Search Results (32)

This study presents the synthesis, characterization, and application of magnetic magnetite–zirconium dioxide (Fe₃O₄–ZrO₂) nanoparticles as an efficient nanoadsorbent for fluoride removal from water. The nanoparticles were synthesized using a wet chemical co-precipitation method with Fe/Zr molar ratios of 1:1, 1:2, and 1:4, and characterized using Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDS). FTIR analysis confirmed the presence of Fe₃O₄ and ZrO₂ functional groups, while XRD showed that increased Zr content led to a dominant amorphous phase. SEM and EDS analyses revealed quasi-spherical and elongated morphologies with uniform elemental distribution, maintaining the designed Fe/Zr ratios. Preliminary adsorption tests identified the Fe/Zr = 1:1 (M1) nanoadsorbent as the most effective due to its high surface homogeneity and optimal fluoride-binding characteristics. Adsorption experiments demonstrated that the material achieved a maximum fluoride adsorption capacity of 70.4 mg/g at pH 3, with the adsorption process best fitting the Temkin isotherm model (R² = 0.987), suggesting strong adsorbate–adsorbent interactions. pH-dependent studies confirmed that adsorption efficiency decreased at higher pH values due to electrostatic repulsion and competition with hydroxyl ions. Competitive ion experiments revealed that common anions such as nitrate, chloride, and sulfate had negligible effects on fluoride adsorption, whereas bicarbonate, carbonate, and phosphate reduced removal efficiency due to their strong interactions with active adsorption sites. The Fe₃O₄–ZrO₂ nanoadsorbent exhibited excellent magnetic properties, facilitating rapid and efficient separation using an external magnetic field, making it a promising candidate for practical water treatment applications. Full article

Calcium ion sensors are essential in clinical diagnosis, particularly in the management of chronic kidney disease. Multiple approaches have been developed to measure calcium ions, including flame photometry and ion chromatography. However, these devices are bulky and require specialized staff for operation and evaluation. The integration of all-solid-state ion-selective determination allows the design of miniaturized and low-cost sensing that can be used for the continuous monitoring of electrolytes. However, clinical use has been limited due to the low electrochemical stability and selectivity and high noise rate. This manuscript reports for the first time a novel miniaturized Ca²⁺ ion-selective sensor, developed by using a two-layer nanocomposite thin film (5 µm thick). The device consists of functionalized silica nanoparticles embedded in a poly(vinyl chloride) (PVC) film, which was deposited onto a nanoporous zirconium silicate nanoparticle layer that served as the sensing surface. Systematic evaluation revealed that perfluoroalkane-functionalized silica nanoparticles enhanced Ca²⁺ selectivity by minimizing K⁺ diffusion, confirmed by both potentiometric measurements and quartz microbalance studies. The final sensor demonstrated a super-Nernstian sensitivity of 37 mV/Log[Ca²⁺], a low signal drift of 28 µV/s, a limit of detection of 1 µM, and exceptional selectivity against Na⁺, K⁺, and Mg²⁺ ions. Long-term testing showed stable performance over three months of continuous operation. Clinical testing was conducted on patients with chronic kidney disease. An accurate real-time monitoring of electrolyte dynamics in dialysate samples was observed, where final concentrations matched those observed in physiological conditions. Full article

Deodorants and antiperspirants available on the market are designed to reduce the discomfort associated with sweating. This study examined the types of active substances contained in deodorants and antiperspirants from international cosmetic brands available in Poland (part of the EU market) and the frequency of their use. Product compositions were analysed based on INCI (International Nomenclature of Cosmetic Ingredients) product labels. The investigation included the following 170 cosmetic products: 50 spray deodorants (from 50 different brands); 50 roll-on deodorants (from 50 brands); 20 stick deodorants (from 20 brands); 40 roll-on antiperspirants (from 40 brands); and 10 stick antiperspirants (from 10 brands). The most popular active components were Triethyl Citrate (51/120 formulations; 42.5%), followed by Alcohol (25.8%), Ethylhexylglycerin (25.0%), Caprylyl Glycol (12.5%), and Potassium Alum (10.0%). Antiperspirant products were dominated by aluminium-based compounds, with the most frequently used being the following aluminium-based salts: Aluminium Chlorohydrate (67.5%), Aluminium Sesquichlorohydrate (25.0%), and Aluminium Chloride (12.5%). In contrast, aluminium–zirconium complexes, such as Aluminum Zirconium Tri-, Penta-, and Octachlorohydrex Gly, were rarely used by cosmetic manufacturers. Additionally, composition complexity, i.e., the number of deodorizing and anti-sweating ingredients per single formulation, was examined for roll-on deodorants, stick deodorants, and roll-on antiperspirants. All tested antiperspirants and most deodorants contained fragrance-imparting ingredients; the most popular were Parfum/Fragrance, Limonene, Linalool, Citronellol, Citral, Benzyl Salicylate, Hexyl Cinnamal, and Geraniol. Full article

