Surface Morphology Research Articles

Effects of collagen modification on the osteogenic performance of different surface-modified titanium samples in vitro.

The aim of this study was to evaluate the effects of collagen modification on the osteogenic performance of different surface-modified titanium, including alkaline etching, alkaline etching followed by silanization, and alkaline etching followed by dopamine modification. The proliferation, adhesion, and osteogenic differentiation abilities of MC3T3-E1 cells on the surfaces with collagen modification were analyzed and compared. Collagen was immobilized on the surfaces of pure titanium (Ti-C), alkaline-etched titanium (Ti-Na-C), alkaline-etched and silanized titanium (Ti-A-C), and alkaline-etched and dopamine-modified titanium (Ti-D-C), with pure titanium (Ti) as the control group. The surface morphology was observed by scanning electron microscopy (SEM), and the surface elemental composition was analyzed by X-ray photoelectron spectroscopy (XPS). Contact angle measurements were conducted to evaluate the hydrophilicity of the surfaces. MC3T3-E1 cells were cultured on the surfaces, and their proliferation, adhesion, and osteogenic differentiation abilities were assessed using CCK-8 assay, laser scanning confocal microscope, alkaline phosphatase (ALP) staining, Alizarin red staining and quantitative analysis, as well as real-time quantitative polymerase chain reaction (RT-qPCR) to evaluate the mRNA expression levels of osteogenic-related genes, including ALP, typeⅠcollagen (COL-1), osteocalcin (OCN), osteopontin (OPN). SEM and XPS results confirmed the successful immobilization of collagen on the titanium surfaces, with the Ti-Na-C group exhibiting a higher amount of collagen modification. Contact angle measurements showed improved hydrophilicity of the surfaces after collagen modification. CCK-8 results indicated good compatibility of the materials with MC3T3-E1, with enhanced cell proliferation on the collagen-modified surfaces. Cell fluorescence staining revealed better cell spreading on the collagen-modified surfaces, and ALP and Alizarin red staining results suggested that the Ti-Na-C group exhibited the best osteogenic performance, with significantly higher absorbance values in the Alizarin red quantification analysis. RT-qPCR analysis showed that the Ti-Na-C group had the highest expression of the osteogenic-related gene OPN. Among the different collagen modification approaches employed in this study, collagen modification on alkaline-etched titanium surfaces showed the most conducive effects on MC3T3-E1 cell adhesion, spreading, proliferation, and osteogenic differentiation. This approach can be considered as the optimal collagen modification strategy for enhancing osteogenesis on titanium surfaces.

Preparation and Optimization of Polyaniline/ Titanium Dioxide/ Carboxymethyl Cellulose Powder for Effective Nickel Adsorption

Hexanoic acid-doped polyaniline (PAni) is a great potential candidate to replace conventional adsorbent towards the removal of heavy metal waste from electroplating industry, especially nickel (Ni). In this study, different weight % (wt %) of titanium dioxide (TiO2) and carboxymethyl cellulose (CMC) are added to form PAni composites with enhanced Ni removal efficiency. All the synthesized samples were examined with FTIR, UV-Vis, conductivity measurement, XRD, TGA, and FESEM to confirm their chemical structures, oxidation states, electrical conductivity, crystallinity and incorporation of metal oxide, thermal stability, and surface morphology, respectively. Among the different samples, PAni / TiO2 20 % exhibited the highest Ni removal efficiency of 37.5 %. Upon further addition of CMC, PAni / TiO2 / CMC 5 % showed the highest Ni removal efficiency of 89.08 %. Optimization of the experimental parameters were conducted and a maximum Ni removal efficiency of 97.88 % was achieved at pH 10, 30 min contact time at a temperature of 30 °C, and with an adsorbent dosage of 0.01 g. This study shows that the composite of PAni / TiO2 / CMC 5 % shows good potential to be applied as adsorbent of the removal of Ni ions.

