High Nanoparticle Concentrations Research Articles

Effect of Temperature, Oil Type, and Copolymer Concentration on the Long-Term Stability of Oil-in-Water Pickering Nanoemulsions Prepared Using Diblock Copolymer Nanoparticles.

A poly(glycerol monomethacrylate) (PGMA) precursor was chain-extended with 2,2,2-trifluoroethyl methacrylate (TFEMA) via reversible addition-fragmentation chain transfer (RAFT) aqueous emulsion polymerization. Transmission electron microscopy (TEM) studies confirmed the formation of well-defined PGMA52-PTFEMA50 spherical nanoparticles, while dynamic light scattering (DLS) studies indicated a z-average diameter of 26 ± 6 nm. These sterically stabilized diblock copolymer nanoparticles were used as emulsifiers to prepare oil-in-water Pickering nanoemulsions: either n-dodecane or squalane was added to an aqueous dispersion of nanoparticles, followed by high-shear homogenization and high-pressure microfluidization. The Pickering nature of such nanoemulsion droplets was confirmed via cryo-transmission electron microscopy (cryo-TEM). The long-term stability of such Pickering nanoemulsions was evaluated by analytical centrifugation over a four-week period. The n-dodecane droplets grew in size significantly faster than squalane droplets: this is attributed to the higher aqueous solubility of the former oil, which promotes Ostwald ripening. The effect of adding various amounts of squalane to the n-dodecane droplet phase prior to emulsification was also explored. The addition of up to 40% (v/v) squalane led to more stable nanoemulsions, as judged by analytical centrifugation. The nanoparticle adsorption efficiency at the n-dodecane-water interface was assessed by gel permeation chromatography when using nanoparticle concentrations of 4.0, 7.0, or 10% w/w. Increasing the nanoparticle concentration not only produced smaller droplets but also reduced the adsorption efficiency, as confirmed by TEM studies. Furthermore, the effect of varying the nanoparticle concentration (2.5, 5.0, or 10% w/w) on the long-term stability of n-dodecane-in-water Pickering nanoemulsions was explored over a four-week period. Nanoemulsions prepared at higher nanoparticle concentrations were more unstable and exhibited a faster rate of Ostwald ripening. The nanoparticle adsorption efficiency was monitored for an aging nanoemulsion prepared at a copolymer concentration of 2.5% w/w. As the droplets ripened over time, the adsorption efficiency remained constant (∼97%). This suggests that nanoparticles desorbed from the shrinking smaller droplets and then readsorbed onto larger droplets over time. Finally, the effect of temperature on the stability of Pickering nanoemulsions was examined. Storing these Pickering nanoemulsions at elevated temperatures led to faster rates of Ostwald ripening, as expected.

Effect of novel fin distribution on the melting process of thermal storage units

Thermal storage units play a crucial role in storing excess energy and utilizing it when required. Enhancing the thermal performance of these units is of utmost importance for better thermal energy management. Therefore, this paper suggests introducing new fin distributions to decrease the thermal resistance of the storage unit and, thus, enhance the melting process. An octagonal tube and shell unit with nanoparticle-enhanced phase change material are suggested. Three considered fin distributions to improve the heat transfer inside the unit are straight dual-radial fins, tree-like fins, and roots-like fins. Also, since copper has high thermal conductivity, its nanoparticles are incorporated with the phase change material with different concentrations, i.e., 0, 4, and 8 vol%. The Galerkin finite element technique is employed to model the storage unit. The results show that using roots-like fins has a significant effect in reducing the phase change material melting time by 56% and 91% lower than dual-radial fins and tree-like fins, respectively. The higher nanoparticle concentration (8 vol%) can also improve the thermal storage unit performance by 28.9% compared to the pristine phase change materials. Thus, this study recommends using roots-like fins with nanoparticles in the thermal storage units to enhance thermal performance.

