Nano SiO2 Research Articles

Nano SiO2 catalytic synthesis, NMR spectral studies, photophysical properties and theoretical studies of some styryl imidazole derivatives

New styryl imidazole derivatives were prepared by using nano SiO2 catalyst and proved it catalytic efficiency. Diminutive reaction time, high yield of the imidazole derivatives and a variety of substitute reactant usage were accomplished by using nano SiO2 catalyst. Solvatochromism of newly synthesized imidazole derivatives have been studied by using Marcus and Reichardt – Dimroth solvent functions. When polarity of the solvent was increased, the absorption position of synthesized styryl imidazole derivatives shifted to higher wavelength, that is bathochromic shift was fashioned. Emission band maxima these imidazole derivatives also shifted to the longer wavelength, which was due to dielectric solute and solvent interactions. HOMO–LUMO energies of imidazole derivatives have been calculated by DFT calculations at B3LYP/6-31G (d, p) using Gaussian-03.

Fabricating multi-porous carbon anode with remarkable initial coulombic efficiency and enhanced rate capability for sodium-ion batteries

Due to the abundant sodium reserves and high safety, sodium ion batteries (SIBs) are foreseen a promising future. While, hard carbon materials are very suitable for the anode of SIBs owing to their structure and cost advantages. However, the unsatisfactory initial coulombic efficiency (ICE) is one of the crucial blemishes of hard carbon materials and the slow sodium storage kinetics also hinders their wide application. Herein, with spherical nano SiO2 as pore-forming agent, gelatin and polytetrafluoroethylene as carbon sources, a multi-porous carbon (MPC) material can be easily obtained via a co-pyrolysis method, by which carbonization and template removal can be achieved synchronously without the assistance of strong acids or strong bases. As a result, the MPC anode exhibited remarkable ICE of 83% and a high rate capability (208 mAh/g at 5 A/g) when used in sodium-ion half cells. Additionally, coupling with Na3V2(PO4)3 as the cathode to assemble full cells, the as-fabricated MPC//NVP full cell delivered a good rate capability (146 mAh/g at 5 A/g) as well, implying a good application prospect the MPC anode has

Fabrication of eco-friendly and efficient flame retardant modified cellulose with antibacterial property

Flame retardant and antibacterial investigation of cellulose has attracted more and more attention. In order to improve the modification efficiency, inspired by multiple hydrogen bonding in spider silk, flame retardant and antibacterial dual function modified cellulose was achieved by multi structure hydrogen bonding in this research. A novel nano SiO2 based Schiff base flame retardant (SiAPH) and dodecyl quaternary ammonium salt (HDAC) were synthesized. Tannin (TA) was introduced as medium to provide synergistic flame retardant and antibacterial with SiAPH and HDAC. The flame retardancy assessment demonstrated that the limiting oxygen index (LOI) of modified cotton fabrics increased from 18% to 26.1%, and the peak of heat release rate (pHRR) decreased by 41.0%, UL-94 vertical combustion proved the modified cotton fabrics had capability of self-extinguishing. The antibacterial of modified fabrics were confirmed against Staphylococcus aureus and Escherichia coli, and the inhibition rate reached to 99.1%. In addition, it worth noting that the biocompatibility and antibacterial activity of modified fabrics were evaluated via MTS assay and establishment of animal wound model. Low toxicity of the fabrics was verified by the L929 fibroblast cells. The anti-infection experiment model showed that the modified fabrics had a positive effect on prevention of infection, and the wound healing rate reached to 86.8% after 14 days’ treatment. The flame retardancy, antibacterial and biocompatibility of the functional cotton fabrics indicated that they were ideal candidate for applications of vehicle interior, soft decoration in public and medical scene.

