Spherical Shape Research Articles

Investigation on the structure and thermal properties of HDPE/Ta2O5-based nanocomposites

This work reports on the influence of tantalum oxide nanoparticles on the structure and thermal properties of HDPE + Ta2O5 based polymer nanocomposites prepared by ex-situ solution casting method. XRD analysis confirmed the orthorhombic structure of Ta2O5 nanoparticles and an increase in the degree of crystallinity of HDPE/Ta2O5 based nanocomposites after the introduction of Ta2O5 into the HDPE matrix. SEM analysis showed that Ta2O5 nanoparticles were distributed over the surface of the sample in a spherical shape. FT-IR analysis confirmed the presence of Ta –O-Ta stretching vibration bands at 557 cm−1, 584 cm−1, 599 cm−1, 614 cm−1 and Ta-O bands at 824 cm−1, 828 cm−1 for HDPE/3-7 wt%Ta2O5 nanocomposites. The results indicate that small amounts of Ta2O5 nanoparticles (3–7 wt.%) introduced into HDPE act as nucleating agents, which enhance the thermal properties of the HDPE/Ta2O5 nanocomposite. Additionally, the properties of the polymer nanocomposite are influenced by both the structural changes in the polymer matrix and the interactions at the nanoparticle-polymer interface.

Optimization of Mesoporous Silica Nanoparticles of Silymarin through Statistical Design Experiment and Surface Modification by APTES

ABSTRACT: The major goal of this study was to create surface-modified mesoporous silica nanoparticles (MSN) of Silymarin, which has a short half-life and requires regular dosing due to first-pass metabolism. MSN was prepared by cost effective Sol-Gel method, functionalized by (3-Aminoprpyl) triethoxysilane (3-APTES). Evaluated and compared the Silymarin-loaded MSN and APTES functionalized MSN for drug loading, in-vitro dissolution, particle size, surface morphology, surface area, pore size and volume. The percent drug loading and encapsulation efficiency of APTES-functionalized MSN were found to be 92.50±0.72 % percent and 93.20±0.13 %, respectively, which showed a higher value in APTES-functionalized MSN as compared to Silymarin-loaded MSN. Drug release of APTES-functionalized MSN was 92.15 0.03%, which was more as compared to silymarin-loaded MSN. XRD showed that after functionalization silymarin changed from crystalline to amorphous form. SEM indicates that MSN was formed in a spherical shape with particle size of 196.7nm. The BET analysis proved that the nanoparticles had a larger surface area, which was reduced after drug loading and functionalization. Also, the pore size was increased and the pore volume was reduced after functionalization, indicating the incorporation of silymarin. The results suggested that the functionalization might successfully increase adsorption capacity, larger surface area, and increased encapsulation. Mesoporous silica nanoparticles also showed a greater impact on dissolution.

Bactericidal effects of silver nanoparticles prepared by green synthesis

This work aims to paper silver nanoparticles (AgNPs) using the green synthesis method, considered a low-cost and environmentally friendly method, and to study the structural properties of these nanoparticles by X-ray diffraction (XRD), scanning electron microscope (SEM), and atomic force microscopy (AFM) measurements. The results of XRD show that the AgNPs are polycrystalline in the dominant direction (122) (111), (200) (220) (311). By studying the surface morphology, the AFM results showed that the average particle size of the AgNPs is (6.73 nm). In contrast, the SEM results showed that the AgNPs have a spherical shape, and the average particle size is (52.532 nm). The chemical signature of AgNPs was known through FTIR measurement and was found to consist of a group of organic compounds. Through biological application, AgNPs were found to be effective in killing Escherichia coli, which is usually present in contaminated water and infects the intestines of humans and animals. That allows the AgNPs to effectively reduce many human diseases caused by these types of bacteria.

