Search

This work aims to modify the surface characteristics of cerium oxide (ceria, CeO 2) nanoparticles using different surface modification strategies for improved CeO 2 nanoparticle dispersion and suspension stability. Analysis and discussion were conducted on the two surface modification processes used by a cationic surfactant like hexadecyl cetyltrimethylammonium bromide (CTAB) and a silane agent like tetraethyl orthosilicate (TEOS). Untreated CeO 2 was used as reference material. The dispersion effect of surface-modified CeO 2 nanoparticles at different pHs was determined by zeta potential measurements. Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Particle size analysis (PSA), Thermogravimetric analysis (TGA), Scanning electron microscope (SEM), Brunauer–Emmett–Teller analysis (BET), and X-ray diffraction (XRD) were used to confirm the efficacy of the surface modification of CeO 2 nanoparticles. First, the results obtained in this experimental work demonstrate that both advanced modifications greatly enhance the dispersion and suspension stability of surface-modified CeO 2 nanoparticles in comparison with untreated CeO 2 nanoparticles. Second, it is also shown that the surface-modified CeO 2 nanoparticles obtained through a silanization surface process with TEOS silane agent had a better dispersion effect and dispersion stability than the surface-modified CeO 2 nanoparticles obtained by surface modification with CTAB cationic surfactant. These results can help better understand how advanced surface modifications can assist the application of well-dispersed CeO 2 nanoparticles in technological applications. [Display omitted] • Surface modification significantly improved the aqueous dispersion and stability of CeO 2 nanoparticles. • The modification improved the CeO 2 dispersion by increasing the spacing and negative charge. • CeO2 dispersion was optimal at a specific pH, with a significant effect of pH. • The modification strategy is crucial for the performance of CeO 2 in technological applications. [ABSTRACT FROM AUTHOR]

Ni 1-x Ag x O nanoparticles (NPs) with x = 0.00, 0.02, 0.04, 0.06, and 0.08) were fabricated using the composite hydroxide mediated (CHM) method. The effects of Ag doping on the structural, magnetic, and antimicrobial characteristics of NiO NPs have been reported. The stretching mode of the Ni–O molecules was identified at 443 cm−1 in the Fourier transform infrared spectra. The aggregation of nanoparticles with different sizes and shapes is seen under transmission and scanning electron microscopes. The blocking temperature (T B) peak in zero-field cooled (ZFC) magnetization curves display the magnetization from the core of NPs. This peak is absent for the samples with x = 0.00 and 0.02 , which show instead a small net magnetization from the antiferromagnetic core of these NPs. However, a T B peak was found for the samples with x = 0.04 , 0.06 and 0.08 , at 22, 72, and 65 K, respectively, which indicates that the magnetization is induced from the AFM core of NiO NPs for higher Ag doping. With an increasing concentration of Ag in the NiO NPs, the net magnetization did increase and a maximum was found for x = 0.04 at 300 K. For a higher doping concentration of 8 % Ag, a sharp decrease in magnetization was observed. Furthermore, the efficacy and synergistic effect of Ag doping had been analyzed for the effective improvement of the antibacterial properties of NiO NPs. Pure and Ag-doped NiO NPs were exploited to assess their anti-microbial activity against Enterobacter sp., E. coli, P. aeruginosa, and S. pyrogens. The study revealed that anti-bacterial or anti-biofouling properties were introduced as an additional attribute to NiO NPs by incorporation of Ag ions due to its inherent nature as an antimicrobial agent and enhanced its capability to sterilize microbial pathogens. [ABSTRACT FROM AUTHOR]

