Average Diameter Of Nanoparticles Research Articles

Sintesis Nanopartikel Perak Menggunakan Ekstrak Daun Salam (Syzygium polyanthum) Sebagai Bioreduktor Dan Uji Aktivitasnya Sebagai Antioksidan

Silver nanoparticles have been synthesized by the reduction method using salam leaf extract (Syzygium polyanthum) as a reducing agent. The silver nanoparticles produced were then tested for their activity as antioxidants. The formation of silver nanoparticles was carried out by adding the leaf extract into the solution of AgNO3 and homogenized using a magnetic stirrer. A UV-Vis spectrophotometer was used to confirm the formation of silver nanoparticles. Particle Size Analyzer (PSA), Scanning Electron Microscope (SEM), X-Ray Diffractometer (XRD) and Fourir Transform Infra Red (FTIR) spectrometers were used to characterize the nanoparticles produced before being tested for antioxidant activity. The results showed that the absorbance value increased with increasing reaction contact time. The maximum uptake was obtained at wavelengths of 432-446 nm using a UV-Vis spectrophotometer. The particle size was determined using a PSA with an average particle size distribution of 45.7 nm. The average diameter of silver nanoparticles was 10.06 – 13.97 nm and the silver nanoparticles had rod-shapes. Functional groups that play a role in the synthesis of nanoparticles were –OH, –C=O, and –C-O groups. Silver nanoparticles inhibited free radicals as antioxidants with the IC50 value of 582.7 ppm.

Multi-scale analysis of amorphous solid dispersions prepared by freeze drying of ibuprofen loaded acrylic polymer nanoparticles

Amorphous solid dispersions (ASDs) consisting of ibuprofen as a model drug, and Eudragit L100-55 as methacrylate copolymer carrier, were prepared by emulsification-diffusion method followed by freeze drying of nanoparticle suspensions. Subsequently, ibuprofen-loaded Eudragit L100-55 nanoparticles with different drug loadings were prepared. To understand the processing-structure-properties relationships, multi-scale analysis was performed. Average diameter of nanoparticles in all formulations was 234 ± 30 nm. Differential scanning calorimetry, X-ray diffraction and infrared spectroscopy showed that the formulations prepared from 9 to 16% of ibuprofen were fully amorphous while nano-crystalline domains localized inside the polymeric nanoparticles thanks to the atomic force microscopy analysis were detected in formulations prepared from higher content of ibuprofen (≥20%). Unexpected increase of the entrapment efficiency with the increase of ibuprofen loading was correlated with the increase of the viscosity of the organic phase. ASDs exhibited good dissolution profiles, characterized by sustained ibuprofen release, followed by supersaturation build-up. Physical stability tests performed on the ASDs showed that ibuprofen remained amorphous after 12 months of storage period. Therefore, Eudragit L100-55 plays a dual role in the ASDs, i.e. kinetic stabilization of ibuprofen in amorphous state during the storage period, and control of the drug release, and subsequent stabilization of the supersaturated state.

Expanded graphene oxide-supported molecularly imprinted polymer nanoparticles based on polystyrene for dibenzothiophene removal

ABSTRACTThis work aimed at synthesizing molecularly imprinted polymer (MIP)-based nanoadsorbent consisting of styrene as functional monomer, expanded graphene oxide (EGO) functionalized with (3-mercaptopropyl) trimethoxysilane (MPS) as support, and dibenzothiophene (DBT) as template. The main goal was to enhance the efficiency of the sample for DBT removal from hexane, and petroleum media. For this purpose, FTIR results at the characteristic peak of 1100 cm−1, and SEM images showed that a complete functionalization of EGO platelets using MPS, and an appropriate changing graphene oxide (GO) to EGO, respectively. The synthesis of styrene-based MIP nanoparticles onto the surface of EGO/MPS was carried out by adjusting the template: monomer molar ratio of 1:4 in which the highest imprinting factor (IF) with a value of 1.81, and the average nanoparticles diameter of 540 nm were attained. Moreover, FTIR outcomes exhibited that EGO/MPS support could remain even after washing of the template from the polymerized nanoparticles to form MIPs. Finally, by evaluating the equilibrium adsorption of DBT using the EGO/MPS-supported MIPs based on polystyrene from hexane (∼150 mg/g of the nanoadsorbent), and petroleum (∼34% after six cycles), it was found that the sample had high potential to adsorb DBT as the main contaminant in the refinery industry.