In this study, cyclic polarization (CP) measurements were conducted on the molybdenum-based titanium–zirconium–molybdenum (TZM) alloy in 3.5% NaCl solutions under varying pH conditions, and the results were compared with those of pure molybdenum. No passivity breakdown was observed during cyclic polarization in acidic and neutral chloride solutions. The surface film formed on the TZM, and pure Mo samples displayed a dual-layered structure, comprising an inner layer of p-type semiconductivity and an outer layer of n-type semiconductivity. The defect density of the n-type layer ranged from 7.5 × 10¹⁷ to 7.5 × 10¹⁹ cm⁻³, while the p-type layer had a carrier density ranging from 2 × 10¹⁸ to 9 × 10¹⁹ cm⁻³. The pure molybdenum samples demonstrated lower passive current densities, lower charge carrier densities, and higher impedance than the TZM alloy. The lower corrosion resistance of TZM alloy could be attributed to the higher dislocation density, which acted as short-circuit paths for Mo diffusion, and the presence of carbides that exhibited a microgalvanic effect. Overall, this study clarified that the localized corrosion reported in the literature was not due to the breakdown of the passive layer but may be linked to the heterogeneous microstructure. Full article

The increasing global production and utilization of zirconium (Zr) compounds, including zirconium chloride (ZrCl₄) and zirconium oxide nanoparticles (NPs-ZrO₂), raises concerns about their potential environmental impact. This study investigated the toxicity mechanisms of ZrCl₄ and NPs-ZrO₂ on the aquatic plant Lemna minor. The physicochemical properties of NPs-ZrO₂ in the test medium were characterized, revealing concentration-dependent changes in the hydrodynamic diameter, zeta potential, and solubility over time. The analysis of Zr speciation showed the predominance of Zr(OH)₄(aq) species from ZrCl₄. Plants of L. minor exposed to ZrCl₄ and NPs-ZrO₂ exhibited differential Zr bioaccumulation, growth inhibition, oxidative stress, and antioxidant responses. ZrCl₄ induced a higher toxicity than NPs-ZrO₂, with bioaccumulation strongly correlating with adverse effects. The differential toxicity impact between these two Zr-compounds was also determined by the lowest observed-effect doses for growth and biochemical parameters. The scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy confirmed internalization of NPs-ZrO₂ and Zr uptake in the L. minor plant. Therefore, these findings highlighted the importance of chemical speciation, environmental transformations, and biological responses in assessing the ecological impact of Zr-compounds for effective risk assessment and management strategies for protecting aquatic ecosystems. Full article

Wettability is recognized as an important property of implant surfaces for ensuring improved biological responses. However, limited information exists on how bone grafting procedures including materials influence the hydrophilic behavior of implant surfaces. This in vitro study aimed to investigate the influence of two bovine grafting materials after hydration on the wettability of four different disk surfaces: commercially pure titanium (CP-Ti), titanium–zirconium dioxide (TiZrO₂-Cerid^®), zirconia (SDS^®), and niobium. Wettability tests were performed on each of the four implant surfaces with a solution of 0.9% sodium chloride after mixture with W-bone^TM (Group A) or Bio-Oss^® (Group B) or 0.9% sodium chloride alone (Group C). In total, 360 contact angle measurements were completed with n = 30 per group. Statistical analysis was performed using a one-way analysis with variance (ANOVA) test with a significant mean difference at the 0.05 level. For pure titanium, Group A demonstrated increased hydrophilicity compared to Group B. Both TiZrO₂ and zirconia showed significant differences for Groups A, B and C, exhibiting a decrease in hydrophilicity after the use of bovine grafting materials compared to titanium surfaces. Niobium remained consistently hydrophobic. In summary, this study revealed that bovine grafting materials may diminish the hydrophilicity of zirconia surfaces and exert varied effects on titanium and niobium. These findings contribute to the understanding of implant surface interactions with grafting materials, offering insights for optimizing biological responses in implantology. Full article