Structural, Magnetic and Electrochemical Properties of Nickel Manganese Ferrite (NixMn1-xFe2O4) Nanoparticles Prepared via Coprecipitation Method

In current work, the co-precipitation approach was effectively used to synthesize NixMn1-xFe2O4 nanoparticles. Thermal stability of the nickel manganese ferrite nanoparticle was observed at temperatures above 390 ºC by TG/DTA analysis. XRD investigation revealed the cubic structure of the synthesized NixMn1-xFe2O4 nanoparticles. The average crystallite size of synthesized nanoparticles determined via Scherrer’s equation, increases linearly with calcination temperature and nickel concentration. The FTIR spectra showed the existence of stretching vibrations of metal oxide, which are ascribed to the formation of nickel manganese ferrite nanoparticles. The surface morphology of NixMn1-xFe2O4 nanoparticles, as observed using FESEM, exhibited a spherical shape. The EDX spectrum indicates the occurrence of Ni, Fe, Mn and O in the synthesized nickel manganese ferrite nanoparticles. The average size of the crystallites, as determined by XRD, closely matches the analysis conducted using HRTEM. The magnetic properties of NixMn1-xFe2O4 nanoparticles were analyzed using VSM. Nickel manganese ferrite nanoparticles exhibit increasing saturation magnetization and coercivity values as nickel concentration increases, indicating soft ferrimagnetic properties and making it appropriate for high-density recording devices. The cyclic voltammetry investigation of Ni0.7Mn0.3Fe2O4 sample, calcinated at 600 ºC, reveals a significant specific capacitance of 590 F g–1 at a scan rate of 2 mV s–1, suggesting its potential use in supercapacitors.

Colloidal Characteristics of Poly(L-Lactic Acid)-b-Poly (ε-Caprolactone) Block Copolymer-Based Nanoparticles Obtained by an Emulsification/Evaporation Method.

Poly(L-lactic acid) (PLLA) and poly(ε-caprolactone) (PCL), two biodegradable and biocompatible polymers that are commonly used for biomedical applications, are, respectively, the result of the ring-opening polymerization of LA and ε-CL, cyclic esters, which can be produced according to several mechanisms (cationic, monomer-activated cationic, anionic, and coordination-insertion), except for L-lactide, which is polymerized only by anionic, cationic, or coordination-insertion polymerization. A series of well-defined PLLA-b-PCL block copolymers have been obtained starting from the same PLLA homopolymer, having a molar mass of 2500 g·mol-1, and being synthesized by coordination-insertion in the presence of tin octoate. PCL blocks were obtained via a cationic-activated monomer mechanism to limit transesterification reactions, and their molar masses varied from 1800 to 18,500 g·mol-1. The physicochemical properties of the copolymers were determined by 1H NMR, SEC, and DSC. Moreover, a series of nanoparticles (NPs) were prepared starting from these polyester-based copolymers by an emulsification/evaporation method. The sizes of the obtained NPs varied between 140 and 150 nm, as a function of the molar mass of the copolymers. Monomodal distribution curves with PDI values under 0.1 were obtained by Dynamic Light Scattering (DLS) and their spherical shape was confirmed by TEM. The increase in the temperature from 25 to 37 °C induced only a very slight decrease in the NP sizes. The results obtained in this preliminary study indicate that NPs have a temperature stability, allowing us to consider their use as drug-loaded nanocarriers for biomedical applications.

Carbonate Nanoparticles Formed by Water–Rock Reactions in Groundwater: Implication of Carbonate Rock Weathering in Carbonate Aquifers

