Iron Alginate Research Articles

Periodontitis therapy with iron alginate and glucose oxidase based on the Fenton reaction

Periodontitis is a frequent chronic inflammatory disease brought on by bacterial infection in the biofilm that forms on the teeth. It can cause the gingival recession and tooth loss, gravely jeopardizing the oral health of people. Current therapies still suffer from issues like bleeding, pain, injured gums, limited treatment effectiveness, a lengthy treatment cycle, and bacterial resistance when using a combination of surgical intervention and antibiotic therapy. Herein, a simple one-step cross-linking process was used to create glucose oxidase (GOD) loaded upon iron alginate (FeAlg/GOD), which has a strong anti-biofilm activity, good biocompatibility, and was successfully used to treat periodontitis caused by biofilms. The results demonstrated that in the presence of a high glucose concentration in the gingival crevicular fluid, FeAlg/GOD could catalyze the conversion of glucose into gluconic acid and hydrogen peroxide. The produced hydrogen peroxide could convert Fe3+ to Fe2+ when it got to the deep periodontal pockets. Following that, the Fenton reaction was activated, producing large amounts of hydroxyl radical (OH). In conclusion, oral plaque biofilms were removed by the FeAlg/GOD. Additionally, successful in vivo treatment was accomplished in rat's experimental periodontitis models, as evidenced by a markedly reduced inflammatory response, decreased bone loss, and made healthier gum tissue. Overall, our biocompatible and antibacterial FeAlg/GOD study presents a novel strategy for effectively speeding periodontal tissue repair and eliminating oral pathogens to tackle the grave threat of biofilm-associated illnesses.

Separable alginate gel spheres encapsulated with La-Fe modified biochar for efficient adsorption of Sb(III) with high capacity

Sb and its compounds have been widely used in various industrial applications. Therefore, the preparation of Sb adsorbents with easy recovery and excellent adsorption levels is an urgent problem that must be resolved. By calcining and treating La/Fe metal–organic frameworks (MOF) biochar as a precursor, a loaded La-Fe-modified water hyacinth biochar was synthesised and used as a filler to synthesise iron alginate composite gel spheres, MBC/algFe. Through a series of static adsorption experiments, the effects of different filler addition ratios, solution pH, reaction time, coexisting ions, and other factors on the adsorption of Sb(III) were investigated. According to the Langmuir model, the maximum adsorption capacity of MBC/algFe at 25 ℃ was 277.8 mg·g−1. The adsorption mechanism mainly involved hydrogen bonding and metal-organic complexation interactions.

Eco-Friendly OSN Membranes Based on Alginate Salts with Variable Nanofiltration Properties

In this work, membranes for organic solvents nanofiltration (OSN) based on a natural polymer, sodium alginate, were fabricated. They are chemically stable in organic solvents, including aprotic polar solvents. The unique advantage of these membranes is the absence of toxic reagents and solvents during their production. This ensures the safety and environmental friendliness of the production process. It has been shown that an operation as simple as changing the cation in alginate (Cu2+, Fe3+, Cr3+, Al3+, Zn2+, Ca2+) makes it possible to control the transport and separating properties of membranes, depending on the organic solvent being separated. Therefore, to isolate RemazolBrilliant Blue with MM = 626 g·mol-1 from ethanol, membranes based on iron alginate with a rejection R = 97% and a permeability of 1.5 kg·m-2·h-1·bar-1 are the most efficient. For isolation of the same solute from DMF and MP, membranes based on calcium alginate with an R of about 90% and a permeability of 0.1-0.2 kg·m-2·h-1·bar-1 are the most efficient. The resulting membranes based on natural biodegradable sodium alginate are competitive compared to membranes based on synthetic polymers.

Green flame-retardant coatings based on iron alginate for polyester fabrics: Thermal stability, flame retardancy and mechanical properties

Polyester (PET) fabrics are widely used in our daily life, but they burn and drip quickly when they encounter flames, and the dripping can cause secondary damage to human bodies. In this study, flame-retardant finishing of PET fabrics was performed by preparing alginate coatings modified with Fe3+. A simple dip-coating technique was used and sodium alginate solution was employed to submerge PET fabrics, after that the coatings were complexed with Fe3+ to endow the flame retardancy of PET fabrics. The micromorphology, mechanical properties, thermal stability, flame retardancy, and burning behaviors of the coated PET fabrics were analyzed. Coated PET fabrics had a limiting oxygen index value of 29%. The vertical flame test illustrated that PET/Iron alginate-2 exhibited excellent self-extinguishing behaviors, no drips appeared. The peak heat release rate of PET/Iron alginate-2 was reduced by 70.3%. In the warp directions, compared with the control, the tensile strength of coated PET textiles increased dramatically. In a word, it is a green method to improve the flame retardancy and anti-dripping of PET fabrics.

