Ferric Oxide Colloid Research Articles

Ferric Oxide Colloid: Towards Green Nano-Fertilizer for Tomato Plant with Enhanced Vegetative Growth and Immune Response Against Fusarium Wilt Disease

Global food crisis due to climate change, pandemic COVID-19 outbreak, and Russia-Ukraine conflict leads to catastrophic consequences; almost 10 percent of the world’s population go to bed hungry daily. Narrative solution for green agriculture with high vegetation and crop yield is mandatory; novel nanomaterials can improve plant immunity and restrain plant diseases. Iron is fundamental nutrient element; it plays vital role in enzyme activity and RNA synthesis; furthermore it is involved in photosynthesis electron-transfer chains. This study reports on the facile synthesis of colloidal ferric oxide nanoparticles as novel nano-fertilizer to promote vegetation and to suppress Fusarium wilt disease in tomato plant. Disease index, protection percent, photosynthetic pigments, and metabolic indicators of resistance in plant as response to induction of systemic resistance (SR) were recorded. Results illustrated that Fe2O3 NPs had antifungal activity against F. oxysporum. Fe2O3 NPs (at 20 µg/mL) was the best treatment and reduced percent disease indexes by 15.62 and gave highly protection against disease by 82.15% relative to untreated infected plants. Fe2O3 NPs treatments in either (non-infected or infected) plants showed improvements in photosynthetic pigments, osmolytes, and antioxidant enzymes activity. The beneficial effects of the synthesized Fe2O3 NPs were extended to increase not only photosynthetic pigments, osmolytes contents but also the activities of peroxidase (POD), polyphenol oxidase (PPO), catalase (CAT) and superoxide dismutase (SOD), enzymes of the healthy and infected tomato plants in comparison with control. For, peroxidase and polyphenol oxidase activities it was found that, application of Fe2O3 NPs (10 µg/mL) on challenged plants offered the best treatments which increased the activities of POD by (34.4%) and PPO by (31.24%). On the other hand, application of Fe2O3 NPs (20 µg/mL) on challenged plants offered the best treatments which increased the activities of CAT by (30.9%), and SOD by (31.33%).

The Impact of Metastable Intermolrecular Nanocomposite Particles on Kinetic Decomposition of Heterocyclic Nitramines Using Advanced Solid‐Phase Decomposition Models

Surface oxygen of oxide catalyst has low coordination number; they are negatively charged. Surface oxygen can act active site for decomposition of energetic nitramines (i.e. HMX). Additionally hydrous catalyst surface can release active OH radicals. Colloidal oxide particles can fulfil these requirements. Furthermore oxide particles can induce thermite reaction with aluminium particles. This study reports on the facile fabrication of colloidal ferric oxide particles of 5 nm average particle size. Aluminium nanoplates of 100 nm particle size were dispersed in ferric oxide colloid. Colloidal Fe2O3/Al binary mixture was integrated into HMX matrix via co-precipitation technique. SEM micrographs demonstrated uniform dispersion of nanothermite particles into energetic matrix. Naonothermite particles experienced dramatic change in HMX thermal behaviour with increase in total heat release by 63% using DSC. The impact of thermite particles on HMX kinetic decomposition was evaluated via an integral isoconversional method using KAS, and Kissinger models. The mean value of apparent activation was reduced by 23.5 and 24.3% using Kissinger and KAS models respectively. This dramatic change in HMX decomposition could be ascribed to ferric oxide reactivity. Facile integration of colloidal thermite particles into HMX can secure high interfacial surface area.

Correction to: Ferric Oxide Colloid: A Novel Nano‑catalyst for Solid Propellants

The original version of this article unfortunately contained a mistake. The authors reused an image taken from a book without referencing them. The missing reference is given below.

Ferric oxide colloid: novel nanocatalyst for heterocyclic nitramines

Highly energetic nitramines such as cyclotetramethylene-tetranitramine (HMX) experience high combustion enthalpy, as well as large volume of gaseous products. Despite the fact that HMX can expose high thermal stability, it exposes low sensitivity to different catalysts. HMX-based propellants will combust at low burning rate. Ferric oxide particles with hydrous surface can offer high catalyzing ability via release of active .OH radicals; active .OH species would attack heterocyclic ring with hydrogen atom abstraction. Highly crystalline, monodispersed Fe2O3 nanoparticles (NPs) of 3.39 nm average particle sizes were developed using hydrothermal processing. Fe2O3NPs were integrated into HMX via co-precipitation technique. The impact of Fe2O3NPs (1 wt%) on HMX thermolysis was investigated using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Fe2O3NPs demonstrated advanced catalytic performance. HMX main exothermic decomposition peak was decreased by 13.0 °C with an increase in decomposition enthalpy by 72.2%. Fe2O3NPs could alter HMX thermolysis from C–N cleavage to hydrogen atom abstraction through the released active surface .OH radical. Additionally released NO2 could be adsorbed on nanocatalyst surface offering high decomposition enthalpy.

