Surface Morphology Research Articles

Boosted photocatalytic performance of cobalt ferrite anchored g-C3N4 nanocomposite toward various emerging environmental hazardous pollutants degradation: insights into stability and Z-scheme mechanism.

In this study, a highly efficient CoFe2O4-anchored g-C3N4 nanocomposite with Z-scheme photocatalyst was developed by facile calcination and hydrothermal technique. To evaluate the crystalline structure, sample surface morphology, elemental compositions, and charge conductivity of the as-synthesized catalysts by various characterization techniques. The high interfacial contact of CoFe2O4 nanoparticles (NPs) with g-C3N4 nanosheets reduced the optical bandgap from 2.67 to 2.5eV, which improved the charge carrier separation and transfer. The photo-degradation of methylene blue (MB) and rhodamine B (Rh B) aqueous pollutant suspension under visible-light influence was used to investigate the photocatalytic degradation activity of the efficient CoFe2O4/g-C3N4 composite catalyst. The heterostructured spinel CoFe2O4 anchored g-C3N4 photocatalysts (PCs) with Z-scheme show better photocatalytic degradation performance for both organic dyes. Meanwhile, the efficiency of aqueous MB and Rh B degradation in 120 and 100min under visible-light could be up to 91.1% and 73.7%, which is greater than pristine g-C3N4 and CoFe2O4 catalysts. The recycling stability test showed no significant changes in the photo-degradation activity after four repeated cycles. Thus, this work provides an efficient tactic for the construction of highly efficient magnetic PCs for the removal of hazardous pollutants in the aquatic environment.

A renewable screen-printed electrode based on magnetic NiCo@N-doped carbon nanotubes derived from Co-MOF for ractopamine detection.

A renewable electrochemical screen-printed electrode (SPE) is proposedbased on magnetic bamboo-like nitrogen-carbon (N-C) nanotubes loaded with nickel-cobalt alloy (NiCo) nanoparticles (NiCo@N-CNTs) for the determination of ractopamine (RAC). During the preparation of NiCo@N-CNTs, Co-MOF-67 (ZIF-67) was firstly synthesized, and then blended with dicyandiamide and nickel acetate, followed by a one-step pyrolysis procedure to prepare NiCo@N-doped carbon nanotubes. The surface morphology, structure, and chemical composition of NiCo@N-CNTs were characterized by SEM, TEM, XRD, XPS, and EDS. The electrocatalytic and electrochemical behavior of NiCo@N-CNTs were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results demonstrated that NiCo@N-CNTs possessed remarkable conductivity and electrocatalysis to the oxidation of ractopamine (RAC). By using screen-printed electrode (SPE), NiCo@N-CNTs, and a designed base support, a magnetic RAC sensor (NiCo@N-CNTs/SPE) was successfully constructed. It presented a detection linear range of 0.05-80μM with a detection limit of 12nM (S/N = 3). It also exhibited good sensitivity, reproducibility, and practicability in spiked real pork samples. Since the adhesion of NiCo/N-CNTs on SPE was controlled by magnet, the NiCo@N-CNTs was easily detached from theSPE surface by magnetism and thus displayed excellent renewability. This work broadened insights into portable devices for on-site and real-time analysis.

Inorganic Phosphate Effect in a Hydrogen Peroxide-based Bleaching Agent: Physicochemical, Mechanical, and Morphological Properties of Dental Enamel.

This in vitro study aimed to assess the impact of incorporating calcium glycerophosphate (CaGP) and sodium fluoride (NaF) in addition to 35% hydrogen peroxide concerning the enamel mechanical and morphological properties. Specimens of bovine enamel were chosen based on their initial surface hardness (SHi) and subsequently divided into five gel groups (n=12): 1) 35% Hydrogen Peroxide (HP) Gel; 2) HP + 0.1% NaF Gel (HP/NaF); 3) HP + 0.25% CaGP Gel (HP/CaGP); 4) HP + 0.1% NaF + 0.25% CaGP Gel (HP/NaF/CaGP) and 5) HP Blue 35% Gel (HP Blue). The bleaching gels were applied thrice, for 40 min, at intervals of 7 days each. After 21 days, the final surface hardness (SHf), integrated hardness (IH), Polydispersity Index (PdI) and Zeta Potential (Zp), surface roughness (Ra, after and before), and surface/structural analysis by Scanning Electron Microscopy (SEM) were determined. The data were submitted to ANOVA (one-way and two-way) followed by the Student-Newman-Keuls test (α=0.05). The addition of NaF to HP reduced demineralization by 11.5% in relation to HP (p<0.05). The NaF/CaGP association reduction is 22.8 and 20% higher in comparison to HP/NaF/CaGP and HP Blue, respectively. The IH when the PH/NaF/CaGP bleaching gel was applied, was 14% higher compared to HP and HP Blue groups. It can be concluded that the association of NaF and CaGP with the 35% hydrogen peroxide gel (HP/NaF/CaGP) significantly changed tooth enamel demineralization in terms of surface, depth, roughness, and enamel morphology.