Poly (ethylene terephthalate) nonwoven fabrics‐based membranes modified by electrospinning of thermoplastic polyurethane, nano SiO2 and Ag particles as medical packing materials

AbstractAiming at development of novel medical packings, poly (ethylene terephthalate) (PET)‐based membranes with hydrophobic and antibacterial properties were prepared by electrostatic spinning of a blend of thermoplastic polyurethane (TPU), nano SiO2 and Ag particles on PET nonwoven. In cooperation with electro‐spun TPU/SiO2 layer, the water contact angle (WCA) of PET nonwoven fabric was improved from 60° to 115–130°, and the water vapour transmission rate was 2200–2500 g/m2/24 h. It indicates that the modified PET nonwoven membrane exhibits a much better water resistance, highly increased hydrophobicity and moderate water permeability. Nano‐silver provided excellent antibacterial properties for this non‐cytotoxic PET/TPU/SiO2/Ag composite membranes. The PET/TPU/SiO2/Ag composite membranes had high mechanical properties, which exhibited a tensile strength of 56 MPa in the longitudinal direction and 35 MPa in the transversal direction, and tear strength of 30 kN/m in the longitudinal direction and 48 kN/m in the transversal direction. This new PET/TPU/SiO2/Ag composite membranes showed broad application prospects in the medical packaging industry.

Utilizing Nanotechnology to Solve Drilling Problems in Iraqi Oil Fields

Nanotechnology is a recent technology which is used in all industry sectors. In the oil and gas industry, this technology is commonly used due to its importance in solving the problems encountered while drilling operations and production stages. Nanotechnology can be used to improve the drilling process by adding nano-materials to drilling fluids in order to reduce drilling problems. This research is extended to previous research that published in journal of petroleum research and studies to compared the effect of nano-materials [Commercial nano-materials Multi Walled Carbone Nano Tube (MWCNT) and nano silicon oxide (SiO2) with nano-silica (rice husks, that prepared in PRDC labs) on water base drilling mud properties].
 All characterization tests were achieved by the Nanotechnology and advanced materials researches center it is belongs to the University of Technology. The investigated properties of drilling mud included rheological properties and filtration. All tests are conducted according to API specifications (American Petroleum Institute).
 The results show an improvement in the rheological properties (plastic viscosity, yield point, apparent viscosity and gel strength) and filtration after adding the commercial MWCNT, nano silicon dioxide(Sio2) and the prepared nano-silica (rice husks) to the water based mud. The results of plastic viscosity of MWCNT,Sio2 and nano silica(rice husks) are 12,20,8 cp after adding 0.7 gm to the water base mud while the amount of filter is 11.8 ml after adding nano particle size of MWCNT , nanoSio2 and 11.6 after adding nano silica(rice husks). The prepared nano silica (rice husks) gave results similar to the results of the commercial nano silicon dioxide (SiO2). Therefore, using of nano silica (rice husks) can be cost effective due to producing these materials locally instead of using the commercial nano SiO2.

Effect of Nano SiO2 Enhanced Polyurethane Road Grouting Material on Folding Strength and Durability of Road Concrete

Effect of Nano SiO2 Enhanced Polyurethane Road Grouting Material on Folding Strength and Durability of Road Concrete

Compressive strength and anti-chloride ion penetration assessment of geopolymer mortar merging PVA fiber and nano-SiO2 using RBF–BP composite neural network

Abstract In this study, we investigated the mechanical properties and chloride ion permeation resistance of geopolymer mortars based on fly ash modified with nano-SiO2 (NS) and polyvinyl alcohol (PVA) fiber and metakaolin (MK) at dose levels of 0–1.2% for PVA fiber and 0–2.5% for NS. The Levenberg–Marquardt (L–M) back propagation (BP) neural network, as well as the radial-based function (RBF) neural network, was used to predict the compressive strength and chloride ion permeation resistance of the geopolymer mortar with different admixtures of nanoparticles and PVA fiber, wherein the electric flux value was used as the index for chloride ion permeation performance. The RBF–BP composite neural network was constructed to study the compressive strength and chloride ion permeation resistance of nanoparticle-doped and PVA fiber ground geopolymer mortars. According to the experimental results of the RBF–BP composite neural network model, the mean square error (MSE) was observed to be 0.00071943, root mean square error (RMSE) was 0.026822, and mean absolute error (MAE) was 0.026822, thereby showing higher prediction accuracy, faster convergence, and better fitting effect compared with the single BP neural network and RBF neural network models. In this study, we combined the RBF–BP composite artificial neural network, providing a new method for the future assessment of the compressive strength and chloride ion penetration resistance of geopolymer mortar merging PVA fibers and NS in experiments and engineering studies.

