Incorporation Of Magnetite Nanoparticles Research Articles

Magnetic Chitosan Bionanocomposite Films as a Versatile Platform for Biomedical Hyperthermia.

Responsive magnetic nanomaterials offer significant advantages for innovative therapies, for instance, in cancer treatments that exploit on-demand delivery on alternating magnetic field (AMF) stimulus. In this work, biocompatible magnetic bionanocomposite films are fabricated from chitosan by film casting with incorporation of magnetite nanoparticles (MNPs) produced by facile one pot synthesis. The influence of synthesis conditions and MNP concentration on the films' heating efficiency and heat dissipation are evaluated through spatio-temporal mapping of the surface temperature changes by video-thermography. The cast films have a thickness below 100µm, and upon exposure to AMF (663kHz, 12.8 kA m-1), induce exceptionally strong heating, reaching a maximum temperature increase of 82 °C within 270 s irradiation. Further, it is demonstrated that the films can serve as substrates that supply heat for multiple hyperthermia scenarios, including: i) non-contact automated heating of cell culture medium, ii) heating of gelatine-based hydrogels of different shapes, and iii) killing of cancerous melanoma cells. The films are versatile components for non-contact stimulus with translational potential in multiple biomedical applications.

A Multiple Remotely Controlled Platform from Recyclable Polyurethane Composite Network with Shape-Memory Effect and Self-Healing Ability.

Stimuli-responsive materials can transform from temporary to permanent shapes by specific external triggers. However, the damage might inevitably occur to them when exposed to complex environments, causing a significant reduction in their lifetime and quality. In this study, recyclable remotely controlled shape-changing polyurethane composite with self-healing compacity is developed from polyethylene glycol, polytetrahydrofuran diol using isophorone diisocyanate as crosslinker. After the incorporation of magnetite nanoparticles (MNPs), remote heating could be generated by near-infrared irradiation and alternating magnetic fields. The results show that MNPs are uniformly distributed in the smart networks, resulting in tunable temperature changes of the polymer composite material under various direct/indirect triggering in bending experiments, presenting different shape recovery rates. Moreover, to enhance the self-healing capability, a disulfide bond is introduced into the polymer networks, and the results show that highly efficient and rapid healing could be achieved from tensile tests, scanning electron microscopy as well as optical microscopy. Additionally, the synergistic effect of transesterification and the dynamic exchange of disulfide bonds brin the networks reproducibility for recycling use. The obtained material is promising to be an alternative material for soft robots and smart sensors.

Remote Spatiotemporal Control of a Magnetic and Electroconductive Hydrogel Network via Magnetic Fields for Soft Electronic Applications.

Multifunctional hydrogels are a class of materials offering new opportunities for interfacing living organisms with machines due to their mechanical compliance, biocompatibility, and capacity to be triggered by external stimuli. Here, we report a dual magnetic- and electric-stimuli-responsive hydrogel with the capacity to be disassembled and reassembled up to three times through reversible cross-links. This allows its use as an electronic device (e.g., temperature sensor) in the cross-linked state and spatiotemporal control through narrow channels in the disassembled state via the application of magnetic fields, followed by reassembly. The hydrogel consists of an interpenetrated polymer network of alginate (Alg) and poly(3,4-ethylenedioxythiophene) (PEDOT), which imparts mechanical and electrical properties, respectively. In addition, the incorporation of magnetite nanoparticles (Fe3O4 NPs) endows the hydrogel with magnetic properties. After structural, (electro)chemical, and physical characterization, we successfully performed dynamic and continuous transport of the hydrogel through disassembly, transporting the polymer–Fe3O4 NP aggregates toward a target using magnetic fields and its final reassembly to recover the multifunctional hydrogel in the cross-linked state. We also successfully tested the PEDOT/Alg/Fe3O4 NP hydrogel for temperature sensing and magnetic hyperthermia after various disassembly/re-cross-linking cycles. The present methodology can pave the way to a new generation of soft electronic devices with the capacity to be remotely transported.

