Scanning Atomic Force Microscopy Research Articles

Exploring the chemical properties and microstructural characterisations of hybrid asphalt binders for enhanced performance

Approximately 3 billion metric tonnes of garbage involving industrial and agricultural waste is expected to be generated by 2030, posing a significant environmental hazard. Notably, recycling or reusing asphalt modification components (palm oil fuel ash (POFA), garnet waste, and sawdust) in pavement construction encounter ongoing challenges. This study comprehensively assessed the chemical characteristics and microstructure analysis of individual wastes and various hybrid asphalt binder and mixtures incorporated with these components. The mixture consisted of asphalt grade 60/70 blended with varying amounts (0%, 3%, 6%, and 9%) of POFA, garnet waste, and sawdust. Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), and X-ray diffraction (XRD) analyses were also employed to examine the chemical compositions of the raw waste materials. Meanwhile, the microstructure properties of various hybrid asphalt binder mixtures were analysed utilising Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Consequently, this study presented that the correlation between the 6% POFA, 6% garnet waste, and 6% sawdust substantially impacted the chemical composition and morphology of the mixture. The findings of this study demonstrated that including POFA, garnet waste, and sawdust in a hybrid asphalt binder and mixture could enhance performance and engineering properties.

Investigation on structural, optical, thermal, and dielectric properties of cellulose propionate/styrene-maleic anhydride copolymer/molybdenum nanocomposite prepared by pulsed laser ablation

Polymer nanocomposite films of cellulose propionate/styrene-maleic anhydride copolymer/molybdenum (CP/SMAC/Mo) were fabricated by pulsed laser ablation of Mo in the polymer solution for 10, 20, and 30 min. The films were then characterized by various analytical methods. X-ray diffraction (XRD) revealed that the addition of Mo to CP/SMAC removed the crystalline peaks of Mo without changing the amorphous nature of the copolymer. According to the scanning electron microscopy (SEM) and atomic force microscopy (AFM) patterns, Mo atoms were trapped in the amorphous polymer stacks. The energy-dispersive X-ray (EDX) spectrum features C, O, and Mo. FTIR confirmed the embedding of Mo in the polymers. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were carried out on the samples. The pristine polymer film exhibited a band gap energy of 2.9 eV, which decreased to 2.05 eV because of the loading of the Mo nanoparticles. The intensity of the photoluminescence (PL) peak of the films increases with ablation time such that the absorption intensity of the film at a λmax of 426 nm increases by trifold during the 30 min of irradiation, which is consequently due to the increased amount of Mo in the nanostructure. The incorporation of Mo in the polymer matrix enhances the dielectric constant (ε') (6.28–18.13) and ac conductivity (σac) (3.19 × 10−5–1.12 × 10−4 S/cm) of the polymer with negligible dielectric loss. The results suggest possible technological utilization of these materials in such applications as supercapacitors, light-emitting diodes, and organic optoelectronic devices, among others.

Adaptive under-sampling strategy for fast imaging in compressive sensing-based atomic force microscopy

Compressive sensing (CS) can reconstruct the rest information almost without distortion by advanced computational algorithm, which significantly simplifies the process of atomic force microscope (AFM) scanning with high imaging quality. In common CS-AFM, the partial measurements randomly come from the whole region to be measured, which easily leads to detail loss and poor image quality in regions of interest (ROIs). Consequently, important microscopic phenomena are missed probably. In this paper, we developed an adaptive under-sampling strategy for CS-AFM to optimize the process of sampling. Under a certain under-sampling ratio, the weight coefficient of ROIs and regions of base (ROBs) were set to control the distribution of under-sampling points and corresponding measurement matrix. A series of simulations were completed to demonstrate the relationship between the weight coefficient of ROIs and image quality. After that, we verified the effectiveness of the method on our homemade AFM. Through a lot of simulations and experiments, we demonstrated how the proposed method optimized the sampling process of CS-AFM, which speeded up the process of AFM imaging with high quality.

