Nanoparticle Coatings Research Articles

Inhibitory effects of cadmium and hydrophilic cadmium telluride quantum dots on the white rot fungus Phanerochaete velutina.

The white rot fungus P. velutina was investigated for its ability to decolorize the reactive textile dye Reactive Black 5 (RB5) that was co-exposed to CdCl2 and quantum dots (QDs) consisting of a CdTe core capped with two different hydrophilic organic ligands (NAC and MPA). Without co-exposure, P. velutina completely decolorizes RB5 within 9 days. The highest inhibitory effect was found for soluble CdCl2 with an EC50 of 583μgl-1, followed by MPA-QDs (10,628μgl-1) and NAC-QDs (17,575μgl-1). The different EC50 values indicate that the nanoparticle coatings have a strong influence on the inhibitory effects, as the organic ligands used for surface passivation prevented the leaching of acute toxic Cd ions from the metallic QD core. Compared to CdCl2, the CdTe QDs were less inhibitory to the formation of fungal metabolites and their decolorization ability on co-exposed textile dyes. In addition, the literature comparison suggests that P. velutina is more resilient to cadmium than other microorganisms. The fungus could therefore be used for bioremediation applications of dye- or QD-contaminated wastewater from the textile or semiconductor industries.

Drug Release Nanoparticle System Design: Data Set Compilation and Machine Learning Modeling.

Magnetic nanoparticles (NPs) are gaining significant interest in the field of biomedical functional nanomaterials because of their distinctive chemical and physical characteristics, particularly in drug delivery and magnetic hyperthermia applications. In this paper, we experimentally synthesized and characterized new Fe3O4-based NPs, functionalizing its surface with a 5-TAMRA cadaverine modified copolymer consisting of PMAO and PEG. Despite these advancements, many combinations of NP cores and coatings remain unexplored. To address this, we created a new data set of NP systems from public sources. Herein, 11 different AI/ML algorithms were used to develop the predictive AI/ML models. The linear discriminant analysis (LDA) and random forest (RF) models showed high values of sensitivity and specificity (>0.9) in training/validation series and 3-fold cross validation, respectively. The AI/ML models are able to predict 14 output properties (CC50 (μM), EC50 (μM), inhibition (%), etc.) for all combinations of 54 different NP cores classes vs. 25 different coats and vs. 41 different cell lines, allowing the short listing of the best results for experimental assays. The results of this work may help to reduce the cost of traditional trial and error procedures.

Challenges of Biological Complexity in the Study of Nanotoxicology.

The scale of nanoparticle use in consumer goods has grown exponentially over several decades owing to the unique properties of materials in this size range. At the same time, well-defined end of life cycle disposal strategies have not been developed for most materials, meaning that we are approaching the potential for a new ecological disaster with the release of millions of metric tons of nanoparticles into the waste stream. The field of nanotoxicology has grown to meet the challenge of investigating the potential hazards of these materials and has already identified toxicity mechanisms that affect multiple tropes of life. However, there are stipulations on how applicable many of these results are to real world applications. These limitations largely arise from the complex network of variables that must be considered during these investigations. Herein, we focus on the challenges posed by the transformations that nanoparticles undergo when they are introduced into a biological environment. For example, biomolecules, such as proteins, rapidly coat nanoparticles with a shell, called a corona, that can modulate the toxicity of the core materials and/or aid its internalization into cells. As such, unlike in the evaluation of small molecule toxicity, one cannot assume that they know the composition of the nanoparticle-biomolecule species at any given time. This additional layer of complication, as well as the noncovalent nature of the corona, have made it difficult to identify consistent toxicity trends. In this Perspective, we highlight current analysis strategies and the difficulties in studying nanotoxicity, recent advances to aid in these studies, and efforts to reduce nanotoxicity and outline remaining challenges.