In light of environmental problems such as the depletion of hydrocarbon resources and global warming, the use of environment-friendly power production has become crucial nowadays. Hydrogen can serve as a globally friendly energy source because the byproduct of hydrogen combustion is only water. By a hydrothermal approach, we synthesized barium manganese oxide (BaMnO 3) embedded on reduced graphene oxide (rGO) as a competent electrocatalyst for OER. We utilized X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive x-rays (EDX), Brunauer Emmette Teller (BET) and Raman to determine the crystal structure, morphology, elemental composition, surface area and lattice phenomena of the fabricated rGO/BaMnO 3 nanocomposite. The BaMnO 3 agglomerated nanoparticles were incorporated into the mesoporous hollow carbon nanosheets to form amorphous textured embedded rGO/BaMnO 3. This enhanced the intrinsic reactivity of rGO/BaMnO 3 nanocomposite for the oxygen evolution reaction (OER) in addition to increasing the effective surface area of the electrolyte. The electrochemical outcomes demonstrate that synthesized nanocomposite exhibited an impressive Tafel slope (36 mV dec−1), lowest overpotential (202 mV) and remarkable stability over 35 h. Therefore, the fabricated nanocomposite displayed exceptional efficiency in OER process as well as for numerous other future applications. [Display omitted] • RGO/BaMnO 3 nanocomposite was fabricated via facile hydrothermal technique. • Various analytical techniques were conducted to evaluate the material's properties. • The developed material exhibit OER process, which can be initiated by applied electrocatalyst at 0.50 V vs RHE using 1.0 ssM KOH solution. • The rGO/BaMnO 3 nanocomposite exhibits the minimal overpotential (202 mV) with low Tafel slope (36 mV dec−1). • RGO decorated BaMnO 3 (rGO/BaMnO 3) exhibiting remarkable stability of 35 h tested via chronoamperometry. [ABSTRACT FROM AUTHOR]

Chemical mechanical polishing/planarization (CMP) slurry contains mainly abrasive grains (primary particles) with few aggregations (secondary particles). Measuring the particle size distribution (PSD) of CMP slurry is crucial for improving the productivity of the CMP process. For the quality management of CMP slurry, it is necessary to evaluate both the sizes and quantities of both the primary and secondary particles. Conventional PSD analysis methods, except for image analysis, face challenges in identifying primary and secondary particles for PSD measurements. For image analysis, the particles must be transferred from a suspension to a substrate using the conventional sampling method; however, this creates aggregates, resulting in a change in the PSD of the particles on the substrate compared to that in suspension under poly-dispersed conditions. Thus, this study proposed a novel particle sizing method using nanoparticle chip (NPC) to assist in the image analysis of the PSD. The NPC can pick up a single particle in a small volume droplet to avoid aggregation and maintain the poly-dispersed condition of the particles in suspension. The primary and secondary particles can be identified using scanning electron microscope (SEM) or atomic force microscope (AFM), and the PSD can be evaluated by measuring the area and height of the particles. Further, the quantities of both the primary and secondary particles can be counted from the substrate. This study presented a comparison of the diameter measurements using NPC and the conventional method. The results show that the NPC identified the primary and secondary particles and decreased the measurement error of the particle diameters. Consequently, the NPC proves to be superior to the conventional method for use in the PSD analysis of CMP slurry. • Nanoparticle chip (NPC) sizing for CMP slurry particle size distribution (PSD). • NPC avoids particle aggregation, maintains PSD in poly-dispersed suspension. • Primary and secondary particles separated to lower equivalent height diameter error. • PSD of primary particles and number of secondary particles measured using NPC. [ABSTRACT FROM AUTHOR]

Probing a cell by fluorescence imaging is very convenient. We have observed that tagging of DNA with some organic dye molecules enhances fluorescence properties. This property of DNA can be utilised to enhance cell imaging quality to track the cell in better way for diagnosis as well as therapy. We have shown internalisation of DNA functionalized cobalt-ferrite nanoparticles (CF-DNA NPs) with cells is better compared to free cobalt-ferrite nanoparticles (CF NPs). Therefore, CF NPs were functionalized by DNA (CF-DNA) and tagged them with a fluorophore like RITC for improvement of cell tracking by fluorescence imaging. Cell imaging and cytotoxicity effects were compared by treating the human mammary carcinoma cells (MDA MB-231) with CF NPs and CF-DNA NPs. An investigation was made on applicability of hyperthermia therapy for these particles under AC magnetic field. A significant enhancement in fluorescence contrast of cancer cells was observed in case of CF-DNA NPs compared to CF NPs and both the particles show less cytotoxic effect for normal cells. A significant cell death and change in cell morphology after hyperthermia treatment was observed by phase contrast microscope and scanning electron microscope (SEM). Monitoring the treatment in a selective region is helped by this technique with the use of a very small quantity of theranostic material. This new treatment protocol may open a new avenue in cancer therapy. [Display omitted] [ABSTRACT FROM AUTHOR]