Iron-tannic acid nano-coating: A promising treatment approach for enhancing Lactococcus lactis antibiotic resistance

The objective of this study was to explore a novel methodology for the synthesis of nanocoated probiotics following their collection and cultivation under optimized conditions, in light of their significant contribution to human health. Probiotics are instrumental in sustaining immune health by modulating the gastrointestinal microbiota and facilitating digestion. However, the equilibrium they maintain can be adversely affected by antibiotic treatments. It is critical to investigate the vulnerability of probiotics to antibiotics, considering the potential implications. This research aimed to assess whether nanoparticle coating could augment the probiotics' resistance to antibiotic influence. A strain of Lactococcus lactis (L. lactis) was isolated, cultured, and comprehensively characterized utilizing state-of-the-art methodologies, including the VITEK® 2 compact system, VITEK® MS, and 16S rRNA gene sequencing. The nanoparticle coating was performed using iron (III) chloride hexahydrate and tannic acid, followed by an evaluation of the probiotics' resistance to a range of antibiotics. The analysis through scanning electron microscopy (SEM) and atomic force microscopy (AFM) demonstrated a partial nanoparticle coating of the probiotics, which was further supported by UV/Vis spectroscopy findings, suggesting enhanced resistance to standard antibiotics. The results revealed that this strain possesses a unique protein profile and is genetically similar to strains identified in various other countries. Moreover, nano-encapsulation notably increased the strain's resistance to a spectrum of standard antibiotics, including Benzylpenicillin, Teicoplanin, Oxacillin, Vancomycin, Tetracycline, Rifampicin, Erythromycin, and Clindamycin. These findings imply that nanoparticle-coated probiotics may effectively counteract the detrimental effects of extended antibiotic therapy, thus preserving their viability and beneficial influence on gastrointestinal health.

Construction of a rough surface in EPDM/CB composite through peroxide curing: A mechanism for optimizing physico‐mechanical properties in automotive paint‐compatible applications

AbstractThis study investigates the profound impact of vulcanization methods on ethylene–propylene–diene monomer (EPDM) composites, with a particular focus on elucidating significant findings and achievements. Exploring eight composites, including sulfur and peroxide‐cured variations, we conducted an in‐depth evaluation of the crucial physico‐mechanical properties of the composites. The study extends to encompass the effects of vulcanization on heat aging parameters, providing a comprehensive understanding of the materials' resilience. Utilizing thermogravimetric analysis, differential scanning calorimetry, and Fourier transform infrared spectroscopy, our research delves into the processes, revealing critical insights into the thermal behavior and composition of the composites. Paint compatibility, a pivotal aspect in automotive applications, was rigorously examined through four different test methods. Surface morphology, investigated through scanning electron microscopy and atomic force microscopy, yielded valuable findings on the role of vulcanization in shaping surface roughness and enhancing paint compatibility. Additionally, the quantitative measurement of surface energy using the sessile drop method provided a deeper understanding of the adhesion properties. The findings distinctly underscore the superiority of peroxide‐cured composites, marking a significant stride toward their potential to revolutionize automotive applications. This research not only contributes to the knowledge base but also sets a foundation for advancements in EPDM composite materials, positioning them as key players in driving innovation within the automotive industry.Highlights Developed a peroxide‐cured EPDM rubber composite with a rough surface. A rough surface is more paint‐compatible than a smooth surface. The roughness of peroxide‐cured EPDM is greater than that of sulfur‐cured one. Peroxide curing introduces more polar functional groups and cross‐links. Peroxide‐cured EPDM has higher thermal stability than sulfur‐cured EPDM.