Microblasting with vegetable and cellulosic media for heritage wood cleaning: effects on surface morphology

In this research, microblasting with powdered vegetable particles (almond and hazelnut husks, cork saw dust and rice husks) and cellulosic fibres was used to analyse their usefulness for cleaning unpainted wooden cultural heritage and their effects on surface morphology. Tests were made on mock-ups of old pine wood from wooden boards with original soiling. Before cleaning powdered particles were characterised by SEM–EDS to analyse their morphology and elemental composition. Wood surfaces were analysed before and after cleaning by means of digital microscope (white and UV light) and SEM–EDS to evaluate cleaning effectiveness, assess effects on the wood surface, and determine eventual soiling and powdered particles larger than 1 µm that might remain in the surface after the procedure. Results indicate that microblasting with powdered vegetable and cellulosic media is a useful and safe technique to remove soiling from wood, including micrometric particles embedded in its texture, with negligible surface changes. Furthermore, residues left after the cleaning procedure are very scarce and chemically compatible with the substrate because they are mainly composed of cellulose, hemicellulose and lignin, the main components of wood.

Mechanism exploration of the modified asphalt binders with sustainable rapeseed-based derivatives using multi-scale evaluation method

Due to the concerns of sustainability, environment, and economy that are associated with non-renewable petroleum-based additives, there has been a growing interest in bio-additives derived from renewable feedstocks. This study aims to reveal the modification mechanism of three bio-additives derived from rapeseed on the base asphalt. The exploration of modification mechanism helped to explain the distinct rheological properties of bio-modified asphalt binders presented in a previous study. The effect of three bio-additives on the surface morphology, micro-mechanical properties, adhesivity, and chemical structure of base asphalt binders were investigated via Atomic Force Microscopy (AFM) and Fourier Transform Infrared spectrometer (FTIR) tests. The Electrostatic potential distribution and the orbital energy was analyzed via density functional theory (DFT) calculation to explore the inherit polarity of both the three bio-additives and asphalt components. Furthermore, molecular dynamic (MD) methods were used to evaluate the compatibility mechanism and aggregation tendency of asphalt components and bio-additives. The results showed that the electrostatic potential and the orbital energy of three bio-additives predominantly centered around the polar group. Specifically, AERO exhibited highest electrostatic potential distribution and lowest energy gap, indicating its heightened polarity. Moreover, the solution parameter difference value of bio-modified asphalt fell within 0.2 (J/m3)0.5, indicating great compatibility between asphalt and bio-additives, especially for ERO. Additionally, three bio-additives mitigated the aggregation of asphaltene within the asphalt due to their electrostatic interaction, especially notable in the cases of ERO and AERO. Furthermore, a cross-link network was formed within AERO-modified asphalt binders owing to its heightened polarity, fostering hydrogen bonding interactions internally and promoting the aggregation of saturate and resin factions around it. Consequently, this led to enhanced modulus and elasticity in the AERO-modified asphalt binders. Rapeseed derivatives as asphalt additives would be a sustainable and durable material for pavement construction and maintenance. It provides a theoretical basis for advancing the practical application of renewable vegetable oils in road engineering, which has exceptional economic and social benefits.

Corrosion and oxidation behaviors of CoAlTiWTa RHEA coating on Inconel 718 superalloy prepared by laser cladding

CoAlTiWTa refractory high-entropy alloy (RHEA) coating was prepared on Inconel 718 superalloy by pulsed laser cladding. Corrosion behavior in 3.5 wt% NaCl solution at room temperature and oxidation behavior at 600 ℃ of the coating were systematically investigated. The electrochemical performance, surface morphology, and corrosion and oxidation products were carefully characterized. The results show that the RHEA coating has a higher corrosion potential, smaller corrosion current, higher resistance value, and a more obvious passivation effect. Duplex-layer oxide film composed of an internal Al2O3-TiO2 layer and an external Co oxide layer is formed on the RHEA coating, improving high-temperature oxidation resistance.