Interaction of Fe2O3 nanoparticles with marine microalga Chlorella sorokiniana: Analysis of growth, morphological changes and biochemical composition

The wide utilization of iron-based nanoparticles (NPs) based on their preferential properties has led to the discharge and accumulation of these materials into the aquatic environment. In this regard, a comparative study of different concentrations of α-Fe2O3 NPs and their micro form was conducted using microalga Chlorella sorokiniana up to the stationary growth phase. This study revealed that high concentrations of NPs (100 and 200 mg L−1) imposed a stressful condition on algal cells documented by a reduction in microalga growth, including cell number and specific growth rate. The physical contact between the algal cells and NPs resulted in a shading effect as well as morphological changes validated by scanning electron microscope results. The biochemical composition of C. sorokiniana exposed to high levels of Fe2O3 NPs was also evaluated. The increase in total carbohydrate content of algal cells along with a significant reduction in unsaturated fatty acids was found. Moreover, Fe2O3 NPs exposure induced oxidative stress evidenced by an increase in lipid peroxidation. To cope with oxidative stress, superoxide dismutase activity and antioxidant potential of microalga as defensive mechanisms increased in the culture with high concentrations of NPs. Besides, due to the interactions, microalga tended to form a protective layer from further cell-NP interactions through the secretion of extracellular polymeric substances. Nonetheless, the nano form of Fe2O3 was more toxic than its micro form due to its small size. Overall, this trial may provide additional insight into the toxicological mechanism and safety assessments of Fe2O3 NPs in the aquatic environment.

Nanocomposites comprising PVA/CMC matrix and CNTs/Fe2O3 nanohybrid: A comparative investigation of structural, optical, electrical, and dielectric properties as an application in advanced electrochemical and optoelectronic devices

This work addresses the fabrication of innovative flexible polymer nanocomposite films for electrochemical products made of poly (vinyl alcohol) (PVA), carboxymethyl cellulose (CMC), multi-walled carbon nanotubes (CNTs), and hematite (α-Fe2O3) nanoparticles (NPs) as nanohybrid. The PVA/CMC-CNTs/Fe2O3 nanocomposite films were characterized using various approaches. The PVA/CMC blend polymer matrix shows significant improvements in terms of amorphous nature with the CNTs/Fe2O3 nanofiller content, resulting in an exceedingly flexible polymer backbone and with higher ionic conductivity of the PVA/CMC-CNTs/Fe2O3 nanocomposites films, as reported by the XRD examination. The nanoparticle surfaces and the blend matrix exhibit a significant interaction, as seen by the FTIR spectra. To learn more about how CNTs/Fe2O3 NPs affect the optical characteristics of the PVA/CMC, its optical characteristics were examined. The absorption edge appeared to migrate towards lower photon energy sides upon the addition of CNTs/Fe2O3 NPs to the PVA/CMC matrix. The Eg (direct and indirect) of pure PVA/CMC was considerably decreased from 5.12 to 3.55 eV and 4.23 to 3.01 eV respectively by adding 3.5 wt% of CNTs/Fe2O3 NPs. The results proved the influence of the nanofiller on the host polymer's decreased band gap energy. The blend nanocomposite had a substantially higher AC conductivity compared with the blend, and the PVA/CMC-3.5%CNTs/Fe2O3 nanocomposite had the highest electrical conductivity. It was discovered that while the dielectric loss and dielectric constant increased with the high content of nanoparticles, they reduced with increasing frequency. These findings demonstrated that the produced films had undergone substantial changes, which allows for the use of flexible films made of PVA/CMC-CNTs/Fe2O3 in a variety of electrochemical and optoelectronic applications.