Phosphorus as a promoter of a nickel catalyst to obtain 1-phenylethanol from chemoselective hydrogenation of acetophenone

Two catalysts were prepared using monodisperse pre-synthetized nanoparticles of metallic nickel and nickel phosphides with the same average diameter. Both nanoparticles species were deposited on the same support: mesoporous silica nano-spheres of MCM-41. This support is suitable to inhibit agglomeration and sintering processes during preparation steps. Therefore, two supported and activated catalysts with the same average nanoparticles diameter were obtained. They differ only in the nature of the active species: metallic nickel and nickel phosphides. The effect of the presence of a second element (phosphorus), more electronegative than nickel, on the activity and selectivity in the chemoselective hydrogenation of acetophenone was studied. The reaction conditions were: H2 pressure of 1 MPa, 80 °C using n-heptane as solvent. With the aim to understand the catalytic results, nanoparticles, support and catalysts were carefully characterized by X-ray diffraction, diffuse light scattering, transmission electron microcopy, high resolution transmission electron microcopy, selected area electron diffraction, scanning electron microcopy, Fourier transformer infrared spectroscopy, N2 adsorption at -196 °C, atomic absorption, H2 and CO chemisorption and volumetric oxidation. Considering these results and geometric and electronic characteristics of the surface of both active species, a change in the adsorption intermediate state of acetophenone in presence of phosphorus is proposed to explain the hydrogenation chemoselectivity of nickel phospides.

Temperature control synthesis of platinum nanoparticle-decorated reduced graphene oxide of different functionalities for anode-catalytic oxidation of methanol

Platinum (Pt) nanoparticles of varying average diameters decorated on exfoliated reduced graphene oxide (Pt/rGO) of various functionalities have been synthesized by monitoring the temperature of co-reduction of PtIV and GO. The as-synthesized composites are characterized by X-ray diffraction, spectroscopic, thermo gravimetric and microscopic studies. The excellent catalytic capability of the composites for methanol oxidation reaction (MOR) is found to be synergistic in reference to single components, Pt and rGO and might be used in high efficient, less emissive, cost-effective direct methanol fuel cell operated in alkali. The poison tolerance capability of the electrodes as measured by the ratio of forward and backward peak currents due to MOR is found to be relatively high in respect to similar data in the literature and increases with the increase of defect concentration as evaluated from Raman spectroscopic study, on rising the temperature of synthesis of the catalyst. The forward peak current density of the electrode made with Pt/rGO composite synthesized at 40 °C is greater by 5.6 and 287 times than these for pure Pt and rGO based electrodes. The electrode exhibits the best catalytic activity due to presence of the lowest but sufficient defect sites, especially for formation of sp2-C-OH groups on the rGO surface in the vicinity of the poisoned Pt-surface and lowest average diameter (7.41 nm) of dispersed Pt nanoparticles.

Novel food-grade Pickering emulsions stabilized by tea water-insoluble protein nanoparticles from tea residues