Butyl rubber dispersed with low-loss Ca0.61Nd0.26TiO3 ceramics for miniaturized flexible microwave substrate applications

Ca0.61Nd0.26TiO3 (CNT)-filled butyl rubber (BR) composites were fabricated via Banbury mixing by changing the ceramic volume fraction from 0 to 0.5. The phase purity of the CNT filler was confirmed using X-ray diffraction, and the morphology of the composite samples was analyzed using scanning electron microscopy and atomic force microscopy. BR/CNT composites filled with 50 vol% filler possessed excellent dielectric properties with a dielectric constant of 11.12 and a very low dielectric loss of 0.0023 in the X-band (8–12 GHz) frequencies. Moreover, the material displayed an appreciable thermal conductivity of 0.883 W/mK, low water absorption of 0.0574 %, and an acceptable CTE of 37.08 ppm/ °C. Thus, the developed BR/CNT composites can be used for flexible microwave circuit applications that require miniaturization.

Corrosion resistance of hybrid plasma electrolytic oxidation coatings on AZ31B magnesium alloy in simulated body fluid

This study examines the effects of a hydroxyapatite/anatase TiO2/CeO2 coating on the corrosion of AZ31B magnesium alloy in a simulated body fluid. Plasma electrolytic oxidation (PEO) is used to create the coating, and the surface properties are analysed using X-ray diffraction (XRD), atomic force microscopy (AFM) and field-emission scanning electron microscopy (FE-SEM). Contact angle measurements adapted to compare the uncoated substrate (144.74 ± 2.08°) with the coated substrates, which exhibit contact angles of (107.92 ± 2.16°), (95.88 ± 2.06°) and (66.05 ± 2.09°) for the respective coating durations. Increasing the thickness of the coating improves its corrosion resistance. Specifically, a 6-minute PEO coating significantly increases the thickness and provides better protection against corrosion for the AZ31B magnesium alloy. Cross-sectional scans of the coated samples revealed an increase in specimen thickness from 32.92 μm to77.17 μm. Potentiodynamic polarisation tests in a simulated body fluid reveal that the 6-minute coated sample shows the highest corrosion resistance, with the lowest corrosion current density (1.9037 × 10-06) compared to other coatings, indicating strong protection against corrosion. This research proposes a novel method to enhance the corrosion resistance of PEO coatings on magnesium alloys by depositing a thicker layer of hydroxyapatite, anatase TiO2 and CeO2. This approach results in a stronger and more effective protective system against corrosion.

Period induced reflectance tuning in transparent gold metasurfaces

Gold (Au) nanodisk arrays are modeled and fabricated for tunable near infrared reflectance with high visible transmittance. Simulations are performed in the visible and near infrared regimes between 400 and 2000 nm with varying period of nanostructures. A progressive increase in period of up to three times the diameter of the nanodisks on polymer and quartz substrates is presented. As a result, an increase in visible transmittance with a decrease in near infrared reflectance peak intensity is observed. Modeling results exhibit a high average visible transmittance of 91.5% (400–700 nm) and average reflectance of 62.9% (750–2000 nm) with diameter (D) variations from D=120 nm to D=500 nm with a period (P) equal to twice the diameter, P=2D for a polymer substrate. Electric field intensities exhibit an increase with a decrease in the period between individual nanostructures for constant unit cell dimensions. Alongside simulations, electron beam lithography and evaporation processes are utilized for the patterning and fabrication. Optical characterizations including scanning electron microscopy (SEM) and atomic force microscopy (AFM) of selected metasurfaces on quartz are performed. For a specific period and diameter, the fabricated metasurfaces exhibit near infrared reflectance having a good agreement with the simulated results about plasmonic wavelengths. Such metasurfaces offer potential to be deployed for applications that require selective reflectance intensities in the near infrared range with high visible transmittance, such as controlled environment agriculture (CEA) or multi spectral near infrared sensing. With tunability over a broadband (750–2500 nm), this simple and fabrication-friendly model may be used as a theoretical guide in quantifying specific design parameters with varying light intensity configurations.

