Nanoparticle Materials Research Articles

Synthesis AgO Nanoparticles by Nd:Yag Laser with Different Pulse Energies

One technique used to prepare nanoparticles material is Pulsed Laser Ablation in Liquid (PLAL), Silver Oxide nanoparticles (AgO) were prepared by using this technique, where silver target was submerged in ultra-pure water (UPW) at room temperature after that Nd:Yag laser which characteristics by 1064 nm wavelength, Q-switched, and 6ns pulse duration was used to irradiated silver target. This preparation method was used to study the effects of laser irradiation on Nanoparticles synthesized by used varying laser pulse energy 1000 mJ, 500 mJ, and 100 mJ, with 500 pulses each time on the particle size. Nanoparticles are characterized using XRD, SEM, AFM, and UV-Visible spectroscopy. All the structural peaks determined by the XRD test can be indexed as face-centered cubic (FCC) type, the stronger crystalline orientation is located in the (111) plane. The nanoscale particles have an almost spherical shape as inferred from the SEM images. In (1000) mJ laser pulse energy the best smallest particle size was produced. According to AFM results of all films, the particle size 32.45nm, 64.3nm, and 67.86nm respectively for 1000 mJ, 500 mJ, and 100 mJ , the surface roughness affected and increased as increase the laser energy because the increase particle size and aggregation of partials. UV-Visible spectroscopy measured the absorbance of the silver nanoparticle prepared which is increased as increase pulsed laser ablation energy at wavelength 440 nm.

Defining the reactivity of nanoparticles to peptides through direct peptide reactivity assay (DPRA) using a high pressure liquid chromatography system with a diode array detector.

The possibility of inducing skin sensitization reactions following exposure to various chemicals can lead to skin diseases, and the evaluation of skin sensitivity to such substances is very important. However, as animal tests for skin sensitization are prohibited, the OECD Test Guideline 442C was designated as part of an alternative testing method. Therefore, in this study, the reactivity of cysteine and lysine peptides to nanoparticle substrates was identified through HPLC-DAD analysis according to the skin sensitization animal replacement test method specified in the OECD Test Guideline 442C. In this study, all criteria for skin sensitization experiments specified in OECD Test Guideline 442C were satisfied. As a result of analyzing the disappearance rates of cysteine and lysine peptides for the five types of nanoparticle substrates (TiO2, CeO2, Co3O4, NiO, and Fe2O3) using the established analytical method, all were identified as positive. Therefore, our findings suggest that basic data from this technique can contribute to skin sensitization studies by providing the depletion percentage of cysteine and lysine peptides for nanoparticle materials that have not yet been tested for skin sensitization.

Low-Energy Ion Scattering Intensities from Supported Nanoparticles: The Spherical Cap Model

Supported nanoparticles are of great importance to many technologies like fuel processing and chemical synthesis using catalysts and electrocatalysts, energy storage and generation using fuel cells and batteries, electrochemistry, magnetic information storage, and more. Low-energy ion scattering spectroscopy (LEIS) with noble gas ions like He+ is a powerful tool for the characterization of nanoparticles dispersed across flat support surfaces due to its ability to probe the elemental composition in the topmost atomic layer of a surface, providing quantitative information regarding the size and number density of nanoparticles. In this work, we present a derivation of the LEIS intensities expected from nanoparticles and the support material as a function of the average particle size, their number per unit area, and their contact angle with the support when modeled as spherical caps of the nanoparticle material dispersed over the surface of a flat support. The model assumes that the ion intensities are determined only by the physical blocking of linear ion trajectories and independent of the tilt angle of the local surface relative to the incident and scattered ion directions, an assumption we support by quantitative modeling of published data which tested tilt-angle effects. The model is a generalization to arbitrary contact angles of the hemispherical cap model, which assumes 90° contact angle and has been widely used to model spectroscopic signals in LEIS (and also in Auger and photoelectron spectroscopies) during nanoparticle growth. This new model quantitatively reveals how LEIS signals are sensitive not only to the diameter and number density of the nanoparticle but also to their contact angle (or height/diameter ratio). With the use of additional data (e.g., from microscopy or adsorption microcalorimetry), the model presented here will enable more accurate determination of the average size, shape, and number density of supported nanoparticles based on LEIS intensity measurements.

