Surface Of ZrO2 Nanoparticles Research Articles

Enhanced photocatalytic and antibacterial properties of silver–zirconia nanoparticles for environmental pollution treatment

Abstract Silver–zirconia nanoparticles (Ag–ZrO2 NPs) were synthesized via an in situ strategy at room temperature using NaBH4 as a reducing agent. The surface modification of ZrO2 nanoparticles with nano silver was confirmed through various characterization techniques including Fourier Transform Infrared Spectroscopy (FTIR), UV–vis Diffuse Reflectance Spectroscopy (UV–vis DRS), X-ray Diffraction (XRD), and Field Emission Scanning Electron Microscopy (FESEM). The obtained results demonstrated that Ag nanoparticles, with a crystallite size of approximately 12 nm, were uniformly distributed on the surface of ZrO2 nanoparticles. The incorporation of Ag nanoparticles to the ZrO2 nanoparticles led to increasing the light absorption ability and reducing the band gap of Ag–ZrO2 nanoparticles, thereby enhancing their photocatalytic performance under infrared lamp exposure. When 1 g/L of Ag–ZrO2 nanoparticles was employed to methylene blue (MB) solution, the degradation of MB reached 90 % after 5 h of exposure. Additionally, the Ag–ZrO2 nanoparticles exhibited a high antibacterial activity against two bacterial strains, E. coli and S. aureus. These findings highlight the potential of Ag–ZrO2 nanoparticles as effective materials for environmental pollution treatment through advanced oxidation processes.

Synthesis and characterization of PMMA-grafted-ZrO2 hybrid nanoparticles

In this study, we reported a facile synthesis and the characterization of PMMA-grafted ZrO2 hybrid nanoparticles from original ZrO2 (oZrO2) nanoparticles. The synthesis process included of three steps: (i) modification of nano ZrO2 with a vinyl silane agent, (ii) graft copolymerization of methyl methacrylate (MMA) monomers and modified ZrO2 (mZrO2) nanoparticles, and (iii) extraction of homo PMMA to obtain the final product of PMMA-g-ZrO2 (gZrO2) nanoparticles. Fourier transform infrared (FTIR) spectra and thermogravimetric analysis (TGA) of mZrO2, oZrO2, and gZrO2 indicated that the silane coupling agent was grafted onto oZrO2 nanoparticles. FTIR spectra of gZrO2 indicated PMMA had been successfully grafted onto the surface of ZrO2 nanoparticles. Using TGA method, the PMMA grafting content onto ZrO2 nanoparticles was evaluated as 9.03 wt.%. The electron microscopy (SEM) images of gZrO2, mZrO2, and oZrO2 indicated that their primary particle size and shape were almost unchanged after modification processes, their particle size was in the range from 50 nm to 140 nm. XRD analysis showed the monoclinic crystalline structure of three kinds of ZrO2 nanoparticles (nanocrystals). The organic gZrO2 nanoparticles can be a better candidate as an opacifier additive for polymer nanocomposites or acrylic bone cement.

Radiolysis of water at the surface of ZrO2 nanoparticles

Radiolysis of water at the surface of ZrO2 nanoparticles was investigated by measuring the production of radiolysis products from nanoparticle/water mixtures under irradiation. A pulse radiolysis study and a gamma radiolysis study were conducted to observe and quantify radiolytically generated hydrated electrons (e-aq) and H2 from ZrO2/water mixtures. The radiolytic yield of e-aq and H2 from ZrO2 nanoparticles (20–5000 nm in diameter) was found to increase with increasing nanoparticle surface area indicating surface enhanced radiolysis. This was attributed to radiolysis of surface adsorbed water molecules. The thickness of the surface adjacent water layer was shown to affect radiolysis, with smaller numbers of water layers increasing radiolysis.

