Nano Al2O3 Research Articles

Enhancement of oxygen sensing performance of metalloporphyrin film modified with nano Al2O3 powder

In this work, the metalloporphyrin film of PtOEP/Poly (St-co-TFEMA) modified by nano Al2O3 powder was prepared, and the enhancement performance of oxygen sensing was studied in detail. It was verified that the modified film extended the residence time of oxygen through the characterization of SEM. The phosphorescence intensity changes with the content of Al2O3 and PtOEP were studied. The Stern-Volmer equations before and after modification of Al2O3 powder was compared. It was found that the linearity of the calibration curve was still high, but the oxygen sensitivity value of KSV was significantly improved due to the increase of quenching probability between indicator and oxygen. Finally, the stability test shows that the Al2O3@PtOEP/Poly (St-co-TFEMA) oxygen sensing film presents a strong anti-photo-bleaching ability, and the response time is shortened.

Mechanical Behavior of Hybrid Laminated Nano Composite Containing Equal Numbers of Glass and Carbon Fiber Plies

Hybrid fiber reinforced polymer with nanofiller composite was introduced into a lot of industries due to its extreme mechanical properties in comparison with non-hybrid material. In this investigation, cross and quasi-fiber laminated epoxy composites with and without nano Al2O3 were fabricated using Vacuum Assisted Resine Infusion Method and Ultrasonic Dual Mixing Method. In general, the results of mechanical properties indicated that the addition of 2% nano Al2O3 enhances the tensile and flexural properties. Cross number 2 with nano Al2O3 laminate had the maximum tensile strength 628 MPa and maximum tensile strain of 1.74%, while cross number 1 with nano Al2O3 laminate had the maximum tensile modulus of 37.756 GPa in the cross group. In the quasi group, quasi number 2 with nano Al2O3 had the maximum tensile strength, maximum tensile strain, and maximum tensile modulus, equal to 294 MPa, 1.98%, and 16.409 GPa, respectively. Regarding the flexural properties, cross number 1 with nano Al2O3 laminate had a maximum flexural strength of 708.2 MPa and maximum flexural strain of 2.027%, while cross number 2 with nano Al2O3 laminate had a maximum flexural modulus of 38.73 GPa in the cross group. On the other hand, quasi number 1 with nano Al2O3 laminate had the maximum flexural strength, maximum flexural strain, and maximum flexural modulus equal to 596 MPa, 2.424%, and 29.2 GPa, respectively in the quasi group. The internal structures of the failure laminated composites through scanning electronic microscopy confirm that the adhesion between fibers and matrix is good.

Evaluation of Flexure Strength of Heat Cure Acrylic Resin Reinforcement with Nano Al2O3 After Polishing with Different Abrasive Materials

Evaluation of Flexure Strength of Heat Cure Acrylic Resin Reinforcement with Nano Al2O3 After Polishing with Different Abrasive Materials

Enhanced interlaminar mechanical behavior of advanced fiber metal laminates via nano Al2O3‐IPN formation and surface pre‐treatments

AbstractThe inferior delamination resistance and out‐of‐plane performance of fiber metal laminates (FMLs) are of serious concerns. This work employs two modification methods, namely metal surface's chemical pre‐treatment and nano Al2O3 embedded interpenetrating polymer network (IPN) formation for improving the delamination resistance of aluminum and glass fiber‐reinforced polymer (GFRP) composite‐based FMLs. The synergetic effect of the two modification techniques resulted in high degrees of improvement in delamination resistance that were ~28% for critical strain energy release rate during mode‐I interlaminar fracture toughness (ILFT), that is (GIC) and ~37% for GIIC. Simultaneously, the flexural strength, tensile strength, and interlaminar shear strength improved by ~23%, ~17%, and ~24%, respectively. Scanning electron microscopy, atomic force microscopy, and surface energy measurement studies showed that the chemical pre‐treatment significantly influenced the surface morphology, surface roughness, and surface energy responses of aluminum, respectively. Fractographic study validated the effect of modification methods on the failure behavior under various testing modes.