Polycarbonate/acrylonitrile butadiene styrene (PC/ABS) blends are widely used as engineering plastic alloys; however, they have a low fire safety level. To improve the flame-retardant property of PC/ABS, a zirconium-based metal-organic framework material (UiO-66) was synthesized with zirconium chloride and terephthalic acid and used as a flame-retardant cooperative agent. Its flame-retardant performance and mode of action in the PC/ABS blends were carefully investigated. The results showed that UiO-66 had good thermal stability and delayed the pyrolysis of the materials, thus significantly enhancing the efficiency of intumescent flame retardants. By compounding 7.0 wt% hexaphenyloxy-cyclotri-phosphazene (HPCTP) with 3.0 wt% UiO-66, the PC/ABS blends reached a limiting oxygen index value of 27.0% and V0 rating in the UL-94 test, showing significantly improved resistance to combustion dripping. In addition, UiO-66 enhanced the smoke and heat suppression characteristics of the intumescent flame-retardant materials. Finally, the flame-retardant mode of action in the blends was indicative of UiO-66 having a cooperative effect on the flame-retardant performance of PC/ABS/HPCTP materials. This work provides good ideas for further development of the flame-retardant ABS/PC. Full article

Crystal violet (CV) is an organic chloride salt and a triphenylmethane dye commonly used in the textile processing industry, also being used as a disinfectant and a biomedical stain. Although CV is widely used, it is carcinogenic to humans and is retained by industrial-produced effluent for an extended period. The different types of metal oxide (MO_x) have impressive photocatalytic properties, allowing them to be utilized for pollutant degradation. The role of the photocatalyst is to facilitate oxidation and reduction processes by trapping light energy. In this study, we investigated different types of metal oxides, such as titanium dioxide (TiO₂), zinc oxide (ZnO), zirconium dioxide (ZrO₂), iron (III) oxide (Fe₂O₃), copper (II) oxide (CuO), copper (I) oxide (Cu₂O), and niobium pentoxide (Nb₂O₅) for the CV decomposition reaction at ambient conditions. For characterization, BET and Raman spectroscopy were applied, providing findings showing that the surface area of the anatase TiO₂ and ZnO were 5 m²/g and 12.1 m²/g, respectively. The activity tests over TiO₂ and ZnO catalysts revealed that up to ~98% of the dye could be decomposed under UV irradiation in <2 h. The decomposition of CV is directly influenced by various factors, such as the types of MO_x, the band gap–water splitting relationship, and the recombination rate of electron holes. Full article

In addressing eutrophication and enhancing water quality, this study builds upon previous research involving the development of an Efficient Phosphorus Removal Composite (EPRC), a material created using modified industrial wastes (steel slag and fly ash) as adsorbent substrates, supplemented with a binder and porosity-forming agent. In this investigation, the EPRC was further enhanced through the addition of zirconium oxychloride octahydrate, resulting in the production of Zr-EPRC particles as reinforced phosphorus removal materials. Comparative experiments were conducted to assess different methods for preparing Zr-EPRC, the static adsorption performance, and dynamic adsorption behavior. The optimal preparation of Zr-EPRC was achieved by separately modifying the base materials, steel slag and fly ash. Loading with mass ratios of zirconium chloride octahydrate to fly ash and steel slag at 0.4 and 0.6, respectively, for a duration of 12 h at a pH of 10 yielded the best results. In static adsorption experiments conducted at temperatures of 15 °C, 25 °C, and 35 °C, Zr-EPRC exhibited saturated phosphorus adsorption capacities of 11.833 mg/g (variance = 0.993), 12.550 mg/g (variance = 0.993), and 13.462 mg/g (variance = 0.996), respectively. Zr-EPRC emerges as a cost-effective and readily available solution with promising stability for general wastewater treatment applications, contributing significantly to the mitigation of eutrophication and the improvement of water quality. Full article

The SEM-EDX method was used to investigate the structure and morphology of organic–inorganic hybrids containing zirconium, boron and phosphorus compounds, synthesized by the sol–gel method. We started by using, for the first time together, zirconyl chloride hexa-hydrate (ZrOCl₂·6H₂O), phenyl phosphinic acid and triethyl borate as precursors and reagents, at different molar ratios. The obtained hybrids showed a very high thermal stability and are not soluble in water or in organic solvents. As a consequence, such hybrid solid materials are suitable for applications at high temperatures. The obtained hybrids have complex 3D structures and form organic–inorganic networks containing Zr-O-Zr, Zr-O-P and Zr-O-B bridges. Such organic–inorganic networks are also expected to form supramolecular structures and to have many potential applications in different fields of great interest such as catalysis, medicine, agriculture, energy storage, fuel cells, sensors, electrochemical devices and supramolecular chemistry. Full article