Bioenergy feedstock production in Chlamydomonas reinhardtii (microalgae) cultivated under mixotrophic growth with cellulose hydrolysate from agricultural waste.

In the present study, cellulose purified from finger millet agricultural waste is subjected to enzymatic hydrolysis, and the hydrolysate (predominantly glucose) is used as a carbon source supplement in the media for the mixotrophic growth of Chlamydomonas reinhardtii. Interestingly, a switch between excess starch production and excess lipid (triacylglycerols, TAG) production occurs by a small change in hydrolysate concentration in the media. Starch production increased 4.5-fold with respect to the photoautotrophic control, with a glucose concentration of 3mg/mL in the media after hydrolysate addition. This culture had TAG production enhancement by 1.5-fold. However, mixotrophic cultivation with 4mg/mL glucose concentration in the media with hydrolysate addition resulted in TAG productivity enhancement by 4.2-fold compared to control and starch amount increase of 1.3-fold. The organic carbon source (glucose) and the inorganic carbon source (citrate ions) in the hydrolysate together played a role in this delicate switching between starch and lipid pathways. Proteins, starch, and TAG molecules are analyzed in the microalgal cells grown under different conditions with FTIR spectroscopy, a rapid, high-throughput method of biomolecular estimation. High-resolution single-cell AFM studies of the cell wall structure reveal enhanced corrugations in surface morphology during mixotrophic growth with cellulose hydrolysate, illustrating an adaptive mechanism with improved mechanical stress management. Lipid droplet morphology at the single-cell level points to two distinct mechanisms of lipid accumulation: one in which the lipids are segregated as droplets, and the other in which lipid molecules are uniformly dispersed in the cytosol as unresolved, ultra-small droplets. The present study therefore analyzes both the bulk and the single-cell level changes when cellulose hydrolysate is used as a carbon source for Chlamydomonas reinhardtii mixotrophic cultivation, which serves a four-fold purpose: value from waste, fixation of atmospheric CO2, production of lipids for biodiesel, and starch for bioethanol.

Copper Oxide Electrochemical Deposition to Create Antiviral and Antibacterial Nanocoatings.

The impact of the reaction environment on the formation of the polycrystalline layer and its biomedical (antimicrobial) applications were analyzed in detail. Copper oxide layers were synthesized using an electrodeposition technique, with varying additives influencing the morphology, thickness, and chemical composition. Scanning electron microscopy (SEM) images confirmed the successful formation of polyhedral structures. Unmodified samples (CuL) crystallized as a mixture of copper oxide (I) and (II), with a thickness of approximately 1.74 μm. The inclusion of the nonconductive polymer polyvinylpyrrolidone (PVP) during synthesis led to a regular and compact CuO-rich structure (CuL-PVP). Conversely, adding glucose resulted in forming a Cu2O-rich nanostructured layer (CuL-D(+)G). Both additives significantly reduced the sample thickness to 617 nm for CuL-PVP and 560 nm for CuL-D(+)G. The effectiveness of the synthesized copper oxide layers was demonstrated in their ability to significantly reduce the T4 phage titer by approximately 2.5-3 log. Notably, CuL-PVP and CuL-D(+)G showed a more substantial reduction in the MS2 phage titer, achieving about a 5-log decrease. In terms of antibacterial activity, CuL and CuL-PVP exhibited moderate efficacy against Escherichia coli, whereas CuL-D(+)G reduced the E. coli titer to undetectable levels. All samples induced similar reductions in Staphylococcus aureus titer. The study revealed differential susceptibilities, with Gram-negative bacteria being more vulnerable to CuL-D(+)G due to its unique composition and morphology. The antimicrobial properties were attributed to the redox cycling of Cu ions, which generate ROS, and the mechanical damage caused by nanostructured surfaces. A crucial finding was the impact of surface composition rather than surface morphology on antimicrobial efficacy. Samples with a dominant Cu2O composition exhibited potent antibacterial and antiviral properties, whereas CuO-rich materials showed predominantly enhanced antiviral activity. This research highlights the significance of phase composition in determining the antimicrobial properties of copper oxide layers synthesized through electrodeposition.