Binary ZnS–ZnO films as an alternative buffer layer for solar cell applications

In this research, binary ZnS–ZnO films were fabricated by a two-step process, offering an alternative buffer layer solution for photovoltaic solar cell applications. ZnS films were attained through thermal evaporation, after which they were annealed in air at separate temperatures resulting in films containing both ZnS and ZnO phases. Structural, electrical, ellipsometric, optical, and surface properties were examined in detail to elucidate their applicability as a buffer layer in photovoltaic applications. X-ray diffraction patterns revealed that the films exhibit cubic ZnS and hexagonal ZnO crystal structures, wherein crystallite size is augmented with higher annealing temperatures. ZnS films exhibited a needle-shaped surface morphology, as confirmed through atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM) images. Annealing caused noteworthy modifications on the surfaces of the films. Additionally, absorption spectra denote two distinct absorption regions forming as a result of the annealing process, possibly indicating the emergence of ZnS and ZnO phases. Photoluminescence analyses demonstrate that binary ZnS–ZnO films exhibit greater emission intensities than single-phase ZnS films. Additionally, the annealing process caused the electrical resistivity of films to reduce from 1.28 × 105 to 3.84 × 101 Ω cm. These results suggest that binary ZnS–ZnO films produced via annealing can be considered as promising buffer layers in potential photovoltaic solar cell applications.

Thermal Transitions and Structural Characteristics of Poly(3,4-ethylenedioxythiophene/cucurbit[7]uril) Polypseudorotaxane and Polyrotaxane Thin Films.

Herein, we report the thermal transitions and structural properties of poly(3,4-ethylenedioxythiophene/cucurbit[7]uril) pseudopolyrotaxane (PEDOT∙CB7-PS) and polyrotaxane (PEDOT∙CB7-PR) thin films compared with those of pristine PEDOT. The structural characteristics were investigated by using variable-temperature spectroscopic ellipsometry (VTSE), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and atomic force microscopy (AFM). VTSE and DSC results indicated the presence of an endothermic process and glass transition in the PEDOT∙CB7-PS and PEDOT∙CB7-PR thin films. X-ray diffraction of PEDOT∙CB7-PS and PEDOT∙CB7-PR powders displayed the presence of interchain π-π stacking revealing a characteristic arrangement of aromatic rings in the internal structure of the crystallites. AFM imaging of PEDOT∙CB7-PS and PEDOT∙CB7-PR thin films exhibited significant differences in the surface topographies compared with those of PEDOT. A high degree of crystallization was clearly visible on the surface of the PEDOT layer, whereas the PEDOT∙CB7-PS and PEDOT∙CB7-PR thin films exhibited more favorable surface parameters. Such significant differences identified in the surface morphology of the investigated layers can, therefore, be clearly associated with the presence of surrounding CB7 on PEDOT skeletons.

Antibacterial and antibiofilm activities of amikacin-conjugated gold Nanoparticles: A promising formulation for contact lens preservation

Contact lenses are a widely utilized tool for both cosmetic and eyesight corrective purposes. Additionally, they are a direct contributor to microbial keratitis and corneal infections, particularly those caused by Pseudomonas aeruginosa infections. This study aimed to conjugate amikacin to gold nanoparticles (GNPs) and assess the formulation's antibacterial and antibiofilm formation within contact lenses. The safe and environmentally friendly method, Pulsed laser ablation (PLAL), was used to prepare the amikacin-conjugated gold nanoparticles (Am@GNPs). The characterization of the produced formula was studied using a spectrophotometer UV light, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transforms infrared (FT-IR). Compared to the GNPs and the antibiotic amikacin, the anti-biofilm activity of Am@GNPs was measured using atomic force microscopy (AFM), whereas the antibacterial activity was measured by the well diffusion and microdilution methods against the most prevalent contact lens microbial isolates, i.e., P. aeruginosa and Streptococcus pneumonia. The formulation, Am@GNPs, was induced higher inhibition zone and lower MIC values compared to the GNPs and the amikacin antibiotic, the effect which was more pronounced against P. aeruginosa than S. pneumonia bacterial strains. Application of Am@GNPs to the contact lenses also potentially reduced P. aeruginosa and S. pneumoniae biofilm formation, with the lowest biofilm thickness compared to the amikacin and GNPs, as demonstrated by the AFM scanning. According to current findings, the prepared Am@GNPs exhibited substantial antibacterial effects and could be a potential preservative formula for contact lenses and other eye-related medical devices.