Recently, food-grade Pickering particles, particularly plant proteins, have attracted tremendous attention because they are biobased, environmentally-friendly and edible. To explore the potential of tea water-insoluble protein (TWIP) nanoparticles from tea residues for stabilizing Pickering emulsions, the average hydrodynamic diameter (DH), zeta potential and morphologic profiles of TWIP nanoparticles were characterized using dynamic light scattering (DLS), laser Doppler velocimetry (LDV) and atomic force microscopy (AFM), respectively. The results indicated that TWIP nanoparticles were irregular colloidal particles with a DH greater than 300 nm and a negative charge of more than −30 mV at ionic strengths of 0–400 mM and a fixed TWIP nanoparticle concentration (2.0%). Furthermore, the effect of the TWIP nanoparticle concentration (0.5–4.0%, w/v) and oil-water ratio (2:8–6:4) on the characteristics of the Pickering emulsions stabilized via TWIP nanoparticles was investigated. Increasing the TWIP nanoparticle concentration generated a firm and thick TWIP nanoparticle-based interfacial layer, as verified by Cryo-scanning electron microscopy imaging, and decreased the droplet size of Pickering emulsions at an oil-water ratio of 4:6. Additionally, an increase of the oil-water ratio to 6:4 favored the formation of emulsions with extraordinary creaming stability at the fixed TWIP nanoparticle concentration of 2.0%. The present study is the first to suggest TWIP nanoparticles as a type of food-grade Pickering particle.

Experimental investigation of thermophysical properties of R718 based nanofluids at low temperatures

An extensive experimental investigation on the thermophysical properties of two different types of R718 (water) based nanofluid was performed for particle volume fractions (ϕ) ranging from 0.25–2.5%. R718 (water) is used as a secondary refrigerant in refrigeration systems; therefore, it is important to measure the variation in the thermophysical properties of R718 due to the addition of nanoparticles. The major highlight of the current work is the measurement of the thermophysical properties at a temperature as low as 278 K. Most of the studies available in the open literature are based on the thermophysical property measurement of nanofluids at elevated temperatures (above 293 K). In the present work, the thermophysical properties such as thermal conductivity, viscosity and density of the nanofluids were measured at a temperature varying from 5 to 25 °C (278-298 K) and were later compared with the existing theoretical models and previous experimental results. The specific heat capacity of Al2O3 and CuO based nanofluids was predicted and analysed using a theoretical model. The thermal conductivity of the nanofluid was measured by the Transient hot-wire method and the viscosity of the nanofluid was measured using a Cannon-Fenske viscometer. Copper oxide (CuO) and aluminium oxide (Al2O3) nanoparticles were chosen for the present investigation. The average particle diameter of CuO and Al2O3 nanoparticles was 30 nm. It was observed that the enhancement in thermal conductivity of nanofluids at low temperature (~278 K) is considerably lower than the enhancements at elevated temperatures. The viscosity measurements also revealed that the classical models can be successfully applied for predicting the viscosity of Al2O3 –R718 nanofluids at low particle volume fractions (ϕ < 0.5%).

Water-in-oil Pickering emulsion polymerization of N-isopropyl acrylamide using starch-based nanoparticles as emulsifier.

Inverse Pickering emulsions stabilized by naturally derived particles are of interesting during the past decade. In this study, starch-based nanoparticles were used as a particulate emulsifier to stabilize a w/o Pickering emulsion. The effects of particle concentration and oil volume fraction on the emulsion type and stability were investigated in detail. Catastrophic phase inversion from o/w to w/o emulsions occurred at a volume fraction of oil of 0.3-0.4, without altering the particle wettability. Further, a linear relation existed between the average droplet diameter and total amounts of starch-based nanoparticles. The obtained starch-based nanoparticles also served as a Pickering stabilizer to conduct a w/o Pickering polymerization. Raspberry-like thermoresponsive starch-poly(N-isopropyl acrylamide) nanocomposites with a well-defined structure were synthesized.

Study of Cu (II), Co (II), Ni (II) and Pb (II) removal from aqueous solutions using magnetic Prussian blue nano-sorbent.

In this study magnetic Prussian blue (MPB) was synthesized and applied as sorbent for the efficient removal of heavy metals (Cu (II), Co (II), Ni (II) and Pb (II)) from aqueous solution. The average diameter of nanoparticles was found to be about 15 nm. The experimental results were fitted to Langmuir, Freundlich and Dubinin-Radushkevich models with high regression coefficients. The kinetics data were expressed by pseudo-first-order, pseudo-second-order and intraparticle diffusion models. The influence of initial concentration, sorbent dosage and time on the heavy metals sorption efficiency was studied using response surface methodology (RSM). Analysis of variance (ANOVA) was included to assess the adequacy of the model.

