Oxide Nanoparticles Concentration Research Articles

Impact of medium parameters on the optoelectronic characteristics of a polymer containing bisphenol A and 1,3,4-oxadiazole chromophore group

The photophysical characterization (absorption and emission spectra, fluorescence quantum yields, preferential solvation) of a polymer containing bisphenol A and 1,3,4-oxadiazole group (OxBisA) was studied in a wide variety of solvents. Influence of the medium characteristics on photophysical behavior was examined. The solvatochromic shifts of the spectral bands were analyzed by multiple parametric regression analysis in terms of solvent parameters of two new solvent scales (Catalan and new Laurence). Also, changes in the electronic emission spectral characteristics of OxBisA molecules were studied in chloroform solution in the presence of various amount of SnO2 and NiO oxide nanoparticles. The fluorescence intensity of polymer OxBisA gradually decreased with increases of oxide nanoparticles concentrations. The emission intensity of studied compound was sensitive to the compositions of the microheterogeneous media (involving different chloroform:methanol ratios).

Fabrication of mixed matrix poly(phenylene ether-ether sulfone)-based nanofiltration membrane modified by Fe3O4 nanoparticles for water desalination

Abstract In the current research, poly(phenylene ether-ether sulfone) (PEES)-co-poly vinyl pyrrolidone (PVP) nanofiltration membranes were prepared by a casting solution technique using N-methyl-2-pyrrolidone (NMP) as a solvent. The ethanol was used as fixed additive for better dispersion of iron oxide nanoparticles into the membranes structure. The effect of iron oxide nanoparticle concentration in the casting solution on the membrane performance/properties was studied. The membrane pure water flux, permeated flux, salt rejection, water content, tensile strength and membrane porosity were studied. Scanning electron microscopy (SEM) analysis was also used for the membrane morphology characterization. The results revealed that water content increased from 70.25% for bare PEES to about 83.25% for the membrane filled with 0.05 wt.% nanoparticles. SEM images showed that the membrane structure changed and turned from sponge shape to finger like. The results showed that porosity was increased from 55.92% for PEES one to 69.65% for M3. Additionally, the maximum value of flux was obtained for M3. Moreover, rejection was improved by the addition of nanoparticles into the casting solution compared to the unfilled one. Obtained results showed more appropriate performance for the modified membrane filled with 0.05 wt.% iron oxide nanoparticles compared to other prepared membranes.

The influence of nanodisperse iron(III) oxide on the morphology of microsized alumina fibers

The influence of fine-disperse iron oxide particles on the structure of alumina fibers prepared via the template synthesis has been studied. The template (fibers of bleached cotton cellulose) has been impregnated with mixed aqueous dispersions of aluminum and iron(III) hydroxides prepared via the sol–gel route. Thermal treatment of the precursor has afforded alumina ceramic fibers with average diameter of 3–10 µm containing uniformly distributed iron(III) oxide nanoparticles at the surface. Increase of the iron(III) oxide nanoparticles concentration has deteriorated the texture properties of the product.

Total reflection x-ray fluorescence spectroscopy as a tool for evaluation of iron concentration in ferrofluids and yeast samples

In this study, total reflection x-ray fluorescent (TXRF) spectrometry was applied for the evaluation of iron concentration in ferrofluids and biological samples containing iron oxide magnetic nanoparticles obtained by the laser target evaporation technique. Suspensions of maghemite nanoparticles of different concentrations were used to estimate the limitation of the method for the evaluation of nanoparticle concentration in the range of 1–5000ppm in absence of organic matrix. Samples of single-cell yeasts grown in the nutrient media containing maghemite nanoparticles were used to study the nanoparticle absorption mechanism. The obtained results were analyzed in terms of applicability of TXRF for quantitative analysis in a wide range of iron oxide nanoparticle concentrations for biological samples and ferrofluids with a simple established protocol of specimen preparation.