Ferric Oxide Colloid: A Novel Nano-catalyst for Solid Propellants

Even though ammonium perchlorate (AP) is universal oxidizer; its initial decomposition is an endothermic process. This feature could render high burning rate regime. Ferric oxide particles are candidate catalyst for AP decomposition. This study reports on sustainable fabrication of colloidal ferric oxide particles. Ferric oxide particles demonstrated stable colloidal suspension with zeta value of 38.5 mV. TEM micrographs revealed mono-dispersed particles of 3 nm average particle size. XRD diffractogram demonstrated highly crystalline structure. Ferric oxide nanoparticles were coated with AP particles via co-precipitation technique. The efficiency of ferric oxide particles as nano-catalyst for AP was evaluated using DSC and TGA. Ferric oxide particles reduced AP initial endothermic decomposition by 40%. The following two exothermic decomposition peaks were combined together into one single peak with an increase in total heat release by 47.5%. These novel catalytic features can extend applications of ferric oxide particles in catalyzed combustion reactions.

Plutonium and neptunium speciation bound to hydrous ferric oxide colloids

Abstract The speciation of plutonium and neptunium in colloid suspension collected from the contaminated aquifer of the “Mayak” site was studied by nano-SIMS, XPS and XANES. At tracer level concentration found in original groundwater sample Pu is sorbed onto hydrous ferric oxide colloids, while at higher concentration relevant to near-field conditions it forms intrinsic PuO 2 × n H 2 O colloids. The formation of such colloids occurs through the reduction of Pu(V) to Pu(IV) upon its sorption.

Chemical Force Microscopy Investigation of Phosphate Adsorption on the Surfaces of Iron(III) Oxyhydroxide Particles

Phosphate-modified AFM tips were prepared by the deposition of self-assembled monolayers (SAMs) of bis(11-thioundecyl) phosphate on Au-coated silicon nitride cantilevers. The properties of the PO 2H-terminated SAMs were investigated by studying the pH-dependent force interactions of the tips with phosphate- and carboxylic acid-terminated SAM control surfaces. The PO 2H functional groups had a p K a of ≈5.0. A chemical force microscopy (CFM) study was conducted on the interactions between the probes and the surfaces of hydrous ferric oxide particles prepared in our laboratory by hydrolytic precipitation from FeCl 3. The forces between PO 2H probes and the hydrous ferric oxide surfaces were seen to exhibit a strong pH dependence, with maximum attractive forces occurring for pH values between 5 and 8. The effects of postprecipitation of the hydrous ferric oxide colloids with orthophosphate, H 2PO 4 −, dimethylphosphate, (CH 3O) 2PO 2H (DMP), and tannic acid (TA) on the adhesive interactions between the PO 2H tips and the solids were also investigated. Attenuated total reflectance infrared spectroscopy (ATR-IR) was used to verify the presence of surface-adsorbed species and zeta potentiometric measurements to determine surface charge on the colloids. We show that the method of chemical force titration using phosphate-terminated tips can differentiate between these various colloids and that it shows promise as a general method for studying this environmentally important class of compounds.

Study of adsorption of rare earth elements by ferric oxide gel

A new secondary ore of rare earth was discovered in the Southwest of China. It is a kind of product of the weathered mineral. The rare earth elements (REE) in it exist probably as ionic characteristic adsorption state in manganesian and ferric oxide colloid mineral, and one bearer of REE is amorphous ferric oxide gel. It is necessary to study the binding state of rare earth elements on manganesian and ferric oxide in order to utilize comprehensively the rare earth resources and avoid latent influence on the environment resulting from the fact that high-content rare earth elements are carried into soil by the mineral efflorescence. A simulating adsorption test of rare earth ions in weak acid media is carried out with ferric oxide gel prepared by sol-gel method. The experimental results show that the characteristics of adsorption isotherm correspond well with the Flory-Huggins equation, but deviated from the Langmuir equation. The standard molar adsorption Gibbs function, standard molar adsorption entropy and standard molar adsorption enthaply are calculated. The measurements of the point of zero charge and isoelectric point show occurrence of the characteristic adsorption. It has been proved that the OH group on the skeleton of ferric oxide gel is the innate cause of the characteristic adsorption.