Nano Iron Oxide-PCL Composite as an Improved Soft Tissue Scaffold

Iron oxide nanoparticles were employed to fabricate a soft tissue scaffold with enhanced physicochemical and biological characteristics. Growth promotion effect of L-lysine coated magnetite (Lys@Fe3O4) nanoparticles on the liver cell lines was proved previously. So, in the current experiment these nanoparticles were employed to fabricate a soft tissue scaffold with growth promoting effect on the liver cells. Lys@Fe3O4 nanoparticles were synthesized via co-precipitation reaction. Resulted particles were ~7 nm in diameter and various concentrations (3, 5, and 10 wt%) of these nanoparticles were used to fabricate nanocomposite PCL fibers. Electrospinning technique was employed and physicochemical characteristics of the resulted nanofibers were evaluated. Electron micrographs and EDX-mapping analysis showed that nanoparticles were well dispersed in the PCL fibers and no bead structure were formed. As expected, incorporation of Lys@Fe3O4 to the PCL nanofibers resulted in a reduction in hydrophobicity of the scaffold. Nanocomposite scaffolds were shown increased tensile strength with increasing concentration of employed nanoparticles. In contrast to PCL scaffold, nearly 150% increase in the cell viability was observed after 3-days exposure to the nanocomposite scaffolds. This study indicates that incorporation of magnetite nanoparticles in the PCL fibers make them more prone to cell attachment. However, incorporated nanoparticles can provide the attached cells with valuable iron element and consequently promote the cells growth rate. Based on the results, magnetite enriched PCL nanofibers could be introduced as a scaffold to enhance the biological performance for liver tissue engineering purposes.

Selective Adsorption of Aqueous Diclofenac Sodium, Naproxen Sodium, and Ibuprofen Using a Stable Fe3O4-FeBTC Metal-Organic Frameworka.

The FeBTC metal–organic framework (MOF) incorporated with magnetite is proposed as a novel material to solve water contamination with last generation pollutants. The material was synthesized by in situ solvothermal methods, and Fe3O4 nanoparticles were added during FeBTC MOF synthesis and used in drug adsorption. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and Raman spectroscopy characterized the materials, with N2-physisorption at 77 K. Pseudo-second-order kinetic and Freundlich models were used to describe the adsorption process. The thermodynamic study revealed that the adsorption of three drugs was a feasible, spontaneous exothermic process. The incorporation of magnetite nanoparticles in the FeBTC increased the adsorption capacity of pristine FeBTC. The Fe3O4–FeBTC material showed a maximum adsorption capacity for diclofenac sodium (DCF), then by ibuprofen (IB), and to a lesser extent by naproxen sodium (NS). Additionally, hybridization of the FeBTC with magnetite nanoparticles reinforced the most vulnerable part of the MOF, increasing the stability of its thermal and aqueous media. The electrostatic interaction, H-bonding, and interactions in the open-metal sites played vital roles in the drug adsorption. The sites’ competition in the multicomponent mixture’s adsorption showed selective adsorption (DCF) and (NS). This work shows how superficial modification with a low-surface-area MOF can achieve significant adsorption results in water pollutants.

Anisotropic Magnetism in Gradient Porous Carbon Composite Aerogels

Porosity is of high importance for functional materials, as it allows for high surface areas and the accessibility of materials. While the fundamental interplay between different pore sizes and functionalities is quite well understood, few studies on gradually changing properties in a material exist. To date, only a few examples of such materials have been synthesized successfully. Herein, we present a facile method for synthesizing macroscopic carbon aerogels with locally changing pore sizes and functionalities. We used ultracentrifugation to fractionate differently functionalized and sized polystyrene nanoparticles. The assembly into gradient templates was conducted in a resorcinol–formaldehyde (RF) sol, which acted as a liquid phase and carbon precursor. We show that the modification of nanoparticles and a sol–gel precursor is a powerful tool for introducing dopants (sulfur and phosphorous) and metal nanoparticles (e.g., Ni) into gradient porous carbons formed during the carbonization of the RF sol. Understanding the underlying interactions between particles and precursors will lead to a plethora of possibilities in the material design of complex functionally graded materials. We showed this by exchanging parts of the template with magnetite–polystyrene composites as templating nanoparticles. This led to the incorporation of magnetite nanoparticles in the formed gradient porous carbon aerogels. Finally, gradually increasing concentrations of magnetite were obtained, ultimately leading to macroscopic carbon aerogels with locally changing magnetic properties, while the graded porosity was maintained.