Synergistic Effects of Iron Alginate on Improving the Fire Safety and Mechanical Properties of Epoxy Resin/Ammonium Polyphosphate Composites

AbstractIron alginate is chosen as an eco‐friendly synergist to improve the flame retardancy, smoke suppression, and mechanical properties of epoxy resin/ammonium polyphosphate composites (EP/APP). The suitable additive amount of iron alginate further enhances the char‐forming ability in the higher‐temperature range and flame retardancy of EP/APP. EP/APP9.0‐iron alginate1.0 retains a char residue of 33.3% at 700 °C and obtains a limiting oxygen index value of 28.4% and vertical burning test (UL‐94) V‐0 rating, while EP/APP10 has no UL‐94 rating. The burning behaviors of EP/APP9.0‐iron alginate1.0 are also suppressed; and the total smoke production value is much lower than that of EP/APP10. EP/APP9.0‐iron alginate1.0 releases less smoke and flammable fragments. The suitable additive amount of iron alginate boosts the mechanical properties of EP/APP, while APP destroys the mechanical properties of EP. Therefore, the addition of suitable amount of iron alginates can further reduce the fire hazard, and improve the mechanical properties of EP/APP composites.

Nanoreactor activated in situ for starvation-chemodynamic therapy of breast cancer

The nano-drug delivery system activated by the tumour microenvironment (TME) can effectively treat tumours with low toxicity. Based on a high level of reductive GSH in TME and the different coordination properties of Fe ions, this project intended to prepare a GSH-activated cascade catalytic nanoreactor for breast cancer treatment using Fe3+/Fe2+ as the molecular switch. In this study, the glucose oxidase (GOx) loaded iron alginate nano hydrogel (FeAlg/GOx) was prepared by the simple one-step titration method. Results showed that FeAlg/GOx could remain stable during in vivo circulation to avoid hypoglycaemia. When it reached the targeted tumour site, reductive GSH can reduce Fe3+ to Fe2+. Thereafter, FeAlg/GOx nanogel was broken and GOx was released to consume the essential nutrient glucose (Glu) to achieve tumour starvation therapy. Next, the substrate H2O2 generated by the reaction between GOx and Glu can be catalysed by Fe2+ to produce highly cytotoxic •OH in situ, which could further kill tumour cells. The in vivo pharmacodynamics results demonstrated that compared with the control group (V/V0 = 8.36 ± 1.73), FeAlg/GOx group showed the most significant anti-tumour effect with V/V0 of 3.08 ± 1.06. In conclusion, this "inactivated" FeAlg/GOx nanogel can be converted into "activated" therapeutic substances in situ to achieve starvation-chemodynamic combined treatment for breast cancer.

Synthesis of calcium, copper and iron alginate hydrogels doped with Ag nanoparticles produced by chemical reduction method

Calcium, copper and iron alginate hydrogels were synthesized at room temperature via using the internal gelation method from sodium alginate precursor. Also, Ag nanoparticles which were produced with chemical reduction method, were added to hydrogels with different ratios (1%, 5% and 10%) to examine the different ratio effect on hydrogel properties, especially for antibacterial behaviors. According to this experimental design, the dopant ratio efficiency of Ag nanoparticles and comparison of divalent crosslinking metal ions (Ca2+, Cu2+, Fe2+) on antibacterial properties of produced hydrogels were compared. SEM-EDS analyze was done to observe Ag nanoparticles. Both SEM and UV–Vis analyzes showed that particle size of produced Ag were ∼10 nm. The chemical structures of each hydrogel were observed with FTIR studies. After structural properties of hydrogels and Ag nanoparticles examinations, antibacterial behaviors were observed with Escherichia coli and Staphylococcus aureus environments. The results showed that 10 wt% Nano-Ag doped copper alginate against Escherichia coli and 10 wt% Nano-Ag doped copper alginate against Staphylococcus aureus showed the highest antibacterial properties.