In recent years, multifunctional hydrogel nanoplatforms for the synergistic treatment of tumors have received a great deal of attention. Here, we prepared an iron/zirconium/polydopamine/carboxymethyl chitosan hydrogel with Fenton and photothermal effects, promising for future use in the field of synergistic therapy and prevention of tumor recurrence. The iron (Fe)–zirconium (Zr)@ polydopamine (PDA) nanoparticles were synthesized by a simple one-pot hydrothermal method using iron (III) chloride hexahydrate (FeCl₃•6H₂O), zirconium tetrachloride (ZrCl₄), and dopamine, followed by activation of the carboxyl group of carboxymethyl chitosan (CMCS) using 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC)/N(4)-hydroxycytidine (NHS). Finally, the Fe–Zr@PDA nanoparticles and the activated CMCS were mixed to form a hydrogel. On the one side, Fe ions can use hydrogen peroxide (H₂O₂) which is rich in the tumor microenvironment (TME) to produce toxic hydroxyl radicals (•OH) and kill tumor cells, and Zr can also enhance the Fenton effect; on the other side, the excellent photothermal conversion efficiency of the incorporated PDA is used to kill tumor cells under the irradiation of near-infrared light. The ability of Fe–Zr@PDA@CMCS hydrogel to produce •OH and the ability of photothermal conversion were verified in vitro, and swelling and degradation experiments confirmed the effective release and good degradation of this hydrogel in an acidic environment. The multifunctional hydrogel is biologically safe at both cellular and animal levels. Therefore, this hydrogel has a wide range of applications in the synergistic treatment of tumors and the prevention of recurrence. Full article

Background: Root canal sealers and repair materials should have the desirable physical, chemical, and biological characteristics, and an antibacterial effect if possible. There is little information available on the biocompatibility of new sealers on the market. Fourier transform infrared spectroscopy (FTIR) can offer trustworthy data to examine chemical structures; another technique for revealing the elements in the constituents that may contribute to the cytotoxicity of these sealers is scanning electron microscopy (SEM), with the goal of elemental mapping utilizing energy-dispersive X-ray spectroscopy (EDX). Methodology: All the root canal sealers were mixed as per the manufacturers’ instructions and allowed to set in molds for 24 h. Then, the samples were placed into an incubator (Memmert GmbH + Co. KG, Schwabach, Germany for 72 h, in a moist environment to allow complete chemical setting of the sealers. The organic and inorganic components of the sample were identified using FTIR with the wavelength length in the infra-red region measuring 400–450 nm. The finely crushed samples were coated with gold metal; following that, the sealer samples were examined under a scanning electron microscope (SEM) at 5000×, 10,000×, and 20,000× magnification, followed by energy-dispersive X-ray spectroscopy. Results: The surfaces of BioRoot and DiaRoot sealers revealed a relatively uniform distribution of irregular micro-sized particles aggregated in clusters, with the particle size ranging from 1 to 65 µm and 0.4 to 55 µm, respectively. OneFill, iRoot, and CeraSeal demonstrated irregularly shaped particles with particle sizes of 0.5 to 105 µm, 0.5 to 195 µm, and 0.3 to 68 µm, respectively. The EDX microanalysis revealed that oxygen, calcium, and carbon were found in all the tested sealer materials. Silicone and zirconium were absent in DiaRoot, but DiaRoot contained fluoride and ytterbium. Moreover, aluminum was noted in DiaRoot, One Fill, and CeraSeal, and chloride was only observed in BioRoot. FTIR analysis revealed strong absorption bands at 666 cm⁻¹ and 709 cm⁻¹ in BioRoot. Bands at 739 cm⁻¹, 804 cm⁻¹, 863 cm⁻¹, 898 cm⁻¹, and 1455 cm⁻¹ were observed in DiaRoot. Bands at 736 cm⁻¹ and 873 cm⁻¹ in OneFill suggested the presence of C-H bending. Similarly, bands were observed at 937 cm⁻¹, 885 cm⁻¹, 743 cm⁻¹, and 1455 cm⁻¹ in iRoot, representing C-H stretching. Conclusions: All root canal sealers had diverse surface morphologies that contained irregular, micro-sized particles that were uniformly distributed, and they lacked heavy metals. All the experimental sealers comprised mainly calcium, oxygen, and carbon. Full article