Nano zirkonyum dioksit doldurucu ilavesinin protez astarlarının renk değişimi, su emilimi ve çözünürlüğüne etkisi

Objective: Zirconium dioxide (ZrO2) nanofillers were added to denture liners to improve their physical properties. The main goal of this research was to evaluate the impact of adding nano zirconium oxide (ZrO2) fillers on color change, water sorption and solubility of silicone and acrylic denture liners. Materials and Method: The surface of ZrO2 nanoparticles was modified via treatment with the silane coupling agent (3-aminopropyl) triethoxysilane. Fourier transform infrared spectroscopy analysis was performed to characterize surfaces untreated or treated with ZrO2. After modification, these nanoparticles were incorporated into silicone and acrylic denture liners. Three subgroups were assigned for each test method. Kruskal-Wallis and Mann-Whitney U tests were used for the statistical analysis (p ≤ 0.05). Results: Water sorption and solubility in water values decreased with the addition of modified ZrO2 nanofiller in both test groups (respectively, acrylic-based tissue conditioner: p = 0.040 and p = 0.020; silicone-based denture liner: p < 0.001 and p = 0.017). The acrylic-based tissue conditioner test group with 1% modified ZrO2 nanofiller showed the greatest color change (ΔΕ = 37.94 ±6.62), whereas the silicone-based denture liner group with 0.5% modified ZrO2 nanofiller presented the lowest (ΔΕ = 5.02 ±2.30). Conclusion: Modified ZrO2 nanofiller–incorporated silicone-based denture liners might show better clinical success than acrylic ones according to the evaluated parameters.

Kinetics of Formation of Molecular Hydrogen during the Radiolysis of Hexane and a Mixture of C6H14–H2O on a Surface of ZrO2 Nanoparticles

Kinetics of Formation of Molecular Hydrogen during the Radiolysis of Hexane and a Mixture of C6H14–H2O on a Surface of ZrO2 Nanoparticles

Tuning the Integration Rate of Ce(Ln)O2 Nanoclusters into Nanoparticulated ZrO2 Supports: When the Cation Size Matters.

Three nanostructured catalysts with low total rare earth elements (REEs) content (i.e., 15 mol.%) were prepared by depositing CeO2 or Ln3+-doped CeO2 (Ln3+ = Y3+ or La3+; Ln/Ce = 0.15) on the surface of ZrO2 nanoparticles, as nanometre-thick, fluorite-type clusters. These samples were subjected to successive reduction treatments at increasing temperatures, from 500 to 900 °C. A characterisation study by XPS was performed to clarify the diffusion process of cerium into the bulk of ZrO2 crystallites upon reduction to yield CexZr1−xO2−δ surface phases, and the influence of the incorporation of non-reducible trivalent REE cations, with sizes smaller (Y3+) and larger (La3+) than Ce4+ and Ce3+. For all nanocatalysts, a reduction treatment at a minimum temperature of 900 °C was required to accomplish a significant cerium diffusion. Notwithstanding, the size of the dopant noticeably affected the extent of this diffusion process. As compared to the undoped ZrO2-CeO2 sample, Y3+ incorporation slightly hindered the cerium diffusion, while the opposite effect was found for the La3+-doped nanocatalyst. Furthermore, such differences in cerium diffusion led to changes in the surface and nanostructural features of the oxides, which were tentatively correlated with the redox response of the thermally aged samples.

Observation of yttrium oxide segregation in a ZrO2‐SiO2 glass‐ceramic at nanometer dimensions

AbstractDopant segregation at grain boundaries (GBs) in ceramics has been widely reported, while whether similar segregation behavior occurs in glass‐ceramics remains unknown. The distribution of dopant in glass‐ceramics may be totally different due to the existence of glass phase. This study examines the distribution of Y3+ ions in a ZrO2‐SiO2 glass‐ceramic. Two samples were prepared by hot pressing, yttrium oxide‐doped, and undoped 65 mol% ZrO2‐35 mol% SiO2 nanocrystalline glass‐ceramics (NCGCs). The NCGCs had the same microstructure, that is, ZrO2 nanoparticles (NPs) embedded in an amorphous SiO2 matrix. XRD results showed that the undoped NCGC was composed of 20.9 wt% (weight percentage) monoclinic ZrO2 (m‐ZrO2) and 79.1 wt% tetragonal ZrO2 (t‐ZrO2), while the yttrium oxide‐doped NCGC was composed of 9.6 wt% m‐ZrO2 and 90.4 wt% t‐ZrO2. X‐ray energy‐dispersive spectrometry (EDS) results in scanning electron transmission microscopy (STEM) mode demonstrated that Y3+ ions segregated both on the surface of ZrO2 NPs and within the thin intergranular glass film (with a thickness of approximately 7 Å) between ZrO2 NPs in the yttrium oxide‐doped NCGC. Interestingly, no obvious Y signals were detected in the amorphous SiO2 matrix. Density functional theory calculation results showed that Y3+ ions had a strong segregation tendency in the GB area and the segregation of Y3+ ions increased the work of separation of GB layer. These findings provide new understanding of the segregation behavior of dopant in glass‐ceramics, which may offer useful guidance for other researchers to tailor the properties of glass‐ceramics through GB engineering.