Low-Temperature Carbonization of P-Phenylenediamine Guided by Iron Alginate Template for Lithium-Ion Capacitors

Low-Temperature Carbonization of P-Phenylenediamine Guided by Iron Alginate Template for Lithium-Ion Capacitors

Low-temperature carbonization of p-Phenylenediamine guided by an iron alginate template for lithium-ion capacitors

A 3.8 V lithium ion capacitor is constructed using lithiated Fe3C@N-doped C as the electrode.

Iron-alginate beads doped with green synthesised ‘nano-CeO2-ZrO2’ as an effective adsorbent for removal of highly toxic Arsenic-ions from polluted water

ABSTRACT Nano-mixed oxides of ‘CeO2-ZrO2ʹare synthesised through green methods. Sapindus plant seeds skins extract functions as an effective stabilising agent in controlling the size of the nano particles of ‘CeO2-ZrO2ʹ. These mixed oxide nano-particles are embedded in ‘Iron alginate (nCeO2-ZrO2-Fe-alig). The beads are investigated as adsorbent for As (III/V) removal. Extraction conditions are investigated and optimised. Adsorption capacities of the beads are as high as:153.25/140.5 mg/g for As (III)/As (V). Sorption nature is analysed adopting FESEM, EDX, XRD and FTIR investigations. Adsorption mechanism is investigated by various isotherm models. Endothermic nature and spontaneity of sorption process are revealed by thermodynamic studies.Pseudo-second-order model defines adsorption kinetics. Spent adsorbent can be reused. Method developed is applied to treat arsenic-polluted ground water in West Bengal, India.

Photoresponsive Nanometer-Scale Iron Alginate Hydrogels: A Study of Gel–Sol Transition Using a Quartz Crystal Microbalance

Alginate/Fe3+ hydrogels were fabricated on hyaluronic acid (HA) and poly(allylamine hydrochloride) (PAH) multilayers to yield photoresponsive nanometer-scale hydrogels. Light irradiation of the resulting hydrogels induced the photoreduction of "hard" Fe3+ to "soft" Fe2+ cations, leading to changes in the mechanical properties of the hydrogels related to their cross-linking behavior. The buildup and the phototriggered response of the supported alginate hydrogels were followed in situ with a quartz crystal microbalance (QCM) using an open cell allowing light irradiation from an LED source on top of the hydrogel. The results were correlated to the release profiles of folic acid, employed herein as a drug model, obtained from light-irradiated supported iron alginate hydrogels.

Electroanalytical techniques applied to monitoring the electro-Fenton degradation of aromatic imidazolium-based ionic liquids

In this study, the degradation of the ionic liquid (IL) 1,3-dicyclohexylbenzimidazolium chloride ([DCy6bim][Cl]) was carried out by applying an heterogeneous electro-Fenton (HEF) treatment using iron alginate spheres (FeAS) as catalyst. Initial trials were performed at current between 50 and 250 mA, different FeAS dosages (1–5 g), and [DCy6bim][Cl] concentrations (70–280 mg L−1) as key parameters for the characterization of the HEF process. Comparative experiments suggest that high current, low FeAS dosage and low [DCy6bim][Cl] concentration are the best conditions to yield near complete total organic carbon decay after 4 h. In order to evaluate the catalyst behaviour and iron leaching during the degradation of [DCy6bim][Cl], differential pulse voltammetry (DPV), a sensitive and selective electroanalytical technique, was used to monitor the IL degradation, by-products and iron evolution into the solution at high concentration levels. The profile of the voltammetric curves obtained by DPV suggests almost complete cleavage of the cation structure of [DCy6bim][Cl] during the first 120 min. At longer treatment times, DPV revealed the generation of iron complex with chloride and carboxylic acids. Finally, chromatographic analysis of these carboxylic acids and inorganic anions permitted to validate the results obtained by DPV and demonstrated the feasibility of the HEF process for IL degradation.