Analysis of CeO2/SiO2 double-layer thin film stack with antireflection effect for silicon solar cells

This study introduces CeO2/SiO2 double-layer film stacks and its antireflection coating effect. Optical properties were analyzed by spectrophotometer measurements; surface morphology and cross-sections were observed by Scanning Electron Microscopy (SEM); elemental distributions and crystallographic properties were determined by Energy Dispersive Spectroscopy (EDS) and X-ray Diffraction (XRD) measurements. Average reflectance of single-layer 0.3MSiO2, 0.6MSiO2, and 0.3MCeO2 thin films were 30.54%, 20.12%, and 14.23%, respectively. Average reflectance was decreased significantly down to 5.9% by 0.3MCeO2/0.6MSiO2 double-layer thin films comparing to those of the results of single-layer films and bare silicon surface reflection (~40%). Antireflective effect of the films on solar cells was estimated by simulation using the measured reflection data. Simulated solar cells indicate that 0.3MCeO2/0.6MSiO2 double-layer antireflective coatings are capable to increase the efficiency significantly and conversion efficiency of 21.7% could be achieved.

Machining damage in the fabrication of polycrystalline diamond micro end mill with laser and grinding combined processing method

The high hardness and wear resistance of polycrystalline diamond (PCD) micro tool make it widely used in precision machining of small parts of difficult-to-machine materials. The laser and grinding combined machining is an effective method to fabricate PCD micro tools, but the machining damage is difficult to control, which will reduce the cutting performance and tool life. Therefore, this paper aims to deeply study the damage forms and damage formation mechanisms during the fabrication process of PCD micro end mills, so as to improve the quality of the PCD micro mills. The laser and grinding combined machining experiments of PCD micro end mill are carried out, and the surface morphology characteristics and cutting edge of the mill are observed and analyzed. The influence of process parameters on the fabrication quality of PCD micro mill is investigated. The experimental results show that the high temperature of the laser is the main factor causing damage, which causes the melting and oxidation of the surface material, and further forms micro cracks, pits and oxidized attachments on the PCD mill. In addition, diamond phase transformation and excessive removal of cobalt-rich layer will also lead to graphitization and micro-grooves on the mill surface. For the grinding process, the cutting edge is fractured by the impact of the wheel, resulting in micro notches, micro pits and micro cracks. The intergranular crack expansion of PCD material and cleavage breakage of diamond particles are the main causes of micro cracks and micro pits on the mill surface. In addition, the chips will also scratch the tool surface to produce micro nicks and cause the chips coating on the rake face. The research results are helpful to further understand the damage mechanism of laser and grinding combined machining PCD mill, so as to improve the fabrication quality of micro tools.

Influence of Ni-doping on CuCo2O4 electrode for enhanced supercapacitor performance and sustainable energy storage

This work provides a revolutionary strategy for creating high-performance supercapacitors by designing and fabricating a unique nanostructured bimetallic oxide electrode. The proposed electrode leveraged the synergistic effects of metal oxides to enhance both energy density and charge-discharge kinetics. Ni-doped CuCo2O4 nanostructures (Cu1-xNixCo2O4) were synthesized in incremental order (x = 0.0, 0.05, 0.10, and 0.15) by facile sol-gel auto-combustion route. The nanostructures analyzed through x-ray diffraction, FTIR spectroscopy, Micro-Raman spectroscopy, x-ray photoelectron spectroscopy (XPS) and Scanning electron microscopy revealed the single phase and polycrystalline nature of CuCo2O4, with some impurity phases of CuO. The surface morphology studies showed numerous pores among the grains of Cu1-xNixCo2O4. Cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy (EIS) were used to investigate the electrochemical performance of synthesized Cu1-xNixCo2O4 samples. In a 3 M KOH electrolyte solution, the Cu1-xNixCo2O4 electrodes with x = 0.05 exhibited 2340 Fg−1 specific capacitance at 5 mVs−1, demonstrating superior electrochemical performance with excellent rate capability. Furthermore, it exhibited 35.88 Whkg−1 energy density, an exceptional 2484.74 Wkg−1 power density, and retained 99.9 % capacitance after 5000 cycles, demonstrating good stability. The results suggest that porous bimetallic oxide nanostructures can be promising candidates for the development of high-performance, environmentally friendly supercapacitors.