Synergetic catalysis of Pt/WN-TiO2 nanocomposites for selective hydrogenation of furfural to valuable furfuryl alcohol

Herein, WN-TiO2 with evenly distributed WN nanoparticles (NPs) were facilely synthesized thru one pot evaporation-induced self-assembly (EISA) and nitridation treatment method, as an active host material for precious Pt NPs. A number of characterization techniques were executed to explore the influence of the synthetic approach upon the surface and catalytic properties of the as-synthesized 2wt%Pt/TiO2 and 2wt%Pt/WN-TiO2 catalysts. As compared to 2wt%Pt/TiO2, the 2wt%Pt/WN-TiO2 catalyst exhibited outstanding performance in the selective hydrogenation reaction of Furfural (FAL) to Furfuryl alcohols (FOL) (conversion (97.8%) and selectivity (98.6%)). The 2wt%Pt/WN-TiO2 catalyst also exhibited an impressive recyclability performance for up to five recycles without significant deactivation in activity and selectivity. The superior catalytic hydrogenation performance can be ascribed to the specific nanostructure characteristics of the catalyst arose from the possible synergistic effect occurred between Pt and WN species of 2wt%Pt/WN-TiO2. Besides, the improved homogeneous dispersion of precious Pt NPs causes more exposed active sites of Pt0 species on the surface of 2wt%Pt/WN-TiO2, which is very beneficial for the improved hydrogenation of FAL to FOL.

Functional Molecular Granular Materials: Advances and Perspectives.

Molecular granular materials (MGMs) are constructed with sub-nanoscale molecular clusters (MCs) as the building units and they have recently been observed to possess enriched functionalities distinct from granular materials of colloid nanoparticles. Herein, the birth and recent research advances in MGMs are summarized with the topics covering the precise synthesis of MC assemblies with target topologies, the hierarchical relaxation dynamics and tuneable viscoelasticity, impact-resistant capacity, and proton conductivity performance. The extremely small size of MC renders them two features: bulk diffusive dynamics with energy scale close to thermal fluctuation energy and the dominant volume fraction of surface structures. This finally leads to the hierarchical relaxation dynamics and broadly tuneable viscoelasticity of MGMs although the structural units are with small sizes and low Mw . Therefore, MGMs have been applied as impact resistant materials and proton conductors for the highly tuneable relaxation dynamics.

Effect of Chromium (VI) on the Oxidation of Methylene Blue Dye by Fe3O4/ Chitosan Composite

Heavy metal ion removal from industrial wastewater treatment systems is still difficult because it contains organic contaminants. In this study, functional composite hydrogels with photo Fenton reaction activity were used to decompose organic contaminants. Fe3O4 Nanoparticle, chitosan (CS), and other materials make up the hydrogel. There are different factors that affected Photo-Fenton activity including (pH, H2O2 conc., temp., and exposure period). Atomic force microscopy was used to examine the morphology of the composite and its average diameter (AFM). After 60 minutes of exposure to UV radiation, CS/ Fe3O4 hydrogel composite had degraded methylene blue (M.B.) dye by 92 percent. In the meantime, following an 1hour of visible irradiation, COD (Chemical Oxygen Demand) dropped to 6.1 mg/l.