Unveiling the potent corrosion-inhibiting power of Ammophila arenaria aqueous extract for mild steel in acidic environments: An integrated experimental and computational study

Plant extracts have emerged as potent inhibiting compounds for metallic corrosion, offering numerous advantages including simple accessibility, low toxicity, eco-friendliness, biocompatibility, effectiveness, and renewability. In this study, the potential of Ammophila arenaria extract as a green corrosion inhibitor for mild steel in 1.0 M HCl over the concentration range of 25–700 ppm was evaluated, using various electrochemical analyses such as Open circuit potential (OCP), potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). Results revealed a notable reduction in the corrosion rate of steel, particularly at 700 ppm, where Ammophila arenaria extract demonstrated its highest inhibition efficiency, reaching 83.67% for polarization and 84.32% for EIS. The cathodic and anodic polarization curves indicated that the aqueous extract of Ammophila arenaria functions as a mixed-type inhibitor. The thermodynamic analysis revealed a negative Gibbs free energy value (∆Gads°), suggesting spontaneous physisorption as the predominant adsorption mechanism. To delve into the inhibition mechanism at the molecular level, the surface morphology of mild steel exposed to 1.0 M HCl solutions, both in the absence and presence of Ammophila arenaria aqueous extract, was scrutinized through Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Theoretical techniques, including Quantum Calculation Theory, Non-Covalent Interaction (NCI), and Atom In Molecule (QTAIM), were concurrently employed, providing valuable insights into molecular-level interactions. Remarkably, the computational studies complemented and corroborated the experimental data. These comprehensive results significantly contribute to the understanding of Ammophila arenaria extract's corrosion inhibiting properties, endorsing its potential as a sustainable and environmentally friendly corrosion inhibitor suitable for diverse industrial applications. The synergistic integration of experimental and computational approaches establishes a robust foundation for future endeavors in the field of green corrosion inhibitors.

Electrowetting-on-dielectric behavior of aqueous droplets and gold nanofluid on an electrospun poly(vinyl chloride) microfiber layer

Morphology and wettability of dielectric layers are crucial properties that affect the electrowetting-on-dielectric (EWOD) performance of a working liquid. In this work, the use of a poly(vinyl chloride) (PVC) microfiber-modified PVC dielectric layer as an electrowetting-on-dielectric (EWOD) substrate is explored. Imaging with scanning electron and atomic force microscopy revealed intertwined microfibers on the original PVC film after PVC deposition via electrospinning. Hydrophobicity of the PVC layer was enhanced by the presence of microfibers, with the contact angle (CA) for a water droplet increasing from 84.9° to 123.9°. EWOD behavior of various liquids on the microfiber-modified PVC layer was investigated within a DC voltage range of 0 to 200 V DC. Gold nanofluid exhibited the largest change in CA of 57°, while smaller changes were observed for KOH (19.6°), KCl (21.2°), and water (21°). A mechanism explaining the observed reduction in contact angle for a gold nanofluid droplet is presented. Our results suggest the promising potential of PVC film-PVC microfiber as a hydrophobic dielectric material for EWOD applications involving diverse liquids, including gold nanofluids.

Chlamydia psittaci infected cell studies by 4Pi Raman and atomic force microscopy.