Carbonate rocks are highly reactive and exhibit higher ratios of chemical weathering compared to most other rock types. A chemo-mechanical mechanism, which is particularly effective in groundwater due to higher ion concentrations, is common in fine-grained carbonates at the nanoscale. As a result, the weathering of carbonate aquifers produces a substantial number of carbonate nanoparticles (CNPs). In this study, we utilized high-resolution transmission electron microscopy (HRTEM) to analyze CNPs formed by water–rock reactions in two types of groundwater from Shandong Province, China. Our findings reveal a significant presence of naturally occurring CNPs in groundwater. The HRTEM results show that CNPs display spherical, cubic, hexagonal, and irregular shapes, with some forming aggregates. Energy-dispersive spectrometry indicates that most nanoparticles contain O, C, Ca, and Fe, with some also containing Si, Mg, S, Sr, and Cl. Selected area electron diffraction (SAED) patterns show that CNPs are mainly amorphous, with some crystalline forms. The diverse shapes and complex compositions of these CNPs suggest that they are not man-made but formed through the weathering of carbonate minerals via chemo-mechanical mechanisms. This discovery provides new insights into carbonate mineral evolution and mineralization during weathering. Given their widespread presence, CNPs in groundwater could represent the transportation of elements in the form of particles.

Water purification and biological efficacy of green synthesized Co/Zn-Doped α-Fe2O3 nanoparticles

In the present study, Co/Zn doped α-Fe2O3 (Hematite) nanoparticles (NPs) were synthesized using polyvinylpyrrolidone (PVP) and Azadirachta indica (AI) leaves aqueous extract. The analytical techniques including XRD, UV, SEM, EDX, VSM, Raman, and FTIR, we were able to identify and characterize the structural, morphological and magnetic attributes of the synthesized NPs. The findings demonstrated that the synthesized NPs exhibit homogeneous spherical shapes with particle sizes ranging from 8.64 to 15.32 nm. The NPs have rhombohedral crystal lattices, with crystallite sizes of 23.25 nm for chemically synthesized doped α-Fe2O3 NPs and 12.52 nm for those synthesized using green methods. The magnetic study has shown that the saturation magnetization (Ms) value of NPs, which ranges from 36 to 45 emu/g at ambient temperature, exhibits superparamagnetic properties (300 K). The treatment of industrial wastewater and its reuse for agricultural purposes are the subjects of the current study. Different concentrations of doped α-Fe2O3 NPs were used as photocatalysts to degrade dyes in a bioreactor under UV light in a heterogeneous mixture. The degradation rates achieved were 96.42 % for Congo Red (CR) and 98.36 % for Eosin Yellow (EY). DPPH assays were conducted to evaluate the antioxidant activity of the synthesized doped α-Fe2O3 NPs. The percentage inhibition of DPPH radicals ranged from 71.13 % to 90.35 %. Our findings indicate that AI leaf extract holds promise as a valuable resource for the development of bioactive compounds and environmentally friendly approaches to synthesizing green NPs. This is primarily attributed to the increased accessibility of bioactive components with potent antioxidant properties. The combination of these benefits provides opportunities for novel uses in environmental cleanup, biological applications, and energy conversion.

Orange peel-mediated synthesis of silver nanoparticles with antioxidant and antitumor activities

Orange (Citrus sinensis L.) is a common fruit crop widely distributed worldwide with the peel of its fruits representing about 50% of fruit mass. In the current study, orange peel was employed to mediate the synthesis of silver nanoparticles (AgNPs) in a low-cost green approach. Aqueous extracts of suitably-processed peel were prepared using different extraction methods; and their phytochemical profile was identified. Based on phytochemical screening, amount of main phytochemicals, free radical-scavenging ability, reducing power and antioxidant activity, the peel extract prepared by boiling seemed to be the most promising. Thus, major compounds of this extract were identified by gas chromatography-mass spectrometry. Potency of the peel extract to mediate the synthesis of AgNPs was then monitored by visual observation, UV-visible spectroscopy, energy dispersive X-ray analysis, transmission electron microscopy and zetametry. Color change of the reaction mixture to brown and absorption peak at 450 nm indicated AgNPs formation. Characterization of AgNPs revealed spherical shape, size of 30–40 nm, zeta potential of -18.2 mV and yield conversion of 82%. The as-synthesized AgNPs had antioxidant capacity (free radical-scavenging ability, reducing power and antioxidant activity) lower than that of the orange peel extract. However, these biogenic AgNPs had antitumor activity (IC50 of 16 ppm against HCT-116 and 1.6 ppm against HepG2 cell lines) much higher than the peel extract that was completely non-toxic to the considered cell lines.

