Search

Higher shear rate possessing homogeneous shear thickening fluids were synthesized using monodispersed silica nanoparticles and polyethylene glycol (PEG). Novel homogeneous methodology was developed for the synthesis of shear thickening fluids using monodispersed silica nanoparticles and PEG. Shear rate of shear thickening fluids (STF) was determined using rheometer at room temperature. The normal shear rate was observed in the range of 100 to 1200 s−1, whereas higher shear rate 2000 s−1 was obtained using monodispersed silica nanoparticles, PEG and shear rate enhancer. Monodispersed silica nanoparticles were synthesized in a typical one-pot using modified Stober's method at room temperature. Precursors were used for the synthesis of monodispersed silica nanoparticles such as tetraethyl orthosilicate (TEOS), ethanol, deionized water and ammonia as catalyst. Particle size of monodispersed silica nanoparticles was in the range of 100–1200 nm, and particle size distribution was varied from 0.000 to 0.221. Synthesis of monodispersed silica nanoparticles was studied by various parameters, namely effect of TEOS concentration, grade of ethyl alcohol, ammonia concentration and water concentration. TEOS concentration effect shows particle size and particle size distribution increases with increase in concentration of TEOS. Even though concentration of TEOS was increased up to 5 times the observation was same for all particle sizes such as 100, 300 and 500 nm. Particularly in the case of 300 nm monodispersed silica nanoparticle synthesis, as TEOS concentration was increased from 1 to 5X (5 times) the particle size was increased from 331.7, 447.8, 497.0, 512.0 and 531.7 nm and particle size distribution was 0.005, 0.000, 0.006, 0.007 and 0.089, respectively. The effect of grade of ethyl alcohol illustrates that Indian rectified spirit shows almost similar results with respect to China make ethyl alcohol. Comparative study of China and Indian rectified spirit shows silica nanoparticle size was 174.6 and 174.2 nm, and particle size distribution was 0.065 and 0.071, respectively. Ammonia concentration effect explains particle size and particle size distribution increases with increase in concentration of ammonia. Water concentration effect shows particle size and particle size distribution increases with increase in concentration of ammonia. Comparative data of water concentration effect for 1316 and 1974 mL shows particle size were 321.7 and 488.0 nm, and particle size distribution was 0.083 and 0.05, respectively, under similar conditions. Morphological studies displayed the shape of the silica nanoparticles was spherical, monodispersed and isolated. A typical TEM image of monodispersed silica nanoparticles for 500 nm was observed with extremely low polydispersity, i.e., 0.000. It is very difficult to get such a type of excellent photograph of monodispersity by Stober's method particularly on large scale. Rheology study of homogeneous shear thickening fluids studied by varying the parameters such as composition of silica nanoparticles with PEG, effect of amount of solvent, effect of refluxing time, effect of additive with respect to the mol. wt. of PEG and effect of additive such as Tannin. All these parameters of STF explored with respect to the shear rate and shear viscosity. Effect of ethanol amount on STF demonstrates the shear rate increases with increase in amount of solvent. Effect of refluxing time on STF exhibits the shear rate increases with increase in refluxing time. Effect of composition based on 500 nm monodispersed silica nanoparticles and PEG 200 with respect to 60:40, 65:35 and 70:30 composition was studied and the results predict that shear rate increases with increase in silica percentage in composition, i.e., 118, 265 and 1200 s−1 for 60:40, 65:35 and 70:30 composition, respectively, whereas maximum viscosity decreases with increase in silica content, i.e., 2.559, 1.420 and 1.200 Pa.s for 60:40, 65:35 and 70:30 composition, respectively. Effect of additive on shear rate and shear viscosity illustrates that shear rate decreases with increase in additive percentage in composition, whereas maximum viscosity increases with increase in additive content. Effect of additives on shear rate and shear viscosity was performed using 65:35 composition with respect to PEG 200 along with PEG 6000 shows shear rate was decreased from 142 to 6.42 s−1 and maximum viscosity was increased from 56.1 to 571.0 Pa.s when the quantity of PEG 6000 was doubled. In general, additive decreases shear rate and increases shear viscosity (maximum). But effect of Tannin as an additive on 500 nm monodispersed silica nanoparticles with PEG 200 using 70:30 composition showed enormous increase in shear rate, i.e., 2000 s−1. This is anomalous behavior of additive was observed. [ABSTRACT FROM AUTHOR]