One-pot hydrothermal synthesis of Pt–TiO2–Carbon as a highly active and stable electrocatalyst for oxygen reduction reaction

Energy conversion from chemical to electrical energy through electrochemical processes using fuel cells is a promising advanced technology to address global environmental issues. However, the development of cathode materials for proton exchange membrane fuel cells (PEMFCs) still faces challenges due to their practical requirements for activity and stability. Introducing oxides into the electrocatalysts is an important way to improve performance. Here, we propose a one-pot hydrothermal synthesis to load Pt and TiO2 nanoparticles (NPs) onto the treated carbon (TC). Through the TiO2 reconciliation between the Pt NPs and the carbon support, the tightly bound Pt–TiO2–TC electrocatalyst shows excellent activity and stability in the oxygen reduction reaction (ORR) due to the strong electronic interaction. At 0.9 V vs. reversible hydrogen electrode, the Pt–TiO2–TC electrocatalyst has about twice the specific activity (SA) and mass activity (MA) of commercial Pt/C. Moreover, the decline of Pt- SA and MA in Pt–TiO2-TC after the accelerated durability test (ADT) was 4.2% and 12.3%, respectively. Therefore, we strongly recommend hybrid metal-oxide-carbon materials with high conductivity, electronic interaction, and carbon corrosion resistance as support materials for Pt NPs to develop Pt-based electrocatalysts for fuel cell applications.

Pd(0)-embedded-lignocellulosic nanomaterials: A bio-tailored reusable catalyst for selective C2–H arylation of free N–H indoles

Lignocellulose-a carbon-neutral renewable source has been utilized as a convenient support material for Pd nanoparticles, without disturbing its natural bio-structure. Herein, we demonstrated a green and rapid assessment of lignocellulosic nanomaterials derived from waste fibrous-feedstock of pomegranate peels using a simple extraction process in aqueous medium. The formation of lignocellulose bio-support has been authenticated by standard spectroscopic analyses. The newly developed features of Pd bio-nanomaterials were exhibited towards directing-group-free catalytic C2–H arylation of indoles with arylboronic acids. Access to vital C2-arylated indoles (62–91%) were achieved with high regioselectivity, reusability for at least five reaction cycles and admirable functionality tolerance of free N–H indole moieties. Further applicability of the catalyst was noted for selective double-functionalization of indole frameworks in a one-pot system.

Emission peak shifted incoherent random laser through the combined effects of coupling of surface plasmons in a triangular shaped silver nanostructure, microbubbles, and the waveguiding mechanism

The random laser (RL) is now becoming an essential tool for various photonics applications, and a plethora of research advancements in RL coupled with developments in the field of techniques of syntheses of various nanostructured materials is taking place. But the realization of tuning the peak emission wavelength of RL is still very challenging. However, in this report we have demonstrated an emission peak shifted tunable low threshold incoherent RL in the visible region in a gain medium of a commercially available dye laser material and by employing the rarely used scatterer materials of triangular silver nanoparticles (TSN), microbubbles, and the waveguiding mechanism. The scattering properties of trapped microbubbles, along with the localized surface plasmon resonance property of TSN of appropriate concentration within waveguided thin films composed of glass substrates, have been methodically investigated to demonstrate the reduction in lasing threshold and tunability in the peak emission wavelength. A two-fold reduction in RL threshold by addition of TSN in the disordered system, along with a considerable narrowing down of the emission spectra to a few nanometers, are obtained. Furthermore, the peak emission wavelength shift of 6 nm is reported by suitably changing the system configuration by the addition of an optimum concentration of TSN along with trapped microbubbles. The as-developed system shows high-quality laser performance with the maximum value of η=0.64, a quantity describing the ratio of the number of stimulated radiative photons within RL and the total number of emissive photons. We propose that the total internal reflections from the microbubble surface, along with plasmonic enhancement and scattering from the TSN, mediate the waveguided RL to achieve the low threshold. Therefore, this report is an early step towards demonstrating efficient RL in a ternary scattering system. Many more avenues for investigating this developing research issue may be helpful for the future development of affordable and robust optoelectronic devices.

