Nanoparticle Size Analyzer Research Articles

Structural evolution in a synthetically produced ultrafine grained low carbon steel

In this work, low carbon of extremely fine grain structure was produced by mechanical alloying of powders of iron and activated charcoal with minor addition of copper (Cu); mechanically alloyed powder was consolidated by spark plasma sintering to obtain a high-density compact. The steel so produced was subsequently subjected to forging followed by normalizing. The characterization was carried out by means of nanoparticle size analyzer, X-ray diffraction, optical microscopy, scanning electron microscopy, transmission electron microscopy, and Vickers microhardness testing. The microhardness value obtained for the steel was found to be significantly high and comparable with that of nanocrystalline/ultrafine grained steels produced by other routes. The increased hardness resulted from the smaller grain size and presence of finely dispersed ultra small sized copper and cementite precipitates.

A facile method for honey mediated bio-synthesis of nickel nanoparticles and its characterisation

In the present research, a statistical model was designed for optimizing three process variables for manufacturing nickel nanoparticles (NiNPs) using honey as bio-supported reducing agent. Characterisation of nanoparticles was performed using UV–vis spectrophotometer, nanoparticle size analysis was conducted by laser diffraction method and transmission electron microscopy (TEM) was used for morphological studies. Fourier transform infrared spectroscopy (FTIR) analysis was done for identifying the chemical nature of the capping agent deposited on the nanoparticle and energy dispersive x-ray (EDX) analysis was carried out for element determination. XRD analysis was used for the crystallographic determination. Characterisation by all the methods pointed to the crystalline nature of the NiNPs with a mean diameter of 31 nm.

Synthesis and properties of TiO2, NiO and ZnO nanoparticles and their possible biomedical application

Purpose: The main purpose of this publication is to bring closer method of synthesis and examining basic properties of TiO2, ZnO and NiO nanoparticles (NPs), and investigate their possible biomedical application. Design/methodology/approach: Nanopowders were made with sol-gel method. Surface morphology studies of the obtained materials were made using Zeiss's Supra 35 scanning electron microscope and the structure using S/TEM TITAN 80-300 transmission electron microscope. In order to confirm the chemical composition of observed nanopowders, qualitative tests were performed by means of spectroscopy of scattered X -ray energy using the Energy Dispersive Spectrometer (EDS). The DLS (Dynamic Light Scattering) method was used to analyse the particle size distribution using the AntonPaar Litesizer 500 nanoparticle size analyser. Changes in particle size distribution at elevated temperatures were also observed. The TiO2, ZnO and NiO NPs with spherical shape were successfully produced by sol-gel method. Findings: The diameter of the as prepared nanoparticles does not exceed 25 nm which is confirmed by the TEM analysis. The highest proportion among the agglomerates of the nanoparticles has been shown to show those with a diameter of 80 to 125 nm. The qualitative analysis of EDS confirmed the chemical composition of the material. Practical implications: Nanoparticles (NPs) has been receiving an incrementally increasing interest within biomedical fields researchers. Nanoparticles properties (physical, chemical, mechanical, optical, electrical, magnetic, etc.) are different from the properties of their counterparts with a larger particle size. Originality/value: The nanoparticles were prepared using sol-gel method which allows the particle size to be controlled in a simple way.

Synthesis and Characterization of PVP-Stabilized Palladium Nanoparticles by XRD, SAXS, SP-ICP-MS, and SEM

Due to increased emissions of palladium nanoparticles in recent years, it is important to develop analytical techniques to characterize these particles. The synthesis of defined and stable particles plays a key role in this process, as there are not many materials commercially available yet which could act as reference materials. Polyvinylpyrrolidone- (PVP-) stabilized palladium nanoparticles were synthesized through the reduction of palladium chloride by tetraethylene glycol (TEG) in the presence of KOH. Four different methods were used for particle size analysis of the palladium nanoparticles. Palladium suspensions were analyzed by scanning electron microscopy (SEM), small angle X-ray scattering (SAXS), single-particle ICP-MS (SP-ICP-MS), and X-ray diffraction (XRD). Secondary particles between 30 nm and 130 nm were detected in great compliance with SAXS and SP-ICP-MS. SEM analysis showed that the small particulates tend to form agglomerates.