Heterogeneous electro-Fenton as plausible technology for the degradation of imidazolinium-based ionic liquids

Conventional water treatments are generally inadequate for degradation of emerging pollutants such as ionic liquids (ILs). The use of heterogeneous electro-Fenton (HEF) has attracted great interest, due to its ability to efficiently oxidize a wide range of organic pollutants operating in cycles or in continuous mode. In this study, the removal of a complex IL from the imidazolinium family (1,3-Bis(2,4,6-trimethylphenyl)imidazolinium chloride), by means of HEF using iron alginate spheres as catalyst has been investigated, resulting in significant TOC decay after 6 h. The optimization of the key process parameters (current, IL concentration and catalyst dosage) has been performed using a Box-Behnken experimental design and achieving 76.98% of TOC abatement in 2 h of treatment. Current proved to be a crucial parameter and high catalyst dosage is required to achieve the maximum removal. In addition, an insight about the availability of iron into the reactor and the evolution of several intermediates has been carried out by employing differential pulse voltammetry on screen-printed carbon electrodes. The evolution of the different voltammetric peaks confirmed the influence of iron release, and the generation of several iron complexes has permitted the comprehension of the degradation pathway, which has been validated by chromatographic techniques.

Synthesis of Fe2O3in situ on the surface of mesoporous carbon from alginate as a high-performance anode for lithium-ion batteries

Inspired by the complexation of sodium alginate, we demonstrate here a facile approach for the formation of Fe2O3in situ on the surface of mesoporous carbon (Fe2O3-MC) from alginate. The freeze-dried iron alginate gel (FeA) is converted into mesoporous carbon loaded with Fe2O3 nanoparticles after calcination in vacuum. When used as anode in lithium-ion batteries (LIBs), the obtained Fe2O3-MC composite shows a high reversible capacity of 703mAhg−1 after 50 cycles at 100mAg−1. At a much high current density of 2 A g−1, the anode based on Fe2O3-MC still exhibits a higher reversible capacity (384mAhg−1) than that of the commercially used graphite. The strategy provides a promising facile synthesis route for the fabrication of transition metal oxide-mesoporous carbon composites, which have great potential applications in energy storage.

Thermal degradation properties of biobased iron alginate film

The flame retardancy and pyrolysis behavior of iron alginate were investigated by a microscale combustion calorimeter (MCC), a thermogravimetric analyzer which was coupled with a Fourier transform infrared spectroscopy and a mass spectrometry (TGA-FTIR–MS), and a pyrolysis-gas chromatography-mass spectrometry (Py-GC–MS), respectively. Large differences in the flame retardancy and pyrolysis behavior were observed from the MCC and Py-GC–MS results of iron alginate and sodium alginate. The MCC results showed that iron ions seriously reduced the value of peak heat release rate (PHRR) of alginate at lower temperature. TGA-FTIR–MS and Py-GC–MS results indicated that iron ions influenced the devolatilisation products upon pyrolysis process. The pyrolysis of iron alginate was found to yield much less gaseous products than sodium alginate. And it was suggested that the iron ions strongly catalyzed alginate to produce H2O, CO2 and other gaseous compounds which owned lower combustion heat values, resulting in the improvement of flame retardancy for iron alginate. On the basis of the results of TG-FTIR–MS and Py-GC–MS of iron alginate, the possible thermal degradation mechanism of iron alginate was proposed. The results obtained from this study might supply useful message for comprehending the flame retardant mechanism of alginates.

Heterogeneous Fenton oxidation of ofloxacin drug by iron alginate support

ABSTRACTA new catalytic wet peroxide oxidation of ofloxacin antibiotic is presented in this work. The removal was achieved using a biodegradable sodium alginate-iron material. Several parameters were studied such as iron content, drying duration of the catalytic support, temperature, solid amount and initial drug concentration. The process showed a strong oxidative ability; at optimum conditions, a nearly complete removal of the drug (around 98%) has been reached after three h of treatment. A relatively low decrease of support activity (around 10%) has been observed after three successive oxidation runs and a low iron leaching has been detected (1.2% of the incorporated quantity). The removal of the substrate has been also examined in the absence of hydrogen peroxide in order to discriminate between the contributions of simple adsorption and oxidation processes in the drug disappearance. We also discussed the influence of the studied experimental parameters on the removal kinetic.