Preparation and catalytic performance of polymer gold nanocomposites

The development of efficient heterogeneous catalysts for reductive conversion of 4-nitrophenol (4-NP) is of vital significance for environmental remediation, dyestuff industry, pharmaceutical industry. We reported that Au@D201, a polymer gold nanocomposite of gold nanoparticles loaded on D201 resin, was prepared using macroporous styrenic ion exchange resin D201 as carrier, chloroauric acid as gold source and sodium borohydride as reducing agent. The average diameter of gold nanoparticles in Au@D201 composites is 5 nm, which has excellent catalytic properties for the reduction of 4-nitrophenol. The Au@D201 was characterized by ultraviolet–visible spectroscopy, X-ray diffraction, mercury injection instrument, transmission electron microscopy and X-ray photoelectron spectroscopy (XPS). The results reveal that some of the gold nanoparticles were loaded on the surface of the resin, and most of the gold nanoparticles were in the resin pores. A strong chemical interaction, between the gold nanoparticles and the resin, is similar to the cross-linking action of the macromolecules. The gold nanoparticles provide a new cross-linking point for the resin, increasing the degree of cross-linking of the resin and causing some degree of resin ordering to occur. XPS shows that the electron density of the outer layer of the gold atom increases, indicating that there are some conjugated interactions between the resin and gold atoms. Conjugated interactions and the gold quantum size effect are the main reasons for improving the catalytic effect of the composite material. When the gold nano-loading amount is 0.1%, it still has an excellent catalytic effect on the reduction reaction of 4-nitrophenol.

Synthesis of nano-dimensional cobalt-zinc ferrites by the low-temperature spray-drying with subsequent thermolysis

Co0,65Zn0,35Fe2O4nanoparticles were produced by spray-drying in air in presence of NaCl from the solution of nitrates, as well as from the suspension of coprecipitated particles. The precursors obtained were annealed at 300–900 °C in the matrix of the inert component in order to increase the crystallinity degree without substantial increase of the nanoparticle size. Microstructure, morphology and magnetic properties of nanoparticles were studied by XRD, FT-IR spectroscopy, TEM / SEM and magnetometry. For the ferrites obtained from nitrate solutions partial oxidation of Co2+ions to Co3+occurs, which leads to the formation of two spinel phases, ferrite and cobaltite. With the increase of annealing temperature the content of cobaltite decreases and content of ferrite increases. No cobaltite formation was observed for annealing the spray-dried suspension. An increase in the temperature of the heat treatment leads to partial recrystallization of the particles and the ordering of the ferrite crystal structure, which causes an increase in the specific magnetization of the materials: from 32.8 emu/g (before annealing) to 91.3 emu/g (annealing at 900 ° C). The average diameter of nanoparticles after heat treatment does not exceed 100 nm.

Encapsulation of Ni nanoparticles with oxide shell in vapor condensation

Controlled input of oxygen into the inert working gas flow during the production of Ni nanoparticles by the electrical explosion of wire (EEW) method leads to the formation of a crystalline oxide shell on the surface of particles during their condensation from the vapor phase. Resulting oxide shells encapsulating Ni particles weaken their agglomeration processes as well as protect the surface of the Ni nanoparticles from further oxidation. The influence of the amount of energy introduced during EEW and the quantity of oxygen added to the working gas in EEW process on the properties of resulting Ni nanoparticles was studied. The obtained nickel nanopowders were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and N2 adsorption (BET) methods, which gave the specific surface area, the average diameter of nanoparticles, their phase composition, the morphology of the particles and the structure of the oxide shells. It was shown that the addition of oxygen leads to a decrease in the average diameter of Ni nanoparticles and reduces the degree of their agglomeration. The encapsulation of Ni nanoparticles with 3-5 nm thick gas-tight oxide shells protects the particles from oxidation and eliminates the pyrophoricity of the powder product.

X-ray powder diffraction to analyse bimetallic core-shell nanoparticles (gold and palladium; 7-8 nm).