The Sr-doped ZnO nanoparticles have been synthesized by the chemical precipitation method at room temperature. The prepared nanoparticles are annealed at 500 °C for 4 h. The nanoparticles have been characterized using X-ray diffraction (XRD) technique, scanning electron microscope and UV–Vis spectroscopy. The XRD studies reveal the formation of a wurtzite geometry. The crystallite size, dislocation density and strain are examined as a function of Sr-doping concentration. The band gap of the prepared nanoparticles ranges from 3.46 eV to 3.56 eV. The nanoparticles have a higher hole concentration than electron concentration. Supercapacitor cells have been prepared by using synthesized nanoparticle electrodes and it is characterized using cyclic voltammetry (CV) by using KOH as an electrolyte solution. The calculated specific capacitance is high at a high doping concentration of 'Sr'. [Display omitted] • Wurtzite geometry undoped ZnO and Sr-doped ZnO nanoparticles have been prepared. • The crystallite size of the nanoparticles ranges from 28.46 to 33.45 nm. • The optical absorbance is enhanced due to doping and the observed band gap is blue-shift due to addition of the dopants. • The nanoparticles have high hole concentration and the charge carrier concentration increases at high doping concentration. • The high specific capacitance 500 F/g is observed in this study which corresponds to the Sr-doped ZnO (4 %) nanoparticles. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the incorporation of copper-modified niobium (Nb/Cu) nanoparticles at concentrations of 0.1 % and 0.3 wt% in a one-step adhesive (PacBond Adhesive). Thirty sound human third molars were randomly divided into three groups: control, 0.1NbCu, and 0.3NbCu. Specimens were restored with PacBond and resin composite OptiComp, Composite LC. Stick specimens (0.64 mm2) were obtained and subjected to microtensile bond strength (MTBS) testing (n = 10) using a universal testing machine at a rate of 0.5 mm/min after 24 h and 6 months. Scanning electron microscope (SEM) analysis, microhardness after 24 h and immersion in ethanol (HK) (n = 7), degree of conversion (DC) (n = 6), and surface mineral deposition (n = 3) were also conducted. Data were analyzed using two-way ANOVA for MTBS and HK, and one-way ANOVA for %SHL and DC, all of them were followed by Tukey's test (p < 0.05). For MTBS, statistical difference in storage times was observed for 0.1NbCu after 24 h (p = 0.007). There was no statistical difference between the control and 0.3NbCu regarding time and materials after 24 h and 6 months (p = 0.065). There was no statistical difference among the groups for DC (p = 0.278), but there was a significant difference among the groups for the factor of time in HK measurements (p = 0.047). The 0.1NbCu and 0.3NbCu groups exhibited absorbance Bands indicative of surface mineral deposition after 14 and 21 days, and the 0.3NbCu interface showed better preservation in SEM analysis. The concentration of 0.3 % NbCu in a one-step adhesive appears promising and may offer enhanced longevity for the tooth/restoration interface. [ABSTRACT FROM AUTHOR]

Nanoparticle agglomeration reduces the modification effect of nanocomposites, and there is a need to investigate a technique for evaluating the overall particle dispersion within the material, which in turn ensures the modification effect of the material. In this paper, a non-destructive testing technique for nanoparticle dispersion based on nonlinear ultrasonic (NLUS) is proposed to rapidly assess the overall nanoparticle dispersion within a material. An interfacial mismatch model describing different degrees of nanoparticle agglomeration was firstly developed, and then the nonlinear acoustic response of the nanoparticle-dielectric system was quantitatively solved, and the theoretical model was validated in conjunction with NLUS tests. The experimental results show that agglomerated interfaces are the source of the nonlinear response of nanodielectrics and that the microscopically generated nonlinear effects can be equivalently accumulated to the mesoscopic domain, with the error in the theoretically calculated values of the two being less than 5%; The NLUS technique eliminates the need for cumbersome steps such as particle size counting, and its small number of rapid detection results are close to the statistical convergence of the particle size of the 250 particles accumulated in the imaging image of the scanning electron microscope, with an error of between 3% ∼ and 13%. With a single inspection area of 339 mm3, the NLUS technology significantly reduces evaluation time and cost while expanding the inspection area, offering the combined advantages of speed, wide field of view, and non-destructiveness. [Display omitted] • NLUS can assess the particle agglomeration degree quantitatively, rapidly, and nondestructively. • Agglomerated interface is the source of the nanodielectric nonlinearity. • The micro-regional nonlinear response can be equivalently accumulated to the mesoscopic domain. [ABSTRACT FROM AUTHOR]

