Functionalized iron oxide nanoparticles (IONPs) are of great interest due to wide range applications, especially in nanomedicine. However, they face challenges preventing their further applications such as rapid agglomeration, oxidation, etc. Appropriate surface modification of IONPs can conquer these barriers with improved physicochemical properties. This review summarizes recent advances in the surface modification of IONPs with small organic molecules, polymers and inorganic materials. The preparation methods, mechanisms and applications of surface-modified IONPs with different materials are discussed. Finally, the technical barriers of IONPs and their limitations in practical applications are pointed out, and the development trends and prospects are discussed.

Surface Modification of Magnetic Iron Oxide Nanoparticles.

Since their discovery, magnetic nanoparticles (MNPs) have become materials with great potential, especially considering the applications of biomedical sciences. A series of works on the preparation, characterization, and application of MNPs has shown that the biological activity of such materials depends on their size, shape, core, and shell nature. Some of the most commonly used MNPs are those based on a magnetite core. On the other hand, synthetic biopolymers are used as a protective surface coating for these nanoparticles. This review describes the advances in the field of polymer-coated MNPs for protein immobilization over the past decade. General methods of MNP preparation and protein immobilization are presented. The most extensive section of this article discusses the latest work on the use of polymer-coated MNPs for the physical and chemical immobilization of three types of proteins: enzymes, antibodies, and serum proteins. Where possible, the effectiveness of the immobilization and the activity and use of the immobilized protein are reported. Finally, the information available in the peer-reviewed literature and the application perspectives for the MNP-immobilized protein systems are summarized as well.

Polymer-Coated Magnetite Nanoparticles for Protein Immobilization.

In the last few decades, there has been a trend involving the use of nanoscale fillers in a variety of applications. Significant improvements have been achieved in the areas of their preparation and further applications (e.g., in industry, agriculture, and medicine). One of these promising materials is magnesium oxide (MgO), the unique properties of which make it a suitable candidate for use in a wide range of applications. Generally, MgO is a white, hygroscopic solid mineral, and its lattice consists of Mg2+ ions and O2− ions. Nanostructured MgO can be prepared through different chemical (bottom-up approach) or physical (top-down approach) routes. The required resultant properties (e.g., bandgap, crystallite size, and shape) can be achieved depending on the reaction conditions, basic starting materials, or their concentrations. In addition to its unique material properties, MgO is also potentially of interest due to its nontoxicity and environmental friendliness, which allow it to be widely used in medicine and biotechnological applications.

Synthesis, Properties and Selected Technical Applications of Magnesium Oxide Nanoparticles: A Review

In recent years, the amount of agricultural and industrial wastes being generated is increasing rapidly. This leads to numerous disposals, governance, and environmental issues. Therefore, the re-utilisation of these wastes into value-added products such as mesoporous silica nanoparticles (MSNs) has attracted great attention. MSNs have garnered immense attention in various applications owing to their tuneable pore dimensions, high surface areas, and tailorable structure, suitable for different post-functionalisation. In this review, recent progress on the synthesis of MSNs from waste using a chemical synthesis route is presented. This route offers the possibility to control silica structure, phase, morphology, and sizes by fine tuning the reaction parameters/conditions. The characteristics and applications of the MSNs produced are also analysed to examine the potential of using agricultural and industrial waste as the silica precursor. Although the use of inexpensive waste-derived materials seems promising for both waste reduction and value-added products synthesis, further research is still needed to boost the production of silica especially at a larger scale. 

Agricultural and industrial waste-derived mesoporous silica nanoparticles: A review on chemical synthesis route

One-step synthesis of γ-Fe2O3/Fe3O4 nanocomposite for sensitive electrochemical detection of hydrogen peroxide

https://iopscience.iop.org/article/10.1088/1757-899X/515/1/012049/pdf

Synthesis of ZnFe2O4 Nanoparticles with PEG 6000 and Their Potential Application for Adsorbent

Magnetite (Fe3O4) nanoparticles has many important applications due to its reactivity, size, and magnetism. Many synthesis methods of the material, including electrochemical, have been developed in order to generate the desired particles. Electrochemical is one simple synthesis method in producing the nanoparticles. Characters of the particles synthesized, such as its size, crystallinity and magnetic property, depend on the electrochemical parameters like the kind and concentration of electrolyte, the kind of electrodes, the inter-electrodes distance, temperature, cell volume, current density or voltage applied. We have been succesfully synthesized monodispersed magnetite nanoparticles by electro-oxidation of iron in plain water without using any surfactant, although there are some impurities in the form of FeOOH, an intermediate species created during the formation of Fe3O4. Nevertheless a high purity of magnetite nanoparticles were required in some special applications. By applying higher voltage in the...