Antibacterial Efficacy of AgNPs synthesized from Aloe vera extract and Staphylococcus aureus Culture Supernatant

Biological synthesis of silver nanoparticles (AgNPs) is an emerging method that avoids the need for costly equipment and hazardous chemicals. Therefore, in this study, Aloe vera (AV) extract and culture supernatant of Staphylococcus aureus (CS-S. aureus) were used to reduce and stabilise silver nanoparticles. The NPs were characterized using UV–vis spectrophotometry at 445 nm for AV-AgNP and 444.5 nm for CS-S.aureus AgNP, and the presence of silver was confirmed by energy dispersive X-ray (EDX). Furthermore, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that the AV-CS of S. aureus-AgNPs had irregular and spherical shapes, with average sizes of 18.5 nm for AvAgNPs and 7.03 nm for CS-S. aureus-AgNPs. Additionally, the minimum inhibitory concentration (MIC) of both AgNPs showed a similar reaction. K. pneumoniae, P. aeruginosa, and S. epidermidis were more sensitive to the AgNPs compared to methicillin-resistant Staphylococcus aureus (MRSA). In conclusion, our study used a green method to synthesise silver nanoparticles using AV extract and CS of S. aureus. The NPs showed a remarkable antibacterial effect, especially CS-S. aureus-AgNP, which could have application as a treatment against both Gram-positive and Gram-negative bacteria.

Morphology and elemental composition of individual solid dust particles: From different sources to the atmosphere

This study investigates the morphology and elemental composition of individual solid dust particles from various sources (e.g., thermal power plant, domestic coal combustion, building construction dust, wind-blown dust, Asian dust storm, and road related dust) to the atmosphere under high and low relative humidity (RH) conditions in a coastal city of north China by using high-resolution electron microscopes. The results showed that distinct variations between dust particles from thermal power plant and domestic coal combustion, despite both using coal as fuel. Specifically, 88.6% (by number) of thermal power plant particles were spherical, whereas only 2 out of 347 particles from domestic coal combustion exhibited a spherical shape. Furthermore, domestic coal combustion particles showed a higher proportion of Ca-rich particles compared to those from thermal power plant. The wind-blown dust and Asian dust storm particles were mainly “Si + Al” subtype (52.0% v.s. 75.3%) and Si-dominant subtype (16.4% v.s. 11.7%) particles, which were mainly from crustal sources. However, wind-blown dust contained a higher fraction of Ca-rich (11.6%) and Fe-rich (5.3%) particles than Asian dust. The building construction dust particles primarily consisted of irregular Ca-dominant (39.4%) and “Ca + Si” subtype (29.8%) particles. Road related dust were also mainly Si-rich particles (52.9%), likely from re-suspended soil, along with a notable presence of spherical (8.0%) and Fe-rich particles (19.3%), possibly linked to vehicle emissions and brake wear. Additionally, relative number percentage of Na-rich particles and the average weigh ratios of Na in the atmospheric particles were higher than those from all above-mentioned source samples, suggesting that sea-salt related particles might be an important source of the atmospheric dust at the coastal city. The results indicated that Ca-rich particles were significantly modified by S and NaCl particles might lose Cl through heterogeneous reactions under higher RH.

Preparation and Characterization of Demineralized Bone Extracellular Matrix/Chitosan Porous Microcarriers

Composite porous microcarriers based on demineralized bone extracellular matrix (DBECM) and chitosan (Cs) were prepared using a combined emulsion and freeze-drying method. The effects of digestion by pepsin on the DBECM properties were investigated. The morphologies and porous structure of the DBECM/Cs porous microcarriers were observed by using a scanning electron microscope (SEM). The cytocompatibility of the DBECM/Cs porous microcarriers were studied by using cell counting kit-8 (CCK-8) and calcein acetoxymethyl ester/propidium iodide (CAM/PI). DBECM was digested into small pieces with a loose porous sponge structure and the digested DBECM showed an amorphous state. The resultant DBECM/Cs porous microcarriers showed a spherical shape and an interconnective porous structure. The CCK-8 and CAM/PI analyses indicated that the DBECM/Cs porous microcarriers were non-cytotoxic and showed good biocompatibility, providing a more favorable growth environment for cells.