Coupled optimization of optical and thermal properties for NaCl-Al2O3 towards efficient thermal energy storage

In this paper, a coupled optimization method of optical and thermal performance was explored by us. The microscopic structure of NaCl-Al2O3 based composite phase change material (CPCM) was established, the thermal properties were obtained by means of molecular dynamics (MD) simulations combined with experiments. The first principle calculations were also carried out to investigate the optical performance of the CPCM. The results indicated that the addition of nano Al2O3 can effectively improve the thermal performance and thermal stability of CPCM, when the mass fraction of Al2O3 nanoparticles in CPCM are 2.2 wt% and 7.2 wt%, the mass loss of CPCM samples were 0.14 % and 0.016 % after 100 times cycle, and the thermal conductivity and specific heat capacity can be increased by 15.45 % and 7.63 % at most. In addition, it was found that the optical performance of the CPCM can be also significantly improved. The microscopic coupled optimization mechanism was successfully revealed by the calculation of phonon density of state and band structures, which is desired to be a candidate approach to improve the photo-thermal conversion efficiency of the heat absorber contained in CSP (concentrating solar power) system.

Miniaturized Flexible Non-Contact Interface Based on Heat Shrinkage Technology.

High-performance miniaturized flexible sensors are becoming increasingly important in wearable electronics. However, miniaturization of devices often requires high-precision manufacturing processes and equipment, which limits the commercialization of flexible sensors. Therefore, revolutionary technologies for manufacturing miniaturized flexible sensors are highly desired. In this work, a new method for manufacturing miniaturized flexible humidity sensor by utilizing heat shrinkage technology is presented. This method successfully achieves much smaller sensor and denser interdigital electrode. Utilizing this method, a miniaturized flexible humidity sensor and array are presented, fabricated by anchoring nano-Al2 O3 into carbon nano-tube as the humidity sensitive film. This heat shrinkage technology, forming wrinkle structure on the humidity sensitive film, endows the sensor with a high sensitivity over 200% (ΔR/R0 ) at humidity levels ranging from 0 to 90%RH and a fast recovery time (0.5s). The sensor allows non-contact monitoring human respiration and alerting in case of an asthma attack and the sensor array can be adaptively attached to the wrist as a non-contact human-machine interface to control the mechanical hand or computer. This work provides a general and effective heat shrinkage technology for the development of smaller and more efficient flexible circuits and sensor devices.

Ultra-thin ceramic coated separator for high energy density lithium-ion battery:In-depth analysis on Al2O3 nano particles penetration into the structure pore

The energy density and power of lithium-ion batteries (LIBs) are undoubtedly essential to fuel the satisfying pursuit of next-generation energy storage systems. However, to ensure the safety of LIBs, a micrometer-thick ceramic coating layer (CCL) is coated on the separator by a conventional slurry process, which reduces the energy density and performance of LIBs. For this purpose, a ceramic-coated separator (CCS) fabricated by sputtering has attracted attention because it can secure thermal stability and performance while minimizing the CCL thickness to nanometers. Nevertheless, the analysis of why a CCL with only nanometer thickness could improve the properties of the separator still needs to be investigated. Theoretically, it could be suggested that sputtered nano ceramic particles could penetrate the internal micropore structure of the separator, but no experiments were conducted to identify this. In this study, depth profiling using time-of-flight secondary ion mass spectrometry was conducted to confirm the distribution of sputtered nano ceramic particles in the internal structure of the separator depending on the porosity. The surface composition of the separator changed by the plasma generated during the sputtering process was observed by X-ray photoelectron spectroscopy. In addition, to investigate the effect of the nm-CCL on the properties and electrochemical performance of the separator, we compared it with commercial slurry CCS and single/double-sided ceramic sputtering samples.