Chlamydia psittaci is an avian bacterial pathogen that can cause atypical pneumonia in humans via zoonotic transmission. It is a Gram-negative intracellular bacterium that proliferates inside membrane bound inclusions in the cytoplasm of living eukaryotic cells. The study of such cells with C. psittaci inside without destroying them poses a significant challenge. We demonstrated in this work the utility of a combined multitool approach to analyze such complex samples. Atomic force microscopy was applied to obtain high-resolution images of the surface of infected cells upon entrance of bacteria. Atomic force microscopy scans revealed the morphological changes of the cell membrane of Chlamydia infected cells such as changes in roughness of cell membrane and the presence of micro vesicles. 4Pi Raman microscopy was used to image and probe the molecular composition of intracellular bacteria inside intact cells. Information about the structure of the inclusion produced by C. psittaci was obtained and it was found to have a similar molecular fingerprint as that of an intracellular lipid droplet but with less proteins and unsaturated lipids. The presented approach demonstrates complementarity of various microscopy-based approaches and might be useful for characterization of intracellular bacteria.

Piezo inkjet formation of Ag nanoparticles from microdots arrays for surface plasmonic resonance

The study aims to explore a novel approach for fabricating plasmonic nanostructures to enhance the optical properties and performance of various optoelectronic devices. The research begins by employing a piezo-inkjet printing technique to deposit drops containing Ag nanoparticles (NPs) onto a glass substrate at a predefined equidistance, with the goal of obtaining arrays of Ag microdots (Ag-µdots) on the glass substrate. This process is followed by a thermal annealing treatment. The printing parameters are first optimized to achieve uniform deposition of different sizes of Ag-µdots arrays by controlling the number of Ag ink drops. Subsequently, the printed arrays undergo thermal annealing at various temperatures in air for 60 min, enabling precise and uniform control over nanoparticle formation. The printed Ag nanoparticles are characterized using field emission scanning electron microscopy and atomic force microscopy to analyze their morphological features, ensuring their suitability for plasmonic applications. UV–Vis spectrophotometry is employed to investigate the enhanced surface-plasmonic-resonance properties of the printed AgNPs. Measurements confirm that the equidistant arrays of AgNPs obtained from annealing Ag microdots exhibit enhanced light-matter interaction, leading to a surface plasmon resonance response dependent on the Ag NPs’ specific surface area. These enhanced surface plasmonic resonances open avenues for developing cutting-edge optoelectronic devices that leverage the benefits of plasmonic nanostructures, thereby enabling new opportunities for future technological developments across various fields.

Investigating the Role of Embedded ZnO Seed Layer Thickness in Electrodeposited Cu2O/Zn(x)Mg(1−x)O/ZnO/FTO Heterojunctions for Photovoltaic Applications

This article represents the construction of Cu2O/Zn(x)Mg(1−x)O/ZnO/FTO heterojunctions by employing a simple electrodeposition approach. The impact of inserting ZnO seed layers with different thicknesses on the various physicochemical properties of the electrodeposited films is explored by applying various techniques. The electrochemical characterization specifies high photoresponses achieving 335.42 μA cm−2 for seeded Cu2O/Zn(x)Mg(1−x)O heterojunctions by increasing the thickness of seeded ZnO layer from 25 to 100 nm. The scanning electron microscopy and atomic force microscopy techniques indicate that the surface texture and smoothness of Cu2O/ZnO heterojunctions have significantly enhanced after increasing the thickness of the ZnO layers. The synthesized ZnO nanostructures are found to be highly crystalline in nature having ZnO with hexagonal phase oriented along (002) direction and Cu2O with cubic structure oriented along (111) direction. This study shows the introduction of ZnO seed layers, enhances the I–V characteristics of Au/Cu2O/Zn(x)Mg(1−x)O/ZnO/FTO solar cells. The ideality factor shows a decreasing tendency from 5.35 to 3.93 while the photoelectric response is increased from 427% to 643% with the increase of the ZnO thickness from 25 to 100 nm, respectively, demonstrating the effectiveness of the seed layers approach.

Atomically Precise Manufacturing of Silicon Electronics.