An intra articular injectable Mitocelle recovers dysfunctional mitochondria in cellular organelle disorders

Mitochondrial dysfunction increases ROS production and is closely related to many degenerative cellular organelle diseases. The NOX4-p22phox axis is a major contributor to ROS production and its dysregulation is expected to disrupt mitochondrial function. However, the field lacks a competitive inhibitor of the NOX4-p22phox interaction. Here, we created a povidone micelle-based Prussian blue nanozyme that we named “Mitocelle” to target the NOX4-p22phox axis, and characterized its impact on the major degenerative cellular organelle disease, osteoarthritis (OA). Mitocelle is composed of FDA-approved and biocompatible materials, has a regular spherical shape, and is approximately 88 nm in diameter. Mitocelle competitively inhibits the NOX4-p22phox interaction, and its uptake by chondrocytes can protect against mitochondrial malfunction. Upon intra-articular injection to an OA mouse model, Mitocelle shows long-term stability, effective uptake into the cartilage matrix, and the ability to attenuate joint degradation. Collectively, our findings suggest that Mitocelle, which functions as a competitive inhibitor of NOX4-p22phox, may be suitable for translational research as a therapeutic for OA and cellular organelle diseases related to dysfunctional mitochondria.

An Extensive Review on Novel Liposomes : Classification, Methodology, Characterization, Current Formulations.

Liposomes are vesicles consisting of a phospholipid, hydrophobic drug, hydrophobic tail, hydrophilic tail, cholesterol, targeting agents, positive and negatively charged lipids, and a drug encapsulated in the center of the phospholipid group having a spherical shape. The phospholipid consists of an equal number of aqueous membranes, making the liposomes an important nanocarrier for the drug delivery to the targeted site. Various liposome-based products have recently been approved and are in clinical trials. This review will discuss the structure, classification, types, and method of liposome preparation and various marketed liposomal products.

화염분무열분해법을 이용한 구형의 고결정성 리튬 과잉 양극재 제조

화염분무열분해법을 이용한 구형의 고결정성 리튬 과잉 양극재 제조

Technetium-99m radiolabeling of graphene quantum dots (GQDs) as a new probe for glioblastoma tumor imaging

Purpose Cancer diagnosis involves a multi-step process. Accurate identification of the tumor, staging and development of cancer cells is crucial for selecting optimal treatments to minimize disease recurrence. Quantum dots (QDs) represent an exciting class of fluorescent nanoprobes in molecular detection and targeted tumor imaging. Materials and methods In this study, graphene quantum dots (GQDs) were synthesized by pyrolysis of citric acid (CA) as a carbon precursor under high temperatures. The morphology of the obtained GQDs was first characterized using physical (TEM and DLS) and spectroscopic (fluorescence, FTIR and UV–Vis) methods. In the following,99mTc-labeled GQDs were prepared in the presence of SnCl2.2H2O as a reducing agent between 95 and 100 °C. The biodistribution and tumor targeting efficiency of radiolabeled GQDs as a novel agent for C6 glioma tumor scintigraphy in an animal model were evaluated. Furthermore, organ uptake, human serum albumin binding and tumor accumulation were measured. Results The TEM image of the prepared GQDs showed a relatively uniform size distribution in the range of diameter 6-9 nm and spherical shape. Radiolabeled GQDs showed a radiochemical yield of >97% (n = 3). Through incubation in human serum, almost 15% of 99mTc-labeled GQDs degraded after 6 h. The amount of uptake in xenograft models of glioma C6 rats was 1.10 ± 0.36% of injection dose per gram after 1 h. The kidneys, intestinal and glioma tumor sites were observed via scintigraphy imaging. Conclusion Our data suggest that 99mTc-labeled GQDs, as a new radiotracer, efficiently accumulate in the tumor site and could be included as a radiotracer for detecting glioma tumors.