Evaluating the use of nano-SiO2/Al2O3 to mitigate damage in cement mortar exposed to magnesium chloride solution under different conditions

In this study, nano-SiO2 (NS) and nano-Al2O3 (NA) were introduced alone and together to modify the MgCl2 attack resistance of cement mortar in the conditions of low air pressure (60 kPa) and low humidity (60% RH), from the aspects of appearance damage, pore structure, product composition and morphology, and compressive strength. The results showed that low pressure environment accelerated the occurrence of damage, exhibiting intact surface and internal expansion and cracking in the evaporation zone of semi-immersed mortar. The MgCl2-induced erosion products mainly include Mg(OH)2, M–S–H, Ca2Al(OH)6Cl·2H2O and Mg2(OH)3Cl·4H2O. The introduction of NS/NA reduced the adsorption height of the solution on the surface of the mortar and alleviated the degree of damage to the mortar exposed to air. Meanwhile, the nano-modification decreased the number of harmful pores above 50 nm and consumed erodible Ca(OH)2 in samples, reducing the generation of erosion products. Finally, the compressive strength of nano-modified mortar under MgCl2 attack coupled with low air pressure environments was enhanced based on the nucleation effect and chemical activity of NS and NA. Among them, the system containing NS performed better.

Comparative analysis of fluid flow in mini channel with nano fluids and base fluid

Comparative study is carrying out between nano fluid Al2O3 + CuO + ZnO + H2O and water as solitary fluid through experimental and simulation result. The outcome of nano fluid and solo base fluid H2O flowing in middle rectangular mini channel with or without insert were admit, for study the conduct of fluid flow and heat exchange features. During composing of nano fluid 0.05%-0.1% volume fraction, 10–20 nm size nano particles were mixed with 0.5 ml CTAB surfactant. Experimentation were manage for different operating parameters under counter flow conditions, where nano fluid is flowing inside mini channel of 2 mm diameter with flow rate 0.0001562 to 0.006255 ml/min and hot water is flowing inside the concentric tube of 3.6 cm diameter with flow rate of 0.000782 ml/min. The operating temperature of nano fluid and hot water were 308 K and 323 K. As per obtained results, the proposed composition of nanofluid showed better performance than normal water due to better thermal conductivity and extra molecular area gain in nanofluid due to addition of nano particle with base fluid, where as better optimum results were observed in case of rectangular mini channel with macro insert compared with other geometry because of rich turbulency gain and extra exposed area due to macro insert.

Strength analysis of hybrid date-wood-Al2O3 polymer composite using Taguchi method

The current study discusses the creation and characterization of a novel set of studies carried out by supplementing the matrix (Polyester resin) with natural materials (date leaf, teak wood dust) and nanoparticles (aluminium oxide). Natural fibres are utilised in the hand lay-up process to manufacture composite materials. The Taguchi approach is utilised in the investigation of different composite reinforcement formulations. The Taguchi design and experimental data analysis are used to investigate the influence of factors such as filler content % and different fillers such as date leaf fiber, teak wood powder, and Al2O3 Nano particles (N). Different composite qualities are developed and studied. Mechanical characteristics, such as tensile and flexural testing, will be performed to evaluate the behaviour of different composites. It was reported that Date leaf fiber was the most influential parameter for increasing the strength of the composite.

Simulation studies on GAX based absorption cooling and power cycle using a mixture of ammonia-water working fluid and aluminium oxide nano particles

The present work is focused on analyzing the influence of nano material aluminium oxide on the performance of generator absorber heat exchange ammonia-water absorption refrigeration system. Matlab code has been used to simulate the performance of the combined cycle. The effect of refrigeration, absorber and condenser temperatures on the combined cycle performance have been studied. The results of the analysis indicate that the performance of the combined cycle is higher by 15 to 20% when Al2O3 nano particles were added when compared to the same cycle without the addition of nano particles.

The Dynamic Behaviour of Symmetrical Laminated Nano-composite Containing Equal Numbers of Glass and Carbon Fibre Layers