Ni/NiO/SiO2/C nanofibers with strong wideband microwave absorption and robust hydrophobicity

Multifunctional microwave absorbers with robust hydrophobicity and enhanced wave absorption are of great significance for human health and the martial applications. Herein, carbon nanofibers (CNFs) inlaid with Ni/NiO and SiO2 nanoparticles were prepared by electrospinning and in-situ annealing method. Contrast experiments at different annealing temperatures had been conducted to illustrate the formation process and microwave loss mechanism of Ni/NiO/SiO2/CNFs. At the annealing temperature of 550 °C, the optimal reflection loss (RL) of −40.1 dB was reached at 16.6 GHz with a thickness of 2.5 mm, the effective absorption bandwidth (EAB) was 5.2 GHz. The maximum EAB of 8.0 GHz was obtained as the thickness close to 3.0 mm, covering the half of X band and entire Ku band. It was worth mentioning that the introduction of nano SiO2 into the Ni/NiO/CNFs annealed at 550 °C could refine the nanoparticles of Ni, promote the formation of Ni, improve the complex permittivity, and ultimately widen the EAB. Moreover, the contact angle (CA) of the Ni/NiO/SiO2/CNFs membranes annealed at 450, 550, 650 and 750 °C was 154.3°, 138.7°, 142.2° and 144.9°, respectively, illustrating that the products were of robust hydrophobicity. Therefore, the as-prepared NFs are promising in multifunction wave absorbers.

Fly Ash-Added, Seawater-Mixed Pervious Concrete: Compressive Strength, Permeability, and Phosphorus Removal.

A mix proportion of off-spec fly ash (FA)-added, seawater-mixed pervious concrete (SMPC) was optimized for compressive strength and permeability and then the optimized SMPC was tested for the rate and extent of aqueous phosphorus removal. An optimum mix proportion was obtained to attain the percentages (% wt.) of FA-to-binder at 15.0%, nano SiO2 (NS)-to-FA at 3.0%, liquid-to-binder at 0.338, and water reducer-to-binder at 0.18% from which a 7-day compressive strength of 14.0 MPa and a permeability of 5.5 mm/s were predicted. A long-term maximum compressive strength was measured to be ~16 MPa for both the optimized SMPC and the control ordinary pervious concrete (Control PC). The phosphorus removal was favorable for both the optimized SMPC and the Control PC based on the dimensionless Freundlich parameter (1/n). Both the optimized SMPC and Control PC had a first-order phosphorus removal constant of ~0.03 h−1. The optimized SMPC had a slightly lower capacity of phosphorus removal than the Control PC based on the Freundlich constant, Kf (mg1−1/n kg−1 L1/n): 15.72 for the optimized SMPC vs. 16.63 for Control. This study demonstrates a cleaner production and application of off-spec FA-added, seawater-mixed pervious concrete to simultaneously attain water, waste, and concrete sustainability.

Preparation of a novel vitrified bond CBN grinding wheel and study on the grinding performance

The vitrified bond CBN grinding wheels are characterized by high efficiency, high precision, and low environmental pollution. In recent years, the vitrified bond CBN grinding wheel has been widely used in manufacturing industries such as aerospace, automotive, and machine tools. In this study, a novel vitrified bond formulation containing nano SiO2 and nano CeO2 is selected to prepare the grinding wheel. The grinding experiments on 45# steel and YG20 alloy indicate that the grinding performance of the nano vitrified bond grinding wheel is significantly better than that of the conventional vitrified bond grinding wheel. The introduction of nano SiO2 and nano CeO2 greatly improves the machining performance of the vitrified bond CBN grinding wheel.

Physical and mechanical properties of hybrid composites using Kevlar fibre and nano-SiO2

ABSTRACT The current study aims to examine the mechanical and physical properties of Kevlar fibre/nano-silica/epoxy hybrid composites. The hand layup process followed by compression moulding was used to prepare a hybrid composite with different weight percentages (0%, 1%, 3%, and 5%) of nano SiO2 and four layers of the Kevlar fibres. Hardness, flexural, tensile, and impact tests were performed to evaluate mechanical properties. Nano SiO2 and Kevlar fibre improve the mechanical properties of the hybrid composites up to 3 wt.%. Rockwell Hardness tests suggest that the hardness of composites (K3) has improved up to 29% compare to K0. Tensile strength is about double at 3 wt.% nano SiO2 compared to neat laminates. The K3 has highest impact strength has increased by 50%. Flexural properties also increase up to 3 wt.% nano SiO2 reinforcement. Density, water absorption, and thickness swelling test wear were performed for the evolution of physical properties. Morphological analysis was done with the help of the field emission scanning electron microscopy (FESEM) technique.