Fabrication and Characterization of Novel Mixed Matrix Polyethersulfone Nanofiltration Membrane Modified by Iron-Nickel Oxide Nanoparticles

In this study, a mixed matrix polyethersulfone/iron-nickel oxide nanoparticle nanofiltration membrane was prepared by the solution casting technique. Polyvinylpyrrolidone was also used as a membrane pore former in membrane fabrication. The effect of iron-nickel oxide nanoparticles concentration in the casting solution on the membrane structure and performance was investigated. Scanning optical microscopy (SOM) and scanning electron microscopy analysis (SEM), water contact angle, NaCl/Na2SO4 salt rejection, water flux and tensile strength measurements were also carried out in membrane characterization. SOM images showed relatively uniform particle distribution and surface for the prepared membranes. Moreover, SEM images showed that the macro-voids’ size was enhanced in the membrane sub-layer with an increase of additive concentration. Results showed that increasing iron-nickel oxide nanoparticles from 0 to 0.1 wt.% in the membrane matrix caused a decrease in contact angle from 63 to 43° and again increased to 56° by increasing the particles concentration to 1 wt.%. The membrane water flux was enhanced sharply with an increase of nanoparticle concentration up to 0.01 wt.% in the membrane matrix and then decreased slightly at higher additive contents. Salt rejection was generally improved with an increase of nanoparticle concentration. Membrane mechanical strength was initially declined by using iron-nickel oxide nanoparticles up to 0.1 wt.% in the membrane matrix and then increased at higher additive contents. The nanocomposite membranes showed more appropriate antifouling capacity compared to a pristine PES membrane. The effect of feed concentration on membrane salt rejection and water flux was also studied.

Abstract 2914: Gold magneto nanoparticles induced apoptosis in liver cancer cells through changes of Ca channel pump detected by LIBS Technique and RT-PCR array

Abstract Laser-induced breakdown spectroscopy technique (LIBS) was used in thesis study to address the effect of gold magneto nanoparticles on the liver cancer cells (HepG2) by examining the variation in genotoxicity and cytotoxicity. HepG2 cell line was cultured at 105 cells/ml and expanded, after which, they were incubated with gold magneto nanoparticles at concentrations 10, 25, 50 μg/ml respectively for 12 hours. The effect of these nanoparticles in cell apoptosis as well as in autophagy was evaluated by acridine orange staining and Annexin V/propidium iodide double staining as well as apoptosis specific PCR array assay for evaluation of apoptosis in the treated cells. At a concentration of nanocomposite 10, 25, 50 μg/ml, cells showed increase in the apoptosis figure from 11.25% ± 3.1% to 28% ± 2.04%, 39% ± 3.6%, 60% ± 4.3% respectively. Apoptosis specific PCR array also, showed very high expression of TNF, BIRC3 and NFKB1 with increasing in the fold regulation ratio of 155.03,158.03 and 149.2- fold respectively. On the other hand, extra investigation of these treated cells by LIBS shows an increasing in the iron oxide nanoparticles concentration as well as calcium concentration. This increase in the calcium content in the treated cells may play an important role in the program cell apoptosis which was prove in our study by both Flow cytometry as well as by profile apoptosis PCR array. Finally, our data showed the possibility of the using LIBS as inductor of cells apoptosis by measurement Ca concentration changes in liver cancer cells (HepG2 cells). Keywords: Apaptosis, LIBS; HepG2 cell; Genotoxicity Citation Format: Ola Ahmed, Hisham Imam, Abdel-Rahman N. Zekri. Gold magneto nanoparticles induced apoptosis in liver cancer cells through changes of Ca channel pump detected by LIBS Technique and RT-PCR array. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2914. doi:10.1158/1538-7445.AM2015-2914

Uptake and clearance analysis of Technetium99m labelled iron oxide nanoparticles in a rabbit brain.

Nanoparticles as solid colloidal particles are extensively studied and used as anticancer drug delivery agents because of their physical properties. This current research aims to prepare water base suspension of uncoated iron oxide nanoparticles and their biodistribution study to different organs, especially the brain, by using a single photon emission computed tomography gamma camera. The water-based suspension of iron oxide nanoparticles was synthesised by a reformed version of the co-precipitation method and labelled with Tc99m for intravenous injection. The nanoparticles were injected without surface modification. X-ray diffraction (XRD), energy dispersive spectrometry (EDS) and transmission electron microscope (TEM) techniques were used for characterisation. Peaks of XRD and EDS indicate that the particles are magnetite and exist in aqueous suspension. The average diameter of iron oxide nanoparticles without any surface coating determined by TEM is 10 nm. These particles are capable of evading the reticuloendothelial system and can cross the blood-brain barrier in the rabbit. The labelling efficiency of iron oxide nanoparticles labelled with Tc99m is 85%, which is good for the biodistribution study. The sufficient amount of iron oxide nanoparticles concentration in the brain as compared with the surrounding soft tissues and their long blood retention time indicates that the water-based suspension of iron oxide nanoparticles may be an option for drug delivery into the brain.