A comparative X-ray powder diffraction study on poly(N-vinyl pyrrolidone) (PVP)-stabilized palladium and gold nanoparticles and bimetallic Pd–Au nanoparticles (both types of core–shell nanostructures) was performed. The average diameter of Au and Pd nanoparticles was 5 to 6 nm. The two types of core–shell particles had a core diameter of 5 to 6 nm and an overall diameter of 7 to 8 nm, i.e. a shell thickness of 1 to 2 nm. X-ray powder diffraction on a laboratory instrument was able to distinguish between a physical mixture of gold and palladium nanoparticles and bimetallic core–shell nanoparticles. It was also possible to separate the core from the shell in both kinds of bimetallic core–shell nanoparticles due to the different domain size and because it was known which metal was in the core and which was in the shell. The spherical particles were synthesized by reduction with glucose in aqueous media. After purification by multiple centrifugation steps, the particles were characterized with respect to their structural, colloid-chemical, and spectroscopic properties, i.e. particle size, morphology, and internal elemental distribution. Dynamic light scattering (DLS), differential centrifugal sedimentation (DCS), atomic absorption spectroscopy (AAS), ultraviolet-visible spectroscopy (UV-vis), high-angle annular dark field imaging (HAADF), and energy-dispersed X-ray spectroscopy (EDX) were applied for particle characterization.

USING γ RAY-INDUCED SILVER NANOPARTICLES ON CONTROL OF CLUBROOT DISEASE OF CHINESE CABBAGE CAUSED BY PLASMODIOPHORA BRASSICAE

Plasmodiophora brassicae- the casual cause of clubroot disease of plants belonging to the family Brassicaceae. This soil-borne fungus infects plants through root hairs. Diseased roots become swollen and deformed. Thus, it’s difficult for plants to absorb water and nutrients. There are some methods used to control this disease including soil fumigation, soil pH control, fungicides, surfactants applications, calcium supplementation, but the results are still restricted. Plasmodiophora brassicae was isolated, identified and artificial inoculated on the Chinese cabbage. The rate of root hair infection and gall formation depended on the spore density and growth media. The increase of the pathogen density lead to the increase of disease symptoms. Silver nanoparticles (SNPs) are widely used as an agent for antifungal treatment. The antimicrobial activity of the nanoparticles varies on the size, shape, and the function of the surface area. The γ - irradiation method to synthesize SNPs is known as a method that can be controlled the out coming sizes, shapes and size distribution of particles. The average diameter of silver nanoparticles in this research was 9.5nm. In the liquid culture and soil, SNPs exhibited a controlling effect on P. brassicae. The fungicide activity depended on the SNP concentrations and the medium; no disease symptoms were found at the SNP concentrations of 1.06 ppm in the liquid culture, and 10 and 20 ppm in soil. Results of the study also showed that the biomass and height of infected plants were much lower than those of the healthy plants. Comparing to the plants that were grown in the sterilized soil, there was not significant difference between the biomass and the height of plants exposed to pathogen and treated with SNPs.

Heat Transfer and Fluid Flow Optimization of Titanium Dioxide–Water Nanofluids in a Turbulent Flow Regime

In this study, the convection heat transfer and pressure drop of titanium dioxide–water nanofluids were modeled by applying the fuzzy C-means adaptive neuro-fuzzy inference system approach for a completely developed turbulent flow based on experimentally obtained training and test datasets. Two models were proposed based on the effective parameters; one model was developed for the Nusselt number considering the effects of the Reynolds number, Prandtl number, nanofluid volume concentration and average nanoparticle diameter. Another model was suggested for the pressure drop of the nanofluid as a function of the Reynolds number, nanofluid volume concentration, and average nanoparticle diameter. The results of these two proposed models were compared with experimental data as well as the existing correlations in the literature. The validity of the proposed models was benchmarked by statistical criteria. Moreover, a modified non-dominated sorting genetic algorithm multiobjective optimization technique was applied to obtain the optimum design points, and the final result was shown in a Pareto front.