Facile Sonochemical Preparation of Au-ZrO2 Nanocatalyst for the Catalytic Reduction of 4-Nitrophenol

High-intensity ultrasonic waves have great potential for the green synthesis of various nanomaterials under mild conditions and offer an excellent alternative for hazardous chemical methods. Herein a facile approach for the eco-friendly synthesis of Au-ZrO2 nanocatalyst with a high catalytic activity using a facile ultrasonic method is presented. Gold (Au) in the nanosize regime was successfully deposited on the surface of solvothermally synthesized monodispersed ZrO2 nanoparticles (ZrO2 NPs) in a very short period of time (5 min) at room temperature. Spherical shape small size Au nanoparticles that are uniformly dispersed on the surface of ZrO2 nanoparticles were obtained. Notably, in the absence of ZrO2 nanoparticles, HAuCl4 could not be reduced, indicating that nano-sized ZrO2 not only acted as support but also helped to reduce the gold precursor at the surface. The as-prepared Au-ZrO2 nanocatalyst was characterized by various techniques. The Au-ZrO2 nanocatalyst served as a highly efficient reducing catalyst for the reduction of 4-nitrophenol. The reaction time decreased with increasing the amount of catalyst.

Solvothermal Preparation and Electrochemical Characterization of Cubic ZrO₂ Nanoparticles/Highly Reduced Graphene (HRG) based Nanocomposites.

A single-step solvothermal approach to prepare stabilized cubic zirconia (ZrO2) nanoparticles (NPs) and highly reduced graphene oxide (HRG) and ZrO2 nanocomposite (HRG@ZrO2) using benzyl alcohol as a solvent and stabilizing ligand is presented. The as-prepared ZrO2 NPs and the HRG@ZrO2 nanocomposite were characterized using transmission electron microscopy (TEM) and X-ray diffraction (XRD), which confirmed the formation of ultra-small, cubic phase ZrO2 NPs with particle sizes of ~2 nm in both reactions. Slight variation of reaction conditions, including temperature and amount of benzyl alcohol, significantly affected the size of resulting NPs. The presence of benzyl alcohol as a stabilizing agent on the surface of ZrO2 NPs was confirmed using various techniques such as ultraviolet-visible (UV-vis), Fourier-transform infrared (FT-IR), Raman and XPS spectroscopies and thermogravimetric analysis (TGA). Furthermore, a comparative electrochemical study of both as-prepared ZrO2 NPs and the HRG@ZrO2 nanocomposites is reported. The HRG@ZrO2 nanocomposite confirms electronic interactions between ZrO2 and HRG when compared their electrochemical studies with pure ZrO2 and HRG using cyclic voltammetry (CV).

Unctuous ZrO2 nanoparticles with improved functional attributes as lubricant additives

One of the main drawbacks in the application of metal-oxide nanoparticles as lubricant additives is their poor stability in organic media, despite the good anti-wear, friction-reducing and high-load capacity properties described for these materials. In this work, we present a novel procedure to chemically cap the surface of ZrO2 nanoparticles (ZrO2NPs) with long hydrocarbon chains in order to obtain stable dispersions of ZrO2NPs in non-aqueous media without disrupting their attributes as lubricant additives. C-8, C-10 and C-16 saturated flexible chains were attached to the ZrO2NP surface and their physical and chemical characterization was performed by transmission electron microscopy, thermogravimetric analysis, attenuated total reflectance Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy and solid-state nuclear magnetic resonance. The dispersion stability of the modified ZrO2NPs in non-aqueous media was studied using static multiple light scattering. Tribological tests demonstrated that dispersions of the long-chain capped ZrO2NPs in base lubricating oils exhibited low friction coefficients and improved the anti-wear properties of the base oil when compared with the raw lubricating oil.