A Novel 3D‐Printed Bi‐Layer Cranial‐Brain Patch Promotes Brain Injury Repair and Bone Tissue Regeneration

AbstractTraumatic brain injury (TBI), recognized as the world's most serious public health problem, currently lacks effective treatment options. The development of the patch has great clinical significance whether it is used as a skull implant material or TBI repair. In response to this critical health challenge, a novel 3D‐printed bi‐layer cranial‐brain patch (SMB6) with dual functionality, addressing both TBI repair and skull regeneration, is developed. In the first layer, the incorporation of high concentrations of mesoporous bioactive glass nanoparticles establishes a microenvironment for bone regeneration. Meanwhile, the second layer, comprised of methacrylated silk fibroin hydrogel, provides essential mechanical support for nanocell membrane vesicles loaded with macrophage colony‐stimulating factor and interleukin‐6. This innovative design aims to interrupt the cascade of secondary brain injury. In experimental models of TBI, SMB6 demonstrates remarkable efficacy in inhibiting brain edema, exerting therapeutic effects on blood vessels, nerves, and inflammation. Additionally, promising outcomes are observed in promoting bone regeneration in skull defect models. This work not only introduces a potential therapeutic patch for TBI‐related diseases but also provides novel insights for the clinical translation of cranial patches.

Seed nano-priming with multiple nanoparticles enhanced the growth parameters of lettuce and mitigated cadmium (Cd) bio-toxicity: An advanced technique for remediation of Cd contaminated environments

Seed nano-priming can be used as an advanced technology for enhancing seed germination, plant growth, and crop productivity; however, the potential role of seed nano-priming in ameliorative cadmium (Cd) bio-toxicity under Cd stress has not yet been sufficiently investigated. Therefore, in this study we investigated the beneficial impacts of seed priming with low (L) and high (H) concentrations of nanoparticles including nSiO2 (50/100 mg L−1), nTiO2 (20/60 mg L−1), nZnO (50/100 mg L−1), nFe3O4 (100/200 mg L−1), nCuO (50/100 mg L−1), and nCeO2 (50/100 mg L−1) on lettuce growth and antioxidant enzyme activities aiming to assess their efficacy for enhancing plant growth and reducing Cd phytotoxicity. The results showed a significant increase in plant growth, biomass production, antioxidant enzyme activities, and photosynthetic efficiency in lettuce treated with nano-primed nSiH + Cd (100 mg L−1), nTiH + Cd (60 mg L−1), and nZnL + Cd (50 mg L−1) under Cd stress. Moreover, nano-priming effectively reduced the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA) in lettuce shoots. Interestingly, nano-primed nSiH + Cd, nTiH + Cd, and nZnL + Cd demonstrated efficient reduction of Cd uptake, less translocation factor of Cd with high tolerance index, ultimately reducing toxicity by stabilizing the root morphology and superior accumulation of critical nutrients (K, Mg, Ca, Fe, and Zn). Thus, this study provides the first evidence of alleviating Cd toxicity in lettuce by using multiple nanoparticles via priming strategy. The findings highlight the potential of nanoparticles (Si, Zn, and Ti) as stress mitigation agents for improved crop growth and yield in Cd contaminated areas, thereby offering a promising and advanced approach for remediation of Cd contaminated environments.

Experimental investigation of a biomass-derived nanofluid with enhanced thermal conductivity as a green, sustainable heat-transfer medium and qualitative comparison via mathematical modelling.