Nanotechnology future in food using carbohydrate macromolecules: A state-of-the-art review

It is commonly known that agricultural pest and disease management is achieved through the use of agricultural chemicals and other synthetic compounds, which can contaminate water, soil, and food. Using agrochemicals indiscriminately has negative effects on the environment and poor food quality. In contrast, the world's population is increasing rapidly, and arable land is diminishing daily. Traditional agricultural methods must be replaced by nanotechnology-based treatments that efficiently address both the demands of the present and the needs of the future. As a promising contributor to sustainable agriculture and food production worldwide, nanotechnology has been applied through innovative and resourceful tools. Recent advances in nanomaterial engineering have increased agricultural and food sector production and protected crops using nanoparticles (1000 nm). Agrochemicals, nutrients, and genes can now be distributed to plants in a precise and tailored manner through nanoencapsulation (nanofertilizers, nanopesticides, and genes). Despite the advancement of technology in agriculture, some areas remain unexplored. The various agricultural domains must therefore be updated in priority order. The development of long-lasting and efficient nanoparticle materials will be key to the development of future eco-friendly and nanoparticle-based technologies. We thoroughly covered the many types of nanoscale agro-materials and gave an overview of biological techniques in nano-enabled tactics that can effectively reduce plant biotic and abiotic challenges while potentially boosting plant nutritional values.

Impact of Indium Oxide Nanoparticles Mouth Wash in Prevention of Human Dental Enamel Caries (In Vitro Study)

Background: Despite the fact that fluoride-based remineralization technologies have dominated preventive dentistry for the past century, new and innovative nanomaterials approaches are transforming the industry. A variety of unique metal nanoparticles (NPs) materials are now be easily available to assist remineralization of the dental enamel surface. Objectives: This study was reported to prevent and treat of dental caries using indium oxide NPs suspension solution application in comparison to de-ionized water and sodium fluoride on human tooth enamel by surface microhardness analysis for the surface dental enamel. Materials and Methods: Field emission scanning electron microscopy, X-ray diffraction, and ultraviolet (UV)-visible absorption spectrophotometer were used to evaluate the physical characteristics of an indium oxide NPs suspension solution that was created by the laser ablation in liquid. Microhardness Vickers test was used to evaluate the microhardness of teeth. Teeth samples were 60 teeth that were divided randomly into two phases; each phase consisted of prevented and treated groups with indium oxide NPs, control-positive group was treated with sodium fluoride, and control-negative group was treated with deionized water. Each group was consisted of 10 teeth. Results: The results showed that there was an increase in microhardness be recorded for both preventive and treatment groups after the application of an indium oxide NPs suspension solution. Conclusion: Laser-prepared indium oxide NPs colloidal suspensions were found to be effective as a remineralizing agent to human dental enamel and thus can be considered as an alternative to sodium fluoride mouth wash.

Joule Heating and Viscous Dissipation Effects on a Stretching/Shrinking Cannel Filled by Micropolar Hybrid Nanofluid in Presence Thermal/Solar Radiation

The main goal for this research is to investigate the effect of two composed hybrid nanoparticle materials in heat transfer with account several parameters and in two cases. In addition, exploring how the micropolar hybrid nanofluid (Cu–TiO2) behaves in a shrinking and expansion of the channel. The model considers external factors such as magnetic fields, heat radiation, and solar radiation. The boundary layer approach has been utilized to create transformations that pout the equations of the system in the dimensionless form. The shooting method has been combined with the fourth-order Runge-Kutta-Gill to numerically solve the modified ordinary differential equations. The impacts of the nanoparticles transport on the heat transfer and fluid flow are addressed, and the results are compared to the case of pure water. The velocity, isotherms, angular-velocity, and concentration distributions, are given in tables or graphs. It was found that the effect of heat on the hybrid nanofluids is directly proportional to its velocity and angular velocity. For mass fraction of the two nanofluids φ1 and φ2, the velocity profile f′(η) has a comparable influence for both hybrid nanofluid and nanofluid. The larger quantity of the factors φ1, φ2, M and Q enhance the temperature. For M, φ1 and φ2, the angular velocity profile g(η) has a comparable influence for both hybrid and magnetic parameter. The absorption parameter storing the radiation energy and augmentation of the solar irradiance immersion capacity leads to a greater heat transfer.

Nanoencapsulation of Grapefruit Seed Extract and Cinnamon Oil for Oral Health: Preparation, In Vitro, and Clinical Antimicrobial Activities.