The efficacy of nanoencapsulation as a technology for enhancing the solubility of active substances has been demonstrated. In this particular investigation, Ganoderic acid DM (GA-DM) was encapsulated within sodium alginate nanoparticles (NPs) using the ionic crosslinking method. The confirmation of the successful loading of GA-DM was ascertained through the analysis of Fourier transform infrared spectrum (FTIR). Empirical evidence derived from the examination of scanning electron microscope (SEM) images, transmission electron microscope (TEM) images, atomic force microscope (AFM) images, and dynamic light scattering (DLS) demonstrated a regular distribution and spherical morphology, with an average particle size of approximately 133 nm. The investigation yielded an encapsulation efficiency of 95.27 ± 0.11 % and a drug loading efficiency of 21.17 ± 0.02 % for the prepared sample. The release kinetics of SGPN was fitted with the Korsmeyer-Peppas kinetic model corresponding to diffusion-controlled release. The incorporation of GA-DM into sodium alginate nanocarriers exhibited a mitigating effect on the cytotoxicity of HaCat and B16, while also demonstrating inhibitory properties against tyrosinase activity and melanin formation. [ABSTRACT FROM AUTHOR]

Herein, 5-fluorouracil and shikonin (extracted from Fusarium tricinctum) were loaded in chitosan/pectin nanoparticle (CS/PEC-NPs), prepared by blending (B-CS/PEC-NPs) and coating (C-CS/PEC-NPs) methods. The nanoparticles characterized by Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), Energy-dispersive X-ray (EDX), Scanning Electron Microscope (SEM) and Differential Light Scattering (DLS). Then, some properties of the nanoparticles such as drug release rate and the nanoparticles cytotoxicity were studied. The FTIR, XRD, EDX, SEM and DLS results showed that the nanoparticles synthesized properly with an almost spherical morphology, an average size of 82–93 nm for B-CS/PEC-NPs, an average diameter of below 100 nm (mostly 66–89 nm) for C-CS/PEC-NPs, and hydrodynamic diameter of 310–817 nm. The drug release results indicated the lower release rate of drugs for B-CS/PEC-NPs relative to C-CS/PEC-NPs at different pHs, high release rate of drugs for the nanoparticles in the simulated large intestinal fluids containing pectinase, and Korsmeyer-Peppas model for release of the drugs. The results showed more cytotoxicity of B-CS/PEC-NPs containing drugs, especially B-CS/PEC-NPs containing both drugs (B-CS/PEC/5-FU/SHK-NPs) after treating with pectinase (IC 50 of 18.6 μg/mL). In conclusion, despite the limitation of C-CS/PEC-NPs for simultaneous loading of hydrophilic and hydrophobic drugs, B-CS/PEC-NPs showed suitable potency for loading and targeted delivery of the drugs. [ABSTRACT FROM AUTHOR]