The wound healing and antibacterial potential of triple-component nanocomposite (chitosan-silver-sericin) films loaded with moxifloxacin

AimThe current study reports the development and evaluation of chitosan-sericin-silver nanocomposite (CSSN) films without and with moxifloxacin (Mox). MethodologyThe film preparation method involved the in-situ synthesis of silver nanoparticles within the chitosan-sericin colloidal composite followed by preparation into a film by solvent casting technique. In-situ formation and the particle size analysis of the silver nanoparticles was performed via UV-Visible and zeta-size spectrometer. The prepared films were tested for swelling ratio, contents uniformity, in-vitro Mox release, and permeation analysis. The morphological (SEM), elemental (EDX), spectral (FT-IR), structural (XRD), and thermal (TGA and DSC) properties of the composites were also inspected. The antibacterial activity of the CSSN films was performed against seven pathogenic bacterial strains including five ATCC and two clinical strains. The potential wound healing activity of the composite films was evaluated on burn wound model induced in Sprague Dawley male rats. ResultsThe prepared films displayed good swelling profile with a sustained in-vitro Mox release and permeation profile; attaining maximum of 78.57% (CSSM3) release and 55.05% (CSSM1) permeation (CSSM1) in 24 h. The prepared films, particularly the Mox-loaded CSSN films displayed a promising antibacterial activity against all the tested strains with the activity being highest against MRSA (clinical isolates). The prepared films indicated a remarkable wound healing applications with successful fibrosis, collagen reorganization, neovascularization, and mild epidermal regeneration after 7 days of treatment with no silver ions detection in animal’s blood. ConclusionThe obtained findings strongly suggest the use of the prepared novel composite dressing for wound care applications.

Rich biomass combustion: Gaseous and particle number emissions

The cone calorimeter is a standard test method for material behaviour in fires. The principle of the cone calorimeter is to use an electric radiant heater to raise the temperature of the combustion zone and ignite the fuel. 35 kW/m2 was used in the present work, as this has been previously shown to be sufficient to establish fully developed combustion of biomass materials such as wood. As one of the main fire loads is wood and wood is the dominant biomass for energy generation, it is reasonable to use the cone calorimeter to characterize the combustion of biomass on a small scale and pine was used in the present work. The cone calorimeter was used in the controlled atmosphere mode with an enclosure around the test biomass that enabled the air flow for biomass combustion to be controlled at 19.2 g/m2s, which corresponds to a combustion heat release rate HRR of 57 kW/m2, assuming all the oxygen in the air is consumed. This air flow will be shown to generate rich combustion at a metered equivalence ratio, Ø, of about 2, which is comparable with the first gasification stage of biomass two stage burning in log burners and pellet burners, where air is added downstream of the gasification stage of biomass combustion. Soot emissions are generated in this rich gasification stage burning and potentially oxidized in the oxidation second stage burning. The rich burning gasification zone particulate emissions were analysed for number size distribution using the Cambustion DMS 500 particle size analyser. The exit from the controlled combustion zone was extended in a 75 mm diameter chimney where a mean gas sample was taken. A heated Gasmet FTIR was used for gas composition analysis, using a heated sample line, filter and pump from the sample point to the analyser. The particles emitted were sampled after the second stage combustion from entrained air into the chimney discharge gases into a dilution tunnel with a fixed gas flow rate of 24 l/s, which gave a dilution ratio of the primary combustion gases of 150/1 which is required for nano-particle size analysis. A Cambustion DMS500 electrical mobility particle number and size instrument was used with size resolution from 5 to 1000 nm. The present results show that in the rich burning first stage chimney sample there were very high levels of 20 nm nanoparticles, 1 × 1010/cc, and an accumulation mode peak at 200 nm. The presence of the 20 nm particles makes the particulate emissions extremely toxic.

Comparison Study on Antimicrobial and Photocatalytic Activity of Different Shaped ZnO Nanoparticles

ZnO nanoparticles (ZnO NPs) were synthesized through surfactant free non-hydrolytic organic phase method in which zinc acetate and zinc acetylacetonate were selected as precursors. Structural and size analysis of the as-prepared nanoparticles performed on X-ray diffractometer, transmission electron microscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy showed that the obtained nanoparticles were crystalline particles with all reflections matching to wurtzite. TEM images revealed that ZnO NPs from synthesis in which zinc acetate involved as precursor had a shape of sphere while zinc acetylacetonate resulted in rod-shaped nanoparticles. Reaction rates from catalytic activity test performed on Methylene Blue dye (MB) were found to be 2.99×10-2 min-1 and 1.98×10-2 min-1 for spherical and rod-shaped ZnO NPs, respectively. Antibacterial activity experiments shows rod-shaped ZnO NPs almost completely (99.75%) inhibited the growth of Escherichia Coli while only around 6.5% was survived after treatment of spherical ZnO NPs under same conditions.