Ferulic acid-arabinoxylan conjugates: Synthesis, characterization and applications in antibacterial film formation

A novel antibacterial film based on arabinoxylan (AX) was prepared by introducing ferulic acid (FA) to AX through a laccase-catalyzed procedure. The ferulic acid-arabinoxylan conjugates (FA-AX conjugates) have been characterized. Results showed that FA was successfully grafted onto the AX chains by covalent linkages, likely through nucleophilic addition between O-Ph in the phenolic hydroxyl group of FA, or through Michael addition via O-quinone intermediates. FA-AX conjugates showed improved crystallinity, thermal stability, and rheological properties, as well as a distinct surface morphology, compared with those of native AX. Moreover, FA-AX conjugates exhibited enhanced antibacterial ability against Staphylococcus aureus, Escherichia coli, Shewanella sp., and Pseudomonas sp. Mechanistic studies revealed that the enhanced antibacterial ability was due to the penetration of bacterial membrane by the phenolic molecule and the steric effect of FA-AX conjugates. The study demonstrates that the laccase-induced grafting method was effective in producing FA-AX conjugates; we have demonstrated its antibacterial ability and great potential in prolonging the shelf life of fresh seafood products.

Effect of laser remelting on surface morphology and mechanical properties of laser deposition manufactured thin-walled Ti-6Al-4V alloy

Effect of laser remelting on surface morphology and mechanical properties of laser deposition manufactured thin-walled Ti-6Al-4V alloy

Investigation on Surface Roughness and Power Consumption for Sustainability Assessment in Hard Turning of HSLA Steel With SPPP‐AlTiSiN–Coated Carbide Tool Under Various Cooling‐Lubrications

ABSTRACTThe present research analyses the power consumption (Pc) and surface roughness (Ra) in hard turning of high‐strength low‐alloy (HSLA) grade AISI 4140 steel using a recently developed AlTiSiN‐coated carbide tool under different cooling‐lubrication conditions (dry, flooded, nanofluid‐MQL). The nanofluid was prepared by mixing the MWCNT nanoparticles with an eco‐friendly automotive radiator coolant (base fluid). The cooling‐lubrication performance is investigated briefly by comparing the machining responses like machined surface morphology, tool wear, cutting force and temperature. The experiments associated with 46 trials were performed by considering various machining variables, namely cutting speed, nose radius, depth of cut, feed and cooling‐lubrication methods. From the perspective of predictive modelling and multi‐response optimisation, response surface methodology has been employed to minimise power consumption and surface roughness. Thereafter, the predictive modelling and optimisation results are implemented for economic analysis and energy‐saving carbon footprint evaluation. This innovative research also addresses comparative environmental sustainability evaluation in hard turning under different cooling‐lubrication conditions using a life cycle assessment methodology for cleaner and safer production. Results indicate that cutting speed was the most influential item in power consumption enhancement. Furthermore, compared with dry and flooded turning, lower cutting force, reduced cutting temperature, shorter width of flank wear and better surface morphology were obtained under nanofluid‐MQL machining. It has been observed that nanofluid‐MQL machining outperformed sustainability improvement concerning techno‐economically viable societal acceptable and environmental friendliness.

Synthesis of Cellulose Acetate Butyrate Microspheres as Precursor for Hard Carbon-Based Electrodes in Symmetric Supercapacitors

Cellulose microspheres have a wide range of applications due to their unique properties and versatility. Various preparation methods have been explored to tailor these microspheres for specific applications. Among these methods, the acetate method using cellulose acetate is well known. However, replacement of the acetate group through the butyrate group significantly extends the variety of morphological properties. In the present work, microspheres based on cellulose acetate butyrate are being developed with modified characteristics in terms of particle size, porosity, surface morphology and the inner structure of the microspheres. While the inner structure of cellulose acetate microspheres is predominantly porous, microspheres prepared from cellulose acetate butyrate are mainly filled or contain several smaller microspheres. Carbon materials from cellulose acetate butyrate microspheres exhibit a high specific surface area of 567 m2 g−1, even without further activation. Activation processes can further increase the specific surface area, accompanied by an adaptation of the pore structure. The prepared carbons show promising results in symmetrical supercapacitors with aqueous 6 M KOH electrolytes. Activated carbons derived from cellulose acetate butyrate microspheres demonstrate an energy density of 12 Wh kg−1 at a power density of 0.9 kW kg−1 .