This study aimed to formulate mucoadhesive antimicrobial nanoparticles using natural antimicrobials and biopolymers for oral health and verify their antimicrobial activity in clinical studies. A combination of grapefruit seed extract and cinnamon oil (GCN) and chitosan/carrageenan (CS/CR) were selected as synergistic antimicrobial combinations and mucoadhesive wall materials for nanoparticles, respectively. GCN nanoparticles (NPs; size = 357 nm and polydispersity index = 0.188) prepared by ionic gelation between CS and CR exhibited synergistic antimicrobial activity between grapefruit seed extract and cinnamon oil and significantly higher antimicrobial activity against Streptococcus mutans and sobrinus than free GCN in a time-kill assay. The clinical antibacterial activity of GCN was significantly increased and sustained by nanoencapsulation in the mouth-rinse test and GCN NP-treated drinking yogurt. These results suggest that GCN-loaded CS/CR nanoencapsulation is a promising technique that can inhibit oral bacteria with or without the presence of other food ingredients.

Performance analysis of sodium alanate hydride reactor with different nanofluids

The thermal management of the hydride based hydrogen storage reactor is the key factor to realize the complete storing potential of hydrides. In this regards a hydride reactor filled with sodium alanate in multiple tubes is numerically analyzed for absorption process. Based on various governing equations, a mathematical model of hydride reactor is developed and validated with the help of ANSYS Fluent. The hydride reactor uses mainly water or oil for heat exchange during hydrogen sorption. In the present study conventional heat transfer fluid (HTF) is replaced with the nanofluid since it has a greater heat exchange properties. The CuO/HTF, Al2O3/HTF and MgO/HTF nanofluids are selected based on previous studies and results of numerical experiment are recorded. The outcomes are attained for various parameters such as material and concentration of nanoparticles, supply pressure of hydrogen and inlet temperature of heat exchange fluid. The CuO/HTF nanofluid with concentration of 5 vol% exhibited better rate of absorption in comparison with other vol% concentrations and other selected nanofluids. It shows improvement in hydrogen absorption time up to 14% under selected conditions. Additionally, it is observed that CuO/HTF nanofluid with 5 vol% concentration is thermodynamically superior to other selected nanofluids; as a result it enhances the rate of the heat exchange up to 10% for hydride reactor. It is realized that the performance of CuO/HTF nanofluid with 5 vol% concentration is superior among picked nanofluids. Therefore for the hydride reactor the use the nanofluid is advantageous.

The Impact of Cavities in Different Thermal Applications of Nanofluids: A Review

Nanofluids and nanotechnology are very important in enhancing heat transfer due to the thermal conductivity of their nanoparticles, which play a vital role in heat transfer applications. Researchers have used cavities filled with nanofluids for two decades to increase the heat-transfer rate. This review also highlights a variety of theoretical and experimentally measured cavities by exploring the following parameters: the significance of cavities in nanofluids, the effects of nanoparticle concentration and nanoparticle material, the influence of the inclination angle of cavities, heater and cooler effects, and magnetic field effects in cavities. The different shapes of the cavities have several advantages in multiple applications, e.g., L-shaped cavities used in the cooling systems of nuclear and chemical reactors and electronic components. Open cavities such as ellipsoidal, triangular, trapezoidal, and hexagonal are applied in electronic equipment cooling, building heating and cooling, and automotive applications. Appropriate cavity design conserves energy and produces attractive heat-transfer rates. Circular microchannel heat exchangers perform best. Despite the high performance of circular cavities in micro heat exchangers, square cavities have more applications. The use of nanofluids has been found to improve thermal performance in all the cavities studied. According to the experimental data, nanofluid use has been proven to be a dependable solution for enhancing thermal efficiency. To improve performance, it is suggested that research focus on different shapes of nanoparticles less than 10 nm with the same design of the cavities in microchannel heat exchangers and solar collectors.

The effect of cerium dioxide nanoparticles on the viability of hippocampal neurons in Alzheimer's disease modeling.

