Two Birds with One Stone: Preparation of 4, 4-Diaminodiphenylmethane Functionalized GO@SiO2 with Mechanical Reinforcement and UV Shielding Properties and Its Application in Thermoplastic Polyurethane

This study prepared 4,4-diaminodiphenylmethane (DDM)-functionalized graphene oxide (GO)@silica dioxide (SiO2) nano-composites through amidation reaction and low-temperature precipitation. The resulting modified GO, that was DDM−GO@SiO2. The study found that DDM−GO@SiO2 showed good dispersion and compatibility with thermoplastic polyurethane (TPU) substrates. Compared with pure TPU, the tensile strength of the TPU composites increased by 41% to 94.6 MPa at only 0.5 wt% DDM−GO@SiO2. In addition, even when a small amount of DDM−GO@SiO2 was added, the UV absorption of TPU composites increased significantly, TPU composites can achieve a UV shielding efficiency of 95.21% in the UV-A region. These results show that this type of material holds great promise for the preparation of functional coatings and film materials with high strength and weather resistance.

Melatonin Alleviates Silica Nanoparticle-Induced Lung Inflammation via Thioredoxin-Interacting Protein Downregulation

Silica dioxide nanoparticles (SiONPs) have been increasingly used in various industries; however, this has raised concerns regarding their potential toxicity. SiONPs are also a major component in the Asian sand dust that causes pulmonary diseases among the general public. Melatonin exerts some inhibitory effects against lung inflammation. In this study, we explored the therapeutic properties of melatonin against lung inflammation using an SiONPs-induced lung inflammation murine model and SiONPs-stimulated H292 cells, human airway epithelial cell line, by focusing on the involvement of thioredoxin-interacting protein (TXNIP) in the modulation of the MAPKs/AP-1 axis. We induced an inflammatory response by exposing mouse lungs and the H292 cells to SiONPs and confirmed the anti-inflammatory effect of melatonin. Melatonin inhibited the expression of various inflammatory mediators, including TNF-α, IL-6, and IL-1β, in SiONPs-exposed mice and SiONPs-stimulated H292 cells; this inhibition contributed to a decline in inflammatory cell accumulation in the lung tissues. Furthermore, melatonin treatment decreased the expression of MAPKs and AP-1 by downregulating TXNIP, eventually decreasing the production of SiONPs-induced inflammatory mediators. Overall, these data suggest that melatonin reduces SiONPs-induced lung inflammation by downregulating the TXNIP/MAPKs/AP-1 signalling pathway, thereby supporting the use of melatonin as an effective approach to control SiONPs-induced lung inflammation.

Study of Electrical and Thermal Properties of PVA-Nanosilica as A Candidate for Supercapacitor Separators

Separator in the supercapacitor that separates the cathode from the anode has an important role in a supercapacitor circuit. Polyvinyl Alcohol (PVA) is a substitute for polyolefin which is commonly used as a supercapacitor separator and PVA has more environmentally friendly properties. The addition of silica dioxide nanocomposites is useful for adding thermal stability and electrical insulators. The method used to make the separator is quite simple, namely by casting a PVA gel membrane with nanosilica on a glass plate and drying it at low temperature. PVA membrane with nanosilica variations different precursors are from sand by coprecipitation method and from TEOS. The properties of the two samples were characterized by scanning electron microscopy (SEM), thermo gravimetric analysis (TGA), and LCR meter. Nanosilica derived from sand and from TEOS have no much different characteristic.

Performances of Reduced Graphene Oxide/Iron (III) Oxide/Silica Dioxide (rGO/Fe3O4/SiO2) as a Potential Oxygen Reduction Electrocatalyst in Fuel Cell

Synthesis of the nanocomposite comprises reduced graphene oxide, iron (III) oxide and silica dioxide nanocomposites which were denoted as rGO/Fe3O4/SiO2. The acquired nanocomposite was determined to be a substitute for platinum electrode in oxygen reduction reaction (ORR) to catalyze reaction, as usage of platinum causes disadvantages in production. The nanocomposite was analyzed physically and electrochemically to ensure the quality of the synthesized compound. Fourier transform-infrared spectroscopy (FTIR) shows the presences of functional groups such as O-H hydroxyl group, C=C, C=O and existence of silica peak in the spectra of rGO/Fe3O4/SiO2, where the data is also supported by SEM-EDS. Raman Spectrophotometer shows the structural change of three different graphene related materials as modification took place and X-Ray Diffraction (XRD) analysis confirms the reduction of GO into rGO, where the crystalline structure decreased significantly approximately about 10 nm. This data supported with Brunauer-Emmett-Teller (BET) analysis through surface area examination. The compound of rGO/Fe3O4/SiO2 was drop-casted onto glassy carbon electrode (GCE) for modification into rGO/Fe3O4/SiO2/GCE to carry out electrochemical analysis where Cyclic Voltammetry (CV) shows current response by modified electrode is greater than bare GCE while Electron Impedance Spectroscopy (EIS) of same modified electrode affirms the sample underwent reversible process with stable and rapid electron transfers with minimal resistance charge transfer (RCT). The study of ORR was carried out and observed a good electrochemical response of the nanocomposite when purged with oxygen gas.