Evolution of Multifunctional Cotton Fabric as the Flame Retardant/Crease Proof/Microbial Resistant Blended With Green Synthesised TiO2 Nanoparticles Coatings

ABSTRACTIn this work, green synthesised TiO2 nanoparticles' coating was used to improve the fire safety and antibacterial property of 100% cotton fabric. In the first stage, Aloe vera extract was prepared, and subsequently used in the synthesis of TiO2 nanoparticles. The average size of these as‐synthesised TiO2 nanoparticles was confirmed to be 16 nm using DLS (dynamic light scattering). Further, XRD (X‐ray diffraction) patterns confirmed the successful synthesis of nanoparticles. The vibrational photon of TiO2 was represented by peaks in the FTIR (Fourier transform infrared spectroscopy) spectrum between 450 and 800 cm−1. Subsequently, in an attempt to establish the flame retardant/crease proof/microbial resistant properties of the as‐synthesised TiO2 nanoparticles, the TiO2 NPs coated cotton fabric was used for the investigations. Based on the investigations, the bending length (measure of fabric stiffness) value of the coated fabric (%) increased from 2.4 cm (uncoated fabric) to 3.71 cm (at 20% TiO2 coating). Also, the crease recovery angle value increased from 71.8 (uncoated fabric) to 98.6 (20% TiO2 coating), respectively. A vertical flammability test revealed that the burning time decreased from 13.31 s (0%) to 10.84 s (20%), confirming a fire‐retardant trait of green synthesised TiO2 nanoparticle coated fabric. Additionally, the disc diffusion method confirmed that the treated coated fabrics exhibit antibacterial properties against both gram‐positive and gram‐negative bacterial cultures: Escherichia coli and Staphylococcus aureus. This study provides an environmentally benign route for producing versatile cotton fabric blended with bioinspired TiO2 NPs possessing improved flame resistance as well as antibacterial attributes.

Combining functionalities-nanoarchitectonics for combatting bacterial infection.

New antimicrobial and anti-inflammatory therapeutics are needed because of antibiotic resistance development and resulting complications such as inflammation, ultimately leading to septic shock. The antimicrobial effects of various nanoparticles (NPs) are currently attracting intensive research interest. Although various NPs display potent antimicrobial effects against strains resistant to conventional antibiotics, the therapeutic use of such materials is restricted by poor selectivity between bacteria and human cells, leading to adverse side effects. As a result, increasing research efforts during the last few years have focused on targeting NPs against bacteria and other components in the infection micro-environment. Examples of approaches explored include peptide-, protein- and nucleic acid-based NP coatings for bacterial membrane recognition, as well as NP conjugation with enzyme substrates or other moieties that respond to bacterial or other enzymes present in the infection micro-environment. In general, this study aims to add to the literature on the antimicrobial effects of nanomaterials by discussing surface modification strategies for targeting bacterial membranes and membrane components, as well as how such surface modifications can improve the antimicrobial effects of nanomaterials and simultaneously decrease toxicity towards human cells and tissues. In doing so, the biological effects observed are related throughout to the physico-chemical modes of action underlying such effects.

ZnOnp/CaCO3 Core–Shell Nanoparticle Coatings on Kraft Paper: A Comparative Study of Antimicrobial Efficacy, Tensile Strength, and Hydrophobicity

This study introduces a novel paper coating approach using modified zinc oxide (ZnO), providing a comparison with conventional materials used in the paper industry. The research focused on determining the concentration for effective microbial growth inhibition and evaluates the impact of different ZnO types on coated-paper properties, including antimicrobial activity, surface morphology, tensile strength, and water absorption. Specifically, ZnO microparticles (ZnOws), ZnO nanoparticles (ZnOnp), and modified ZnOnp (ZnOnp-CaCO3, with a core–shell structure composed of calcium carbonate [CaCO3] and nano-zinc oxide) were incorporated into coating formulations at varying concentrations (0 × MIC, 1 × MIC, 2 × MIC, and 3 × MIC, based on minimum inhibitory concentrations [MICs]). The results demonstrated that among all tested microorganisms, ZnOnp-CaCO3 showed the lowest MIC values. ZnOnp-CaCO3-coated paper exhibited superior antimicrobial activity against both Gram-positive and Gram-negative bacteria, as well as fungi, outperforming ZnOws and ZnOnp. At 1 × MIC, %inhibition for E. coli, S. aureus, and A. niger were 98.3%, 99.1%, and 90.8%, respectively. Additionally, ZnOnp-CaCO3 coatings caused minimal color change in the paper compared to the other ZnO variants. The coating did not negatively impact the mechanical properties of the paper across all ZnO types and concentrations. Water absorption tests showed increased hydrophobicity with higher ZnO content, with ZnOnp and ZnOnp-CaCO3 exhibiting greater reductions in water absorption than ZnOws. Overall, ZnOnp-CaCO3 showed strong potential as an antimicrobial agent for paper surfaces, making it ideal for packaging and hygiene products. By partially replacing ZnOnp with inexpensive CaCO3 core particles, ZnOnp-CaCO3 delivers enhanced performance, reduced costs, and greater sustainability for large-scale applications.