Harnessing Potential of ω-3 Polyunsaturated Fatty Acid with Nanotechnology for Enhanced Breast Cancer Therapy: A Comprehensive Investigation into ALA-Based Liposomal PTX Delivery

Our hypothesis posited that incorporating alpha-linolenic acid (ALA) into liposomes containing Paclitaxel (PTX) could augment cellular uptake, decrease the therapeutic dosage, and alleviate PTX-related side effects. Our investigation encompassed characterization of the liposomal formulation, encompassing aspects like particle size, surface morphology, chemical structure, drug release kinetics, and stability. Compatibility studies were performed through Fourier transform infrared spectroscopy (FTIR). By utilizing the Box–Behnken design (BBD), we developed ALA-based liposomes with satisfactory particle size and entrapment efficiency. It is noteworthy that ALA incorporation led to a slight increase in particle size but did not notably affect drug entrapment. In vitro drug release assessments unveiled a sustained release pattern, with ALA-PTX liposomes demonstrating release profiles comparable to PTX liposomes. Morphological examinations confirmed the spherical structure of the liposomes, indicating that substituting ALA with phosphatidylcholine did not alter the physicochemical properties. Cellular uptake investigations showcased enhanced uptake of ALA-based liposomes in contrast to PTX liposomes, likely attributed to the heightened fluidity conferred by ALA. Efficacy against MCF-7 cells demonstrated concentration-dependent reductions in cell viability, with ALA-PTX liposomes exhibiting the lowest IC50 value. Morphological analysis confirmed apoptotic changes in cells treated with all formulations, with ALA-PTX liposomes eliciting more pronounced changes, indicative of enhanced anticancer efficacy.

Subnanoscale Ion Beam Modification-Assisted Smoothing of Heterostructure Surfaces.

Glass ceramic (GC) is the most promising material for objective lenses for extreme ultraviolet lithography that must meet the subnanometer precision, which is characterized by low values of high spatial frequency surface roughness (HSFR). However, the HSFR of GC is typically degraded during ion beam figuring (IBF). Herein, a developed method for constructing molecular dynamics (MD) models of GC was presented, and the formation mechanisms of surface morphologies were investigated. The results indicated that the generation of the dot-like microstructure was the result of the difference in the erosion rate caused by the difference in the intrinsic properties between ceramic phases (CPs) and glass phases (GPs). Further, the difference in the microstructure of the IBF surface under different beam angles was mainly caused by the difference in the two types of sputtering. Quantum mechanical calculations showed that the presence of interstitial atoms would result in electron rearrangement and that the electron localization can lead to a reduction in CP stability. To obtain a homogeneous surface, the effects of beam parameters on the heterogeneous surface were systematically investigated based on the proposed MD model. Then, a novel ion beam modification (IBM) method was proposed and demonstrated by TEM and GIXRD. The range of ion beam smoothing parameters that could effectively converge the HSFR of the modified surface was determined through numerous experiments. Using the optimized beam parameters, an ultrathin homogeneous modified surface within 3 nm was obtained. The HSFR of GC smoothed by ion beam modification-assisted smoothing (IBMS) dropped from 0.348 to 0.090 nm, a 74% reduction. These research results offer a deeper understanding of the morphology formation mechanisms of the GC surfaces involved in ion beam processing and may point to a new approach for achieving ultrasmooth heterostructure surfaces down to the subnanometer scale.

Fast fabrication, gas sense characteristics and kinetics of cubic Ti-BIPA-TC-MOF film composite optical waveguides