Microwave – Assisted production of hydrophilic carbon-based magnetic nanocomposites from saw-dust for elevating oil from oil field waste water

The current study aimed at developing new advanced, environmentally friendly and cost-effective materials in order to facilitate oil/water separation. In this study, novel synthesis of activated carbon was achieved from saw-dust which is considered as an environmentally hazardous waste. Moreover, it was further modified by the incorporation of magnetite nanoparticles. Moreover, hydrophilic nanomaterials i.e. silica and bismuth oxide nanoparticles, were added and the fabricated nanocomposites were referred to as MAC/SiO2 and MAC/Bi2O3. The prepared nanocomposites were synthesized via green microwave-assisted pyrolysis of saw-dust followed by incorporation of nanomaterials via co-precipitation method. Characterization of the prepared nano materials was achieved by using several analytical techniques including; FESEM, HR-TEM, DLS and Zeta potential, TGA, FTIR, and XRD. A column separator was designed for oil water recovery by the prepared nanocomposite materials. Different parameters which affect the oil-separation process were studied including; amount of nanocomposites, initial oil concentration, pH and water salinity. This was performed by the response surface methodology (RSM). An optimal design of experiment (ODOE) was employed to investigate the effect of the individual and the interaction between the studied parameters. It was designed at 95% confidence. Afterwards, the simulation of oil-recovery efficiency by nanocomposites were optimized and modulated under these operational parameters assisted by ANOVA analysis. The data were fitted with polynomial equation with R2 value of ≈0.99 and low error analysis was obtained between the experimental results and the predicted values. High oil recovery with oil separation rate was attained at optimum conditions even after 5 cycles and reached 99.4% for MAC/SiO2,93.9% for MAC and 90.6% for MAC/Bi2O3.

Synthesis and optimization of reaction variables in the preparation of pine-magnetite composite for removal of methylene blue dye

Purity and quality of water is a basic concern to mankind. The environment is deteriorating daily due to industrial pollution. Dyes discharged together with industrial textile wastewaters are main organic pollutants because they are highly visible and undesirable even at low concentrations in water. Natural biomaterials have been applied previously as adsorbents for dyes from aqueous solution, but their application has been limited by low adsorption capacity. In this study, pine cone biomass, a naturally occurring agricultural waste was treated with 0.15 M NaOH solution to remove unwanted plant extracts and iron oxide magnetic particles which was coated on the pine surface. The main focus of the study was to prepare and optimize the working conditions for the pine magnetite composite. The bionanocomposite material was synthesized by a complete co-precipitation method of Fe2+: Fe3+ (1:2) under alkaline conditions in an inert environment followed by addition of the biomass. The variables used for the experiments were volume of NH4OH varied from 5 to 40 ml, reaction temperature varied from 40 to 100 °C, effect of time varied from 15 to 60 min and mass from 1.0 to 3.5 g. Incorporation of magnetite nanoparticles onto the surface of the biomass was confirmed by FTIR, TGA and XRD. TEM showed particles size ranging from 8.23–11.73 nm. XRF showed the iron oxide content ranging from 57 to 74%.

Enabling magnetic resonance imaging of hollow-core microstructured optical fibers via nanocomposite coating.

Optical fibers are widely used in bioimaging systems as flexible endoscopes that are capable of low-invasive penetration inside hollow tissue cavities. Here, we report on the technique that allows magnetic resonance imaging (MRI) of hollow-core microstructured fibers (HC-MFs), which paves the way for combing MRI and optical bioimaging. Our approach is based on layer-by-layer assembly of oppositely charged polyelectrolytes and magnetite nanoparticles on the inner core surface of HC-MFs. Incorporation of magnetite nanoparticles into polyelectrolyte layers renders HC-MFs visible for MRI and induces the red-shift in their transmission spectra. Specifically, the transmission shifts up to 60 nm have been revealed for the several-layers composite coating, along with the high-quality contrast of HC-MFs in MRI scans. Our results shed light on marrying fiber-based endoscopy with MRI to open novel possibilities for minimally invasive clinical diagnostics and surgical procedures in vivo.