Green Chemically Synthesized Iron Oxide Nanoparticles-Chitosan Coatings for Enhancing Strawberry Shelf-Life.

To enhance the preservation of strawberries, a novel coating formulation was developed using chitosan (CH) and iron oxide (IO) nanoparticles (NPs) supplemented with ginger and garlic extracts and combined with varying concentrations of 1%, 2%, and 3% Fe3O4 NPs. The results of XRD revealed an average crystalline size of 48.1 nm for Fe3O4 NPs. SEM images identified Fe3O4 NPs as bright spots on the surface of the fruit, while FTIR confirmed their presence by detecting specific functional groups. Additional SEM analysis revealed clear visibility of CH coatings on the strawberries. Both uncoated and coated strawberry samples were stored at room temperature (27 °C), and quality parameters were systematically assessed, including weight loss, firmness, pH, titratable acidity (TA), total soluble solids (TSSs), ascorbic acid content, antioxidant activity, total reducing sugars (TRSs), total phenolic compounds (TPCs), and infection rates. The obtained weight loss was 21.6% and 6% for 1.5% CH and 3% IO with 1.5% CH, whereas the obtained infection percentage was 19.65% and 13.68% for 1.5% CH and 3% IO with 1.5% CH. As strawberries are citric fruit, 3% IO with 1.5% CH contains 55.81 mg/100 g ascorbic acid. The antioxidant activity for 1.5% CH coated was around 73.89%, whereas 3% IO with 1.5% CH showed 82.89%. The studies revealed that coated samples showed better results, whereas CH that incorporates Fe3O4 NP coatings appears very promising for extending the shelf life of strawberries, preserving their quality and nutritional value during storage and transportation.

Effectiveness of coatings in reducing biofilm adhesion on arch wires: A systematic review

To evaluate the Effectiveness of coatings in reducing biofilm adhesion on arch wire. A literature search was performed on PubMed, Medline, Google Scholar, and Science Direct to examine studies that compared the uncoated group of arch wires to those with nano coatings and assessed the anti-adherent property. After extracting the data from each study, two risk of bias assessment tools were employed and tabulated data was obtained. 8 Studies met the requirements for inclusion. For majority of the included articles, the risk of bias assessment indicated a low to moderate risk. The antibacterial properties of various nanoparticle coatings were examined and evaluated.Regardless of patient compliance, a proper application of each type of coated arch-wire can help prevent white spot lesions and reduce bacterial aggregation around orthodontic attachments. Majority of the studies that made up this systematic review have a risk of bias grade of "fair." A meta-analysis was not feasible because of heterogeneity in the different coating techniques used to test the antibacterial property.

Surface Coating of ZIF-8 Nanoparticles with Polyacrylic Acid: A Facile Approach to Enhance Chemical Stability for Biomedical Applications.