A cubic Ti-metal-organic framework (MOF) ([Ti2–(TpA)2–H2BIPA]), constructed from a titanium metal centre and a benzo-imidephenanthroline tetracarboxylic acid (H4BIPA–TC) ligand was photo-inductively grown on the surface of a titanium dioxide (TiO2) composite optical waveguide (COWG) substrate and the influence of photo-inductive growth period on the [Ti2–(TpA)2–H2BIPA] film surface morphology, optical properties and gas adsorption/sensing characteristics was investigated. The results showed that [Ti2–(TpA)2–H2BIPA] formed a cubic structure after grew for only 5 min. As an ideal gas adsorbent, it exhibits a specific response to ethylenediamine (EDA) among various benzene, amine and acid gases, due to the intrinsic electron deficiency, rich COOH active sites of the Ti–BIPA–TC–MOF–5 frame and the higher molar refractive indexes or dipoles of EDA than other gases. In the EDA concentration range from 10 ppt to 100 ppm, the Ti–BIPA–TC–MOF–5 film COWG exhibited a rapid, repeatable response. Moreover, the Ti–BIPA–TC–MOF–5 film COWG was relatively stable, within 17 d of EDA detection, the response intensity was almost constant and slightly decreased within 40 d. In a static gas adsorption stage at 283–313 K, the EDA gas adsorption behaviour of the Ti–BIPA–TC–MOF–5 film is consistent with the pseudo-second-order kinetic model.

Effect of ceria morphology on hydrogen production via methane steam reforming for membrane reformer

AbstractHydrogen is a potential energy carrier in comparison to conventional fuels due to its high energy content. Methane is an attractive source for ‘on‐site’ production of hydrogen by using membrane reformer due to its low cost. However, such reformers are not well studied and high temperature operation of steam methane reforming (SMR) makes the integration with membrane separation difficult. Further, the main product of SMR is CO and H2 in which CO has an inhibition effect on the membrane separation process. Therefore, it is vital to synthesize a low temperature and low CO selective catalyst for a suitable integration with membrane reformer. Nickel‐based catalyst is widely used for SMR due to its low cost and high catalytic activity. CeO2 is a favoured support as it mobilizes the lattice oxygen and reduces the coke formation and CO selectivity. Though several studies are reported on CeO2 based support, the effect of CeO2 surface morphology is not studied for SMR. In the current work, Ni/CeO2 of different shapes (nanocube and nanorod) are synthesized. The complete characterization of the support was performed. The effect of support shape, calcination temperature, and reduction temperature on SMR activity is found at different operating temperatures. For each condition conversion, CO, CO2 selectivity, and hydrogen yield are calculated. The results show the CeO2 morphology has a considerable effect on conversion, CO selectivity, and hydrogen yield. It is found that ceria nanocube calcined at 550°C provides better performance at high temperature.

Immobilizing Antibody Biorecognition Layers on Au-TiO2 Thin Films: Direct (physisorption) vs. DSP-crosslinking (chemisorption) Surface Functionalization

Abstract The immobilization design strategy plays an important role in biosensor development and its sensing performance. Both adsorption (physisorption) and cross-linker functionalization (chemisorption) are common approaches for immobilizing a bioreceptor layer. In this work, these two approaches were studied and compared, envisaging a functional and strongly attached bioreceptor layer onto sputtered Au-TiO2 thin films. DSP cross-linker (Lomant's reagent) was used in the thin film’s functionalization, and the effect of different concentrations on the development of an adhesion layer was investigated. Surface morphology analysis of functionalized thin films suggested the development of uniformly coated self-assembled layers. However, DSP islands with a fractal structure were found for a concentration of 4 mg mL-1. Infrared spectroscopy confirmed the cross-linker functionalization at the thin film’s surface. Confocal microscopy of immobilized fluorescent antibodies revealed that DSP islands improve the chemical surface area available for bioreceptor immobilization. Moreover, an immunoassay using mouse IgG interaction with fluorescent anti-mouse IgG (Fab specific), working as capture and detection antibody, respectively, showed that DSP functionalization favors antibodies orientation and adhesion strength to the surface, when compared to physisorption.

Synergetic Effect of Chemical Components in a Tungsten CMP Slurry and the Evolution of Tungsten Surface Species

Abstract A novel slurry containing 50 ppm Fe3+, 2 wt.% H2O2, 75 ppm oxalic acid, and abrasive nano-silica particles were utilized in a W chemical mechanical planarization process. Using this slurry, a W material removal rate of 710 Å/min and surface roughness of 1 nm were achieved. According to X-ray photoelectron spectroscopy data, surface W was first transformed to WO2 via its dissolution in H2O2, and then Fe3+ ions serving as a catalyst promoted the conversion of tungsten to WO3 through the WO2 intermediate in the presence of H2O2. Oxalic acid was added to coordinate with H2O2 and thus improve the slurry stability through a “wrapping” mechanism without decreasing the W material removal rate. Scanning electron microscopy and atomic force microscopy observations revealed that the W surface morphology changed first from coarse elongated grains to a discontinuous structure after the uneven oxidation by H2O2 and then to a wrinkled soft surface by Fe3+ and H2O2. Finally, it was ground with abrasive nano-silica particles to achieve a high degree of flatness.