Enhancing the heat transfer and photothermal conversion of salt hydrate phase change material for efficient solar energy utilization

Solar energy is intermittent, resulting in a discrepancy between the solar energy supply and building energy demand. Salt hydrate phase change material (PCM) is a promising material for use as an energy storage medium, but it suffers from a high supercooling degree, low thermal conductivity, and insufficient photothermal conversion efficiency. In this work, a novel sodium acetate trihydrate (SAT) composite was developed by synergistically using nano SiO2 (NS) as the nucleating agent, silicon carbide (SiC) foam as the thermal conductivity enhancer, and carbon nanotubes (CNT) as the photothermal enhancer. The supercooling degree of the modified SAT composite was only 1.4 °C, whereas the thermal conductivity and photothermal conversion efficiency could be increased to 1.54 W/(m•K) and 94.2 %, respectively. Most importantly, the payback period for applying the modified SAT composite in solar energy storage for domestic hot water supply is only 3.1 years, and the carbon dioxide emission could be reduced by approximately 1379.1 kg CO2-eq/year for a typical four-person family. Overall, the modified SAT composite with stable and excellent thermophysical properties offers great potential for the storage of solar thermal energy.

Application of Nano SiO2 in Pervious Concrete Pavement Using Waste Bricks as Coarse Aggregate

Application of Nano SiO2 in Pervious Concrete Pavement Using Waste Bricks as Coarse Aggregate

The Effect of Active Additives and Coarse Aggregate Granulometric Composition on the Properties and Durability of Pervious Concrete.

Pervious concrete (PCO) has many advantages and applications, such as water pooling reduction, noise attenuation, replenishment of groundwater reserves, etc. However, the use of pervious concrete is limited due to its low compressive strength and durability, especially as a result of portlandite leaching from concrete exposed to flowing water. The effects of active additives (nano SiO2 (NS) spent catalyst generated at the fluid catalytic cracking unit (FCCCw) and paper sludge waste burned at 700 °C (PSw)) along with particle size distribution of the coarse aggregate on the properties and durability of pervious concrete were determined in the research. Active additives used in the binder were found to reduce portlandite leaching from concrete exposed to flowing water to significantly increase the resistance of concrete to freezing and thawing cycles and to increase sound absorption, compressive strength and infiltration rate. In addition, industrial waste (FCCCw and PSw) used as active additives significantly reduced the use of clinker in concrete applied in the construction of water pervious systems. The coarse aggregate size distribution had the greatest effect on the density, ultrasound pulse velocity (UPV), porosity, compressive strength and infiltration rate of pervious concrete.

Rotatory flow of MHD (MoS2-SiO2)/H2O hybrid nanofluid in a vertical channel owing to velocity slip and thermal periodic conditions

BackgroundThe present article is a mathematical study on oscillatory pressure-driven MHD flow of a hybrid nanofluid in a vertical rotating channel. Hall current effect along with velocity slip and thermal periodic boundaries are the main focus of the present mathematical analysis. In the present investigation Molybdenum disulfide and silicon dioxide, nano-scaled particles are suspended in water. MethodologyMathematical modeling is carried out by considering rotating frame in the rectangular coordinate system and suitable non-dimensional variables are incorporated for simplification and non-dimensionalization of the problem. The hybrid nanofluid velocity and temperature distributions are derived in closed form with the aid of mathematics software MATHEMATICA. The prominent parameters’ effect on flow and heat transfer is investigated and studied through graphs. Significant findingsIt is concluded that hybrid nanofluid transport is highly influenced by surface roughness within the channel. Mixed convection and rotation parameters contribute to decelerating primary velocity and accelerating secondary velocity for both silicon dioxide as well as MoS2−SiO2 nano and hybrid nanofluids, respectively.