New Polylactic Acid Multifunctional Ultrasound Contrast Agent Based on Graphene Oxide as the Carrier of Targeted Factor and Drug Delivery.

In recent years, the development of ultrasound contrast agents has encouraged their use as a drug system for diagnosis and therapy. In this paper, polylactic acid (PLA) composite microbubbles (FA/DOX/GO/DOX/PLA) were prepared with graphene oxide (GO) as a carrier of the targeted factor folic acid (FA) and doxorubicin (DOX) by the multiple emulsification–solvent evaporating process. Appearance, particle size, and zeta potential of PLA composite microbubbles were characterized by using a nanoparticle size analyzer and transmission electron microscopy. Breast cancer cells MCF-7 were used to evaluate the antitumor activity of PLA composite microbubbles in vitro by using the CCK-8 and acridine orange staining method. The ultrasonic imaging effect of PLA composite microbubbles was investigated in New Zealand white rabbits by the Doppler color ultrasound imaging system. With Kunming mice as the research model, the acute toxicity of PLA composite microbubbles was examined. The experimental results showed that the prepared PLA composite microbubbles presented a hollow and spherical shape with a particle size of 600 nm or so and a zeta potential of −37.5 ± 10.0 mV. They had a good effect of the enhancing imaging, and clear ultrasound imaging can be obtained. PLA composite microbubbles showed a significant proliferation inhibition effect on breast cancer cells MCF-7 in a dose-dependent manner. After PLA composite microbubbles were modified by FA, they were good for targeting FA receptors on the surface of MCF-7 cells, which increased the inhibition rate of the tumor cells. LD50 of PLA composite microbubbles was 87.529 mg·kg–1; the mice did not show the acute toxicity when the dose of composite microbubbles was lower than this value.

Magnetic nanoparticles for specifically capturing endothelial progenitor cells and evaluation of its cellular compatibility

Immobilization of CD34 antibody on ferroferric oxide magnetic nanoparticles was achieved by the traditional carboxyl-amine conjugation reaction. Fourier transform infrared spectroscopy (FT-IR), nanoparticle size analysis (dynamic light scattering and transmission electron microscope), and other testing methods were used to detect the surface modified magnetic nanoparticles. The endothelial progenitor cells (EPCs) were cultured with the surface modified magnetic nanoparticles to evaluate cell compatibility and the combination effect of nanoparticles on EPCs in a short period of time. Directional guide of the surface modified magnetic nanoparticles to EPCs was evaluated under applied magnetic field and simulated dynamic flow condition. The results showed that the magnetic nanoparticles were successfully modified with CD34 antibody, which had good cell compatibility within a certain range of the nanoparticle concentrations. The surface modified nanoparticles can combine with EPCs effectively in a short time, and those nanoparticles combined EPCs can be directional guided under the magnetic field in the dynamic flow environment.

Colour removal of phthalocyanine based reactive dye by nanoparticles

Synthesized iron-nickel (Fe–Ni) bimetallic nanoparticles (NPs) were utilized for the colour removal of C. I. Reactive Blue 21 (RB21) dye. NPs agglomeration was prevented using polyvinyl pyrrolidone (PVP) as a capping agent. The NPs were characterized by nanoparticle size analysis, TEM, XRD and EDX. The operational conditions like pH, NPs concentration and initial dye concentration for decolourization were optimized using mathematical modelling, and its kinetics were studied. Influence of the presence of alkali and salt on dye decolourization was also investigated. Decolourization products were analysed by using FTIR and GCMS analysis. 93.46% of dye decolourization was obtained and a reduction in COD, BOD values was achieved along with minimal sludge generation.

Nanoparticle size and zeta potential express analysis in initial material’s control at the enterprises of powder industry

The first part of the article describes the current situation in the field of additive technologies, existing international and Russian associations. The problem of lack of uniformity of measurements and imperfection of the regulatory documentation is also identified.In the second part of the article the problem of particles' agglomeration during the technological processes (creation of adhesive glasses, multilayer films, semiconductor plates, etc.) is revealed and solution is proposed. One of the reasons for this problem is the lack of precise control of the particle zeta potential.The importance of determining the zeta potential is that its value is related to the stability of colloidal systems. Zeta potential determines the degree and nature of the interaction between the particles in dispersion.