Background: Ultrasound-triggered sonodynamic therapy (SDT), as a noninvasive approach, has attracted considerable attention in a wide variety of malignant tumors and other diseases. Over the past 2 decades, the number of scientific publications on SDT has increased rapidly. However, there is still a lack of one comprehensive report that summarizes the global research trends and knowledge landscapes in the field of SDT in detail. Thus, we performed a bibliometric analysis on SDT from 2000 to 2021 to track the current hotspots and highlight future directions. Methods: We collected publications on SDT research from the Web of Science Core Collection database. The annual number of publications and citations, major contributors, popular journals, international collaborations, co-cited references and co-occurrence keywords were analyzed and visualized with CiteSpace, VOSviewer, and R-bibliometrix. Results: A total of 701 publications were included. The annual publication output increased from 5 in 2000 to 175 in 2021, and the average growth rate was 18.4%. China was the most productive country with 463 documents (66.05%), and Harbin Medical University was the most prolific institution (N = 73). Ultrasound in Medicine and Biology published the most papers related to SDT. Materials Science, and Chemistry were the research areas receiving the most interest. All the keywords were divided into four different clusters including studies on mechanisms, studies on drug delivery and nanoparticles, studies on cancer therapy, as well as studies on ultrasound and sonosensitizers. In addition to nanomaterials-related studies including nanoparticles, mesoporous silica nanoparticles, nanosheets, liposomes, microbubble and TiO2 nanoparticle, the following research directions such as immunogenic cell death, metal-organic framework, photothermal therapy, hypoxia, tumor microenvironment, chemodynamic therapy, combination therapy, tumor resistance, intensity focused ultrasound, drug delivery, and Staphylococcus aureus also deserve further attention and may continue to explode in the future. Conclusion: SDT has a bright future in the field of cancer treatment, and nanomaterials have increasingly influenced the SDT field with the development of nano-technology. Overall, this comprehensive bibliometric study was the first attempt to analyze the field of SDT, which could provide valuable references for later researchers to better understand the global research trends, hotspots and frontiers in this domain. [ABSTRACT FROM AUTHOR]

Recently, as a novel broad-spectrum fungicide, prothioconazole has attracted much attention. However, the use and registration of prothioconazole in China were restricted due to its metabolites which has great health risks to operators. Therefore, an effectively method to decrease its toxicity is the preparation of the slow release formulation. In this work, the slow release system of prothioconazole-loaded fluorescent mesoporous nanoparticles was prepared. The surface morphology and structure were characterized and analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) surface analysis, thermogravimetric analysis (TGA) and high performance liquid chromatography (HPLC). The release behavior of nanoparticles was evaluated by the dialysis bag method. The growth rate method was employed to study the virulence against Fusahum graminearum Sehw. The optical properties was investigated by fluorescence spectrometer and the transmission of the nanoparticles in fungi and wheat plant were characterized by confocal laser scanning microscopy (CLSM). The results showed that the prepared pesticide-loaded nanoparticles (Pro@FL-MSN) exhibited regular appearance with the maximum drug loading of 27.14% and the average particle size was 139 nm. The results of the release study indicated that the release rate was consistent with the Ritger-Peppas equation. The fungicidal activity of Pro@FL-MSN was similar to that of prothioconazole technical. Moreover, CLSM results showed that the fluorescent silica nanoparticles could be absorbed and transfer into the mycelium and the roots of wheat plant. [ABSTRACT FROM AUTHOR]

Nanosilica has a number of properties that pose advantages in a range of applications. In this study, we performed a series of experiments to prepare nanosilica particles from blast furnace slag. The collected samples were initially treated using nitric acid to remove insoluble silica, and the influence of various key factors on the silica extraction efficiency was examined. The optimum values of liquid-to-solid ratio, temperature, leaching time, and acid concentration were 2.3:1, 120 °C, 90 min, and 50%, respectively. Optimal silica nanoparticles were obtained via filtration and modification using cetyltrimethyl ammonium bromide, a cationic surfactant. The specific surface area (SBET) of unmodified silica was 303.83 m2/g, while that of silica particles modified with cetyltrimethyl ammonium bromide increased to 1506 m2/g, corresponding to ultrafine particles. In addition, this research was performed using a waste by-product and then converted it into a high-quality, valuable product, which can help to mitigate the significant environmental problems caused by blast furnace slag waste in both China and Pakistan. This study may be used as a reference for nanosilica particle preparation from blast furnace slag. [ABSTRACT FROM AUTHOR]

Coalbed methane (CBM) reservoirs in China are featured in remarkable nanosized pores below 200 nm, acknowledged natural cleats, and tectonic fractures. This paper discussed the possibility that a clay free microfoamed drilling fluid could be stabilized by silica nanoparticles (CFMDF-NP) so as to avoid formation damage of CBM drilling. In accordance with the experimental results of foaming capacity and foam stability test, basic drilling fluid performance appraisal, micromorphology observation, swelling test, and gas permeability test, the mechanism of the CFMDF-NP was discussed in this paper. The results indicated that, with 10–20 nm nano-SiO2, the foaming volume of traditional foamed drilling fluid could be improved by up to 50% and an increased half-life period by up to 200%. Chemically treated nano-SiO2 dispersions functioned as a foam stabilizer and a foaming agent as well. The CFMDF-NP had controllable density (0.7~1 g/cm3) and excellent rheological and sealing properties, which could satisfy the drilling requirements of the low pressure coal seams. With 5–8 mm slicing on the contaminated side of coal cores, the contaminated zone could be removed and the recovery rate of gas permeability could reach up to 70%. The CFMDF-NP laid good technical foundation to decrease formation damage of CBM reservoir. [ABSTRACT FROM AUTHOR]