Ultrasound-assisted surface treatment of ZrO2 with BSA and incorporating in PVC to improve the properties of the obtained nanocomposites: Fabrication and characterization

This paper describes the preparation of poly(vinyl chloride) (PVC) nanocomposites (NCs) reinforced with modified zirconia (ZrO2) nanoparticles (NPs). The ZrO2 NPs were defined as efficient filler for PVC NCs. For achieving the best dispersion and improvement of properties, the surface of ZrO2 NPs was modified by Bovine Serum Albumin (BSA). Carboxylic acids and amines are important functional groups of BSA which handle the grafting BSA on the surface of ZrO2 NPs. The PVC/ZrO2-BSA NCs were fabricated by incorporation of various amounts of the ZrO2-BSA NPs (3, 6 and 9wt%) into PVC matrix. All the above processes were accomplished by ultrasonication asa green and environmentally-friendly method. Also, the magnetic and mechanical stirrer was used for the preparation of samples but the results are not suitable and the aggregation was observed which indicated the use of ultrasonic irradiation is the best method for the preparation of NC. The products were characterized by Fourier transform infrared spectroscopy, Transmission electron microscopy, Field emission scanning electron microscopy, X-ray diffraction, Thermogravimetric analysis, Ultraviolet–visible spectroscopy, photoluminescence spectroscopy, energy dispersive X-ray spectroscopy, wettability, and mechanical tests. The achieved PVC/ZrO2-BSA NCs showed high thermal stability, good mechanical, optical and wettability properties compared to the pure PVC. In addition, among the obtained NCs, the PVC/ZrO2-BSA NC 6wt% showed the best improvement.

The synthesis of poly(vinyl chloride) nanocomposite films containing ZrO2 nanoparticles modified with vitamin B1 with the aim of improving the mechanical, thermal and optical properties

In the present investigation, solution casting method was used for the preparation of nanocomposite (NC) films. At first, the surface of ZrO2 nanoparticles (NPs) was modified with vitamin B1 (VB1) as a bioactive coupling agent to achieve a better dispersion and compatibility of NPs within the poly(vinyl chloride) (PVC) matrix. The grafting of modifier on the surface of ZrO2 was confirmed by Fourier transform infrared spectroscopy and thermogravimetric analysis (TGA). Finally, the resulting modified ZrO2 (ZrO2–VB1), was used as a nano-filler and incorporated into the PVC matrix to improve its mechanical and thermal properties. These processes were carried out under ultrasonic irradiation conditions, which is an economical and eco-friendly method. The effect of ZrO2–VB1 on the properties and morphology of the PVC matrix was characterized by various techniques. Field emission scanning electron microscopy and transmission electron microscopy analyses showed a good dispersion of fillers into the PVC matrix with the average diameter of 37–40 nm. UV–Vis spectroscopy was used to study optical behavior of the obtained NC films. TGA analysis has confirmed the presence of about 7 wt% VB1 on the surface of ZrO2. Also, the data indicated that the thermal and mechanical properties of the NC films were enhanced.

Structure and magnetic properties of multi-layered ZrO2 nanoparticles embedded in Al2O3 matrix and doped with 57Fe3+ ions

The multi-layered 3–8 nm ZrO2 particles doped with 57Fe3+ ions were synthesized by successive impregnations of Al2O3 with a solution of Zr isopropoxide and 57Fe acetylacetonate. This gave (FeZrO2)/Al2O3 samples containing ZrO2 (≈30 mass%) and different Fe content (0.06–0.26 mass%). By means of XRD, TEM and EDS techniques, it was found that the size of ZrO2 nanoparticles in the (FeZrO2)/Al2O3 samples increases in proportion to the Fe content. According to magnetic measurements and Mössbauer spectroscopy data, (FeZrO2)/Al2O3 samples contain two types of paramagnetic high-spin 57Fe3+ ions. The 57Fe3+ ions of type (I) are most probably adsorbed on the outer surface of ZrO2 nanoparticles and are responsible for the spin-lattice relaxation observed in the (FeZrO2)/Al2O3 samples. The 57Fe3+ ions of type (II) are embedded in the bulk of ZrO2 nanoparticles by replacing the octahedral Zr4+ positions to give a mixed oxide. As the Fe content in the (FeZrO2)/Al2O3 samples increases, the fraction 57Fe3+ ions of type (I) decreases, while that of 57Fe3+ ions of type (II) increases.