Development and Evaluation of Voriconazole Loaded Invasomes Gel for Enhanced Antifungal Activity.

Although it has limited solubility and poor permeability to the skin, voriconazole (VRC) is a viable choice for the topical treatment of fungal infections. Owing to these constraints, treating the inflection requires several injections over an extended period. The goal of this work was to produce a VRC invasome gel with improved topical antifungal activity. The Box-Behnken design (BBD) program was utilized to optimize the IVS after it was created using the thin-film hydration process. The optimized invasome formulation through BBD has 159.9 nm of vesicle size, 68.58% of entrapment efficiency, and 23.5 mV of zeta potential. The spherical shape of the vesicle was revealed using scanning microscopy. According to FTIR spectra, the medication and polymers do not interact. The optimized invasomal VRC gel exhibited an optimum of 345 to 589 cp. Ex-vivo permeation studies of IG4 exhibited a higher flux of 0.168 as compared to pure voriconazole. An antimicrobial study was accepted to check the antimicrobial efficiency of voriconazole gel (IG4). The study confirmed a good zone of inhibition of the fungus infection (C. albicans). The voriconazole invasome’s potential diffusion and antibacterial efficacy are demonstrated here. Invasomal gel was found to be an effective carrier and a desirable strategy for improving the topical distribution of VRC to treat fungal infections.

Effect of Phase Structure on the Viscoelasticity and Mechanical Properties of Isotactic Polypropylene Multicomponents Polymerized with Non-Conjugated α,ω-Diene.

Increasing of rubber content in isotactic polypropylene/ethylene-propylene rubber (iPP/EPR) alloys can extend the applications of this kind of polyolefin. The EPR content and phase structure of isotactic polypropylene multicomponents have great effect on the viscoelasticity and mechanical properties. iPP/EPR in-reactor alloys with a high EPR content were obtained through the in situ crosslinking of EPR chains with α,ω-diene. The morphological observation results indicate that the crosslinked iPP/EPR in-reactor alloys have a good spherical shape with clean and rough external surfaces. The high EPR content is finely dispersed in the crosslinked iPP/EPR alloys in areas ranging in size from tens of nanometers to several micrometers, which implies that a sufficient crosslinking degree of EPR chains can effectively prevent their aggregation and restrict macro-phase separation. The rheological results show a clear plateau in the terminal region, which reveals an entangled polymer chain network in the crosslinked iPP/EPR alloys. The well-dispersed EPR and the bi-continuous phase structure have a great effect on the mechanical properties of the isotactic polypropylene multicomponent which were assessed.

Development of a Polymer Ultrasound Contrast Agent Incorporating Nested Carbon Nanodots