Evaluation of the Performance of Conventional Water-Based Mud Characteristics by Applying Zinc Oxide and Silica Dioxide Nanoparticle Materials for a Selected Well in the Kurdistan/Iraq Oil Field

Nanomaterials have gained a wide interest in the oil and gas industry due to their immense applicability. Nanomaterials are being used to formulate a new generation of drilling mud known as Nanomud or Smart mud, where it has the ability to improve mud properties and eliminate borehole problems. Using nanoparticles as an additive agent in conventional drilling mud can lead to a more efficient drilling process in troublesome formations. In this study, several conventional water-based muds from a selected well drilled in the Kurdistan/Iraq oil field have been prepared. Then, nanodrilling muds were formulated by dispersing SiO2 and ZnO nanoparticles in concentrations ranging from 0.25 to 1 wt.% to conventional water-based mud (WBM). This study aims to evaluate and compare the performance of conventional water-based muds after adding SiO2 and ZnO nanoparticles. This evaluation was performed by carrying out a series of laboratory experiments to determine the rheological and mud filtrate properties. The results demonstrated that nanomuds improved the rheological behaviors and provided better filtration control compared to conventional drilling muds. However, there was little or no impact of the nanomaterials on the mud density for all mud systems.

A review on properties and applications of nano clay, silica dioxide and titanium oxide

Nanoparticles have recently been used as fillers or additives in materials for different desired applications. Due to the environmental concerns and rising of nanomaterials usages worldwide, nanoparticles have been focused in research and development. An increase in consumption is indicated by various applications of nanomaterials for both commercial and domestic applications. Nanoparticles own special physical and chemical properties which help in modifying performance of materials or final products. The characterisation of nanoparticles includes crystallographic structure, surface morphology, particles’ size and functional groups. Nano clays and metal oxides of titanium and silica are selected nanoparticles to be discussed on their properties that affect the performance of materials. Along with the studies investigating the properties of the nanoparticles, an interesting concern is to discover the changes in properties of materials when nanoparticles are being added. Properties include mechanical, thermal and physiochemical are improved due to the presence of the nanoparticles in the materials’ matrices, thus existing the applications for the food packaging, the lubricant oils and as the antimicrobial agent. This paper reviews the physical and chemical properties of nano clay, silica oxide and titanium oxide as well as the enhanced properties of materials when being filled with nanoparticles in specific applications.

Mengkaji Tindakbalas Nanozarah Silika Dioksida (SiO2) dengan Lisozim Dalam Larutan Penimbal

Kajian ini dilakukan untuk mengkaji kesan tindak balas nanozarah polimer, silika dioksida (SiO2) dengan protein, (Lisozim) dalam larutan penimbal. Tujuan kajian adalah untuk menentukan kestabilan serta kesan interaksi nanozarah SiO2 dengan lisozim sebagai fungsi kepekatan yang dikaji dengan menggunakan spektroskopi ultralembahyung-cahaya nampak (U.V.-Visible). Kaedah yang digunakan dalam kajian ini iaitu kaedah penambahan (serbuk), kaedah cecair homogen, kaedah perpisahan fasa dan kaedah penyerapan (tindakbalas). Hasil kajian mendapati penjerapan lisozim yang bercas positif (hidrofobik) terhadap permukaan nanozarah SiO2 yang bercas negatif (hidrofilik) adalah sesuai pada pH 7.8. Bagi perbezaan nisbah berat SiO2: Lisozim sama ada berat lisozim atau SiO2 tetap, puncak yang diperolehi adalah sekitar 280nm. Kadar penjerapan lisozim bergantung kepada masa tindak balas dan juga faktor pembauran. Saiz nanozarah SiO2 yang kecil menyebabkan ianya mempunyai luas permukaan yang besar berbanding isipadu dan membolehkan lisozim dijerap pada permukaannya tanpa sebarang halangan. Oleh yang demikian dapat disimpulkan bahawa, wujud kestabilan antara lisozim dan SiO2 yang membolehkan penjerapan berlaku dan terbentuknya gumpalan akibat daripada kesan tindak balas. This study was conducted to study the interaction effect of polymer nanoparticles, silica dioxide (SiO2) with protein, (Lysozyme) in buffer solution. The purpose of the study was to determine the stability and the effect of the interaction of SiO2 nanoparticles with lysozyme as a concentration function studied using ultraviolet-visible (U.V.-visible) spectroscopy. The methods used in this study are the addition method (powder), homogeneous liquid method, phase separation method and absorption method (interaction). The results of the study found that the adsorption of positively charged (hydrophobic) lysozyme to the surface of negatively charged SiO2 nanoparticles (hydrophilic) is suitable at pH 7.8. For the difference weight ratio in SiO2: Lysozyme either lysozyme weight or fixed SiO2, the peak obtained is around 280nm. The rate of absorption of lysozyme depends on the reaction time as well as the diffusion factor. The small size of the SiO2 nanoparticles causes it to have a large surface area compared to the volume and allows lysozymes to be adsorbed on its surface without any obstruction. Therefore, it can be concluded that there is a stability between lysozyme and SiO2 that allows adsorption to occur and the formation of agglomeration as a result of the interaction effect.

Experimental Research on Heat Transfer Performance in MQL Grinding With Different Nanofluids

An investigation into the effect of nanofluid minimum quantity lubrication (MQL) on the temperatures in surface grinding is presented and discussed. Six types of nanoparticles, namely molybdenum disulfide (MoS2), zirconium dioxide (ZrO2), carbon nanotube (CNT), polycrystalline diamond, aluminum oxide (Al2O3), and silica dioxide (SiO2), are considered to mix individually with a pollution-free palm oil in preparing the nanofluids. A commonly used Ni-based alloy was chosen as the workpiece material. It is shown that CNT nanofluid results in the lowest grinding temperature of 110.7°C and the associated energy proportionality coefficient of 40.1%. The relevant physical properties of the nanofluids such as the coefficient of thermal conductivity, viscosity, surface tension, and the contact state between the droplets and workpiece surface (contact angle) were discussed to shine a light on their effect on the cooling performance. A mathematical model for convective heat transfer coefficient was then developed based on the boundary layer theories.