The consistently increasing use of zinc oxide nanoparticles (ZnONPs) in crop optimization practices and their persistence in agro-environment necessitate expounding their influence on sustainable agro-environment. Attempts have been made to understand nanoparticle-plant beneficial bacteria (PBB)- plant interactions; the knowledge of toxic impact of nanomaterials on soil-PBB-vegetable systems and alleviating nanotoxicity using PBB is scarce and inconsistent. This study aims at bio-fabrication of ZnONPs from Rosa indica petal extracts and investigates the impact of PBB on growth and biochemical responses of biofertilized eggplants exposed to phyto-synthesized nano-ZnO. Microscopic and spectroscopic techniques revealed nanostructure, triangular shape, size 32.5 nm, and different functional groups of ZnONPs and petal extracts. Inoculation of Pseudomonas fluorescens and Azotobacter chroococcum improved germination efficiency by 22% and 18% and vegetative growth of eggplants by 14% and 15% under NPs stress. Bio-inoculation enhanced total chlorophyll content by 36% and 14 %, increasing further with higher ZnONP concentrations. Superoxide dismutase and catalase activity in nano-ZnO and P. fluorescens inoculated eggplant shoots reduced by 15–23% and 9–11%. Moreover, in situ experiment unveiled distortion and accumulation of NPs in roots revealed by scanning electron microscope and confocal laser microscope. The present study highlights the phytotoxicity of biosynthesized ZnONPs to eggplants and demonstrates that PBB improved agronomic traits of eggplants while declining phytochemicals and antioxidant levels. These findings suggest that P. fluorescens and A. chroococcum, with NPs ameliorative activity, can be cost-effective and environment-friendly strategy for alleviating NPs toxicity and promoting eggplant production under abiotic stress, fulfilling vegetable demands. [Display omitted] • Zinc oxide nanoparticles phyto-fabricated from R. indica petals decline growth and alter biochemical responses of eggplants. • Scanning electron microscopy and confocal laser microscopy revealed cellular damage in NPs-treated eggplants. • Plant-beneficial bacteria, P. fluorescens and A. chroococcum , enhance eggplant defense against NPs toxicity. • Plant-beneficial bacteria caused metabolic shifts in proline, malonaldehyde, and antioxidants and alleviated abiotic stress. • NPs alleviation potential of P. fluorescens and A. chroococcum can magnify eggplants production even under abiotic stress. [ABSTRACT FROM AUTHOR]

Zinc oxide and zinc sulphide nanoparticles were produced using the sol-gel method. We employed nanoparticle identification methods for the examination of several factors. The precursor solutions are converted into an intermediate state that mimics gel during the sol-gel process, and then solidified. This technique provides fine control over the size, shape, and crystallinity of the resultant ZnO nanoparticles, hence modifying their electrochemical behaviour in the context of supercapacitor applications. An X-ray diffraction (XRD) examination revealed that the synthesized ZnO nanoparticles had a hexagonal character, while the ZnS nanoparticles had a cubic nature with diameters of around 22 nm and 36 nm, respectively. A transmission electron microscope (TEM) and a scanning electron microscope (SEM) are used to study the morphology and structural analysis. A particle size, surface area, production methods and testing settings are only a few of the variables that affect certain capacitances. In general, ZnO is recognized for displaying a certain capacitance that is frequently cited as being higher than ZnS. At a scan rate of 5 mV, the specific capacity of ZnO nanoparticles was found to be 33.2 F/g, whereas that of ZnS nanoparticles was found to be 6.5 F/g at a scan rate of 10 mV. One way to monitor pseudo capacitive behavior is by cyclic voltammetry. [ABSTRACT FROM AUTHOR]

In recent years, the incorporation of nanoparticles and corrosion inhibitors into epoxy coatings has become increasingly important in order to address the growing demand for advanced anti-corrosion coatings. In this study, various amounts of extracted chitin and chitosan nanoparticles from shrimp ranging from 0 to 3% wt. were added to an epoxy coating. The zeta potential of particles and scanning electron microscope were applied to determine average particle size and distribution of particle in the epoxy coating. Thermal stability, adhesion properties and corrosion behavior of reinforced coating were investigated. The epoxy coating with a 2%wt chitin additive showed a more uniform distribution. Fourier transform infrared spectrometry and the thermogravimetric analysis test (TGA) illustrated that the addition of chitin and chitosan additives lead to chemical changes in the structure and improve the thermal stability of epoxy coatings. The addition of 2%wt chitin nanoparticles improved the mechanical properties of the coatings, particularly the adhesion resistance. Corrosion testing revealed that the epoxy coating containing 2% chitin and chitosan nanoparticles exhibited a low corrosion rate, high load transfer resistance, and a double layer capacity when exposed to a 3.5% NaCl solution. • Addition of Chitin & Chitosan nanoparticles enhanced anti-corrosion of epoxy coating. • Chitin nanoparticles fills the pores and lengthens the path of electrolyte diffusion. • More than 2%wt chitin nanoparticles lead to agglomeration and increase corrosion. • Chitin showed better anti-corrosion performance compared to chitosan. [ABSTRACT FROM AUTHOR]