Polymer microbubbles have garnered broad interest as potential theranostic agents. However, the capabilities of polymer MBs can be greatly enhanced, particularly regarding the imaging performance and functional versatility of the platform. This study investigates integrating fluorescent carbon nanodots within polylactic acid (PLA) microbubbles. First, the formulations are characterized by their size, microbubble counts, zeta potential, and resonance frequency. Then, the fluorescence capabilities, nanoparticle loading, and acoustic capabilities are examined. Unmodified (U-), carboxylated (C-), and aminated graphene quantum dots (A-GQDs) were separately suspended and synthesized at a 2% w/w ratio with PLA in the organic phase of the water/oil/water double emulsion process. The new microbubbles were characterized using an AccuSizer, Zetasizer, scanning electron microscopy, fluorescence microscopy and fluorimetry, a custom-built acoustic setup, and clinical ultrasound. The GQD microbubbles were sized between 1.4 and 1.9 µm (U = 1.90, C = 1.44, A = 1.72, Unloaded = 2.02 µm). The U-GQD microbubble exhibited a higher bubble concentration/mg PLA ( p < .05) and the A-GQD microbubbles exhibited the greatest shift in zeta potential. Electron microscopy revealed smooth surfaces and a spherical shape, showing that the nanoparticle addition was not deleterious. The A-GQD microbubbles were specifically detectable using DAPI-filtering with fluorescence microscopy and had the highest TRITC-filtered fluorescence. The C-GQD microbubbles had the highest loading efficiency at 59.4% ( p < .05), and the lowest max acoustic enhancement at 5 MHz (U = 19.8, C = 17.6, A = 18.9, Unloaded = 18.5 dB; p < .05). Additionally, all microbubbles were visible and susceptible to inertial cavitation utilizing clinical ultrasound. The A-GQDs showed promise toward improving the theranostic capabilities of the microbubble platform. They have imbued the most advantageous fluorescence capability and slightly improved backscatter enhancement while retaining all the necessary capabilities of an ultrasound contrast agent. Future studies will investigate the coloading potential of A-GQDs and drug within microbubbles.

Ablation and molten layer flow simulation for plate model of SiO2f/SiO2 composite material using particle method

In this paper, the moving particle semi-implicit method (MPS) is extended from calculating free mobility to simulating the extremely viscous and temperature-dependent molten layer flow of SiO2f/SiO2 composite material under aerodynamic heating conditions, which includes strong heating and shear of incoming flow. A method for applying heat flux and airflow shear, based on the conceptual particle approach, has been established. Heat transfer, melting, solidification, and evaporation behaviors are considered, with temperature-dependent viscosity variations also accounted for. The ablative regression of the plate model is verified using experimental results of the SiO2f/SiO2 composite material, and results from convergence analysis demonstrate the accuracy of the space step size selection. Surface morphology analysis through three-dimensional computation indicates that the extended particle method also accurately describes the surface morphology of SiO2f/SiO2 composite material under aerodynamic heating conditions. Thus, the extended particle method accurately simulates both the ablation process and the surface morphology of the SiO2f/SiO2 composite material. The influences of acceleration and surface tension are discussed. Ablative recession, when subject to acceleration, is smaller than that observed in its absence. When exposed to surface tension, the liquid layer tends to form a spherical shape, and the particles behave as a cohesive unit, resulting in smaller ablative recession than in the absence of surface tension.

Green synthesis of silver nanoparticles for antifungal activity against tomato fusarium wilt caused by Fusariumoxysporum

Fusarium wilt caused by Fusarium oxysporum f. sp. radicis-lycopersici is one of the most important diseases in tomatoes, resulting in severe yield loss and mycotoxin infection in food and feed. The management of Fusarium wilt is based heavily on chemical fungicides, but these chemicals have many environmental concerns. Silver nanoparticles (AgNPs) are gaining importance as emerging resistance-free alternatives of chemical fungicides. In this study, AgNPs were synthesized using the aqueous leaf extract of Viola odorata as a green approach. The antifungal activity of these biosynthesised AgNPs was evaluated in vitro against F. oxysporum using the agar well diffusion method. AgNPs were also evaluated against tomato Fusarium wilt diseases using the foliar spray method in the greenhouse. The characterization of AgNPs revealed that AgNPs were of spherical shape, crystalline in nature, and had an average size of 18 nm. In the antifungal assay, 60 mg/l AgNPs strongly inhibited the growth of F. oxysporum with a growth zone of 18 ± 0.89 mm compared to fungicide (23 ± 1.20 mm) and AgNO3 (52 ± 2.33 mm). Similarly, 60 mg/l of AgNPs when sprayed on tomato plants in the greenhouse showed a survival rate of about 80% with no observable phytotoxic effect. This study provides a first baseline to control Fusarium wilt in tomato using biosynthesised AgNPs without affecting the health of crops.