Lipopolysaccharide induced MAP kinase activation in RAW 264.7 cells attenuated by cerium oxide nanoparticles.

High mortality rates are associated with the life threatening disease of sepsis. Improvements in septic patient survivability have failed to materialize with currently available treatments. This article represents data regarding a study published in biomaterials (Vellaisamy et al., Biomaterials, 2015, in press). with the purpose of evaluating whether severe sepsis mortality and associated hepatic dysfunction induced by lipopolysaccharide (LPS) can be prevented by cerium oxide nanoparticles (CeO2NPs) treatment in male Sprague Dawley rats. Here we provide the information about the method and processing of raw data related to our study publish in Biomaterials and Data in Brief (Vellaisamy et al., Biomaterials, 2015, in press; Vellaisamy et al., Data in Brief, 2015, in press.). The data contained in this article evaluates the contribution of MAPK signaling in LPS induced sepsis. Macrophage cells (RAW 264.7) were treated with a range of cerium oxide nanoparticle concentration in the presence and absence of LPS. Immunoblotting was performed on the cell lysates to evaluate the effect of cerium oxide nanoparticle treatment on LPS induced changes in Mitogen Activated Protein Kinases (MAPK) p-38, ERK 1/2, and SAPK/JNK phosphorylation.

Reducing the optical band gap of polyvinyl alcohol (PVA) based nanocomposite

Optical properties of pure polyvinyl alcohol (PVA) and PVA based nanocomposite films have been investigated. The nano-composite samples were prepared by the well known solution cast method. The experimental results shows that the absorption and absorption coefficient parameters are greatly affected by variation of copper oxide (CuO) nanoparticles concentration. The absorption versus wavelength for the doped samples is exponential while the absorbance of pure PVA is sharply varied with wavelength. An obvious surface plasmonic resonance peaks for the nano-composite samples were appeared. The absorption edge was greatly shifted to lower energy for the PVA doped samples. It was observed that optical band gap of pure PVA is significantly reduced upon the addition of CuO nanoparticles. The increase of refractive index with increasing CuO concentration is an evidence for the formation of new energy states and thus decreasing the energy band gap of PVA. The increase of optical dielectric constant was observed upon the addition of CuO nanoparticles. The optical dielectric loss peaks are shifted to higher wavelength with increasing the CuO concentration. The optical conductivity is increased upon the addition of CuO nanoparticles. The dispersion region in the refractive index spectra are well obeyed the single oscillator of the Wemple–Didomenico model for all the samples.

Lipoamino Acid Coated Superparamagnetic Iron Oxide Nanoparticles Concentration and Time Dependently Enhanced Growth of Human Hepatocarcinoma Cell Line (Hep‐G2)

Superparamagnetic iron oxide nanoparticles (SPION) have been widely used in medicine for magnetic resonance imaging, hyperthermia, and drug delivery applications. The effect of SPION on animal cells has been a controversial issue on which there are many contradictions. This study focused on preparation of SPION with novel biocompatible coatings, their characterization, and cytotoxicity evaluation. An amino acid (glycine) and two novel lipo‐amino acids (2 amino‐hexanoic acid and 2 amino‐hexadecanoic acid) coated magnetic nanoparticles were characterized by various physicochemical means such as X‐ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), differential scanning calorimetry (DSC), and infrared spectroscopy (FT‐IR). The cytotoxicity profile of the synthesized nanoparticles on Hep‐G2 cells as measured by MTT assay showed the nanoparticles are nontoxic and the cell growth is promoted by SPION. Moreover, lipoamino acid coating SPION appear more beneficial than the other ones. By increasing concentration of SPION, growth enhancing impact will attenuate and toxicity will appear. Although the aggregation of SPION can affect the results, the gradual delivery of ferric/ferrous ions into cells is the main cause of this growth promotion effect. Conclusively, this study shows that lipoamino acid coating SPION can be used for various biomedical purposes.