Structure Optimization for Cellulose‐Based Separator through Fiber Size Regulation for High Performance Lithium Metal Batteries

Cellulose‐based separator exhibits excellent electrolyte affinity, thermal stability, and mechanical strength, which acts as a promising alternative to commercial polyolefin separators in lithium metal batteries (LMBs). Fiber size in cellulose‐based separators plays a crucial role in determining their physicochemical structure and mechanical strength, as well as the electrochemical performance of corresponding LMBs. Herein, the fiber size in cellulose‐based separators was first time regulated to optimize their mechanical stability and the related battery performance. The influences of fiber size in the separator on chemical structure, mechanical properties, surface morphology, electrochemical behavior were investigated in detail, in which the underlying mechanism between separator structure and the related performance was elucidated. As a result, the separator optimized by fiber size regulation exhibited excellent thermal stability under 180 °C, good tensile strengths of 6.0 MPa and Young's moduli of 315.9 MPa, superior room temperature ionic conductivity of 1.87 mS cm‐1, as well as significantly improved electrochemical performance of corresponding batteries. It can be concluded that structure optimization for cellulose‐based separator through fiber size regulation is an effective and indispensable approach towards high safety and high performance LMBs.

Enhancing corrosion resistance of 316L stainless steel through electrochemical deposition of polyaniline coatings in acidic environments

AbstractStainless steel is widely used because of its excellent corrosion resistance in typical environments. However, it is susceptible to corrosion in acidic media, therefore, to address this issue, the electrochemical deposition of polyaniline coatings on 316L stainless steel was investigated using cyclic voltammetry at different potential windows and scan rates. The successful polymerization and surface morphology were analyzed using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), respectively. Moreover, thermal stability of the PANI coating was assessed through thermo gravimetric analysis while the corrosion behavior of bare and coated steels immersed in 1M H2SO4 was studied using electrochemical impedance spectroscopy (EIS). Based on the Nyquist plots obtained from the EIS revealed that the corrosion resistance of the PANI coating improved significantly with a decrease in scan rate and by limiting the upper potential, especially during longer exposure times up to 72 h. Results suggest that controlling the deposition parameters and optimizing the electrochemical conditions can lead to even greater improvements in the corrosion resistance of the stainless steel. These findings offer valuable insights for researchers and engineers in the field of materials science and corrosion protection, enabling them to develop more precise and efficient strategies for enhancing the durability and performance of stainless steel in acidic environments.

Contaminant-free layer-by-layer annealing to improve the properties of HfO2/SiO2 optical films for the fs laser

The low laser-induced damage threshold (LIDT) of HfO2/SiO2 films is an important factor in limiting the further development of high repetition rate femtosecond (fs) laser systems. Conventional whole-layer annealing can effectively improve the properties of SiO2 films, but it is difficult to improve the properties of HfO2 films located in the intermediate layer and is also prone to introduce contaminants. In this study, an innovative magnetron sputtering-vacuum tube furnace combined system was presented to deposit and anneal the HfO2/SiO2 films without contaminant. The layer-by-layer annealing optimizes the stoichiometric ratio, stress, and surface morphology of HfO2/SiO2 films. The fs laser damage test at a high repetition rate indicated that the LIDT of the layer-by-layer annealed films reached 1.15 J/cm2 and 1.99 J/cm2 at 515 nm and 1030 nm, which were about 28% and 25% higher than those of the un-annealed films, respectively. This work provides a way to effectively avoid the contaminant introduction during annealing and improve the damage threshold of bilayer films by layer-by-layer annealing in the magnetron sputtering-vacuum tube furnace combined system.