In this study, bio-based carbon nanospheres (CNSs) were synthesized from lignocellulosic-rich groundnut skin (Arachis hypogaea) and tested for their practical application in nanofluids (NFs) for enhanced heat transfer. The CNSs were characterized using various techniques, including FESEM, EDS, XRD, Raman spectroscopy, zeta potential analysis, and FTIR. Thermal conductivity (TC) and viscosity measurements were conducted using transient plane source (TPS) technique with a Hot Disk thermal analyser and discovery hybrid rheometer, respectively. The nanoparticles (NPs) were dispersed in two base fluids: ethylene glycol (EG) and a 60 : 40 mixture of deionized water (DI) and EG. Optimization studies were performed by varying the stirring and measurement times to improve TC values. The results showed that when a power source of 40 mW was applied at a high concentration of nanoparticles (i.e., 0.1 wt%), there was a 91.9% increment in thermal conductivity (TC) compared to the base fluid EG. DI-EG-based nanofluids (NFs) exhibited enhancements of up to 45% compared to the base fluid DI-EG (60 : 40), with a heating power of 80 mW and concentration of 0.1 wt%. These results demonstrated significant TC improvements with NP incorporation. Further experiments were performed by varying the temperature in the range of 30-80 °C with readings taken for every 10 °C increase, which showed a direct relation with the TC values. At 80 °C, EG-based NFs showed increments of 77%, 111.49%, 139.67% and 175% at 0.01, 0.02, 0.05 and 0.1 wt% concentrations of NPs, respectively. It was also found that with the increase in the concentration of NPs, viscosity increased, whereas an increase in the temperature led to a decrease in viscosity. The CNS nanofluid exhibited a Newtonian behaviour with the nanoparticle concentration and temperature, resulting in an approximately 114% enhancement compared to the base fluid when the concentration of CNSs was 0.1 wt% at 30 °C but decreased by up to 18% when the temperature was increased to 90 °C. Using appropriate mathematical models for assessing thermophysical quantities, it was discovered that the model values and experimental values correspond reasonably well. Our method thus validates our experimental results and deepens the understanding of the mechanisms behind enhancing thermal conductivity in biomass-derived nanofluids. In summary, our work advances sustainable nanomaterial synthesis, providing a new solution for boosting thermal conductivity while maintaining environmental integrity, thereby inspiring further research and innovation in this field.

Synthesis and characterization of acrylamide/zeolite nanocomposite hydrogels for aqueous zinc-ion batteries

Polyacrylamide (PAM)/zeolite nanocomposite hydrogels were synthesized as novel gel polymer electrolytes (GPEs) for flexible zinc-ion batteries. The hydrogels were prepared by in-situ free radical polymerization of acrylamide in the presence of dispersed zeolite nanoparticles. Fourier transform infrared spectroscopy confirmed the formation of crosslinked PAM and its interaction with zeolite nanoparticles. Scanning electron microscopy revealed increased porosity and improved zeolite dispersion with higher nanoparticle content. Thermogravimetric analysis indicated enhanced thermal stability with zeolite incorporation. The compressive modulus increased from 0.25 MPa for the neat hydrogel to 1.12 MPa for the nanocomposite containing 20 wt% zeolite, demonstrating improved mechanical strength. Electrochemical impedance spectroscopy showed that the ionic conductivity increased from 0.75 mS/cm for pristine PAM hydrogel to 1.85 mS/cm for the nanocomposite hydrogel with 15 wt% zeolite, attributed to increased porosity and zeolite's ion-exchange capacity. Cyclic voltammetry revealed faster redox kinetics with increasing zeolite content. Galvanostatic cycling demonstrated that the PAM/zeolite nanocomposite GPE with 15 wt% zeolite delivered the optimal zinc-ion battery performance, with a high initial discharge capacity of 125 mAh/gZn, coulombic efficiency exceeding 98 %, and capacity retention of 87 % after 100 cycles. The results indicate that zeolite incorporation significantly enhanced the thermal, mechanical and electrochemical properties of the PAM hydrogels for application as GPEs for flexible zinc-ion batteries.

Spreading dynamics of a droplet upon impact with a liquid film containing solid particles.

This study examines how a deionized water droplet behaves when it centrally collides with a liquid film containing TiO2 nanoparticles at low impact velocities, aiming to understand how nanoparticles affect droplet spreading, in particular its maximum spreading diameter. Typically, we found that both the spreading velocity and dynamic contact angle of the droplet would be similarly affected by increasing TiO2 nanoparticle concentration. During retraction, the droplet's dimensionless spreading diameter oscillates, with more pronounced oscillations at higher nanoparticle concentrations. Moreover, both the droplet's maximum dimensionless rebound height and dynamic contact angle show similar trends with increasing TiO2 nanoparticle concentration. Interestingly, we proved that the influence of the solid-liquid interaction (Stokes force) on the fluid during the spreading process accounts for less than 2% of the surface energy when the droplet reaches its maximum spreading diameter, indicating a negligible effect on droplet spreading. We hypothesize that the droplet's initial energy is fully converted into surface energy and viscous dissipation at maximum spreading diameter, which involves viscous dissipation both between the fluid and the solid wall surface and the fluid and solid particle surface. Based on this, we developed a model for predicting the droplet's maximum spreading diameter that includes parameters associated with the solid particles. Compared to models in the literature that do not consider the effect of solid particles, our model aligns more closely with experimental data. The results indicate that adding solid particles leads to increased viscous dissipation, which in turn reduces the droplet's maximum spreading diameter.

