antimicrobial activity against S. aureus, attributed to QCH. These findings underscore the pivotal role of film surface properties in governing bioactive characteristics and offer a promising pathway for enhancing food packaging functionality.

Fabrication of SnO2/NGO hybrid nanocomposite as an effective photocatalyst for binary dye degradation under sunlight illumination

We successfully synthesized nitrogen-doped graphene oxide grafting tin oxide nanoparticles (SnO2/NGO nanocomposite). To evaluate the surface, optical and morphology characterization of synthesized SnO2/NGO nanocomposites was done using various analytical techniques. The XRD data indicate the crystallinity of a high-purity SnO2/NGO nanocomposite in nature. The Raman spectra of the resultant SnO2/NGO nanocomposite exhibit moderate graphitization with a ID/IG intensity of 0.98. Under sunlight irradiation, the photocatalytic activity of a produced SnO2/NGO nanocomposite on the breakdown of toxic binary organic dyes (methylene blue/methyl orange) was examined. On MB and MO, the resultant SnO2/NGO nanocomposite had a maximum degradation efficiency of 150mins and 89.4%, 93.7%, respectively. Furthermore, the simple and inexpensive hydrothermal-derived SnO2/NGO nanocomposite exhibits rapid photocatalytic degradation on MB and MO when exposed to sunlight illumination.

Bioinspired core-shell nanofiber drug-delivery system modulates osteogenic and osteoclast activity for bone tissue regeneration

Osteogenic-osteoclast coupling processes play a crucial role in bone regeneration. Recently, strategies that focus on multi-functionalized implant surfaces to enhance the healing of bone defects through the synergistic regulation of osteogenesis and osteoclastogenesis is still a challenging task in the field of bone tissue engineering. The aim of this study was to create a dual-drug release-based core-shell nanofibers with the intent of achieving a time-controlled release to facilitate bone regeneration. We fabricated core-shell P/PCL nanofibers using coaxial electrospinning, where alendronate (ALN) was incorporated into the core layer and hydroxyapatite (HA) into shell. The surface of the nanofiber construct was further modified with mussel-derived polydopamine (PDA) to induce hydrophilicity and enhance cell interactions. Surface characterizations confirmed the successful synthesis of PDA@PHA/PCL-ALN nanofibers endowed with excellent mechanical strength (20.02 ± 0.13 MPa) and hydrophilicity (22.56°), as well as the sustained sequential release of ALN and Ca ions. In vitro experiments demonstrated that PDA-functionalized core-shell PHA/PCL-ALN scaffolds possessed excellent cytocompatibility, enhanced cell adhesion and proliferation, alkaline phosphatase activity and osteogenesis-related genes. In addition to osteogenesis, the engineered scaffolds also significantly reduced osteoclastogenesis, such as tartrate-resistant acid phosphatase activity and osteoclastogenesis-related gene expression. After 12-week of implantation, it was observed that PDA@PHA/PCL-ALN nanofiber scaffolds, in a rat cranial defect model, significantly promoted bone repair and regeneration. Microcomputed tomography, histological examination, and immunohistochemical analysis collectively demonstrated that the PDA-functionalized core-shell PHA/PCL-ALN scaffolds exhibited exceptional osteogenesis-inducing and osteoclastogenesis-inhibiting effects. Finally, it may be concluded from our results that the bio-inspired surface-functionalized multifunctional, biomimetic and controlled release core-shell nanofiber provides a promising strategy to facilitate bone healing.

Experimental evaluation of atmospheric plasma treatment effects on different textures of CFRP composite for aircraft applications

This article examines the impact of Atmospheric Plasma Treatment (APL) on the chemical composition and fracture properties of various textured surfaces (tool and bag side) of carbon fiber/epoxy (CFRP) composites utilized in aircraft applications. For this purpose, parameters of atmospheric plasma (APL) surface treatment were evaluated in comparison to chemical cleaning and peel-ply applications, taking into account its effects on surface properties and adhesive bond strength. A comprehensive variety of surface characterization techniques were utilized to analyze surface modifications, including water and diiodomethane contact angle measurements for assessing surface hydrophilicity, Fourier Transform Infrared Spectroscopy with Attenuated Total Reflection (FTIR-ATR) and X-ray Photoelectron Spectroscopy (XPS) for analyzing chemical composition and functional groups, and Profilometry, Atomic Force Microscopy (AFM), and Scanning Electron Microscopy (SEM) for evaluating surface topography and morphology. Experimental results indicated that the reduction in the contact angle following plasma treatment correlated with the elevated oxygen concentration and the presence of polar functional groups (e.g. -OH, -NH2, -NH3, C=O, O-C=O) on the composite surface. Plasma treatment, especially at low nozzle speeds, increased surface roughness on the bag side surfaces. This prevented adhesive penetration and led to gas entrapment, resulting in adhesive failure mode and reduced single lap shear strength for the bag side. In contrast, on the tool side surfaces, the plasma treatment led to a remarkable 19.7% enhancement in shear strength, highlighting its effectiveness.