Study on the influence of wood ray morphological characteristics on the tensile strength of wood parallel to grain

The tensile strength of wood parallel to grain is one of the important indicators of wood physical and mechanical properties. Cross-sectional shape possesses a significant effect on the tensile strength parallel to grain, especially for broad-leaved trees with broad wood rays. However the influence of the structural feature of wood rays on the test results, which was commonly ignored. The article focuses on the beech tree with two types of wood rays: broad and narrow, poplar wood with extremely fine wood rays, and dilleniad with extremely rich wood rays. The relationship between the inclination angle and fracture mode of wood rays and the microstructure of wood rays is studied, in order to provide a more accurate scientific basis for determining the tensile strength of wood parallel to grain. The results showed that the inclination angle between the wood ray and the tensile direction has a significant impact on the fracture mode and tensile strength, and the tensile strength parallel to grain without inclination angle is greater than that with inclination angle. Different types of wood rays have a effect on the coefficient of variation of the tensile strength parallel to grain of the specimen. Under the same inclination angle, the Pearson correlation between the wood ray parenchyma ratio and the tensile strength parallel to grain is significantly negative at the 0.01 level (double tailed) or 0.05 level (double tailed). Besides, as the wood ray parenchyma ratio gradually increases, the overall tensile strength of wood parallel to grain shows a downward trend. The fracture surface morphology characteristics of specimens with different fracture modes are different.

Efficient removal of Zn(II) ions from aqueous media using a facilely synthesized nanocomposite based on chitosan Schiff base

The development of nanomaterials incorporating organic components holds significant importance in addressing the efficient removal of metal ions through adsorption. Hence, in this study, a novel MnFe2O4/chitosan/Schiff base nanocomposite was successfully synthesized by crosslinking MnFe2O4 nanoparticles with functionalized chitosan using a novel Schiff base. The Schiff base was created through the condensation reaction between 2-aminophenol and terephthalaldehyde. Comprehensive characterization of the synthesized nanocomposite was performed through FT-IR, XRD, SEM, and VSM analyses, revealing a less crystalline arrangement compared to pure chitosan, a rough and non-uniform surface morphology, and a reduced magnetization value of 30 emu/g. Furthermore, the synthesized MnFe2O4/chitosan/Schiff base nanocomposite was working as an adsorbent for the effective disposal of Zn(II) ions from aqueous solutions. The synthesized nanocomposite exhibited a maximum sorption capacity of 289.86 mg/g for Zn(II) ions. Additionally, the results indicated that the removal of Zn(II) ions by the synthesized nanocomposite was a spontaneous, chemical, and endothermic process, aligning well with the Langmuir isotherm as well as the pseudo-second-order model. Furthermore, at pH 7.5, with a contact duration of 100 min and a temperature of 328 K, the fabricated nanocomposite reached its maximum sorption capacity for Zn(II) ions. The results of this study demonstrate the effectiveness of the newly synthesized MnFe2O4/chitosan/Schiff base nanocomposite in removing Zn(II) ions from aqueous media. The novel synthesis approach and the high adsorption capacity of 289.86 mg/g underscore the potential of this composite for practical applications in industrial wastewater treatment. The dual removal mechanism involving electrostatic attraction and complexation processes further enhances its utility, making it a valuable contribution to the field of environmental remediation.

Experimental and Computational Study of Modified Biopolymer Xanthan Gum with Synthetic Vinyl Monomers for Enhanced Oil Recovery

AbstractUtilizing xanthan gum, a biodegradable polymer, in enhanced oil recovery (EOR) is imperative wherever there is a need for innovation in oil production that is both cost-effective and environmentally friendly. Xanthan, chosen for its natural sourcing, availability, controllability, eco-friendliness, and biodegradability, proves resilient against harsh reservoir conditions owing to its rigid structure and elongated polysaccharide chains. This study investigates two modified xanthan gum composites, achieved by grafting with synthetic vinyl monomers through emulsified polymerization. Spectroscopic characterization using FTIR and 1H-NMR, along with surface morphology analysis via atomic force microscopy (AFM) and thermal behavior screening through TGA analysis, elucidates the properties of these modified composites. Rheological behavior under reservoir conditions, including stress scanning and viscosity/shear rate dependency, was evaluated. Material modeling with the Materials Studio program simulated the equilibrium adsorption of xanthan and modified biopolymer chains on SiO2-quartz crystal to assess wettability alteration. Simulation results indicate that XG-g-AM, MMA&TEVS exhibit greater stability and surface coverage with more negative electrostatic energies compared to XG and XG-g-AM&MMA. The laboratory runs on a sandstone-packed model to identify the disclosed XG-g-AM&MMA and XG-g-AM, MMA&TEVS biopolymers as promising EOR candidates and wettability modifiers in challenging sandstone reservoirs, as per experimental outcomes.