Gold Nanoparticles in Nanomedicine: Unlocking Therapeutic Potential for Precision Diagnosis and Treatment

Nanomedicine is a relatively new interdisciplinary field that combines medicine and nanotechnology. It offers remarkable opportunities for precise diagnosis and treatment. Because of the unique physicochemical properties that they possess, Gold Nanoparticles (GNPs) are used extensively in the field of nanomedicine. This study aims to introduce a novel approach known as Gold Nanoparticles in Nanomedicine (GNP-NM), which uses GNPs to enhance the precision of diagnosis and treatment for patients. Several noteworthy qualities are associated with GNP-NM, including therapeutic efficacy, considerable nanoparticle aggregation, controlled drug discharge, and remarkable biocompatibility. According to the data, the drug is delivered at an average rate of 9.99 µg/h, there is a high concentration of nanoparticles at 1.66E+11 particles/mL, the therapy is highly successful with therapeutic effectiveness of 92.1%, and the cells continue to be highly viable at 92.1% throughout the process. These findings demonstrate the robustness and dependability of the technique, suggesting that it can revolutionize nanomedical treatments significantly. Due to the many benefits that GNP-NM offers, it has the potential to become a platform for the expansion of precision medicine. This highlights the relevance of GNP-NM in defining the future outcomes of nanomedicine applications.

Hydrothermal scenario of buoyancy-driven magnetized multi-walled carbon nanotube-Fe3O4-water hybrid nanofluid flow within a discretely heated circular chamber fitted with fins

This investigation unfolds the hydrothermal changes of magnetized buoyancy-driven multi-walled carbon nanotube (MWCNT)-Fe3O4-water hybrid nanofluidic flow through two centrally placed circular cylinders. Four rectangular T-shaped fins are affixed with the internally placed comparatively small-sized heated cylinder, while the outer cylinder is discretely heated. Four different types of heater-cooler segment arrangements along the outer cylinder periphery are set to execute the investigation. The flow-related leading equations and boundary restrictions are presented and altered to their dimensionless form via suitable similarity transformations. Both nondimensional momentum and energy equations are solved by employing the Galerkin-finite-element technique. Numeric and experimental comparisons are executed to ensure the model’s accuracy. Several streamlines, isotherms, and Nusselt number graphics are revealed to explore the parametric impacts. Results assure accelerated velocity trajectory for Rayleigh numbers, while the flow seems to decelerate for magnetic effect and higher nanoparticle concentrations. Case 1 and Case 3 exhibit higher velocity magnitude and heat transmission out of all four designed cases. Case 1 promotes a 4.68% enhancement in heat transference compared to Case 3 for Rayleigh numbers within the range 104 to 105. Enhanced nanoparticle concentrations assist Case 1 in disclosing 8.13% higher heat transport compared to Case 3. This hydrothermal numeric investigation of natural convective magnetized hybrid nanofluidic inside discretely heated annular chambers might have promising applications in gas turbines, thermal storage devices, heat exchangers, solar receivers, electronic cooling, etc.