Surface functionalization of zirconium dioxide nano-adsorbents with 3-aminopropyl triethoxysilane and promoted adsorption activity for bovine serum albumin

Surface functionalization of zirconium dioxide (ZrO2) nano-adsorbents was carried out by using 3-aminopropyl triethoxysilane (APTES) as the modifier. The addition amount of APTES was varied to determine the optimum modification extent, and the bulk ZrO2 microparticles were also modified by APTES for comparison. Some means, such as TEM, XRD, FT-IR, XPS and TG-DSC were used to character these ZrO2 particles. The results showed that the APTES molecules were chemically immobilized on the surface of ZrO2 nanoparticles via ZrOSi bonds, and the nano-ZrO2 samples showed larger special surface area. In the adsorption of bovine serum albumin (BSA), nano-ZrO2 samples exhibited enhanced adsorption activity, and APTES modified nano-ZrO2 with proper APTES content presented the best adsorption property. Under the same adsorption conditions, the equilibrium adsorption capacity of BSA on APTES-ZrO2-2 was almost 2.3 times as that on pristine nano-ZrO2 and 3.0 times as on bulk ZrO2 microparticles. The increased adsorption capacity of APTES-ZrO2 nano-adsorbents can be attributed to the chemical interaction between amino and carboxyl groups at APTES-ZrO2/BSA interface. The pH-dependent experiments showed that the optimum pH value for the adsorption and desorption was 5.0 and 9.0, respectively, which suggested that the adsorption and release of BSA could be controlled simply by adjusting the solution pH condition.

A Highly Efficient ZrO2 Nanoparticle Based Electrochemical Sensor for the Detection of Organophosphorus Pesticides

AbstractA sensitive electrochemical method for square‐wave voltammetric detection of organophosphate (OP) compounds was developed based on zirconia (ZrO2) nanoparticles modified electrode. The electrode was fabricated using electrochemical deposition and characterized by scanning electron microscopy (SEM), which confirmed the successful formation of nanoparticles. Due to the strong affinity of ZrO2 with the phosphoric group, nitroaromatic OPs can strongly bind to the surface of ZrO2 nanoparticles (ZrO2NPs). Under optimized operational conditions, SWV was employed for Omethoate (a model of OP compounds) detection with 5 min absorption, which showed a wide detection range from 98.5 pmol·L−1 to 985 nmol·L−1, with a detection limit as low as 52.5 pmol·L−1. This electrochemical sensor has good selectivity, stability and reproducibility, and great potential in the detection of OP compounds in agriculture area.

Novel polyvinylpyrrolidone nanocomposites with dispersed poly(amide-imide)/nano-ZrO2 as new nano-filler: morphology, thermal and optical properties

In this paper, ultrasonic technique and a biocompatible coupling agent were used for the surface modification of ZrO2 nanoparticles (NPs). The grafting of N-trimellitylimido-l-leucine as bioactive and biocompatible coupling agent on the surface of ZrO2 NPs was confirmed by Fourier transmission infrared spectroscopy and thermogravimetric analysis. Subsequently, the modified NPs were incorporated into the poly(amide-imide) (PAI) matrix through good dispersion. Therefore, poly(amide-imide)/nano-ZrO2 nanocomposite (PAI/nano-ZrO2) was synthesized via ultrasonic technique. Field emission scanning electron microscopy and transmission electron microscopy images of the obtained PAI/nano-ZrO2 illustrated nanostructured morphology. Then, PAI/nano-ZrO2 was used as a nano-filler and was embedded into the polyvinylpyrrolidone (PVP) in various weight percent to form PVP NCs to improve its properties. These NCs were investigated by different analyses. Change in the results of analysis when compared to the pure PVP confirmed that there are good interactions between nano-filler and the PVP matrix as a result of hydrogen bonding. The thermal stability of the PVP was enhanced with the addition of small amounts of nano-filler. Also, the incorporation of the PAI/nano-ZrO2 influenced the UV–Vis absorption of the pure PVP.