Nanoparticles of zeolitic imidazole framework-8 (ZIF-8 NPs), which are the subclass of metal-organic frameworks consisting of Zn ion and 2-methylimidazole, have been identified as promising drug carriers since their large microporous structure is suited for encapsulating hydrophobic drug molecules. However, one of the limitations of ZIF-8 NPs is their low stability in physiological solutions, especially in the presence of water and phosphate anions. These molecules can interact with the coordinatively unsaturated Zn sites at the external surface to induce the degradation of ZIF-8 NPs. In this study, herein a facile approach is reported to enhance the chemical stability of ZIF-8 NPs by surface coating with polyacrylic acid (PAA). The PAA-coated ZIF-8 (PAA-ZIF-8) NPs are prepared by mixing ZIF-8 NPs and PAA in water. PAA coating inhibits the degradation of ZIF-8 NPs in water as well as phosphate-buffered saline over 6 days, which seems to be due to the coordination of carboxyl groups of PAA to the reactive Zn sites. Furthermore, the PAA-ZIF-8 NPs loaded with the anticancer drug doxorubicin (Dox) show cytotoxicity in human colon cancer cells. These results clearly show the feasibility of the PAA coating approach to improve the chemical stability of ZIF-8 NPs without impairing their drug delivery capability.

Energy Storage in Carbon Fiber-Based Batteries: Trends and Future Perspectives

Carbon fiber-based batteries, integrating energy storage with structural functionality, are emerging as a key innovation in the transition toward energy sustainability. Offering significant potential for lighter and more efficient designs, these advanced battery systems are increasingly gaining ground. Through a bibliometric analysis of scientific literature, the study identifies three primary research areas: (i) the development of anodes for lithium-ion batteries, tackling challenges such as dendrite formation and performance degradation; (ii) the creation of new carbon fiber-based cathodes with coatings of LiFePO4, LiCoO2, or other nanoparticles, alongside efforts to develop cobalt-free alternatives; and (iii) the advancement of solid electrolytes that achieve a balance between ionic conductivity and mechanical strength. These advancements position carbon fiber-based batteries as promising solutions for seamless integration into various structural applications. The analysis of publication trends, citation patterns, and collaboration networks provides critical insights into the ongoing technological developments, current research challenges, and emerging trends in this field. Moreover, the study highlights potential research directions, underscoring the importance of continuous innovation to fully realize the potential of carbon fiber-based energy storage technologies.

Optimising titanium implant stability and infection resistance through iron nanoparticle coatings: A preclinical investigation

BackgroundAttaining adequate osseointegration and mitigating infections are paramount issues in implantology, especially within dental and orthopaedic domains. Titanium implants have been utilised for their biocompatibility and mechanical strength; yet, problems such as peri‑implant infections and inadequate bone integration may undermine their efficacy. Coating titanium implants with iron nanoparticles (FeNp) has surfaced as a promising approach to improve osseointegration and antibacterial characteristics. FeNp's distinctive capacity to react to magnetic fields and produce reactive oxygen species (ROS) has the potential to enhance implant results. ObjectiveTo assess the influence of FeNp-coated titanium implants on osseointegration, mechanical stability, osteogenesis, and antibacterial effectiveness against prevalent implant-associated infections, Staphylococcus aureus and Escherichia coli. Materials and methodsIn vivo investigations were performed on animal models to evaluate implant stability by resonance frequency analysis (RFA) and removal torque measurements at 6 and 12 weeks post-implantation. Histopathological assessment was conducted to analyze the osseous formation and vascularization surrounding the implants. Furthermore, in vitro experiments were employed to assess the antibacterial efficacy of magnetized FeNp against S. aureus and E. coli. ResultsAt 6 weeks, no substantial change was detected in (RFA) or removal torque between the control group (GROUP A) and the test group (GROUP B). However, by 12 weeks, GROUP B demonstrated significantly higher RFA scores (75.02 ± 5.11) compared to GROUP A (67.41 ± 9.85), indicating improved implant stability (p < 0.05). Removal torque values were also significantly higher in GROUP B at 12 weeks (76.30 ± 14.20) compared to GROUP A (46.10 ± 9.25), suggesting enhanced mechanical integration (p < 0.01). Histopathological analysis revealed greater new bone formation, increased osteoblast activity, and improved vascularization around FeNp-coated implants in GROUP B. Additionally, in vitro antibacterial testing demonstrated that FeNp coatings effectively inhibited the growth of Staphylococcus aureus and E. coli, providing further evidence of its antimicrobial effect ConclusionFeNp-coated implants have dual advantages: improved osseointegration and antibacterial defence. The findings indicate that FeNp coatings might substantially enhance implant longevity and diminish the likelihood of infection, offering a potential approach for clinical applications, especially for patients at elevated risk of implant failure. Subsequent research should concentrate on enhancing the application of FeNp coatings in clinical environments and further examining their long-term biocompatibility and effectiveness.

