Preparation of Nano-sized Magnesium Oxide by Electrospinning Technique and Its Adsorbability to Methylene Blue

Polymer matrix nano-sized oxide composites were fabricated by using a modified injection molding in which nano-sized silicon oxide and nano-sized magnesium oxide were contained. Thermal decomposition and evaporation of organic resin depended on the composition of the composites. Nano-sized oxides were uniformly distributed in the composites produced by a modified injection molding combining vacuum degassing and curing at a moderate temperature. 0.2 wt.% of silicon oxide addition to epoxy resin showed the maximum electric field of 3.6, whereas, 2.0 wt.% of magnesium oxide addition was required to reach the same value of electrical field. Both of thermal conductivity and thermal diffusivity of the nano-sized silicon oxide-epoxy composites tended to be increased with silicon oxide content. The relative permittivity of the nano-sized silicon oxide-epoxy composites increased from 5.16 to 5.31 by adding 0.6 wt.% silicon oxide, whereas, magnesium oxide addition up to 2.0 wt.% little influenced to the permittivity. Epoxy matrix-nano-sized silicon oxide composites were more suitable than magnesium oxide for the high performance capacitance.

A systematic study on evaluating the effect of micro- and nano-sized magnesium oxide (MgO) particles on the mechanical properties of carbon fiber/epoxy composites was conducted by adding various contents of MgO particles into an epoxy resin matrix. The impact and flexural strengths were determined by the Charpy impact tests and three-point bending experiments, respectively. We found that the carbon fiber/epoxy composites filled with nano-MgO particles had higher mechanical strength than that of the carbon fiber/epoxy composites filled with micro-MgO particles. Both impact and flexural strength were enhanced by adding the proper content of nano-MgO particles. Although the impact strength was increased by adding micro-MgO particles, the flexural strength was decreased by adding micro-MgO particles. In addition, the influence of the nano- and micro-particles on the failure modes of the fiber/epoxy composites was also studied and is described.

Nano-sized magnesium oxide (MgO) has been a promising potential material for biomedical pharmaceuticals. In the present investigation, MgO nanoparticles synthesized through in-situ solid-phase transformation based on the previous work (nano-Mg(OH)2 prepared by precipitation technique) using magnesium nitrate and sodium hydroxide. The phase structure and morphology of the MgO nanoparticles are characterized by X-ray powder diffraction (XRD), selected area electronic diffraction (SAED) and transmission electron microscopy (TEM) respectively. In vitro hemolysis tests are adopted to evaluate the toxicity of the synthesized nano-MgO. The results evident that nano-MgO with lower concentration is slightly hemolytic, and with concentration increasing nano-MgO exhibit dose-responsive hemolysis.

To understand DC breakdown phenomena of low density polyethylene (LDPE) mixed with nano-sized magnesium oxide (MgO), the electric properties, namely, DC breakdown strength, conduction current, space charge formation and local heat generation up to the breakdown under increasing field with a particular rate of increase was investigated. DC breakdown strength of nanocomposite was found to be high compared to that of LDPE. The increasing rate of the conduction current in nanocomoposite with respect to the average field (under high field) was suppressed by the addition of MgO nano-filler. The space charge formation and the local heat generation were also suppressed under high field. From these results, it is suggested that the suppression effect of conduction current affected by the space charge led to higher DC breakdown strength of nanocomposite material.

First, nano-sized magnesium oxide (MgO) particles were prepared with magnesium nitrate hexahydrate as raw material and plant extract Angelica dahurica as a protective agent and dispersant. Then, MgO nano particles (MgO NPs) were loaded on the cotton fabric surface by dipping method. Finally, using hexadecyl trimethoxysilane (HDTMS) as a modifier and ammonia as a catalyst, the cotton fabric was hydrophobically modified to prepare a super hydrophobic multifunctional cotton fabric. FTIR indicated that long carbon chain silane was successfully introduced onto cotton fabric. SEM and XRD analysis showed that the micro-nano rough structure was formed on the MgO/HDTMS/cotton fabric surface, and its crystal structure was unchanged. The water contact angle of cotton fabric modified by MgO/HDTMS reached 153°, which made it super hydrophobic. Moreover, MgO/HDTMS/cotton fabric has excellent antibacterial properties with the antibacterial rates against S. aureus and E. coli of 95.50% and 95.30%, respectively. After 10 times of cyclic washing, both the water contact angle and the antibacterial rate for S. aureus and E. coli of the fabric showed a slight decrease, which indicated that it has good washing durability.