Incorporation of magnetite nanoparticles in poly(vinyl chloride) microfiltration membrane for improving antifouling property and desalination performance

Incorporation of magnetite nanoparticles in poly(vinyl chloride) microfiltration membrane for improving antifouling property and desalination performance

Hybrid Adsorbent Materials Obtained by the Combination of Poly(ethylene-alt-maleic anhydride) with Lignin and Lignosulfonate

Lignin is one of the most available biomass products, but its potential for the development of functional materials has yet to be unleashed. Here, the modification of lignin and lignosulfonate with poly(ethylene-alt-maleic anhydride) [P(E-alt-MA)], a functional polymer of wide industrial use, is accomplished by means of a simple esterification reaction. As a result, hybrid adsorbent materials for water purification can be obtained, which were thoroughly characterized. The combination of P(E-alt-MA) with lignin increased hydrophilicity of the latter, making it dispersible in aqueous environments, while with lignosulfonate it gave rise to a water-insoluble, thus easily recoverable, product. The adsorption properties of the resulting products have been tested against a model water pollutant (methylene blue), demonstrating remarkable adsorption speed (in the order of minutes), adsorption efficiency and stability over a wide range of pH (2–12). Moreover, after the incorporation of magnetite nanoparticles by in situ synthesis, adsorbent materials able to be magnetically recovered were developed.

HYDROLYTIC HYDROGENATION OF INULIN WITH USE MAGNETIC-SEPARATE Ru-CONTAINING CATALYST

The combined hydrolysis and hydrogenation of inulin was studied on Ru-containing magnetically recoverable catalyst, using subcritical water as solvent. The Ru−Fe3O4−SiO2 catalysts are synthesized by incorporation of magnetite nanoparticles (NPs) in mesoporous silica pores followed by formation of 2 nm Ru NPs. The latter was obtained by thermal decomposition of ruthenium acetylacetonate in the pores. Magnetic properties of Fe3O4−SiO2 are typical for superparamagnetic iron oxide NPs of comparable size and allow to make a fast magnetic separation of the catalyst. The results of liquid nitrogen adsorption measurements are typical for mesoporous materials. The BET surface area of catalyst is 280 m2/g, what is allowed for mesoporous catalytic materials. The XPS spectra of Ru-Fe3O4-SiO2 demonstrate a good homogeneity of the sample. The catalyst was tested in hydrolytic hydrogenation of inulin. Inulin is hydrolyzed with formation of fructose and a small amount of glucose. There is a hydrogenation of fructose and glucose in hydrogen with receiving a mannitol and sorbitol, respectively. Mannitol is widely used in production of medicines and pharmaceutics, liquid fuel, the chemical and food industry, biotechnology and production of cosmetics. Mannitol presents in many plants and seaweeds. However, the extraction of mannitol from these raw materials is not a profitable process. Instead, fermentation and catalytic hydrogenation processes are used industrially. Nowadays, mannitol can be obtained by catalytic hydrogenation of monosaccharides like fructose or from glucose-fructose mixtures, using heterogeneous catalyst. During the researches key parameters of process, such as temperature and time of reaction, partial pressure of hydrogen are varied. At optimum reaction conditions: temperature of 150 °C, partial pressure of hydrogen of 60 bars in 45 min, – conversion of inulin was achieved of 100 %, a mannitol yield was 44.3 %. The used catalyst has shown high activity and stability in hydrothermal conditions. Stable magnetic properties of the catalyst cause his easy separation from reactionary mixture by means of external magnetic field.Forcitation:Ratkevich E.A., Manaenkov O.V., Matveeva V.G., Kislitza O.V., Sulman E.M. The hydrolytic hydrogenation of inulin catalyzed by Ru-containing magnetically recoverable catalyst. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 4-5. P. 76-81

A Novel Stimuli-Responsive Magnetite Nanocomposite as De Novo Drug Delivery System

ABSTRACTA novel stimuli-responsive magnetite nanocomposite as de novo drug delivery system for cancer chemotherapy is developed successfully through the incorporation of magnetite nanoparticles into PEG-b-(PNIPAAm-b-PAA)2 copolymer. The chemical structures of samples were characterized using FTIR and 1H NMR spectroscopies. Furthermore, thermal property, morphology, size, and magnetic properties of the nanocomposite were investigated. The DOX loading and encapsulation efficiencies as well as stimuli-responsive drug release ability of the nanosystem were studied. As results, at pH 5.3 and temperature of 41°C the nanocomposite exhibited higher drug release values, which qualified it for cancer chemotherapy according to especial features of cancerous tissue.