Removal of Impurities from Refractory Gold Ore using Bio-reduction and Bio-oxidation processes

Gold in refractory gold ore is difficult to be extracted by conventional metallurgical method due to the presence of sulfide minerals with elevated levels of iron (Fe), sulfur (S), and arsenic (As) as impurities, resulting in low gold (Au) recovery. Conventional methods such as cyanide leaching has been proven ineffective for gold extraction from refractory ore due to gold being intricately bound within the sulfide minerals. Consequently, this study explores the application of bioleaching as an alternative to conventional cyanide leaching. Shewanella oneidensis (S. oneidensis) and Acidithiobacillus ferroxidans (A. ferroxidans) serve as bio-reduction and bio-oxidation agents, respectively in the bioleaching process. The composition of minerals in the ore was determined through XRD analysis (Model: Rigaku’s Miniflex 600) and EDX analysis (Model EDX 3). Meanwhile, SEM analysis (Zeiss EVO LS15 SEM) was utilized to examine the morphology structure. The concentrations of impurities (Fe, S, and As) were assessed using a spectrophotometer (Model: DR3900 Hach) meanwhile the Au concentration was determined through ICP-OES (Model: G8015A5110 ICP-OES). Sieved refractory gold ore samples with less than 32 um and varying in weight (0.5 g, 1.0 g, 1.5 g, 2.0 g), underwent bio-reduction and bio-oxidation processes. The results indicated a rougher surface morphology of raw sample as observed through SEM analysis. Furthermore, XRD and EDX results demonstrated a decrease in impurity concentrations, suggesting a potential increase in gold purity. Notably, the bio-reduction process exhibited a superior enhancement in Au concentration with the values of 138.89% compared to biooxidation with the value 122.22%. Thus, the bio-reduction process proved more effective in increasing Au concentration compared to bio-oxidation.

Template Evolution Induced Relay Self-Assembly for Mesoporous Carbonaceous Materials via Hydrothermal Carbonization.

Constructing carbonaceous materials with versatile surface structures still remains a great challenge due to limited self-assembly methods, especially at high temperatures. This study presents an innovative template evolution induced relay self-assembly (TEIRSA) for the fabrication of large polyoxometalate (POM)-mixed carbonaceous nanosheets featuring surface mesoporous structures through hydrothermal carbonization (HTC). The method employs POM and acetone as additives, cleverly modulating the Ostwald ripening-like process of P123-based micelles, effectively addressing the instability challenges inherent in traditional soft-template methods, especially within the demanding carbohydrate HTC process. Additionally, this method allows for the independent regulation of surface architectures through the selection of organic additives. The resulting nanosheets exhibit diverse surface morphologies, including surface spherical mesopores, 1D open channels, and smooth surfaces. Their unexpectedly versatile properties have swiftly garnered recognition, showing potential in the application of lithium-sulfur batteries.

Nano Zinc Oxide Particle Synthesis from Bio-Waste Selaginella willdenowii Leaf Extract: A Multi-Faceted Approach for Environmental and Biomedical Applications

Selaginella willdenowii, a commonly used greenhouse fern, was often used as a biowaste to synthesize zinc oxide nanoparticles (ZnO NPs) in an eco-friendly and cost-effective way. UV–Visible spectra studies were carried out to confirm the synthesis of S. willdenowii-mediated ZnO NPs (SW-ZnO NPs), and a peak at 367[Formula: see text]nm with a sharp band gap of 3.415[Formula: see text]eV was observed. The X-ray diffraction analysis indicated that the crystalline size of the synthesized SW-ZnO NPs was 11.971[Formula: see text]nm. The phytochemicals present in the extracts and the compounds involved in the reduction of metal to nanoparticles were determined by Fourier Transform Infrared analysis. Scanning electron microscopy was utilized to analyze the surface morphology and size of the obtained SW-ZnO NPs. The examination revealed that they exhibited a hexagonal shape, with an average size falling within the range of 17–23[Formula: see text]nm. Under ultra-violet light, reactive blue 220 and reactive yellow 145 dyes showed 78.06% and 60.14% degradation, showing potential photocatalytic degradation activity. The synthesized SW-ZnO NPs also exhibited antimicrobial activity against bacterial strains (Escherichia coli and Bacillus subtilis) and fungal cultures (Candida tropicalis and Candida albicans) showed cytotoxic activity against Hep-G2 cell lines. Our results suggest the green synthesized SW-ZnO NPs have potential photocatalytic, antimicrobial and cytotoxic potential.