To understand the space charge formation of low-density polyethylene (LDPE)/nano-sized magnesium oxide (MgO) nanocomposite materials, the breakdown strength and the space charge formation influenced by DC prestress were investigated. DC breakdown strength (Fb) of LDPE decreased with increase of DC prestress. A packet-like charge was observed under DC pre-stress. When the applied field turned to a ramp field from a constant field, the space charge decreased with incase of applied field. A packet-like charge, enhancing the local filed in bulk, might bring to many dissociated carrier. Therefore, it was considered that DC-Fb of LDPE decreased with increase of DC pre-stress field because bulk of LDPE became more conductive condition by generation of a packet like charge. On the other hand, DC-Fb of LDPE/MgO nanocomoposite increased with increase of DC pre-stress field. In case of MgO content of 1 phr, a packet-like charge was not observed under DC pre-stress field and a little positive space charge was formed in the bulk The positive charge decrease gradually with increase of ramp filed. When the MgO content was 5 phr, little space charge was observed under DC constant or ramp fields. The MgO nanofiller may trap the space charge, and the homo space charge in the vicinity of electrodes suppressed the carrier injection.

To understand the space charge formation of low-density polyethylene (LDPE) / nano-sized magnesium oxide (MgO) nanocomposite materials, the space charge and the conduction current were simultaneously measured up to the breakdown under increasing DC ramp field. A negative charge was dominated in the sample without nanofiller (0 phr sample). A positive charge was dominated in nanocomoposite sample. The field increment (= the maximum field - the average field) of the 0 phr sample increased with increasing average field and then was saturated with many small rises and falls and finally falls before the breakdown. In the 1 phr sample, after showing the peak, the field increment turned to decrease with further increase of the average field. The conduction current of 0 phr sample and 5 phr sample increased monotonically with increase of the average field. The conduction current of the 1 phr sample showed great increase under one average field, and the field increment at the average field turned to decrease. From these results, it was considered that the homo space charge effect at the anode brought by charge trapping effect of MgO nanofiller controlled the space charge formation and the space charge influenced to the conduction current under a high field.

Mesoporous carbon material as cathode for high performance lithium-ion capacitor

Nano-sized magnesium oxide (nano-MgO) was investigated for adsorption of fluoride from water. The pure and fluoride adsorbed nano-MgO were characterised by Brunauer–Emmett–Teller, high resolution transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray analyses. The surface area of the adsorbent was found to be 92.46 m2/g. Maximum (90%) fluoride removal was obtained with 0.6 g/L dosage of nano-MgO. Fluoride adsorption by nano-MgO was found to be less sensitive to pH variations. Fluoride sorption was mainly influenced by the presence of OH− ion. The presence of other ions studied did not affect the fluoride adsorption capacity of nano-MgO significantly. It has been observed that Freundlich model was better fitted as compared to Langmuir model which indicated the multilayer adsorption of the adsorbent following a pseudo-second order kinetics. Regeneration study showed that 1 M HCl was the best eluent with 95% desorption capacity towards fluoride removal followed by NaOH (2 M) with 25% regeneration of the adsorbent.