High-gravity-assisted scalable synthesis of zirconia nanodispersion for light emitting diodes encapsulation with enhanced light extraction efficiency

Zirconia-based hybrid polymers has become one of the ideal encapsulation material for light emitting diodes (LEDs) with high extraction efficiency due to their proper refractive index to those of semiconductor chips. However, the controlling of the dispersion for zirconia nanoparticles in polymeric hosts to obtain optically transparent hybrid nanocomposites has been one of the major challenges. Herein, we reported the synthesis of zirconia nanodispersion via high-gravity-assisted homogeneous precipitation in an internal circulation rotating packed bed (RPB) reactor followed by two-step modification. An alternative to conventional precipitation in batch stirred tank reactors (STR), the process intensification by high-gravity RPB results in homogeneous micromixing during the nucleation and growth of zirconia particles, which are benefit for continuous and reproducible production of ultrasmall zirconia nanoparticles. The obtained zirconia nanoparticles are purely cubic phase with narrow size-distribution in the range of 3–5 nm according to the X-ray diffraction and transmission electron microscopy characterization, which were similarity to that by the conventional methods. Nevertheless, the average hydrodynamic diameters of zirconia nanoparticles in aqueous solutions obtained by RPB methods were much smaller than those prepared in conventional STR, which enabled easy control and surface modification for highly dispersed nanodispersion in organic solvents and/or polymeric hosts. After two-step surface modification, zirconia nanoparticles with goal-directed structures were obtained, with highly dispersity in various organic solvents (e.g. toluene, trichloromethane, tetrahydrofuran, etc.) and aliphatic epoxy resin, forming transparent hybrid films with tunable refractive indexes. The preliminary applications of these zirconia nanodispersions for LEDs encapsulation were demonstrated. The light extraction efficiency of the LEDs devices packaged with zirconia/epoxy hybrid material increased by 10 percent when the doping content of zirconia nanoparticles was 0.2, compared to the devices encapsulated by original epoxy.

Experimental study to obtain the viscosity of CuO-loaded nanofluid: effects of nanoparticles’ mass fraction, temperature and basefluid’s types to develop a correlation

In this study, the impacts of temperature, nanoparticles mass fraction, and basefluid types were investigated on the dynamic viscosity of CuO-loaded nanofluids. The nanoparticles were dispersed in deionized water, ethanol, and ethylene glycol as basefluids separately and the measurements were performed on samples with nanoparticles loads ranging from 0.005 to 5 wt%, and the temperature range of 25 to 70 °C. TEM analysis were performed on dried nanoparticles and the results showed the average mean diameter of CuO nanoparticles ranged from 10 to 50 nm. The results of DLS analysis confirmed the results of nanoparticles size obtained by TEM analysis in mentioned basefluids and Zeta-Potential tests exhibited the high stability of the nanoparticles in the basefluids environment. The results indicate that by adding tiny amount of CuO nanoparticles to basefluids, relative viscosity of nanofluid increases. By the increase in nanoparticles load higher than 0.1 wt% the effect of both nanoparticles mass fraction and temperature would be more tangible, while for nanoparticles mass fraction lower than 0.1 wt% no significant change in viscosity was observed. In addition, the results declare that viscosity of nanofluid remains constant at various applied shear rates indicating Newtonian behavior of nanofluid at various nanoparticles load and temperature. According to experimental data, it is also evident that with the increase in temperature, the value of relative dynamic viscosity decreases significantly. Also it is concluded that for CuO/ethanol nanofluid, more interfacial interaction is resulted that causes higher relative dynamic viscosity while for CuO/water lower interfacial interaction between nanoparticles surface and water molecules are resulted which leads to the lower values for this parameter. The results of this study implied that with increase the temperature from 25 to 70 °C at the condition where nanoparticles mass fraction was chosen to be 5 wt%, the value of dynamic viscosity of CuO/ethanol, CuO/deionized water, CuO/ethylene glycol declined 69%, 66%, and 65% respectively. Finally, a correlation was proposed for the relative dynamic viscosity of nanofluid based on the CuO nanoparticles mass fraction and temperature of the basefluid and nanoparticles.