Palladium functionalized carbon xerogel nanocomposite for oxygen reduction reaction

The design of an electrocatalyst with high efficiency and stability for oxygen reduction reaction is a crucial parameter in the field of fuel cells. Herein, a facile synthesis for palladium/carbon xerogel is reported. The effect of acidic and basic preparation conditions on the surface area, crystallite size, particle size, and morphology of the palladium/carbon composite was studied. Carbon-isolated spheres with lower crystallite size were obtained in case of acidic preparations than in basic preparations. While, upon application as electro-catalysts for the oxygen reduction reaction in an alkaline medium (0.1 M KOH), better activity was achieved for the palladium/carbon xerogel prepared in basic conditions. A promising limiting current density of −9.8 mA cm−2 is achieved at a rotating speed of 2500 rpm at a scan rate of 5 mV s−1. In addition, the lowest onset potential, Vonset of 0.8 V is also delivered by Pd/CB against RHE. Moreover, enhanced stability that reaches 99 % is obtained after 100th repetitive cycles. This higher activity for Pd/CB may be attributed to (i) its large pore width of 4.1 nm, (ii) higher crystallite size of 23.1 nm, (ii) high concentration of Pd nanoparticles over the carbon surface, and (iv) high content of oxygen surface which can act as additional active sites for oxygen adsorption. The acidic preparation method for palladium-doped-carbon can open the door for future research in preparing well-dispersed and low-size palladium nanoparticles inside the support material, hence reducing its leaching into the liquid phase, and improving its stability.

Effect of Iron Oxide Nanoparticles Prepared by Chemical Method on the Kidneys, Liver and Brain of Male Mice

This study was conducted to investigate the toxic effect of Fe2O3 nanoparticles on the histological changes of the vital organs of male mice. The iron oxide nanomaterials were prepared by chemical method; several doses of it were used at different concentrations, which are 12, 10, 8, 6%. The dose is administered to the mice orally every 48 hours for a period of 60 days. The mice were divided into 6 groups in addition to the control group during the mentioned period; weights were taken for all groups throughout the experiment period. After the completion of the experimental period, the mice of all the mentioned groups were killed. The results of the histological examination with the first and second concentrations did not show any toxic effects or changes in the functional structures of the mentioned organs. while slight changes appeared in the high concentrations of nanoparticles, as it was found that there was some blood congestion and inflammation in the kidneys. There is also congestion in parts of the liver with enlargement in some cells, as well as congestion in the brain, at concentrations of 12.10%. While no structural changes appeared in the first and second concentrations, also in the control group, no changes appeared in the functional structure of the above members. From the results of the study, we conclude that the use of high concentrations of nanoparticles of iron oxide may lead to changes in the functional structures of the kidneys, liver and brain, and may lead to toxic effects on the rest of the body.

Mixed convective magnetohydrodynamic and thermally radiative flow of reactive couple stress MWCNT–Ag/C2H6O2 hybrid nanofluid in a porous vertical channel: Entropy analysis

This paper is concerned with the analysis of the mixed convective magnetohydrodynamic (MHD) flow of a reactive couple stress multi-walled carbon nanotube −Ag/C2H6O2 hybrid nanofluid in a porous vertical channel subjected to quadratic thermal radiation along with a uniform inclined magnetic field applied to the channel walls. The flow is driven by the pressure gradient force and the buoyancy force, which is modeled based on the nonlinear Boussinesq approximation. The temperature-dependent reaction rate of the reactant molecule is derived using the Arrhenius law. The momentum and energy equations that govern the system are modeled in consideration of slip and convective conditions. The governing equations are non-dimensionalized by applying relevant dimensionless parameters and are solved using the homotopy analysis method (HAM). To analyze the irreversibilities in the system, the entropy generation number and the Bejan number are defined. Different important physical parameters developing in the system are considered for analysis, and their effects are scrutinized on the velocity and temperature profiles along with entropy generation. The emphasis is given to the concentration of nanoparticles along with the parameters arising due to the reactions of the fluid, buoyancy force, inclined magnetic field, thermal radiation, and porous material. The analysis reveals that the velocity and temperature of the fluid lowers with a higher concentration of nanoparticles, radiation parameter, and Hartmann number, whereas develops for the higher slip parameters and inclination of the magnetic field. The entropy generation rate increases with rising slip parameters and depletes for higher nanoparticle concentration, radiation parameter, Hartmann number, and inclination angle. The irreversibility in the system remains dominant due to heat transfer with higher Frank-Kameneskii and activation energy parameters, Hartmann number, and angle of inclination.