Removal of organic water pollutant using magnetite nanomaterials embedded with ionic copolymers of 2‐acrylamido‐2‐methylpropane sodium sulfonate cryogels

AbstractMagnetite cryogel composites as macroporous crosslinked matrices have received wide attention and attract much interest in the water purification and desalination industry. They can be used to produce effective adsorbents with high adsorption rate, capacity and desorption for water pollutants. In this work, the incorporation of magnetite nanoparticles into cryogels by the in situ method is proposed to increase the dispersion of nanoparticles in the gel composites and to produce effective magnetic materials with high adsorption capacities. Ionic sodium‐2‐acrylamido‐2‐methylpropane sulfonate (Na‐AMPS) monomer was selected to prepare cryogels as the homopolymer or copolymers with 2‐hydroxyethyl methacrylate (HEMA) or N‐vinyl pyrrolidone (VP) by the crosslinking polymerization technique in the frozen state. Magnetite nanoparticles were introduced into the cryogel by the in situ co‐precipitation method after introducing iron cations into the cryogel networks. The surface morphologies, crystal structure, magnetite content, thermal stability and magnetic properties were determined for the cryogels and their magnetite composites. The magnetite cryogel composites show significantly enhanced methylene blue dye removal in short times with higher adsorption efficiencies and good regeneration to form an effective adsorbent for water treatment. © 2017 Society of Chemical Industry

Electrocatalytic activity of starch/Fe3O4/zeolite bionanocomposite for oxygen reduction reaction

The present work demonstrated an eco-friendly and facile method for the preparation of starch/Fe3O4/zeolite-bionanocomposite (BNC) at moderate temperature. Zeolite and starch were used as solid support and stabilizer, respectively. The analysis of UV–vis showed the appearance of surface plasmon resonance. From PXRD analysis, the incorporation of magnetite nanoparticles (NPs) in zeolite substrate results in reducing of intensities and broadening of the zeolite peaks of BNC. The TEM analysis showed the formation of highly distributed Fe3O4-NPs with an average diameter and standard deviation of 9.24 ± 3.57 nm. The FESEM and EDX analyses imply that Fe3O4-NPs were homogeneously formed on the surface of the zeolite substrate. VSM analysis illustrated the as prepared BNC possessed magnetic behaviour with a saturation magnetization and coercivity of 1.84 emu g−1 and 17.76 G, respectively. The prepared BNC showed potential applicability in energy as low-cost electrode material. The BNC was used as a non-precious catalyst for oxygen reduction reaction (ORR) in the alkaline medium. The presence of starch and zeolite promoted long term stability up to 1000 cycles and avoid the dissolution and agglomeration of iron oxide. The ORR commences at the onset potential of 0 V follows by the two successive reduction peaks at −0.48 V and −1.00 V.

Ru-Containing Magnetically Recoverable Catalysts: A Sustainable Pathway from Cellulose to Ethylene and Propylene Glycols

Biomass processing to value-added chemicals and biofuels received considerable attention due to the renewable nature of the precursors. Here, we report the development of Ru-containing magnetically recoverable catalysts for cellulose hydrogenolysis to low alcohols, ethylene glycol (EG) and propylene glycol (PG). The catalysts are synthesized by incorporation of magnetite nanoparticles (NPs) in mesoporous silica pores followed by formation of 2 nm Ru NPs. The latter are obtained by thermal decomposition of ruthenium acetylacetonate in the pores. The catalysts showed excellent activities and selectivities at 100% cellulose conversion, exceeding those for the commercial Ru/C. High selectivities as well as activities are attributed to the influence of Fe3O4 on the Ru(0)/Ru(4+) NPs. A facile synthetic protocol, easy magnetic separation, and stability of the catalyst performance after magnetic recovery make these catalysts promising for industrial applications.

Enhanced selectivity and capacity of clinoptilolite for Cd2+ removal from aqueous solutions by incorporation of magnetite nanoparticles and surface modification with cysteine.