In silico estimation of polyethylene glycol coating effect on metallic NPs radio-sensitization in kilovoltage energy beams

PurposeNanoparticles (NPs) as radiosensitizers present a promising strategy for enhancing radiotherapy effectiveness, but their potential is significantly influenced by the properties of their surface coating, which can impact treatment outcomes. Most Monte Carlo studies have focused on metallic NPs without considering the impact of coating layers on radiosensitization. In this study, we aim to assess both the physical and radiobiological effects of nanoparticle coatings in nanoparticle-based radiation therapy.Materials and methodsIn this simulation study, we used Geant4 Monte Carlo (MC) toolkit (v10.07.p02) and simulated the bismuth, gold, iridium and gadolinium NPs coated with polyethylene glycol (PEG-400: Density: 1.13 g/cm³, Molar mass: 380–420 g/mol) as radiosensitizer for photon beams of 30, 60 and 100 keV. Secondary electron number and reactive oxygen species enhancement factor were estimated. Also, dose enhancement factor (DEF) was determined in spherical shells with logarithmic scale thickness from the nanoparticle surface to 4 mm.ResultsSecondary electron emission was highest at 30 keV for gold, bismuth, and iridium NPs, while gadolinium NPs peaked at 60 keV. Coating reduced electron emissions across all energies, with thicker coatings leading to a more significant decrease. DEF values declined with increasing radial distance from the NP surface and were lower with thicker coatings. For gadolinium NPs, DEF behavior differed due to K-edge energy effects. Reactive species generation varied, showing maximum production at 30 keV for gold, bismuth, and iridium NPs, while gadolinium NPs showed peak activity at 60 keV. PEG coatings enhanced reactive species formation at 100 keV.ConclusionThe findings indicate that the coating layer thickness and material not only influence the emission of secondary particles and DEF but also affect the generation of reactive species from water radiolysis. Specifically, thicker coatings reduce secondary particle emission and DEF, while PEG coatings demonstrate a dual behavior, offering both protective and enhancing effects depending on photon energy. These insights underscore the importance of optimizing NP design and coating in future studies to maximize therapeutic efficacy in nanoparticle-based radiation therapy.

In vitro determination of genotoxicity and cytotoxicity induced by stainless steel brackets with and without surface coating in cultures of oral mucosal cells

BackgroundOrthodontics is a speciality of dentistry that uses a plethora of devices made from myriad materials to manage various malocclusions. Prolonged contact of orthodontic appliances with oral tissues can lead to cellular damage, highlighting the need for biocompatible materials to mitigate health risks.ObjectivesTo analyze the genotoxicity and cytotoxicity produced by metal brackets and coated metallic brackets with polymeric and nanoparticle coatings in oral mucosal cells.Materials & methodsThe current study compares the toxicity of 3 different types of orthodontic brackets with control groups of oral mucosal cells. Each of the three treatment groups consisted of 10 samples of orthodontic brackets: stainless steel brackets(Group 1), nanoparticle-coated brackets(Group 2), and polymeric-coated brackets(Group 3) exposed to corrosion eluates employing an oral biomimicry model. Two types of oral mucosal cells- Human Gingival Fibroblasts and Buccal Epithelial Cells were used to study the cytotoxic and/or genotoxic effects of the elutes. Intergroup comparisons were conducted using one-way analysis of variance, while scanning electron microscopy evaluated surface characteristic.ResultsThe interaction between metal ions and oral mucosal cells showed no statistically significant difference for toxicity assays between the three groups(p > 0.005). However, polymeric and nanoparticle-coated groups showed reduced cellular differentiation when compared with conventional stainless-steel brackets.ConclusionThis in-vitro study shows that polymeric or nanoparticle coating of conventional metal brackets aids in enhancing corrosion-resistant characteristics of orthodontic appliances and reduces the toxic oral environment created by metal release in the oral cavity.