To enhance the purity and crystallinity of magnetite nanoparticles prepared by surfactant-free electrochemical method by imposing higher voltage

This research discusses the development of magnetic materials as an effort to produce renewable catalysts in overcoming the energy crisis. The purpose of this study was to synthesize and characterize MgO/CoFe2O4 nanoparticles using the coprecipitation method. The synergy between substances that are catalysts, namely MgO and CoFe2O4 to MgO/CoFe2O4 was expected to produce a superior catalyst for biodiesel production. The stages of this research were to synthesize MgO nanoparticles and CoFe2O4 nanoparticles by coprecipitation and continued with MgO impregnation on the CoFe2O4 surface to become MgO/CoFe2O4 with a mole ratio of 5: 1, then characterize them using X-Ray Diffraction and Scanning Electron Microscopy. The results of XRD analysis showed that MgO/CoFe2O4 nanoparticles were successfully synthesized according to the standard curves of MgO and CoFe2O4 (JCPDS Cards No. 89-7746 and 22-1086). SEM analysis results show that impregnated particles have spherical morphology and are larger in size than the two constituent components. The mean particle sizes of MgO, CoFe2O4, and MgO/CoFe2O4 were 29.588 nm, 42.282 nm and 65.953 nm, respectively. EDX analysis shows the appropriate atomic percentage and mass of each of the constituents of MgO/CoFe2O4 namely Magnesium, Iron, Cobalt, Oxygen.

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Synthesis of MgO/CoFe2O4 nanoparticles with coprecipitation method and its characterization

One of the nanoparticles which have been developed is magnetite. Due to its magnetism and reactivity, this particle can be used in various fields including technology, environment, and biomedical. One simple method to synthesize magnetite is electro-oxidation of iron in the water. The particle size produced by this method can be adjusted by controlling the electrochemical cell parameters. Unfortunately, this method usually releases polydispersed particles. One solution to overcome this problem is by using an in situ PEG in the synthesis process. In this research, PEG 6000 was chosen as a template, so the synthesis process was performed by electro-oxidation of iron in the dilute solution of PEG. Particles with an average diameter of 62.5 nm were obtained. The monodispersity, surface area, and crystallinity of the particles increased in this way. The specific surface area increased from 55.322 to 391.314 m2/g. The results of XRD and FTIR analysis showed that PEG acted as a template in the synthesis process. In addition, the yield obtained with PEG template was larger than without the template. This method is quite promising as a way of synthesis of magnetite nanoparticles.

Synthesis of Fe3O4 Nanoparticles using PEG Template by Electrochemical Method

Until now, used cooking oil (jelantah) has not been utilized optimally. This study seeks to convert this waste into biodiesel. Used cooking oil usually contains high concentration of free fatty acids which can be converted into methyl esters through trans-esterification by methanol. This effort is in line with the increasing need for renewable energy sources. Because the waste still contains high concentrations of free fatty acids, it is necessary to think about the right process and catalyst in converting it as biodiesel. One heterogeneous catalyst that is thought to excel in biodiesel production is ferrite-based nanocomposites, namely CaO@CoFe2O4 nanoparticles. The advantages of this catalyst are: it has high reactivity, thermal and chemical stability, and can be drawn by magnetic fields. This last property facilitates the catalyst isolation at the end of the process for recycling purposes. The catalytic power is expected to increase through impregnation with alkaline earth metal oxides which have a relatively high basicity, namely CaO. The purpose of this study was to synthesize and to characterize CaO@CoFe2O4, then to study its potential catalytic in biodiesel production from used cooking oil in various weight percent of catalyst. The main steps include: (1) synthesis of CoFe2O4 by coprecipitation; (2) Impregnation of CaO into CoFe2O4 and converted to CaO@CoFe2O4; (3) Characterization of the synthesized material by XRD, BET, and SEM/EDX; (4) application of CaO@CoFe2O4 in biodiesel production from used cooking oil; (5) characterization of biodiesel produced by viscosity measurement, yield and GC-MS analysis results. Based on the results of XRD and SEM/EDX analysis, the CaO@ CoFe2O4 catalyst has been successfully synthesized. Under optimal conditions, the yield of methyl ester produced with the addition of 2% of catalyst was 80.62%.

Nazriati

Papers

Synthesis of ZnFe2O4 Nanoparticles with PEG 6000 and Their Potential Application for Adsorbent

To enhance the purity and crystallinity of magnetite nanoparticles prepared by surfactant-free electrochemical method by imposing higher voltage

Synthesis of MgO/CoFe2O4 nanoparticles with coprecipitation method and its characterization

Synthesis of Fe3O4 Nanoparticles using PEG Template by Electrochemical Method

Synthesis of CaO@CoFe2O4 Nanoparticles and its Application as a Catalyst for Biodiesel Production from Used Cooking Oil