Stress Corrosion Cracking of 304 Austenitic Stainless Steel in H2SO4/NaCl Media at Room Temperature

ABSTRACT The effects of Cl− ion concentration, H2SO4 concentration, the applied potential, and the strain rate on the stress corrosion cracking (SCC) of 304 stainless steel were investigated. The post-fracture SEM micrographs of the fractured surfaces revealed that solutions of high H2SO4 concentration combined with low Cl− ion concentration resulted in corrosion (active dissolution), while solutions of very low H2SO4 concentration combined with a relatively moderate Cl− ion concentration resulted in ductile failure. Solutions with moderate concentrations of H2SO4 and Cl− ions resulted in transgranular stress corrosion cracking (TGSCC). The susceptibility to SCC and the fracture surface morphology were found to depend on the [H2SO4]/[Cl−] ratio, the strain rate, and the applied potential. The average crack growth rate (ACGR) was found to depend on the strain rate and the applied potential. For specimens undergoing SCC at the open circuit potential (OCP), the ACGR increased with increasing the strain rate. For specimens undergoing SCC under applied potential in the active range, the ACGR increased with increasing the applied potential. The specimen eventually failed in a ductile manner when tested under an applied anodic potential in the passive range. The increase in the ACGR with increasing the strain rate and the applied anodic potential is attributed to the enhanced dissolution at the crack tip. Moreover, secondary cracks formed when relatively high strain rates were used. The secondary cracks are believed to propagate mainly along the slip planes. The fracture surface morphology shows the {110} planes are the preferred fracture planes, with the fracture surface consisting of parallel facets separated by steps. Finally, the results indicate that hydrogen may play an indirect role in SCC.

Investigate on the mechanical properties and microscopic three-dimensional morphology of rock failure surfaces under different stress states

The macro and micro morphology of rock failure surfaces play crucial roles in determining the rock mechanical and seepage properties. The morphology of unloaded deep rock failure surfaces exhibits significant variability and complexity. Surface roughness is closely linked to both shear strength and crack seepage behavior. Understanding these morphology parameters is vital for comprehending the mechanical behavior and seepage characteristics of rock masses. In this study, three-dimensional optical scanning technology was employed to analyze the micromorphological properties of limestone and sandstone failure surfaces under varying stress conditions. Line and surface roughness characteristics of different rock failure surfaces were then determined. Our findings reveal a critical confining pressure value (12 MPa) that influences the damage features of Ordovician limestone failure surfaces. With increasing confining pressure, pore depth and crack formation connecting the pores also increase. Beyond the critical confining pressure, the mesoscopic roughness of the failure surface decreases, and the range of interval-distributed pore roughness diminishes. Additionally, we conducted a detailed investigation into the water conductivity properties of rocks under different stress states using Barton's joint roughness coefficient (JRC) index and rock fractal theory. The roughness features of rock failure surfaces were classified into three categories based on mesoscopic pore and crack undulation forms: straight, wavy, and jagged. We also observed significant confining pressure effects on limestone and sandstone, which exceeding the critical confining pressure led to increased water conductivity in both rocks, albeit through different mechanisms. While sandstone exhibits fissures running across it, limestone shows shear abrasion holes. Beyond the critical confining pressure, the rock failure surface becomes smoother, leading to decreased water flow blocking capacity. The fractal dimension of Ordovician limestone increases significantly under critical confining pressure, leading to a more complex mesoscopic crack extension route.

Adverse effects of sterilization processes on the fundamental topographic properties of modified dental implant surfaces