Development of Titanium Dioxide Coating for Self-Cleaning Photovoltaic Panels

Amid escalating global energy demands and environmental concerns, the transition to renewable sources like solar power is imperative. Despite the advancements in photovoltaic (PV) technology promising increased efficiency, soiling on PV panels—composed of dust, bird droppings, and contaminants—poses a significant challenge, obstructing sunlight and reducing energy conversion efficiency. Building upon existing research on titanium dioxide (TiO2) nanoparticle coatings, our study investigates their super-hydrophilic and anti-soiling characteristics to enhance self-cleaning capabilities in solar applications. Furthermore, our research investigates the application of (3-aminopropyl)trimethoxy silane as an interlayer to reinforce the adherence of the TiO2 coating to PV panel glass, thereby enhancing its durability. Preliminary results highlight the coating’s exceptional super-hydrophilic properties, with water contact angle measurements less than 10°, indicative of TiO2’s strong water affinity. Spectrophotometer measurements show that the developed coating maintains high optical transmittances for the wavelength range from 350 to 800 nm, which is the most crucial factor for energy conversion in solar panels. Our contributions aim to advance solar energy technologies and support the shift towards more sustainable energy solutions, highlighting the role of innovative materials science in addressing solar power’s operational challenges.

Evaluation of imidazole blocking layers for perovskite stability

The prevention of AgI formation is critical for ensuring long term stability of perovskite solar cells. While sputtered metal oxide films are known for uniform dense film formation, solution phase nanoparticle coatings of metal oxides are prone to pinholes through which free iodide can migrate leading to AgI formation at the back contact. Iodide migration can be prevented through the addition of passivator or blocking layers at the perovskite/charge transport or charge transport/Ag interfaces. In this paper we evaluated a series of imidazoles as interfacial layers to prevent iodide migration from the perovskite to the Ag back contact through solution phase deposited Y:SnO2. We identified structural features of the imidazoles that contribute to an effective blocking layer. Specifically, it was found that imidazoles with conjugated planer systems and hydrogen bonding heteroatoms were able to prevent ion migration while retaining device performance. Of the materials evaluated 4-(Imidazol-1-yl)phenol had the best performance with a 60 % increase in stability verse the control under illumination at short circuit conditions.

Evaluation of Cytotoxicity and Characterization of Strontium Phosphate–Chitosan Nanoparticle Coating on Magnesium for Bioimplant Applications: A Preliminary In Vitro Study

Evaluation of Cytotoxicity and Characterization of Strontium Phosphate–Chitosan Nanoparticle Coating on Magnesium for Bioimplant Applications: A Preliminary In Vitro Study

Piezoelectric barium titanate/hydroxyapatite composite coatings on Ti-6Al-4V alloy via electrophoretic deposition

Electrophoretic deposition (EPD) is a widely accepted, cost-effective and simple method to obtain conformal coatings of dense nanoparticles via application of a DC voltage. This paper reports the physical and mechanical properties of nanostructured barium titanate/hydroxyapatite (BT/HA) ceramic composites coated onto Ti-6Al-4V alloy via cathodic EPD in various ratios of 40:60, 50:50 and 60:40 (HB4, HB5 and HB6) respectively. Homogenous BT/HA coatings were obtained at a notably low voltage of 10 V. The crystallinity and phase analysis confirmed the formation of tetragonal phase of BT indicating the piezoelectric property. HB6 exhibits maximum piezoelectric coefficient (d33) of 159 pC/N and Vicker's hardness of 242.31 HV. The cross-sectional electron micrographs show well connected and homogeneous coatings with increasing amounts of BT. Human mesenchymal stem cell lines were utilized in biocompatibility experiments, which revealed that HB composites had greater viability of HW-MSCs cells than pure BT, with HB6 exhibiting a maximum cell viability of more than 90 %.