Availability of colloidal ferric oxides to coastal marine phytoplankton

Cell growth of a coastal marine diatom, Phaeodactylum tricornutum (stock cultures), and two red tide marine flagellates, Heterosigma akashiwo and Gymnodinium mikimotoi (stock cultures), in the presence of soluble chelated Fe(III)-EDTA (1:2) and of four different phases of ferric oxide colloids were experimentally measured in culture experiments at 20°C under 3000 lux fluorescent light. Soluble Fe(III)-EDTA induced the maximal growth rates and cell yields. The short-term uptake rate of iron by H. akashiwo in Fe(III)-EDTA medium was about eight times faster than that in solid amorphous hydrous ferric oxide (Fe2O3·xH2O) medium. In culture experiments supplied with four different ferric oxide forms, the orders of cell yields are amorphous hydrous ferric oxide>γ-FeOOH (lepidocrocite)>Fe5O7(OH)·4H2O (hydrated ferric oxyhydroxide polymer >α-FeOOH (goethite). The specific growth rates (μ) at logarithmic growth phase in Fe(III)-EDTA, amorphous hydrous ferric oxide and γ-FeOOH media were significantly greater than those in Fe5O7 (OH)·4H2O and α-FeOOH media. The thermodynamically stable forms such as Fe5O7(OH)·4H2O and α-FeOOH supported a little or no phytoplankton growth. The iron solublities and/or proton-promoted iron dissolution rates of these colloidal ferric oxides in seawater at 20°C were determined by simple filtration techniques involving γ-activity measurements of 59Fe. The orders of solubilities and estimated dissolution rate constants of these ferric oxides in seawater were consistent with that of cell yields in the culture experiments. These results suggest that the availability of colloidal iron to provide a source of iron for phytoplankton is related to the thermodynamic stability and kinetic lability of the colloidal ferric oxide phases, which probably control the uptake rate of iron by phytoplankton.

Application of thermal lens spectrometry to kinetic speciation studies of metal ions in natural water models with colloidal ligands

Thermal lensing spectrometry (TLS) has been applied to measurement of kinetics with the aim of extending kinetic speciation methods to the low concentrations of metal ions in the presence of colloidal ligands which are important in many natural systems. Using bromination of acetone as a test reaction, it is shown thatn 2–3 significant figure rate constants can be obtained from runs with a total absorbance change of < 0.003. Results are presented on TLS kinetic analysis of hydrous ferric oxide colloids hydrolyzing in the presence of sulfosalicylic acid (SSA) to give FeSSA and on the kinetic analysis of Cu(II) bound to hydrous ferric oxides. In both cases, it is seen that lability is increased at the lower concentrations accessed by TLS as compared to behavior previously reported at concentrations required for analysis by conventional spectrophotometry. That this is a change of the colloids and not a disagreement between TLS and conventional methods is confirmed by demonstrating agreement between the two methods at different concentrations of samples of Cu(II) ion exchanged into zeolite particles of defined size. Noise levels were higher than in bromination of acetone. Studies using colloidal latex particles of known size show that light scattering by nonabsorbing particles causes no interference in TLS absorbance measurements but homodisperse hematite colloids which absorb at the pump laser wavelength cause a significant noise increase.

Kinetic study of the speciation of copper(II) bound to a hydrous ferric oxide

The equilibrium distribution of metal ions over distinguishable sites of a heterogeneous complexant may be determined by monitoring the rate of reaction of the equilibrated system with a ligand capable of stripping the metal ion off the various sites. This kinetic speciation method has the advantage that it indicates not only the equilibrium distribution but also the relative lability of complexes. It may also reveal lability differences among complexes of very similar thermodynamic stability. This kinetic method has been applied to the speciation of Cu-(II) in the presence of a hydrous ferric oxide colloid using a copper-selective color-forming chelating ligand. The pH (4.5-1.0) range spans the region over which an «adsorption edge» is observed in conventional isotherm measurements

The interaction of a soil fulvic acid with precipitating hydrous ferric oxide at pH = 6

A kinetic method of analysis which distinguishes Fe(II) from Fe(III) and Fe(III) forms of various labilities from each other is based on spectrophotometric monitoring of the reaction of Fe(II) with ferrozine. Reduction of Fe(III) with hydroxylamine hydrochloride allows the single colourimetric reagent to detect all forms of Fe. The method is applied to study of the effects of a well characterized soluble soil organic acid sample, a fulvic acid, on the speciation of Fe(III) under conditions (pH = 6) where Fe(III) forms a colloidal hydrous oxide in the absence of fulvic acid. The effect of fulvic acid is to greatly increase the lability of Fe(III) compared to that in a hydrous oxide colloid. However, ultrafiltration and light scattering experiments indicate that the Fe(III) – fulvic acid species is larger than the hydrous ferric oxide colloid particles. Kinetic studies in the absence of hydroxylamine hydrochloride show that fulvic acid can act as a reducing agent for iron in the presence of an Fe(II) complexing agent like ferrozine but neither kinetic studies with an Fe(III) reagent nor Mössbauer spectra suggest significant initial presence of Fe(II) in the aged Fe(III) – fulvic acid samples.