Erosion Wear and Hardness of Glass Fiber / Epoxy with Nano and Micro TiO2 Hybride Composites

The objective of this research is to prepare and study (Glass Fiber / Epoxy) with nano and micro Titanium dioxide (TiO2) composites with different volume percentage of nano and micro TiO2 powder of 2%, 4%, and 6% volume fraction. Atomic force microscopy techniques was used to measure the grain size of nano TiO2 powder (average diameter was 46 nm) and particle size analyzer techniques was used. Erosive wear behavior of this composite under three different impingement angles of 30°, 60° and 90° and three angular silica sand abrasive particle sizes approximately 425, 600 and 850 μm and hardness (shore D) were studied. In general the erosion wear of micro composites have lower erosion resistance than other nano-based compounds. Erosion resistance increase as the volume fraction increase. Nano composites of GF / EP with TiO2 have many advantages over micro composites from the view point of wear and hardness tests. The worn surface features of unfilled and filled G-E composites were examined using scanning electron microscopy (SEM) and results indicates more severe damage to matrix and glass fiber in unfilled composite system as compared to TiO2 filled composites.

Decolourization by PVP stabilized Fe-Ni nanoparticles of Reactive Black 5 dye

Nanoscale Fe-Ni bimetallic particles with Polyvinyl pyrrolidone (PVP) as a stabilizer were synthesized for dye decolourization and characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and nano particle size analyser. Analysis of variance (ANOVA) for decolourization was done by the central composite design (CCD) with response surface methodology (RSM). Three operational factors concentration of nanoparticles, concentration of dye and pH were selected for design of experiments. The influence of reaction duration, alkali and salt addition on dye decolourization was also studied. Dye degraded product and breaking of chromophoric group was analysed by gas chromatography–mass spectrometry (GCMS) and FT-IR analysis. The dye decolourization of was 97.89% obtained with reduction in COD and BOD value was achieved with negligible generation of the sludge.

Synthesis and characterization of ethyl cellulose micro/nanocapsules using solvent evaporation method

In this study, oil-filled micro/nanocapsules were synthesized by the emulsion-solvent evaporation method using ethyl cellulose as a shell-forming material containing linseed oil. Shape and morphology of the prepared micro/nanocapsules were evaluated using scanning electron microscopy. The particle size distribution of nanocapsules was investigated using nanoparticle size analyzer. The micro/nanocapsules core and shell material were characterized by Fourier transform infrared spectra. Oil-filled micro/nanocapsules with a regular spherical shape were successfully synthesized in various diameters ranging from 33 nm to 400 μm. The size distribution of capsules was successfully controlled by controlling emulsion agitation rate in their synthesis process.

Porphyrin Derivative Conjugated with Gold Nanoparticles for Dual-Modality Photodynamic and Photothermal Therapies In Vitro.

Gold nanoparticles (Au NPs) have been confirmed to show excellent photothermal conversion property for tumor theranostic applications. To improve the antitumor efficacy, a novel nanoplatform system composed of porphyrin derivative and Au NPs was fabricated to study the dual-modality photodynamic and photothermal therapy with laser irradiation. Modified chitosan was coated on the Au NPs surface via ligand exchange between thiol groups and Au. The chitosan-coated Au NPs (QCS-SH/Au NPs) were further conjugated with meso-tetrakis(4-sulphonatophenyl)porphyrin (TPPS) via electrostatic interaction to obtain the porphyrin-conjugated Au hybrid nanoparticles (TPPS/QCS-SH/Au NPs). Size, morphology, and properties of the prepared nanoparticles were confirmed by Zeta potential, nanoparticle size analyzer, transmission electron microscopy (TEM), and UV-vis spectroscopy. Moreover, both photothermal therapy (PTT) and photodynamic therapy (PDT) were investigated. Compared with alone Au NPs or TPPS, the hybrid TPPS/QCS-SH/Au NPs with lower cytotoxicity showed durable elevated temperature to around 56 °C and large amount of singlet oxygen (1O2) produced from TPPS. Thus, the hybrid nanoparticles showed a more significant synergistic therapy effect of hyperthermia from PTT as well as 1O2 from PDT, which has potential applications in the tumor therapy fields.

Temporal and Spectral Characterization of Breakdown Plasma Induced by Laser Radiation in Colloidal Solutions of Gold Nanoparticles

Temporal and spectral characteristics of laser-induced breakdown plasma in colloidal solutions of gold nanoparticles were experimentally studied. Near-infrared laser sources of nanosecond pulses were used. It was shown that under certain experimental conditions nanosized plasma around nanoparticles might change to laser-induced breakdown plasma in liquid. The dependencies of the plasma temporal and spectral characteristics on laser pulse duration as well as resulting nanoparticles properties were studied. Laser-induced breakdown plasma lifetime was shown to be comparable with laser pulse duration. The efficiency of gold nanoparticles fragmentation was shown to depend on laser pulse duration. Similar experiments were carried out under reduced external pressure. It turned out to affect the properties of both plasma plume and nanoparticles. Transmission electron microscopy and disc measuring centrifuge were used for nanoparticle morphology and size analysis. Extinction spectra of colloidal solutions and emission spectra of plasma were studied by means of optical spectroscopy.

