In modern-day research, nanoparticles (size < 100nm) are an indispensable tool for various applications, especially in the field of biomedicine. Although enormous efforts have been made to understand ...the properties and specificities of nanoparticles, many questions are still not answered and the new ones arise. In this review we summarize current trends in the nanoparticle synthesis and characterization and interpret the stability of nanoparticles in various media from aqueous solutions to biological milieu important for the in vitro and in vivo studies. To get more detailed insight into nanoparticle charging properties and interactions of nanoparticles with interfaces the theoretical models are presented. Finally, the overview of nanoparticle applications is given and the future prospects are discussed.
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•Review of nanoparticle's synthesis, characterization and stability.•Theoretical models: nanoparticles properties and their interactions with interfaces.•Applications of nanoparticles and future prospects.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The present study aims at enhancing the thermal performance of SAE 50 engine oil by adding zinc oxide nanoparticles. The investigations are performed in the thermal range of 25 to 55 °C and at the ...volume fractions of 0.125 to 1.5%. In this regard, first, the characterization of nanoparticles was performed to examine their surface and atomic structure. Moreover, following the manufacture of the nano-lubricant, its stability was investigated by the DLS test. After ensuring the results of nano-lubricant stability, different samples were prepared according to the variations in volume fraction, followed by the experimental measurement of the thermal conductivity of nano-lubricant. The obtained results revealed an ascending trend in thermal conductivity by increasing temperature and concentration. The maximum thermal conductivity enhancement was 8.74%. Based on the experimental results, a sharply precise relation was proposed to predict the ratio of nano-lubricant thermal conductivity to that of the tested base fluid.
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•Enhancing the thermal performance of SAE 50 engine oil by adding zinc oxide nano-powder.•Performing the characterization of nanoparticles to examine their surface and atomic structure.•Investigating the stability by the DLS test.•An ascending trend in thermal conductivity by increasing temperature and concentration.•Proposing a novel correlation to predict the nano-lubricant thermal conductivity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Development of nanotechnology and corresponding industries during the last decade resulted in a new challenge for analytical science. This includes an ultrasensitive detection and characterization of ...nanoparticles of different origin and other nanomaterials in various media, including so complex ones as food, biological or environmental samples. The goal of this review is a systematic analysis of possible approaches and description of physical principles behind these methods. The main attention is paid to optical methods which are considered by authors to be mostly effective for the formulated task. Different approaches for detection and analysis of nanoparticles in a volume as well as of those adsorbed on a surface are discussed. While the technologies based on direct analysis of nanoparticle suspensions belong to the established approaches whose development potential has been in large extent exhausted, the novel technologies based on the surface sensing of adsorbed nanoparticles demonstrate intensive development. Therefore, the final part of the review is focused on the wide-field surface plasmon resonance microscopy. It allows one an ultrasensitive detection and characterization of individual nanoparticles of different origin in complex media and provides numerous possibilities for subsequent chemical identification of the detected particles using a hyphenation with other analytical technologies.
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•Optical techniques for ultrasensitive analytics nanoparticles are reviewed systematically.•The main drawbacks and advantages of various techniques are compared.•Analytical performance and applications of surface plasmon microscopy are discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The present research study is focused on green fabrication of superparamagnetic Phytogenic Magnetic Nanoparticles (PMNPs), and then its surface functionalization with 3-Mercaptopropionic acid ...