Evaluation of the toxicity of ZnO nanoparticles obtained by a chemical route on the nasal respiratory epithelium of the biomodel Mus musculus

Zinc oxide nanoparticles (ZnO-NPs) have antimicrobial and a number of other properties, rendering apt their use in biomedicine, environmental remediation, agriculture, and other fields. Given the potential use of these nanoparticles (NPs) in these areas, it is necessary to determine their toxic effects on biological systems. This work therefore analyzed the histological changes in the respiratory nasal epithelium of Mus musculus biomodels exposed to atmospheres containing ZnO-NPs at different concentrations (6, 15, and 40 mg/m3). The NPs were synthesized using the Pechini polymeric complex method and characterized using techniques such as IR and Raman spectroscopies, X-ray diffraction (XRD), transmission (TEM), and scanning electron microscopy (SEM). The ZnO-NPs obtained had a wurtzite-type structure, with spheroidal morphology and a particle size of ~ 50 nm, and the Raman spectrum showed the presence of defects in its structure. The results of the treatments to which the biomodels were subjected showed that the inhalation of ZnO-NPs caused significant morphological changes in their nasal epithelium (squamous metaplasia and vascular congestion) and an acute inflammatory response when exposed to high concentrations of NPs (40 and 15 mg/m3).Graphical

Effects of Silver Nanoparticles on Growth of E. coli: A Study Examining Various Antibiotic Factors

Nanomedicine, an emerging and revolutionary scientific field, warrants greater scientific investigation on the antibacterial applications of AgNPs; hence, this research serves to assess AgNPs’ antibacterial effectiveness on the growth of E. coli while establishing the antibiotic’s optimal conditions for drug delivery. The hypothesis expects that optimal drug delivery of AgNPs will occur at higher concentrations of AgNPs and neutral pHs. To demonstrate this, 1:10 serial AgNP dilutions were placed in E. coli cultures and were treated with the varying environmental factors of concentration and pHs. The results supported our hypotheses with the exception of our pH hypothesis, for the data showed that having a basic pH increased the efficiency of the nanoparticles for all concentrations, except for the 500 µg/L concentration. Nevertheless, higher concentrations of nanoparticles have the highest and fastest increases in their zones of inhibitions. The concentration and pH experiments yielded statistical significance. With nanomedicine’s ability to diagnose, detect, and deliver drugs, its research applications are endless, proving it has a significant impact in the fields of cancer drug delivery, E. coli toxicity, and ectopic pregnancies, and ultimately, having the potential to save over two million lives every year.

Toxic effects and mechanisms of engineered nanoparticles and nanoplastics on lettuce (Lactuca sativa L.)

Engineered nanoparticles (ENPs) and nanoplastics (NPs) are typical nanoparticles in terrestrial environments. Till now, few studies have compared their toxicity and mechanism to plants. Here we investigated the effects of CuO, nZVI ENPs and polystyrene (PS) NPs on lettuce growth, metabolic functions, and microbial community structure. Results showed that low concentrations of nanoparticles decreased root biomass and promoted photosynthetic indicators, whereas increased reactive oxygen species (ROS) were detected in roots exposed to high concentrations of nanoparticles. High-dose CuO ENP exposure significantly raised the MDA content by 124.6 % compared to CK, causing the most severe membrane damage in the roots among the three types of nanoparticles. Although linoleic acid metabolism was down-regulated, the roots alleviated CuO stress by up-regulating galactose metabolism. Uptake of PS by roots similarly caused ROS production and activated the oxidative stress system by altering amino acid and vitamin metabolism. Faster microbial responses to nanoparticles were observed in the nZVI and PS networks. The root toxicity was indirectly mediated by ion release, NP uptake, or ROS generation, ultimately impacting root cell metabolism, rhizospheric microorganism and plant growth. These findings provide theoretical basis for assessing environmental impact of nanoparticles and their possible ecological risks.