Cytotoxic Activity and Kinetic Release Study of Lovastatin-Loaded Ph-Sensitive Polymersomes

Triblock poly(e-caprolactone) â�� poly(ethylene glycol) â�� poly(e-caprolactone) (PCL-PEG-PCL) copolymers were synthesized and used to prepare polymersomes for controlled release of lovastatin (LOV) as hydrophobic drug. Biodegradable PCL-PEG-PCL copolymer nanoparticles were prepared and the drug loading, release, release kinetics, and anti-cancer activity of these drugs was investigated. The PCL-PEG-PCL copolymer was synthesized by ring-opening polymerization of e-caprolactone in the presence of mPEG as the initiator and Sn(Oct)2 as the catalyst. The synthesized copolymers and nanoparticles were characterized by FTIR, 1H NMR, DLS, and AFM techniques. The efficiency of drug loading and release from nanoparticles in vitro was studied by UV-Vis spectrophotometry. Additionally, MTT assays on HFF-2 cell lines were performed for determining the biocompatibility of polymersomes. Finally, the antiproliferative activity of polymersomes was examined on MCF-7 breast cancer cell line. The obtained results showed that the average diameter of nanoparticles was less than 57 nm. The loading capacity and encapsulation efficiency of LOV was 16.1 ± 0.36% and 59.01 ± 0.78%, respectively. In vitro release study showed that the release rate of polymersomes depended on pH and was higher at lower pH than under neutral condition. The result of cell viability assay on the MCF-7 line proved that bare nanoparticles showed little inherent cytotoxicity whereas the LOV-loaded nanoparticles were cytotoxic. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.

Quantitative Description of Properties of Nickel-Containing Nanocomposites Affecting Their Magnetic Characteristics

Multiple regression equations linking properties of nanocomposites synthesized by thermolysis of unsaturated nickel dicarboxylates in an argon medium and magnetic characteristics have been obtained by processing experimental data. The equations obtained enable one to predict the magnetic characteristics on the basis of data on the phase composition of the nanocomposite, the content of nickel, and average diameter of nickel-containing nanoparticles; moreover, information on the effect of characteristics on the magnetic properties can be obtained.

Pt-Zn/HZSM-5 as a highly selective catalyst for the Co-aromatization of methane and light straight run naphtha

Selectivity of catalysts has become increasingly important in the petrochemical industry in order to reduce waste, maximize efficiency, and reduce costs. Reported here is a catalyst in the form of Pt-Zn/HZSM-5 with low acidity to reduce over cracking and maximize selectivity of benzene, toluene, and xylene (BTX) during the aromatization of naphtha under methane environment. The Pt-Zn combination when coupled with HZSM-5 support over light straight run naphtha (LSR) and methane, is capable of BTX selectivity of 94.4% with no formation of detrimental polyaromatics and olefins. Such a performance is attributed to the appropriate distribution of acid sites (seen via NH3-TPD and pyridine DRIFT) with regards to strength and type because of loading Pt and Zn as well as Zn’s ability to reduce coke formation as seen via TGA-DSC (1 μg coke/(g cat·h) for Zn/HZSM-5 and 5.9 μg coke/(g cat·h) for HZSM-5). TEM imaging shows that a methane environment effectively suppresses metal particle agglomeration (1.4 nm average metal nanoparticle diameter) compared to nitrogen (2.1 nm average metal nanoparticle diameter) with XRD showing Pt’s ability to maintain catalyst crystallinity during moderate temperature and moderate pressure as well as reaction time of 1 h. It has been seen here that by employing Zn and Pt in tandem over HZSM-5, catalytic performance can be greatly increased (22.4% BTX yield) when compared to sole loading of Zn (13.4%) or Pt (13.1%), thus a positive synergetic effect is witnessed. Such a selective and coke resistant catalyst shows great promise for the future of LSR reformation to valuable products with methane as a very feasible co-reactant capable of contributing to positive liquid products.