(3-MPA). The resulting material (i.e. 3-MPA@PMNPs) characterized by FTIR, powder XRD, SEM, TEM, EDX, VSM, BET and TGA techniques and then further employed for the investigation of the adsorptive removal of lead (Pb2+) and cadmium (Cd2+) ions from aqueous solutions in single and binary systems. The material showed fastest adsorptive rate (98.23%) for Pb2+ and (96.5%) Cd2+ within the contact time of 60 min at pH 6.5 in the single system. The experimental data were fitted well to Langmuir isotherm, indicated monolayer adsorption of both metal ions onto 3-MPA@PMNPs and an estimated comparable adsorptive capacity of 68.41 mg·g−1 (Pb2+) and 79.8 mg·g−1 (Cd2+) at pH 6.5. However, kinetic data agreed well with pseudo-second-order model, and indicated that the removal mainly supported chemisorption and/ or ion-exchange mechanism. Thermodynamic parameters such as ΔGo, ΔHo, and ΔSo, were −3259.20, 119.35 and 20.73 for Pb2+, and −1491.10, 45.441 and 7.87 for Cd2+ at temperature 298.15 K, confirmed that adsorption was endothermic, spontaneous and favorable. The material demonstrated higher selectivity of Pb2+ and its removal efficiency was (98.20 ± 0.3)% in binary system experiments. The material persisted performance up-to seven (07) consecutive treatment cycles without losing their stability and offered comparable fastest magnetic separation (35 s) from aqueous solutions. Therefore, it is recommended that the prepared material can be employed to remove toxic heavy metal ions from water/wastewaters and this “green” method can easily be implemented at large scale in low economy countries.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Two different gold-silica-based nanomaterials were prepared: (i) silica-supported gold nanoparticles (AuNP/SiO2); and (ii) gold-silica core-shell nanoparticles (AuNP@SiO2). Three strategies for ...sample treatment (S), consisting in acid treatments, were employed: (S1) HNO3; (S2) HNO3 + HCl; and (S3) HF + HNO3 + HCl, applying microwave oven digestion for S2 and S3. From three calibration curves, slope, intercept, and linear correlation coefficient were obtained. The accuracy of the methods was evaluated by comparing the gold contents in a sample determined by flame atomic absorption spectrometry (FAAS) and by inductively coupled plasma atomic emission spectrometry (ICP-OES). Finally, the amount of gold for all samples was determined by FAAS. UV-Vis spectroscopy and transmission electron microscopy (TEM) were used to compare the material before and after sample treatment. By comparison, the application of S2 and S3 allowed the presence of gold on or in the silica matrix to be determined and the amount quantified.
In this paper, we implement a Whispering Gallery mode microbubble resonator (MBR) as an optical transducer to detect the photoacoustic (PA) signal generated by plasmonic nanoparticles. We simulate a ...flow cytometry experiment by letting the nanoparticles run through the MBR during measurements and we estimate PA intensity by a Fourier analysis of the read-out signal. This method exploits the peaks associated with the MBR mechanical eigenmodes, allowing the PA response of the nanoparticles to be decoupled from the noise associated with the particle flow whilst also increasing the signal-to-noise ratio. The photostability curve of a known contrast agent is correctly reconstructed, validating the proposed analysis and proving quantitative PA detection. The experiment was run to demonstrate the feasible implementation of the MBR system in a flow cytometry application (e.g., the detection of venous thrombi or circulating tumor cells), particularly regarding wearable appliances. Indeed, these devices could also benefit from other MBR features, such as the extreme compactness, the direct implementation in a microfluidic circuit, and the absence of impedance-matching material.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Selenium nanoparticles (SeNPs) are specific form of this element that has recently become the subject of numerous research, especially in the field of biomedicine. Several synthesis procedures for ...obtaining SeNPs have been developed so far, among those including reduction of selenium salts are the most frequently used. In this work, it is examined the effect of two stabilizing agents on morphology, size, and crystallinity of obtained SeNPs. For this purpose, bovine serum albumin (BSA) and polyglutamic acid (PGA) were used as stabilizing agents while reduction of sodium selenite with ascorbic acid was elected as a synthesis procedure. Based on the results obtained from scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), selected area electron diffraction (SAED), and measurements of zeta potential, it was determined that the mechanism of stabilization i.e. choice of stabilizing agent can promote different crystalline arrangement within SeNPs. The BSA proved as a more effective stabilizing agent for SeNPs, as it provides obtaining the smaller, more uniform, and amorphous nanoparticles.
The synthesis of Copper Oxide nanoparticles was carried out using tree gum extract as a template. The nanoparticles were characterized by UV–Vis, SEM and XRD. Scanning electron microscopy shows a ...beautiful needle like structure implanted inside the gum framework. Tree gum acts as a good binding agent. X ray diffraction patters show the formation of both CuO and Cu2O nanoparticles of size in the range of 25.40 and 51.56 nm for Moringa Olifera and Acacia Nilotica. The CuO nanoparticles showed good antibacterial activity against two bacterial strains which increase its potential applications. Though the characterization studies of CuO nanoparticles with two different gums showed different ratios of Cu2O and CuO, the antibacterial studies showed fairly similar results.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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