Dry carbothermal reaction-enabled ultra-dense nanoparticle coatings for high-performance Li-S batteries

Electrocatalysts are crucial for facilitating the sluggish conversion between S and sulfide in Li-S batteries. Despite recent exploration of advanced materials, there remains a significant gap in the morphology design rationale oriented towards practical operation conditions. In this study, we introduce a dry process based on the carbothermal reaction of oxides to achieve nanoparticle (NP) electrocatalyst coatings. This process enables us to produce ultra-high-density NPs with several tens of particles per 100 nm x 100 nm area. We unveil that this high coating density boosts the conversion kinetics by dominating a solution-phase disproportionation reaction, thereby promoting the growth of non-passivating particulate sulfide. With this NP-coated cathode, we achieve excellent kinetic performance, maintaining 53 % of cell capacity retention even with a 50-fold increase in C-rate, and exhibiting only a 0.04 % capacity decay per cycle over 300 cycles at 10C. Remarkably, our cathode achieves an initial areal capacity of 7.51 mAh cm−2 in a full cell, significantly outperforming cells reported in previous studies as well as conventional Li-ion batteries.

Laser Metal Printing from Nanoparticles Prepared by a Gas Aggregation Source.

This study demonstrates the use of nanoparticles prepared by a gas aggregation source for fabricating structures by combining laser sintering and ablation. At first, the morphology and optical properties of prepared nanoparticle coatings were characterized. Then, the response of coatings to laser irradiation at different powers or exposure times was studied by in situ time-of-flight mass spectrometry, followed by scanning electron microscopy measurements of the resulting structures. By comparing the numbers of detected Ag ions, that were ablated and desorbed, with changes in morphology after irradiation, the optimum conditions for laser sintering and ablation of Ag nanoparticle coatings were found. As a proof of concept we fabricated micromirrors from sintered metal, microwires from both sintered metal and interconnected nanoparticles, and arbitrary metallic bulky or nanoparticle patterns. Vacuum compatibility and the possibility of fabrication of both metallic and nanoparticle structures in one step predetermines applications of developed method in electronics or sensing.

Surface Modification of Ti-6Al-4V Alloy by Composite Coating of Polycaprolactone Nanofibers-Fluoroapatite Nanoparticles Doped with Silicon and Magnesium

The purpose of this research was to create polycaprolactone nanocomposite coating - fluor apatite nanoparticles doped with silicon and magnesium, as well as polycaprolactone coating on the alloy in order to improve and modify the biological properties of this alloy. For this purpose, nano composite coating and polycaprolactone coating were first created by immersion methode. Then the physical, corrosion and biological properties of the coating created by different methods were investigated. The results indicated the creation of a uniform nanocomposite coating with a thickness of about 6.26 micrometers, with appropriate structure and phases, and an increase in roughness by adding nanoparticles to the polycaprolactone coating. Electrochemical measurements Ti&amp;lt;sub&amp;gt;6&amp;lt;/sub&amp;gt;Al&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;V showed that the sample coated with polycaprolactone with nanoparticles has polarization R&amp;lt;SUB&amp;gt;P&amp;lt;/SUB&amp;gt;=5.349×10&amp;lt;sup&amp;gt;5&amp;lt;/sup&amp;gt; Ωcm&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; resistance, which is higher than the sample coated with caprolactone with polarization resistance R&amp;lt;SUB&amp;gt;P&amp;lt;/SUB&amp;gt;=1.191×10&amp;lt;sup&amp;gt;5&amp;lt;/sup&amp;gt; Ωcm&amp;lt;sup&amp;gt;2 &amp;lt;/sup&amp;gt;and the sample without coating with polarization resistance R&amp;lt;SUB&amp;gt;P&amp;lt;/SUB&amp;gt;=5.2453×104 Ωcm&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;. Cytotoxicity test showed the non-cytotoxicity of the coatings. Also, the cell growth and proliferation of the sample with nano composite coating compared to the sample without coating has a statistically significant difference. Cell adhesion on the sample with nanocomposite coating was also much better than the sample without coating and the sample with polycaprolactone coating.