To understand basic electric properties of nano-sized magnesium oxide (MgO) / low-density polyethylene (LDPE) nanocomposite materials, the temperature dependence of breakdown strength and the space charge up to the breakdown has been investigated under DC ramp field. At temperatures at which these investigations were carried out, DC breakdown strength of the sample with the MgO nano-filler (hereafter, called 0 phr sample) exhibited higher DC breakdown strength compared with the sample with the MgO nano-filler (hereafter, called 1 phr sample). DC breakdown strength of 0 phr and 1 phr samples decreased with increasing temperature. In the case of 0 phr sample at 303 K, the negative charge was observed in the bulk and was found to be saturated before the breakdown. The hetero charge was observed at 333 K shortly before the breakdown. In the case of 1 phr sample at 303 K, the positive charge increased with increasing average field until the average field reached a certain value and then decreased with increasing average field until the breakdown occurred. The field increment (maximum field - average field), brought by the space charge, of 0 phr sample at 303 and 333 K increased with increasing average field and found to be saturated before the breakdown. As different from 0 phr sample, the field increment of 1 phr sample turned to decrease after showing a peak under the high field.

On the synthesis and optical absorption studies of nano-size magnesium oxide powder

To understand basic electric properties of nano-sized magnesium oxide (MgO) / low-density polyethylene (LDPE) nanocomposite under DC voltage application, the volume resistivity, the space charge distribution and the breakdown strength were investigated. By the addition of nano-sized MgO filler, both the DC breakdown strength and the volume resistivity of LDPE increased. At the average DC electric field of about 85 kV/mm and more, a positive packet space charge was observed in LDPE without MgO nano-filler, whereas a little homogeneous space charge was observed in MgO/LDPE nanocomposite material at the front of electrode. From these results, it is confirmed that the addition of MgO nano-filler leads to the improvement of DC electrical insulating properties of LDPE.

To understand the space charge formation of nano-sized magnesium oxide (MgO)/low-density polyethylene (LDPE) nanocomposite materials, the space charge and the conduction current up to the breakdown has been investigated under increasing DC ramp field. A negative charge was dominated in the 0 phr sample. A positive charge was dominated in nanocomoposite sample. The field increment (= the maximum field - the average field) of the 0 phr increased with increasing average field and then was saturated with a few rises and falls before the breakdown. In the 1 phr sample, after showing the peak, the field increment turned to decrease with further increase of the average field. In the 2 phr and more, the clear decrease of the field increment was not observed due to a few positive charges. The conduction current of 0 phr sample and 5 phr sample increased monotonically with a increase of the average field. The conduction current of the 1 phr and the 2 phr showed great increase under one average field. From these results, it was considered that the homo space charge effect at the anode brought by charge trapping effect of MgO nano-filler controlled the space charge formation and the space charge influenced to the conduction current under a high field.

Magnesium ion-conducting gel polymer electrolytes dispersed with nanosized magnesium oxide

This critical review comprehensively analyses nano-sized metal oxide fertilizers (NMOFs) and their transformative potential in sustainable agriculture. It examines the characteristics and benefits of different NMOFs, such as zinc, copper, iron, magnesium, manganese, nickel, calcium, titanium, cerium, and silicon oxide nanoparticles. NMOFs offer unique advantages such as increased reactivity, controlled-release mechanisms, and targeted nutrient delivery to address micronutrient deficiencies, enhance crop resilience, and improve nutrient efficiency. The review underscores the essential role of micronutrients in plant metabolism, crop growth, and ecosystem health, highlighting their importance alongside macronutrients. NMOFs present significant benefits over traditional fertilizers, including enhanced plant uptake, reduced nutrient losses, and decreased environmental impact. However, the review also critically examines potential risks associated with NMOFs, such as nanoparticle toxicity and environmental persistence. A comparative analysis of different metal types used in nanofertilizers is provided, detailing their primary advantages and potential drawbacks. The review emphasizes the need for cautious management of NMOFs to ensure their safe and effective use in agriculture. It calls for comprehensive research to understand the long-term effects of NMOFs on plant health, soil ecosystems, and human health. By integrating insights from material science, plant biology, and environmental science, this review offers a holistic perspective on the potential of NMOFs to address global food security challenges amid resource constraints and climate change. The study concludes by outlining future research directions and advocating for interdisciplinary collaboration to advance sustainable agricultural practices and optimize the benefits of NMOFs.