Color Generation and Polarization-Sensitive Encryption by Laser Writing on Plasmonic Reflector Arrays.

Plasmonic color printing presents a sustainable solution for vibrant and durable color reproduction by leveraging the light-manipulating properties of nanostructures. However, the fabrication of plasmonic nanostructures has posed challenges, hindering widespread adoption. In this paper, we introduce plasmonic reflector arrays (PRAs) composed of three layers─Ag nanoparticles (NPs), an Al2O3 spacer, and an Ag reflector─deposited via physical vapor deposition (PVD). By employing nanosecond and femtosecond laser writing techniques, we manipulate the surface morphology of silver nanoparticles on PRAs, resulting in a diverse range of structural colors that are both polarization-insensitive and polarization-sensitive. Furthermore, we demonstrate the versatility of nanosecond laser writing in creating intricate patterns on PRAs. Additionally, we propose a novel two-step method combining nanosecond and femtosecond laser processing to embed QR code patterns into PRAs, showcasing their potential for secure data encryption and transmission. This research underscores the promising applications of PRAs in advanced color printing and secure optical data encoding.

The tribological properties of PPS-PTFE/SiO2 coating deposited on the textured surfaces processed by ultrasonic rolling

Abstract In this paper, ultrasonic rolling textures were fabricated on 42CrMo steel substrates, and the polyphenylene sulfide-polytetrafluoroethylene/silicon dioxide (PPS-PTFE/SiO2) lubricating coatings were deposited on the textured surfaces to improve the tribological properties of the coating-substrate system. The influences of textures with different shapes (spiral, linear, wavy textures) and step distances (100, 150, 200, 250 μm) on the surface morphologies and strengthening effects of the substrates were investigated. The results showed the wavy texture with a step distance of 200 µm had the best strengthening effect, which increased the surface hardness and residual compressive stress by 126.1% and 5.1 times compared to the substrate, respectively. The influences of different textures on the friction and wear properties of lubricating coatings were studied by dry reciprocating friction testings. The results showed that the coating on the spiral textured surface with a step distance of 250 µm had the best tribological properties, and the average friction coefficient and wear rate were reduced by 45.5% and 49.5% compared to the coating on the substrate. The influence of ultrasonic rolling texture on the tribological properties of the lubricating coating was a combined result of the strengthening effect and texture structure. The strengthening effect provided a steady gain, while the texture structure provided either a gain or a deterioration.&amp;#xD;

Photo-responsive anti-fouling polyzwitterionic brushes: a mesoscopic simulation.

The antifouling effects of a toothbrush-shaped photo-responsive polyzwitterionic membrane were studied via dissipative particle dynamics simulations in this work. The results reveal that the membrane modified by spiropyran methacrylate brushes displays photo-switchable and antifouling capability due to the photo-induced ring-opening reaction. Namely, surface morphology and hydrophilicity change in response to visible or UV light irradiation, which can be observed visually by protein adsorption and desorption. Further study indicates that: (1) brush-modification density can influence the structure and properties of the membrane. With low modification density, systems cannot establish an intact selective layer, which hinders the antifouling ability; as the modification density increases, the intact selective layer can be formed, which is conducive to the expression of photo-responsiveness and antifouling capability. (2) Factors of toothbrush-hair length and grafting ratio can influence the establishment of a light-responsive surface: as the grafting ratio and toothbrush-hair length increase, the light-responsive surface is gradually formed, meanwhile, the antifouling ability can be continuously reinforced under UV light irradiation. (3) As the brushes switch into a zwitterionic merocyanine state under UV exposure, the selective layer swelling becomes stronger than that with a hydrophobic spiropyran state under visible exposure. This is owing to the enhanced interaction between zwitterionic brushes and water, which is the root of the antifouling effect. The present work is expected to provide some guidelines for the design and development of novel antifouling membrane surfaces.