Novel antibacterial electrospun mats based on poly(d,l-lactide) nanofibers and zinc oxide nanoparticles

This investigation addresses the morphological, mechanical, and antibacterial evaluation of nanocomposite mats based on poly(d,l-lactide) nanofibers with different zinc oxide nanoparticles (nano-ZnO) concentration, that were elaborated by two techniques, i.e., electrospinning of polymer/ZnO solutions and the combination of electrospinning of polymer solutions with electrospraying of nano-ZnO dispersions. The analysis of the precursory solutions was carried out in order to understand the achieved morphology of nanofibers. The obtained poly(d,l-lactide)/ZnO fibrous mats showed a uniform morphology with an average porosity ca. 55 % and average pore size around 45 μm. The presence of ZnO nanoparticles increased the toughness of the mats, and an optimal nano-ZnO concentration (i.e., 3 wt%) was observed at which the tensile strength and Young’s modulus could be improved. Concerning to the antibacterial properties, a relatively low concentration of nanoparticles provoked a growth inhibition of the Gram-negative Escherichia coli and the Gram-positive Staphylococcus aureus bacteria. The mats have potential features for use as antimicrobial wound dressings.

Investigation of antibacterial effect of Cadmium Oxide nanoparticles on Staphylococcus Aureus bacteria.

BackgroundInorganic antibacterial factors provide high bacterial resistance and thermal stability. Inorganic nanomaterial consists of modern formulation, biological, chemical, and physical properties produced on the basis of their function and influenced by their nano scales, the reason for which they have become very popular. The antibacterial effect of Cadmium Oxide Nanoparticles on Staphylococcus Aureus has been studied for the first time in this research because of their resistance to antibiotics.Materials and methodsDifferent concentrations consist of 10 μg/ml, 15 μg/ml, and 20 μg/ml have been provided and their effects were studied in the agar and broth against the foregoing bacteria. Needless to say, the optimization of their non-microbial effect in variable times, pH, and temperatures of exposure was analyzed.ResultsThe results represented that there is a direct association between the nanoparticles applied dosage and the restrain effect augmentation of applied dosage results in increase in restrain effect. In the study of environmental factors (pH and temperature), the results are in line with the inherent physiology of the bacteria; however, there was a significant decline in the number of analyzed bacteria cells due to the “Double Effect” of nanoparticle-pH variations as well as nanoparticle-temperature variables. In the very study, the promotion of Cadmium Oxide nanoparticles concentration leads to the elevation of antimicrobial feature and the reduction of bacteria growth rate is consistent with the other surveys about the nanoparticles effects on microorganisms to be more specific, one can come to this conclusion that the presence of nanoparticles prompts cellular destruction.ConclusionIn the recent study, by elevation in Cadmium Oxide nanoparticles concentration, the antimicrobial property augments and the bacteria growth rate declines, that are in line with other researches about the nanoparticles effect on microorganisms.

The Effect of Inversion Time on the Relationship Between Iron Oxide Nanoparticle Concentration and Signal Intensity in T1-Weighted MR Images

Background:Magnetic nanoparticles have been widely applied in recent years for biomedical applications. Signal intensity (SI) of magnetic resonance (MR) images depends on the concentration of nanoparticles. It is important to find the minimum concentration of iron oxide nanoparticles that produces maximum SI and determines the minimum injection dose for clinical studies.Objectives:This study was performed to determine the relationship between the iron oxide nanoparticle concentration and SI using inversion recovery (IR) sequence in T1-weighted MR images.Materials and Methods:Different concentrations of carboxydextran-coated iron oxide nanoparticles 20 nm in size were prepared. In vitro MR imaging was performed with inversion times (TI) of 100-400 ms (interval of 20 ms) and IR Turbo-FLASH (Turbo fast low angle shot) pulse sequence using a 1.5 T MRI system. Then the SI produced by each concentration of nanoparticles was measured and the minimum nanoparticle concentration that led to the maximum SI was determined. Coil non-uniformity was also considered for measuring the accurate SI of each image.Results:The results indicate that SI depended on the concentration of nanoparticles and TI. In addition, SI increased by increasing the TIs ranging from 200 to 400 ms for all studied concentrations. The linear relationship between the nanoparticle concentrations and SI that gave a square correlation coefficient (R2) equal to 0.99 was seen up to 76.83 µmol Fe/L in 400 ms for long TI and 239.16 µmol Fe/L in 200 ms for short TI.Conclusions:TI is an important parameter to consider in the relationship between SI and nanoparticle concentrations. An increase in TI leads to a decrease in the range of linearity.