Repairing materials are well-known to play an important role in rehabilitating and extending the service life for hydraulic concrete structures. However, current underwater repairing materials possess several problems, including insufficient bond tensile strength, inconsistency with the deformation of the old substrate, and insufficient underwater self-sealing ability. In the present paper, an experimental study was carried out to evaluate the influence of silica nanoparticles (SNs) on the properties of underwater composite-repairing materials. The underwater deformation, impermeability, bond tensile strength, and compressive strength of the SN-modified underwater composite-repairing materials were used as the properties' evaluation indices. The results show that, within a certain range, the performance of the repairing material increase with increased SN percent. The deformability, impermeability grade, underwater bond tensile strength, and compressive strength of the SN-modified composite underwater repairing materials are 2.2%, 8, 2.91 MPa, and 115.87 MPa, respectively, when the mass ratio of the mortar, the curing agent and the SNs is 8:1:0.002. The proposed material is employed to repair the dam for a hydropower station in Guizhou province, China. Results show the seepage discharge is reduced by 8.6% when the dam is repaired. The annual average generating capacity is increased by 1.104 × 105 kWh. Meanwhile, CO2 and NOx emissions are reduced by 1.049 × 105 and 220.8 kg annually, respectively. [ABSTRACT FROM AUTHOR]

Much attention is currently being paid to the behaviour and effects of engineered silica particles, but there is only limited information available on the natural silica particles. In this study, we have found for the first time that natural silica can occur as spherical amorphous nanoparticles and silica fine disperse particles in the soil aerosol after studying nine areas from northern to southern China. These particles are usually 10 to 600 nm in diameter and contain a high content of impurities. Amorphous nature of the particles has been proved by the electron diffraction images. These findings indicate that nanoparticles and fine disperse particles in vapor phase could be an important transport form for natural silica and during the transportation in the vapor phases many elements could also accompany nanoparticles and finely disperse particles. The aggregative growth of SiO 2 nanoparticles is also observed for the first time in the natural system. In addition, these particles may be a perfect candidate to prospect blind ore. [ABSTRACT FROM AUTHOR]

Invited for this month's cover is the group of Dr. Hua Dong from Chengdu University of Technology, China. The cover picture shows a nonmetal catalyst (SiO2@H+PEI) that promotes hydrogen production by hydrolysis of NaBH4. This newly developed catalyst, which is fabricated by covalently modifying SiO2 nanoparticles with protonated poly(ethylene imime), provides a promising choice for the cheap and efficient catalysis of NaBH4 hydrolysis. Read the full text of the article at10.1002/cplu.201900609. [ABSTRACT FROM AUTHOR]

Cardiovascular malady (CVM) isn't just the essential driver of death in created western nations, yet additionally, its sickness load is expanding in China. Oxidative pressure initiated free radicals assume a basic job in cell forms involved in atherosclerosis and numerous other heart illnesses. Quercetin (QC) is cancer prevention agents medicate which is demonstrated that successfully secures against CVMs. Encapsulations of medications in polymeric materials are generally utilized in creating continued and controllable medication discharge, or to keep away from the debasement of non-discharged medications. In this present work, a novel arrangement of polymeric superparamagnetic nano-silica (SiN)@poly(lactic- co -glycolic acid) (PLGA) (SiN@PLGA) stacked with QC was created by means of lyophilization method so as to improve poor watery solvency and steadiness of the medication with the point of preventing atherosclerosis. The aftereffects of SEM investigation and the checking, TEM affirmed the manufacture of the circular nanocomposite, smooth surface, and thin size dispersion. The discharge profile of QC from the particles was explored by deciding the medication sum discharged at explicit interims for by iridescence. The data got from this investigation encourages the structure and manufacture of nanocomposite as conceivable conveyance frameworks for epitome, assurance and controlled arrival of the flavonoid QC which is expecting to secure against CVMs. Unlabelled Image • SiN@PLGA-polymeric biocomposite of quercetin were developed. • SiN@QC-PLGA nanocarrier showed significant drug release. • SiN@QC-PLGA nanocarrier showed significant in vitro cardiac proteins expression activity. • SiN@QC-PLGA nanocarrier show negligible toxicity to the mice. [ABSTRACT FROM AUTHOR]