The possibilities of using nanoparticle materials based on cerium dioxide (CNPs) are exciting since they are low toxic and have specific redox, antiradical properties. It can be supposed that CNPs' biomedical use is also relevant in neurodegenerative diseases, especially Alzheimer's disease (AD). AD is known as the pathologies leading to progressive dementia in the elderly. The factor that provokes nerve cell death and cognitive impairment in AD is the pathological accumulation of beta-amyloid peptide (Aβ) in the brain tissue. In our studies, we examined the impact of Aβ 1-42 on neuronal death and evaluated the potential neuroprotective properties of CNPs during AD modeling in cell culture. Our findings show that, under AD modeling conditions, the number of necrotic neurons increased from 9.4% in the control to 42.7% when Aβ 1-42 was used. In contrast, CNPs alone showed low toxicity, with no significant increase in the number of necrotic cells compared to control conditions. We further explored the potential of CNPs as a neuroprotective agent against Aβ-induced neuronal death. We found that introducing CNPs 24 h after Aβ 1-42 incubation or prophylactically incubating hippocampal cells with CNPs 24 h before amyloid administration significantly reduced the percentage of necrotic cells to 17.8 and 13.3%, respectively. Our results suggest that CNPs in the cultural media can significantly reduce the number of dead hippocampal neurons in the presence of Aβ, highlighting their neuroprotective properties. These findings suggest that CNPs may hold promise for developing new treatments for AD based on their neuroprotective properties.

Adsorption of Sr(II) cations onto titanium dioxide, doped with Boron atoms

The adsorption of Sr(II) cations by Boron-doped TiO2 was investigated. The adsorbent samples were obtained by liquid-phase sol-gel method using the aqua complex precursor [Ті(ОН2)6]3+‧3Cl- and modifying reagent hydrogen borate Н3ВО3. It was found, that single-phase rutile titanium dioxide or two-phase anatase-rutile oxide materials were formed under the different initial ratios of components. Boron atoms are combined with Oxygen atoms into triangular structural cell ВО3 in the rutile sample 0.5В-ТіО2 and are localized in the surface layer of the nanoparticle material as a grouping =О2ВОН. The introduction of Boron atoms into the structure of the rutile adsorbent causes an increase in its adsorption capacity for the binding of Sr(II) cations in the aqueous electrolyte. The maximal adsorption values for Sr(II) cations by the rutile adsorbent in a neutral electrolyte environment reach 102.3 mg‧g-1, while it is equal to 68.8 mg‧g-1 for the unmodified anatase adsorbent a-TiO2.
 The number of acid adsorption centers ≡ТіОНδ+ on the surface of the rutile adsorbent 0.5В-ТіО2 is ~ 50 units on a surface area of 10 nm2, which is twice the number of centers on the surface of the anatase adsorbent a- ТіО2. Anatase-rutile adsorbents 1.0В-ТіО2 and 1.5В-ТіО2 contain, respectively, 70% and 57% of the anatase phase. They are significantly inferior in adsorption ability toward cations of Sr(II) compared with the rutile adsorbent 0.5В-ТіО2. This is because Boron atoms are mainly localized in the anatase phase and with oxygen atoms form tetrahedral groups of ВО4-.

Improved anti-diabetic and anticancer activities of green synthesized CuO nanoparticles derived from Tabernaemontana divaricate leaf extract.

Copper oxide nanoparticles (CuO NPs) are among the most commonly employed nanoparticle materials owing to their antibacterial qualities, although their primary mechanism of action (MOA) is still not completely understood. CuO NPs are synthesized in this study using leaf extract of Tabernaemontana divaricate (TDCO3), and they are then analyzed using XRD, FT-IR, SEM, and EDX analysis.The zone of inhibition of TDCO3 NPs against both gram-positive (G+) B.subtilis and gram-negative (G-) K. pneumoniae bacteria was 34 mm and 33 mm,respectively. Furthermore, Cu2+/Cu+ ions promote reactive oxygen species and electrostatically bind with the negatively charged teichoic acid in the bacterial cell wall. The anti-inflammatory and anti-diabetics analysis was conducted using standard BSA denaturation and α-amylase inhibition technique with cell inhibition values of 85.66 and 81.18% for TDCO3 NPs. Additionally, the TDCO3 NPs delivered prominent anticancer activity with the lowest IC50 value 18.2 μg/mL in the MTT assay technique against HeLa cancer cells.