Electrochemical characterization of mixed matrix heterogeneous cation exchange membrane modified by aluminum oxide nanoparticles: Mono/bivalent ionic transportation

Polyvinylchloride/aluminum oxide nanoparticles mixed matrix heterogeneous cation exchange membranes were prepared by solution casting technique. The effect of Al2O3 nanoparticles concentration on membrane electrochemical properties was studied. It was found that membrane water content was enhanced by increase of additive concentration in prepared membrane. Increase of aluminum oxide nanoparticles loading ratio in casting solution also caused to decrease in ion exchange capacity. Obtained results revealed that membrane permselectivity and transport number were improved initially in sodium chloride and barium chloride ionic solutions by increase of aluminum oxide nanoparticles concentration up to 2wt% in prepared membranes and then showed decreasing trend by more increase in additive content. Also membranes exhibited lower selectivity and transport number for bivalent ions in comparison with monovalent ones. Furthermore, membrane ionic permeability and flux were decreased initially by increase in aluminum oxide nanoparticles loading ratio up to 2wt% and then increased again by more additives concentration. Opposite trend was found for membrane areal electrical resistance. Results showed that modified membranes in this study are comparable with that of other commercial ones.

Kinetics of Nano-catalysed Dark Fermentative Hydrogen Production from Distillery Wastewater

Kinetics of nano-catalysed dark fermentative biohydrogen production from molasses-based distillery wastewater has been reported. Iron oxide nanoparticle was supplemented (10-200 mgL-1) to the wastewater to enhance the biohydrogen production. Andrew's inhibition model was employed to evaluate the rate of hydrogen production (RH2) and hydrogen yield at different concentration of iron oxide nanoparticles. The maximum RH2 and specific hydrogen yield (SHY) for the fermentative hydrogen production system at different concentration of iron oxide nanoparticle were found to be 80.7ml/hr and 44.28ml H2/g COD. Michaelis-Menton equation was applied to determine the rate of hydrogen production (RH2) and yield of H2 (SHY) at different initial pH (5, 6 & 7). Andrew's inhibition model has been used to describe the inhibitory effect of substrate concentration on the rate of H2 production (RH2). RH2 decreased with the increase in substrate concentration but SHY first decreased with substrate concentration and it is maximum at higher substrate concentration of 110 gL-1. Monod model has been used to determine the growth kinetic parameters. The values of maximum rates of microbial growth (μm) and substrate utilization (Rsu) were 0.1g biomass/g biomass/day and 14.03g COD/g biomass/day respectively at different iron oxide nanoparticles concentration.

Electrochemical, morphological and antibacterial characterization of PVC based cation exchange membrane modified by zinc oxide nanoparticles

In the current research, mixed matrix polyvinylchloride based heterogeneous cation exchange membranes were prepared by solution casting technique. Zinc oxide nanoparticle was also utilized as additive in membrane fabrication. The effect of ZnO nanoparticles concentration in casting solution on physico-chemical and antibacterial characteristics of membranes was studied. SEM images showed compressed structure for the modified membranes. Images also exhibited relatively uniform surfaces for the membranes. 3D SEM images showed smooth surface for membranes at high ZnO loading ratio content. X-ray diffraction results revealed that membrane crystalinity was improved by increase of nanoparticles’ concentration. The membrane selectivity and transport number were increased initially by increase of additive content up to 8 %wt in casting solution and then showed decreasing trend by more ZnO concentration to 16 %wt. The membrane ionic flux also enhanced initially by increase of zinc oxide nanoparticles content up to 4 %wt and then began to decrease. The modified membrane containing 4 %wt zinc oxide nanoparticles showed superior characteristics compared to other modified membranes and pristine/unmodified ones. The modified membranes also showed good ability in E.coli removal.