New approaches on heterogeneous electro-Fenton treatment of winery wastewater

ABSTRACT A new approach on heterogeneous electro-Fenton of winery wastewater was investigated. The high organic load and the dependence on the wine industry period makes necessary to find an appropriate treatment able to efficiently reduce the environmental risk of this waste. For this purpose, the electro-Fenton process was improved by searching different catalyst supports (manganese alginate gel beads (Mn-AB); iron alginate gel beads (Fe-AB) and iron loaded activated carbon (Fe-AC)) and evaluating the applied potential difference effect. Fe-AC attained a fast decolorization and high degradation results at 15 V. To further understand the main degradation mechanisms on this new catalyst, the contribution of the HO generated in solution and on the anode surface was analyzed. In addition, the positive effect of nickel foam on an extra input of H 2 O 2 production through the generation of O 2 − and its effect on the treatment were proved.

Fenton oxidation of indole-3-acetic acid by iron alginate beads

A heterogeneous Fenton reaction using Iron alginate beads (Fe-AB) was evaluated for the removal of an N-heterocyclic compound indole-3-acetic acid (IAA), which ranked as uremic toxin and an herbicide derivative. The efficiency of the process was studied as a function of the experimental conditions: initial pH; H2O2 dose, temperature, initial concentrations of IAA, and Iron alginate beads loading. Under the best experimental conditions: pH 3.0; H2O2 dose = 9.8 mM; and [alginate beads] = 1.0g L−1, it was possible to remove 100% of 0.11mM IAA in 120 min in a batch reaction at 25°C. The experimental results indicate also that the use of this catalyst allows a significant removal of total organic carbon without significant leaching of Fe ions. A kinetic analysis showed that the removal of IAA followed a first-order kinetics model. In addition, the Fe-AB catalyst can be reused for successive runs, without significant loss of activity.

Targeted removal of trichlorophenol in water by oleic acid-coated nanoscale palladium/zero-valent iron alginate beads

A new material was developed and evaluated for the targeted removal of trichlorophenol (TCP) from among potential interferents which are known to degrade removal activity. To achieve TCP-targeted activity, an alginate bead containing nanoscale palladium/zero-valent iron (Pd/nZVI) was coated with a highly hydrophobic oleic acid layer. The new material (Pd/nZVI-A-O) preferentially sorbed TCP from a mixture of chlorinated phenols into the oleic acid cover layer and subsequently dechlorinated it to phenol. The removal efficacy of TCP by Pd/nZVI-A-O was not affected by co-existing organic substances such as Suwannee River humic acid (SRHA), whereas the material without the oleic acid layer (Pd/nZVI-A) became less effective with increasing SRHA concentration. The inorganic substances nitrate and phosphate significantly reduced the reactivity of Pd/nZVI-A, however, Pd/nZVI-A-O showed similar TCP removal efficacies regardless of the initial inorganic ion concentrations. The influence of bicarbonate on the TCP removal efficacies of both Pd/nZVI-A and Pd/nZVI-A-O was not significant. The findings from this study suggest that Pd/nZVI-A-O, with its targeted, constant reactivity for TCP, would be effective for treating this contaminant in surface water or groundwater containing various competitive substrates.

The flame retardancy and thermal degradation behaviors of trivalent metal-alginate films

Alginate, one of the most abundant biodegradable and sustainable natural resources in the world, is an alternative to petroleum-based polymers (traditional plastics). The coordination structure, flame retardancy, thermal stabilities and degradation mechanism of aluminum alginate and iron alginate films were studied by Fourier transform infrared spectroscopy (FTIR), limited oxygen index (LOI), vertical burning (UL-94) and thermogravimetric analysis tests. The FTIR results showed that the coordination structures of aluminum alginate and iron alginate were correlated to the monodentate geometry and the bidentate chelating mode, respectively. The LOI values were 35·1 and 42·0 for aluminum alginate and iron alginate, respectively, and UL-94 of them achieved V-0 rating without any addition of other flame retardants, while the LOI value of sodium alginate was 24·5 with no UL-94 rating. The TG results showed that the addition of aluminum and iron cations catalyzed the decomposition of alginates in the lower-temperature zones, which exhibited the amounts of residues for aluminum alginate and iron alginate were less than that of sodium alginate. Compared thermal oxidative decomposition behaviors in air with those in N2, the oxygen in air did not take part in the thermal decomposition process in the lower temperatures.