Effects of nano-SiO2 modification on rubberised mortar and concrete with recycled coarse aggregates

Abstract With the recent acceleration of industrialisation and urbanisation, increasing quantities of demolished construction waste and waste tyres are being produced. The production of recycled coarse aggregate (RCA) and rubber particles from this waste, for use as partial or full replacements of normal aggregate in cement concrete, is attracting attention as a solution to the problem of solid waste management. However, the greater incidence of defects in RCA and rubber particles than in normal aggregate limits their application in construction industries. This study evaluated an economic and environmental approach to optimise the performance of rubberised concrete with RCA. Two types of nanomaterials, nano-SiO2 (NS) solution and NS sol–gel, were used to pretreat RCA and rubber. The effect of the treatment time on the physical properties of the RCA was tested, and the mechanical properties of the rubberised mortar prepared with pretreated rubber were investigated. In addition, a compression test for the rubberised recycled aggregate concrete (RRAC) was designed using the Taguchi method. The effects of four factors (water–cement ratio, rubber content, rubber size, and aggregate treatment) on the stress–strain curve, compressive strength, elastic modulus, specific toughness, and failure patterns of RRAC were also analysed. The results showed that the NS-treated RCA exhibited lower water absorption rate and better mechanical properties. Moreover, the NS-modified rubber enhanced the compressive and flexural strengths of the rubberised mortar by 35 and 17%, respectively. Interestingly, it was found that simultaneous treatment of both RCA and rubber could negatively affect RRAC. Scanning electron microscopy indicated that NS improved the interfacial transition zone separating RCA and rubber from the cement matrix, whereas the pretreated RCA tended to bond with the pretreated rubber in RRAC.

Analysis of cutting fluid on minimum quantity lubrication by using vegetable oil

In all metal operations, Metal turning is a major operation on the material. For industrial pollution and health pollution, we have enhanced the conventional system to a new system that consists of minimum quantity lubrication. In this paper experimental investigation by using different nanomaterial and Minimum Quantity Lubrication. The material selected is Mild steel which is regularly used in small-scale industries. Due to hard turns, it is difficult to material remove and requires large force. In this research paper, we used three different nanoparticles nano Al2O3, nano ZnO, and nano SiO with palm oil. We analyzed cutting force, surface roughness on the machine.

Influence of SiO2, MgO, and Fe2O3 metallic nano cutting fluids of AA6061 in MQL environment

Metallic nano-lubricant tri-hybridization was used to study the mechanical and process of machining analysis for metallic nano-lubricant utilizing a predetermined volumetric ratio of SiO2, MgO, and Fe2O3 metallic nanoparticles in cold-pressed coconut oil. For aluminium end milling, an alternative to dry and wet machining processes is needed because of the high productivity and surface quality requirements.As a result, the produced nanofluids were examined for rheological behaviour before being used in the milling of AA6061 to solve the problem. When compared to traditional approaches, the nanofluids performed admirably. Results show that trio-hybridized lubricant reduces cutting force, tool wear and surface roughness more effectively than monotype nano fluids. With nano fluids and low quantities of lubricant, the interaction between process variables can be studied using response surface methods. All three of these metrics were reduced while using hybrid cutting fluids and the results were within acceptable parameters.

Silanizing Nano Sio2 and its Application in Recycled Nitrile Rubber to Preparesuper Oil Resistant/Superhydrophobic/Superoleophilic Oil/Water Separator

Silanizing Nano Sio2 and its Application in Recycled Nitrile Rubber to Preparesuper Oil Resistant/Superhydrophobic/Superoleophilic Oil/Water Separator

Uticaj sadržaja oksida na zavarivanje u zaštitnom gasu sa netopljivom elektrodom sa aktivnim topiteljem

In this paper, welding-remelting of AISI 304L (X2CrNi19-11) austenitic stainless steel was performed by using TIG process with activating flux, that is, A-TIG process. Fluxes were prepared by mixing 5, 10, 20, 30 and 40 % SiO2 nano particles with acetone solvent, while the application of the flux was done by a brush, prior to electric arc engagement. Characterization was done by visual testing and macro section analysis, with the main stress aimed at penetration depth as the dominant parameter used to assess the effectiveness of the flux. It was found that the highest penetration was obtained with 5 and 40 % of nano particles, with the wider weld obtained with 40 % of nano particles. However, from the point of welding technology, it was assessed that this is of secondary importance and that the optimal flux contains 5 % nano particles, primarily due to a lower cost, simpler mixing, lower viscosity and an easier flux application on the base metal.