Polymer-Hematite Nanocomposites: Templating Effect of Commercial Ion-Exchangers in the Growth of Size-Controlled Iron Oxide Nanoparticles

The commercially available ion-exchange resin Amberlite IR120 has been used as the stabilizing agent for the preparation of a size controlled nanostructured hematite phase. The employed synthetic approach, based on the loading of Fe3+ by ion exchange and the subsequent treatment with an aqueous base solution, produces a nanocomposite material with a remarkably high content of oxide nanoparticles (iron content = 18.8% w/w, corresponding to 24.9% w/w of Fe2O3). Scanning electron microscopy and energy dispersive X-ray spectroscopy investigation show that the iron distribution is egg-like and parallels the distribution of the sulfonic groups of the ion-exchanger. Transmission electron microscopy characterization reveals that the size of the ferric oxide nanoparticles in the nanocomposites is narrowly distributed in the 4-6 nm range and that it is the same after the first and the fifth ion-exchange-precipitation cycle. Selected area Electron Diffraction (SAED) analysis of the nanostructured oxide after five ion-exchange-precipitation cycles indicates that it is hematite with a distorted structure.

Influence of metal oxide nanoparticles concentration on their zeta potential

In an attempt to estimate the zeta potential of various metal oxide nanoparticles (NPs) dispersed in water, it is interesting to observe that both the magnitude and the sign of this property depend highly upon their concentration. For example, in the case of naked TiO2 at pH 6, the zeta potential increased from −6.7 to 8.2mV as the particle concentration varied from 0.5 to 5mgL−1. As a result, the isoelectric points of naked TiO2, Fe3O4, Fe(OH)3, and Al2O3-coated TiO2 could deviate ca. one, one, two, and three pH units, respectively, depending upon the particle concentration. We showed that these behaviors arise mainly from that the dissolved ambient CO2 reacts with the particle surface functional groups to form MOCO2-, which neutralizes or even overcompensates the particle surface charge. The surface density of M–OCO2-, M–OCO2-S depends upon the particle concentration; if it is sufficiently high, M–OCO2-S becomes negligible, so is its influence on the zeta potential. We concluded that the zeta potential measurements for the tested NPs are reliable only if their concentration exceeds a certain level. This also applies to other metal oxides or hydroxides, the surface of which reacts appreciably with dissolved CO2. The results gathered are of practical significance in estimating the surface properties of unknown and/or newly synthesized NPs since conventional measurements are usually made at dilute particle concentrations.

The effect of metal oxide nanoparticle concentrations in PEDOT:PSS layer on the performance of P3HT:PCBM organic solar cells

An improved organic solar cell was obtained by focusing on the effects of metal oxide nanoparticles (NPs) concentrations in the buffer layer. The performance was compared by mixing metal oxide nanoparticle into PEDOT:PSS (Poly(3,4 ethylenedioxy-thiophene) Poly(styrene-sulfonate)) based buffer layer. We studied the effect of Fe2O3 NPs by changing its concentration from 0.1 to 1wt.%. Increasing concentrations of NPs showed good light absorption ability. The solar cells with a bare active layer showed a power conversion efficiency (PCE) of 2.79% while with Fe2O3 NPs at 0.7wt.% concentration, showed higher performance resulting a PCE of 3.68% under AM 1.5G illumination. A decline in PCE was seen at 1wt.% of Fe2O3 NPs. This phenomenon was also compared with the use WO3 NPs in place of Fe2O3 NPs.

Effect of Zinc Oxide Nanoparticles Concentration on the Mechanical Properties and UV Protection of In Situ Synthesized ABS Based Nanocomposites

AbstractA series of ABS/ZnO nanocomposites with different nanoparticles content were synthesized by mass‐mass and mass‐suspension processes. Because nanocomposites obtained through mass‐suspension process had a greater impact resistance than those derived from mass‐mass process, they were subjected to twin‐screw extrusion. The extrusion led to a dramatic morphological change and increase in impact resistance, higher than 100% in most of the cases. On the other hand, the higher the ZnO content, the higher the UV blocking (>95% for 1 and 3% of ZnO) for both materials, before and after extrusion.