Exploring the role of biopolymers and surfactants on the electrical conductivity of water-based CuO, Fe3O4, and hybrid nanofluids

The research on the application of nanofluids in the thermal management of electric components is gaining widespread attention. In this context, and as past studies on nanofluids mainly focus on thermal properties, the investigation of the electrical properties of nanofluids has become important. The role of dispersants on the electrical conductivity of nanofluids stabilized using two biopolymer dispersants, chitosan, and gum arabica (GA), and a synthetic dispersant Sodium Dodecyl Benzoic Sulfate (SDBS) is investigated in this work. The nanofluids are prepared with water, nanoparticles (0.1 wt%), and dispersants (0.05 and 0.5 wt%), and the electrical conductivity is measured to examine the role of nanoparticle materials (CuO, Fe3O4, and CuO + Fe3O4), dispersants, and temperatures (25–40 °C). According to observations, the dispersants significantly affect the electrical conductivity, while nanoparticle material has a minimal impact. At 0.5 wt% concentration, SDBS stabilized nanofluids have electrical conductivity 708.7 times higher than water, whereas, with chitosan and GA, it is 144.2 and 12.8 times higher than water, respectively. CuO-water nanofluids show relatively higher electrical conductivity than Fe3O4 and hybrid CuO + Fe3O4 water nanofluids. Measured electrical conductivity is used for regression analysis using response surface methodology (RSM). Three quadratic nonlinear polynomial equations are developed to predict the electrical conductivity based on the input parameters (dispersant concentration and temperature). The predicted and measured values were in excellent agreement with each other. The current study offers a novel perspective on the electrical behavior of nanofluids with biopolymer dispersants and provides a prediction model for nanofluid electrical conductivity.

The effects of short-term dietary exposure to SiO2 nanoparticle on the domesticated lepidopteran insect model silkworm (Bombyx mori): Evidence from the perspective of multi-omics

Silicon dioxide nanoparticles (nSiO2) are one of the widely utilized nanoparticle (NPSs) materials, and exposure to nSiO2 is ubiquitous. With the increasing commercialization of nSiO2, the potential risk of nSiO2 release to the health and the ecological environment have been attracted more attention. In this study, the domesticated lepidopteran insect model silkworm (Bombyx mori) was utilized to evaluate the biological effects of dietary exposure to nSiO2. Histological investigations showed that nSiO2 exposure resulted in midgut tissue injury in a dose-dependent manner. Larval body mass and cocoon production were reduced by nSiO2 exposure. ROS burst was not triggered, and the activities of antioxidant enzymes were induced in the midgut of silkworm exposure to nSiO2. RNA-sequencing revealed that the differentially expressed genes induced by nSiO2 exposure were predominantly enriched into xenobiotics biodegradation and metabolism, lipid, and amino acid metabolism pathways. 16 S rDNA sequencing revealed that nSiO2 exposure altered the microbial diversity in the gut of the silkworm. Metabolomics analysis showed that the combined uni- and multivariate analysis identified 28 significant differential metabolites from the OPLS-DA model. These significant differential metabolites were predominantly enriched into the metabolic pathways, including purine metabolism and tyrosine metabolism and so. Spearman correlation analysis and the Sankey diagram established the relationship between microbe and metabolites, and some genera may play crucial and pleiotropic functions in the interaction between microbiome and host. These findings indicated that nSiO2 exposure could impact the dysregulation of genes related to xenobiotics metabolism, gut dysbiosis, and metabolic pathways and provided a valuable reference for assessing nSiO2 toxicity from a multi-dimensional perspective.