A sustainable separation concept for large-scale recycling of NdFeB magnets under atmospheric pressure was developed by utilizing a combination of two separation concepts known from the literature: (I) selective pre-separation by in situ chlorination and evaporation of ground oxidized NdFeB material and (II) subsequent distillation for high-purity recovery of all recyclable chlorinated material components, especially its Rare Earth Elements (REEs). Theoretically, simplified estimations of the time conversion curves at 1173 K, 1273 K, and 2000 K of a single particle resulted in the idea of realizing chlorination in some kind of combustion chamber, fluidized bed, or continuous combustion chamber. After chlorination, all non-volatile components, such as REE chlorides, are condensed out of the vapor phase in a single-stage phase separator. For subsequent fine separation by distillation (1292–1982 K for Rare Earth Chlorides and 418–867 K at 2500 kPa for boron and zirconium chloride recovery), simplified simulations were performed in a total-reflux column under ideal phase equilibrium conditions to show the estimated minimum separation effort. Using two composition examples from the literature, high-purity separation of the major Rare Earth Chlorides within a twelve-stage distillation column as a residual heavy boiling product has been demonstrated to be potentially technically feasible. Full article

Tenofovir disoproxil fumarate (TDF) is an antiretroviral medication with significant curative effects, so its quantitative detection is important for human health. At present, there are few studies on the detection of TDF by electrochemical sensors. This work can be a supplement to the electrochemical detection of TDF. Moreover, bare electrodes are susceptible to pollution, and have high overvoltage and low sensitivity, so it is crucial to find a suitable electrode material. In this work, zirconium oxide (ZrO₂) that has a certain selectivity to phosphoric acid groups was synthesized by a hydrothermal method with zirconyl chloride octahydrate as the precursor. A composite modified glassy carbon electrode for zirconium oxide-chitosan-multiwalled carbon nanotubes (ZrO₂-CS-MWCNTs/GCE) was used for the first time to detect the TDF, and achieved rapid, sensitive detection of TDF with a detection limit of sub-micron content. The ZrO₂-CS-MWCNTs composite was created using sonication of a mixture of ZrO₂ and CS-MWCNTs solution. The composite was characterized using scanning electron microscopy (SEM) and cyclic voltammetry (CV). Electrochemical analysis was performed using differential pulse voltammetry (DPV). Compared with single-material electrodes, the ZrO₂-CS-MWCNTs/GCE significantly improves the electrochemical sensing of TDF due to the synergistic effect of the composite. Under optimal conditions, the proposed method has achieved good results in linear range (0.3~30 μM; 30~100 μM) and detection limit (0.0625 μM). Moreover, the sensor has the merits of simple preparation, good reproducibility and good repeatability. The ZrO₂-CS-MWCNTs/GCE has been applied to the determination of TDF in serum and urine, and it may be helpful for potential applications of other substances with similar structures. Full article

In this study, by adding zirconium anhydride (ZrO₂) particles to a solution of N–methylmorphorphine–N–oxide (NMMO) and bamboo cellulose (BC), we used interfacial polymerization (IP) to obtain regenerated cellulose nanofiltration membranes (IP–ZrO₂/BC–NFMs) that exhibited high water flow and rejection of salts and dyes. During interfacial polymerization, anhydrous piperazine (PIP) was used as the waterborne monomer, and 1,3,5–trimesoyl chloride (TMC) and n–hexane were used as the organic phase. The procedure was adjusted by analyzing the impacts of the concentrations of the water and organic phase monomers and the reaction duration on the performance of the developed IP–ZrO₂/BC–NFMs. The chemical structures and morphologies of the as–obtained IP–ZrO₂/BC–NFMs were examined using various characterization techniques. The performance of these membranes for removal of inorganic salts and dyes as well as their water flow were investigated. IP–ZrO₂/BC–NFMs obtained at a pressure of 0.5 MPa, PIP concentration of 1.5 wt.%, TMC concentration of 0.15 wt.%, and polymerization period of 2 min displayed the highest water flux (55.12 LMH) and the best desalination effect (NaCl rejection rate = 19.15%). Over 90% of both Methyl Blue (MB) and Congo Red (CR) dyes were intercepted. We demonstrated that the addition of ZrO₂ to nanofiltration membranes significantly enhanced the water flow of the IP–ZrO₂/BC–NFMs as well as the salt ion rejection rate. Full article