Preparation and characterization of starch nanocrystals combining ball milling with acid hydrolysis

Waxy maize starch was mechanically treated with a planetary ball mill. X-ray diffraction analysis was employed to determine the optimal ball milling time. After ball milling, the pretreated starch was hydrolyzed with H2SO4. The hydrolysates were obtained and their relative crystallinity, morphology, and particle size were estimated by X-ray diffraction analysis, atomic force microscopy, and nanoparticle size analyzer, respectively. The results revealed that it is possible to obtain starch nanocrystals (SNCs) after a combination of ball milling and 3days of H2SO4 hydrolysis with a yield of 19.3wt% with a shape similar to those acquired by the conventional procedure after 5days of sulfuric acid hydrolysis, with a yield of 15.8wt%. Round-edge SNCs with an average diameter of approximately 31nm were observed. The results revealed that by controlling some parameters, certain mechanical processing methods considered unsuitable could also be applied to the preparation of SNCs.

Microbial production of coconut fiber nanolignin for application onto cotton and linen fabrics to impart multifunctional properties

Lignin is the second most abundant renewable carbon source available on Earth. It is available in plenty as a by-product of pulp and paper industries, but it has largely been discarded. In this work, controlled microbial hydrolysis process was employed to produce nanolignin from the bulk lignin extracted from coconut fibers. The ligninase secreting fungal isolate, Aspergillus nidulans was used for this purpose. The size reduction of lignin was monitored by DLS nanoparticle size analyzer and, once the size reached below 100 nm, the nanolignin was purified and characterized. Nanolignin (size: 27.5 nm ± 2.7 nm) was applied onto the surface of cotton and linen fabrics by pad-dry-cure method using acrylic binder and characterized by FTIR, SEM and XRD. The finished cotton and linen fabrics showed excellent antibacterial (as per AATCC-100 standard method), UV blocking (as per AATCC-186 standard method) and antioxidant (as per DPPH method) properties. This work demonstrates the newer application of microbial produced nanolignin for multifunctional finishing of cotton and linen fabrics.

Combination of thresholding and fitting methods for measuring nanoparticle sizes and size distributions in (S)TEM

The practical need for a simple and reliable tool for routine size analysis of nanoparticles with diameters down to a few nm embedded in a polymer matrix motivated the development of a new approach. The idea underlying the method proposed in this work is to combine intensity thresholding and contrast fitting procedures in the same software for particle recognition and measurements of sizes and size distributions of nanoparticles in transmission and scanning transmission electron microscopy images. Particle recognition in images is performed in an interactive process of manual setting the numerical threshold level after image preprocessing. We show that fitting the calculated gray level distribution to the real images is able to provide a maximum accuracy in measurements of the particle diameters in contrast to thresholding approaches. The fitting procedure is applied in the vicinity of nanoparticle images with the mass-thickness, diffraction, and chemical contrast. The grayscale function associated to the nanoparticle thickness is described using polynomial gt=g0+g1t+g2t2+g3t3… with degree ⩾ 2 and undetermined coefficients. The program for particle detection and size measurement-Analyzer of Nanoparticles (AnNa)-has been written and is described here. It was successfully tested on systems containing Ag nanoparticles grown and stabilized in aqueous solutions of different polymers for biomedical use and is available from the authors.

Experimental Study of Imbibition Characteristics of Silica Sol in Coal-Measure Mudstone Matrix

Coal-measure mudstone is a typical dual-porosity media, and grouting in a matrix system is dominantly controlled by the imbibition effect for silica sol. This paper studies the imbibition effect using mudstone in the Huaibei mining area and silica sol as grouting material as an example. Groutability, driving force, and diffusion difficulty affecting the imbibition effect were tested by a mercury porosimeter, nanoparticle size analyzer, optical contact-angle measuring device, surface tension meter, and rotary viscosity meter. After finely grinding a mudstone sample, a pressureless imbibition process was conducted through nuclear magnetic resonance equipment for 216 h to study colloid spontaneous migration and phase characteristics. Results show that silica sol absorption rate follows a power function and that the spectrograms of T2 are distributed in a triple peak pattern, with a tendency to move to the right of vertex time. The paper lays a theoretical and experimental foundation for field grouting in the coal mine.