Preparation and characterization of reinforced poly(vinyl alcohol) films by a nanostructured, chiral, L-leucine based poly(amide-imide)/ZrO2 nanocomposite through a green method

Abstract In the present investigation, at first, the surface of ZrO2 nanoparticles was modified with a bioactive and biocompatible diacid based on leucine amino acid as a coupling agent. The grafting of diacid on the surface of ZrO2 was confirmed by Fourier transform infrared spectroscopy and thermogravimetric analysis. Then, the synthesis of poly(amide-imide)/ZrO2 nanocomposite (PAI/ZrO2 NC) was performed through ultrasonic technique. The obtained NCs demonstrated good thermal stability. Field emission scanning electron microscopy and transmission electron microscopy analysis showed that the average diameter of NP was around 15–20 nm. Finally, the resulting NC, was used as a nano-filler and was incorporated into the poly(vinyl alcohol) (PVA) in order to improve its mechanical and thermal properties. The PVA/PAI–ZrO2 NC films were characterized by different techniques. The data indicated that the thermal and mechanical properties of the PVA/PAI–ZrO2 NC were enhanced. It was attributed to the good dispersion of filler into the PVA matrix as a result of hydrogen bonding.

Surface modification of ZrO2 nanoparticles with styrene coupling agent and its effect on the corrosion behaviour of epoxy coating

The surface of ZrO2 nanoparticles was modified by styrene coupling grafting method to improve the dispersion and interaction of the nanoparticles with the epoxy coating in which the modified ZrO2 nanoparticles were used as an additive. The grafting performance and microstructure of the nano-ZrO2/epoxy coating were analyzed by Fourier transformation infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The corrosion behavior of the nano-ZrO2/epoxy coating on mild steel was evaluated in neutral 3.5 wt% NaCl solution using electrochemical impedance spectroscopy (EIS). Both the coating capacitance and coating resistance fitted by the equivalent circuit from EIS were used to evaluate the protective performance of the coating towards the mild steel. The results show a superior stability and efficient corrosion protection by the modified ZrO2 nanoparticles. The epoxy coating containing 2 wt% modified ZrO2 nanoparticles exhibited the best corrosion performance among all the coating specimens. This research may provide an insight into the protection of mild steel using modified epoxy coatings.

Radiolysis of Water on ZrO2 Nanoparticles

The radiolysis of water adsorbed on the surface of ZrO2 nanoparticles has been examined using a variety of spectroscopic techniques. Irradiations were performed with fast electrons, γ rays, and 5 MeV helium ions. Infrared spectroscopic analysis of the surface reveals little change in the surface stoichiometry, which probably indicates the relative insensitivity of this technique to the doses given. X-ray photoelectron spectroscopy reveals a loss in the relative number of terminal OH groups on the surface with radiolysis. The maximum production of excess H2 is found when a single water layer or less is adsorbed on the terminal OH surface layer. Little or no H2 seems to come from the surface-bound OH groups.

Fabrication of transparent polymer-matrix nanocomposites with enhanced mechanical properties from chemically modified ZrO2 nanoparticles

Optically transparent nanocomposites with enhanced mechanical properties were fabricated using stable dispersions of sub 10 nm ZrO2 nanoparticles. The ZrO2 dispersions were mixed with a commercially available bisphenol-A-based epoxy resin (RIMR 135i) and cured with a mixture of two amine-based curing agents (RIMH 134 and RIMH 137) after complete solvent removal. The colloidal dispersions of ZrO2 nanoparticles, synthesized through a non-aqueous approach, were obtained through a chemical modification of the ZrO2 nanoparticle surface, employing different organic ligands through simple mixing at room temperature. Successful binding of the ligands to the surface was studied utilizing ATR–FT-IR and thermogravimetric analysis. The homogeneous distribution of the nanoparticles within the matrix was proven by SAXS and the observed high optical transmittance for ZrO2 contents of up to 8 wt%. Nanocomposites with a ZrO2 content of only 2 wt% showed a significant enhancement of the mechanical properties, e.g., an increase of the tensile strength and Young’s modulus by up to 11.9 and 12.5%, respectively. Also the effect of different surface bound ligands on the mechanical properties is discussed.