In this study, magnetic zeolite (MZ) nanocomposite modified with cysteine was developed in order to enhance selectivity and capacity of clinoptilolite for cadmium ion. The prepared MZ nanocomposite is containing clinoptilolite and magnetite nanoparticles with weight ratio of 3:1. The synthesized nanocomposite was characterized by transmission electron microscopy, X-ray diffraction and vibrating sample magnetometer. Surface modification was confirmed by Fourier transform infrared spectrometer. Experiments were carried out to find the optimum conditions for modification of clinoptilolite and to investigate the effective parameters (pH, adsorbent dosage, contact time, and temperature) on the adsorption of Cd(2+) ion by modified clinoptilolite. The results showed enhanced selectivity of modified MZ in the presence of other naturally occurring cations (Na(+), K(+), Ca(2+) and Mg(2+)) and ammonium. Kinetic and equilibrium data were well fitted by a pseudo second-order and Langmuir model, respectively, with high correlation coefficients. The maximum adsorption capacities of the modified and non-modified clinoptilolite were found to be 20.0 mg/g and 5.2 mg/g, respectively. Thermodynamic parameters revealed that the adsorption process is spontaneous and endothermic under studied conditions.

Photophysics of an octasubstituted zinc(II) phthalocyanine incorporated into solid polymeric magnetic and non-magnetic PLGA–PVA nanoparticles

Abstract 2,3,9,10,16,17,23,24-octakis[( N , N -dimethylaminoethylsulfanyl)]phthalocyaninatozinc (II) ( S1 ) was used as a lipophilic photosensitizer to be encapsulated into biodegradable poly( d , l lactide-co-glycolide)-polyvinyl alcohol nanoparticles. The synthesis, size, and spectroscopic, photophysical, and magnetic properties of nanoparticles, were analyzed. A greater number of sonication cycles afforded smaller nanoparticles. The stabilization by means of polyvinyl alcohol of all the nanoparticles synthesized provided a negative charge to the systems in a wide pH range. The thermograms obtained by differential scanning calorimetry showed that the nanoparticles were stabilized by polyvinyl alcohol. The incorporation of magnetite nanoparticles was verified by FT-IR, magnetization measurements by means of hysteresis curves and potential Z. S1 retained its efficiency in generating singlet oxygen. The incorporation of magnetite into the nanoparticles showed an increase in singlet oxygen quantum yields due to the heavy atom effect.

Performance improvement of macroporous polypyrrole sensor for detection of ammonia by incorporation of magnetite nanoparticles

In this work, polystyrene spheres were employed as templates to prepare polypyrrole inverse opal films on the surface of platinum electrodes. The facilitated access for both outer and inner active sites, as well as the exhibited electrochemical behaviour, turned macroporous PPy into a material more suitable than bulk PPy for electrochemically determining ammonium in samples. However, independently of employing bulk or macroporous polypyrrole, the loss of conductivity suffered by the polymer during the mediating process led to an irreversible increase of the electrical resistance that compromised the sensor's analytical performance. Here, it is shown that the incorporation of magnetite nanoparticles into the walls of the polypyrrole inverse opal films generated a protective effect. This increased the stability of the macroporous mediator due to the preservation of the polaron state, as shown by Raman spectroscopy experiments. Finally, the interaction between polypyrrole and magnetite also positively affected the observed analytical parameters, improving linear range, detection limit and sensitivity of the ammonium sensor.

Thermal, electrical and tensile properties of synthesized magnetite/polyurethane nanocomposites using magnetite nanoparticles derived from waste iron ore tailing

The synthesis of magnetite nanoparticles (MNP) using waste iron tailing as one of the starting materials and its use in preparation of MNP/polyurethane (MNP/PU) nanocomposites with bio-based PU were described. A comparison of XRD patterns, FT-IR and UV–vis diffuse reflectance spectra of neat MNP, neat PU and MNP/PU nanocomposites indicated the incorporation of MNP in PU resin. The SEM and TEM micrographs showed nearly uniform dispersion of MNP in MNP/PU nanocomposites. Both thermal stability and electrical conductivity of MNP/PU nanocomposites were increased with increase of MNP loading while MNP addition significantly improved the tensile properties of PU. The magnetic measurements revealed a transition from superparamagnetic behaviour of neat MNP to ferromagnetic in MNP/PU at lower MNP content. The MNP/PU nanocomposites may be exploited further for electronic and optoelectronic applications.