The employ of sterilization processes are essential to investigate biomaterials aiming for experimental, preclinical, or clinical applications with biological tissues. However, responsive surface properties of biomaterials may be susceptible to sterilization processes, compromising important physio-chemical characteristics. For that reason, this in vitro study aimed to investigate the effects of three different processes for sterilization (humid heat under pressure, UVC-light exposure, and Gamma irradiation) on the major topographical properties of implant surfaces applied to dental bone-anchored implants and/or implant-abutments. Three groups of implant surfaces were developed: a smooth machined surface, a micro-texturized surface, and a hydrophilic micro-texturized surface. The implants were sterilized with three methodologies and characterized regarding surface morphology, elemental surface composition, roughness parameters, wettability characteristics, and compared to the samples as-developed. Surface morphology and roughness parameters were not modified by any of the sterilization processes applied. On the other hand, hydrophilic implants were negatively affected by autoclaving. After package opening, hydrophilic features showed to be sensible to atmospheric air exposition independently of the sterilization process performed. Our findings revealed significant chemical changes on the implant surfaces caused by autoclaving and UVC exposure; additionally, the results showed the importance of selecting an appropriate sterilization method when investigating hydrophilic implants so as not to generate imprecise outcomes.Graphical

Se-functionalized ZIF-8 nanoparticles: synthesis, characterization and disruption of biofilms and quorum sensing in Serratia marcescens

The majority of research on nanomaterials has been concentrated on metal nanoparticles since they are easily made and manipulated. Nanomaterials have shown a wide range of applications in biology. Nevertheless, their bioactivity declines due to their extreme susceptibility to and novel Se@ZIF-8 by chemical method. The sizes and morphologies of Se (0) and Se@ZIFchemical and physical stimuli. The goal of encapsulating these nanomaterials in a matrix is gradually being pursued, which boosts their affordability, stability, and usability. Metal-organic frameworks, often known as MOFs, have the potential to be the best platforms for encapsulating metal nanoparticles due to their well-defined frameworks, persistent porosity, and flexibility in modification. In this investigation, we report the synthesis and optimization of polyvinylpyrrolidone-stabilized Se(0) nanoparticles -8 were affected by the ratios of Se/Zn2+and [hmim]/Zn2+used. The optimized Se@ZIF-8 nanoparticles exhibited a particle size and zeta potential of 319 nm and -34 mv respectively. Transmission electron microscopy displayed spherical morphology for Se(0) nanoparticles, whereas the surface morphology of novel Se@ZIF-8 nanoparticles was drastically changed to hexagonal shaped structures with smooth surface morphologies in scanning electron microscopy (SEM). The DTA, TG/DTG, XRD analysis confirmed the presence of novel Se incorporated ZIF-8 nanoparticulate framework. The synthesized novel Se@ZIF-8 nanoparticles showed efficient antibacterial activity as evidenced by low MIC values. Interestingly, these Se@ZIF-8 NPs not only inhibited biofilm formation inS. marcescens,but also effectively eradicated mature biofilms by degrading the eDNA of the EPS layer. It was validated by confocal laser scanning microscopy and SEM analysis. It was observed that Se@ZIF-8 targeted the Quroum Sensing pathway and reduced its associated virulence factors production. This work opens up a different approach of Se@ZIF-8 nanoparticles as novel antibiotics to treat biofilm-associated infections caused byS. marcescensand offer a solution for antimicrobial resistance.

Effect of ZrB2 on the wear resistance and corrosion properties of nanocrystalline Ni-Cu coatings fabricated by electrodeposition

In this study, a pulsed electrodeposition approach was used to create a Ni-Cu/ZrB2 composite coating on the surface of J55 steel. Ni-Cu/ZrB2 composite coatings with different material additions were prepared, and the surface morphology, grain size, microhardness and wear and corrosion resistance were investigated. The results confirmed that the embedding of ZrB2 in the Ni-Cu coating can refine the grains and make the coating surface denser. Furthermore, ZrB2 can effectively increase the wear resistance and corrosion resistance of the coating; the Ni-Cu/ZrB2 (1.0 g/L) composite coating reflects this by having the shallowest and narrowest wear cross-section as well as the lowest average friction coefficient (0.537). Additionally, the composite coating has the highest impedance modulus, reaching 83.60 kΩ/cm2. The composite coating improved corrosion resistance by 63.1% compared to the pure sample. The enhancement in the coating's corrosion resistance can be attributed to three factors. Firstly, the addition of zirconium diborate refines the coating grain and changes the corrosion type from pitting corrosion to homogeneous corrosion. Secondly, zirconium diborate forms a physical barrier against corrosive ions. Lastly, the formation of the oxide layer on the coating during the process of corrosion, also enhances the material's resistance to corrosion.