Atomically precise manufacturing (APM) is a key technique that involves the direct control of atoms in order to manufacture products or components of products. It has been developed most successfully using scanning probe methods and has received particular attention for developing atom scale electronics with a focus on silicon-based systems. This review captures the development of silicon atom-based electronics and is divided into several sections that will cover characterization and atom manipulation of silicon surfaces with scanning tunneling microscopy and atomic force microscopy, development of silicon dangling bonds as atomic quantum dots, creation of atom scale devices, and the wiring and packaging of those circuits. The review will also cover the advance of silicon dangling bond logic design and the progress of silicon quantum atomic designer (SiQAD) simulators. Finally, an outlook of APM and silicon atom electronics will be provided.

Physical Characteristics of Sintered Silver Nanoparticle Inks with Different Sizes during Furnace Sintering.

The influence of nanoparticle (NP) size on the physical characteristics of sintered silver NP ink was studied using four different types of inks. The Ag NP inks were spin-coated on glass substrates with an average thickness of 300 nm. Each sample was sintered for 30 min, with temperatures from 50 °C to 400 °C by an interval of 50 °C. After sintering, the specific resistance of each case was obtained using the resistance and surface profile measurements. The minimum specific resistance obtained by the experiment was 2.6 μΩ·cm in the case in which 50 nm-sized Ag NP ink was sintered at 350 °C. The transformed surface morphology and grain size of each case were observed using scanning electron microscopy and atomic force microscopy. The results of this study can be a reference for future manufacturers in selecting the Ag NP size and the sintering temperature.

Improvement of cross-linked films based on chitosan/diepoxy-poly (ethylene glycol) incorporating trans-cinnamaldehyde essential oil: Preparation, properties, and application in banana storage

In this study, development of bioactive coatings containing 1 % (w/v) chitosan (CS), 0.6 % (w/v) diepoxy-polyethylene glycol (PEG), and trans-cinnamaldehyde (CIN) was achieved. The physicochemical and biological properties of the coatings were investigated. The tensile strength, light transmission, water vapor permeability (WVP), and antibacterial properties were enhanced by the incorporation of CIN. The CIN-containing films appeared compact and rough, as observed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). In addition, the quality attributes of the bananas were evaluated at room temperature for 24 days, and the results showed that the CS/PEG/CIN coating delayed the respiration peak, weight loss, sugar content loss, and maintained firmness, color, total soluble solids (TSS), titratable acid (TA), and the appearance of the bananas. Principal component analysis (PCA) revealed that the bioactive coating significantly affected the respiration rate and weight loss of bananas.

Selected Area Manipulation of MoS2 via Focused Electron Beam-Induced Etching for Nanoscale Device Editing.

We demonstrate direct-write patterning of single and multilayer MoS2 via a focused electron beam-induced etching (FEBIE) process mediated with the XeF2 precursor. MoS2 etching is performed at various currents, areal doses, on different substrates, and characterized using scanning electron and atomic force microscopies as well as Raman and photoluminescence spectroscopies. Scanning transmission electron microscopy reveals a sub-40 nm etching resolution and the progression of point defects and lateral etching of the consequent unsaturated bonds. The results confirm that the electron beam-induced etching process is minimally invasive to the underlying material in comparison to ion beam techniques, which damage the subsurface material. Single-layer MoS2 field-effect transistors are fabricated, and device characteristics are compared for channels that are edited via the selected area etching process. The source-drain current at constant gate and source-drain voltage scale linearly with the edited channel width. Moreover, the mobility of the narrowest channel width decreases, suggesting that backscattered and secondary electrons collaterally affect the periphery of the removed area. Focused electron beam doses on single-layer transistors below the etching threshold were also explored as a means to modify/thin the channel layer. The FEBIE exposures showed demonstrative effects via the transistor transfer characteristics, photoluminescence spectroscopy, and Raman spectroscopy. While strategies to minimize backscattered and secondary electron interactions outside of the scanned regions require further investigation, here, we show that FEBIE is a viable approach for selective nanoscale editing of MoS2 devices.