Silver nanoparticles as a new sintering additive for the fabrication of YAG:Ce optical luminescent ceramics

AbstractIn this study, silver nanoparticles (NPs) were considered for the first time as a sintering additive in the manufacture of YAG:Ce luminescent ceramics. The influence of the addition of silver NPs on the sintering kinetics of ceramics was investigated. It was found that the addition of Ag NPs in the concentration range of 0.027–0.44 wt% does not result in the formation of secondary phases in YAG:Ce ceramics. It was demonstrated that the light transmission of ceramics is dependent on the concentration of Ag NPs. The use of NPs additive has made it possible to increase the light transmission of ceramics compared with the reference sample without sintering additives. The combination of two sintering additives, TEOS and silver NPs, enables the achievement of enhanced optical transparency in ceramics compared to the individual application of sintering additives. At an optimal silver concentration of 0.11 wt%, in combination with 0.5 wt% TEOS, a ceramic light transmission value of 77% was attained. The study has identified a correlation between the luminescence intensity of YAG:Ce ceramics and the concentration of silver NPs. It was observed that the utilization of low concentrations of the Ag additive had negligible impact on the luminescence properties, whereas the introduction of high concentrations of Ag NPs led to a deterioration in the luminescence and optical transparency of the ceramic.

The mathematical model and analysis of the nanoparticle-stabilized foam displacement

This work proposes a mathematical model to study the foam displacement in porous media stabilized by nanoparticles. We consider a simplification of the Stochastic Bubble Population balance model in local equilibrium, with nanoparticle dependence inspired by the experimental data from the literature. It consists of a non-strictly hyperbolic system of conservation laws, which is solved for the generic initial and injection conditions. We investigate the existence of a global solution as a sequence of waves following the Conservation Laws Theory. When the solution is composed of two or more waves, we present necessary and sufficient conditions to guarantee the compatibility of these wave sequences. The analytical solution for the nanoparticle-stabilized foam displacement in porous media allowed us to quantify the effect of nanoparticles on foam displacement, focusing on the breakthrough time and cumulative water production. In agreement with the literature, when only gas is injected, the breakthrough time and the water production increase with the nanoparticle concentration. Although, we also observe that the effect of nanoparticles is less pronounced for high nanoparticle concentration. Counterintuitively, during gas-water co-injection for a certain parameter range, adding nanoparticles changes the mathematical solution qualitatively, yielding a negligible effect on water production. We discuss the most favorable conditions to observe the action of nanoparticles in laboratory experiments.

Enhanced Thermal Stability of Polymers by Incorporating Novel Surface-Decorated SrTiO3@Graphene Nanoplatelets

Polyvinylidene fluoride (PVDF) is a vital component in the manufacturing of flexible dielectric capacitors due to its exceptional electrical insulation properties. However, its thermal stability remains a significant concern. To address this, we have developed a novel approach in which surface-decorated SrTiO3@Graphene (STO@G) nanoplatelets were prepared using a wet-chemical method. Subsequently, STO@G/PVDF nanocomposite films were synthesized via a solution-casting method using an automatic film coater. X-ray diffraction (XRD) analysis confirmed the presence of the required strontium titanate (SrTiO3), graphene, and STO@G phases. Further, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDXS) were used to examine the STO@G nanoplatelets' even distribution inside the PVDF polymer, even at higher nanoparticle concentrations (10wt.%), revealing no porosity or morphological defects and demonstrating its potential for flexible dielectric capacitors. Thermogravimetric analysis (TGA) was used to assess the thermal stability of 10wt.% STO@G/PVDF nanocomposite films, demonstrating a positive impact on PVDF's thermal stability. Specifically, the thermal stability of PVDF was enhanced until 170 oC. These findings demonstrate that our approach provides a promising strategy to enhance the thermal stability of PVDF for various applications, including energy storage and conversion, sensors, and electronic devices, ultimately improving its reliability and durability by increasing its operational temperature range.