Fibre-reinforced polymer composite has many uses in structural components that required high strength, stiffness, and damping capacity. Cross and quasi-laminated epoxy composites with and without nano Al2O3 were used in this investigation to determine flexural modulus, natural frequency, damping ratio, and mode shapes by using analytical, experimental, and numerical (ANSYS) methods. It was demonstrated that adding 2 % nano Al2O3 improved the flexural modulus and the damping ratio while decreased the natural frequency. Cross number 2 and quasi number 2 had the highest natural frequency for cross and quasi laminate groups which are equal to 23.5 Hz and 20.25 Hz experimentally, respectively. On the other hand, the higher damping ratio was achieved for cross number 1 with nano Al2O3 and quasi number 2 with nano Al2O3 for both cross and quasi laminates, which are equal to 0.707 % and 0.693 %, respectively. The flexural modulus and damping ratio are inversely related to each other. However, the novelty in this article is that by adding two glass plies at the outer surface of quasi group laminate the flexural modulus, natural frequency, and damping ratio are increased simultaneously, as in the configurations quasi number 2 and quasi number 2 with nano Al2O3 in comparison with quasi number 1 and quasi number 1 with nano Al2O3.

Preparation and characterization of binary eutectic phase change material laden with thermal conductivity enhancer for cooling steel slag asphalt pavement

The active asphalt pavement cooling strategy using phase change material (PCM) is crucial for mitigating urban heat island impacts and reducing high-temperature rutting distress. However, most PCM-incorporated pavements use single pure PCM for temperature regulation, resulting in either a discrepancy between phase change temperature and pavement rutting sensitive temperature or a low phase change enthalpy. Moreover, their unacceptable low thermal conductivity can dramatically lower the PCM thermal performance in cooing asphalt pavements. This study aimed to develop a novel PCM-incorporated cooling asphalt pavement, which consists of a binary eutectic mixture of fatty acid PCMs (palmitic acid (PA) and stearic acid (SA)), a supporting material (waste steel slag aggregate (SSA)), and a thermal conductivity enhancer (TCE, Nano Al2O3). The PCM composite of PA-SA was screened out first based on a binary eutectic system. The composite phase change steel slag aggregate (CPC-SSA) and the TCE-based CPC-SSA asphalt mixture were then designed and developed with three types of TCEs. The performance tests were finally conducted to examine the thermal and rutting resistance performance of the PCM-incorporated asphalt pavement. The test results showed that the pavement incorporated with the PCM composite of PA-SA and Nano Al2O3 is capable of effectively cooling asphalt pavement and alleviating its high-temperature rutting distress. The findings of this study are expected to promote sustainable resource utilization and cooling strategies developed for the mitigation of high pavement temperature distresses and urban heat island impacts.

Simultaneous enhancement in interlaminar– shear strength and fracture toughness through nano Al2O3 dispersion in glass fiber/IPN multiscale composites

Simultaneous implementation of two polymer hybridisation routes, namely, interpenetrating polymer network (IPN) formation and nanofiller (nano Al2O3) addition, resulted in considerable increments in the mechanical performance of GFRP composites. Improvements of ∼18%, ∼8%, ∼14%, ∼19 %, and ∼29% in flexural strength, tensile strength, interlaminar shear strength (ILSS), critical strain energy release rate (GIC) during mode-I interlaminar fracture toughness (ILFT), and GIIC during mode-II ILFT values of nano-Al2O3 modified composites, respectively, were observed over composite without nano Al2O3. Composite with 0.1 wt.% of nano Al2O3 showed the highest mechanical properties in all the modes of testing except for mode-II ILFT testing, where composite with 0.4 wt.% of nano Al2O3 showed the highest toughness value. The synergy between the constituents and the thermal stability of the composites were analyzed via Fourier transform infrared spectroscopy and differential scanning calorimetry, respectively. Fractography was performed to understand the composites' failure criteria and toughening mechanisms.

The effect of Cu coated Al2O3 particle content and densification methods on the microstructure and mechanical properties of Al matrix composites

In the study, aluminum-based nanocomposites were reinforced with different concentrations of Al2O3 nanoparticles ranging from 0 to 15 wt. %. The Al2O3 nanoparticles were coated by nano Ag and nano Cu by the electroless chemical composition to improve the wettability between the matrix and the reinforcement phase. The influence of the suggested deformation technique and the concentrations of Al2O3 nanoparticles on the microstructure, density, and mechanical properties in terms of hardness and compressive strength of the hot extruded Al/Al2O3 nanocomposites was studied. Results revealed that, as the concentration of nano Al2O3 particles increases, the mechanical properties were improved. XRD, FE-SEM equipped with EDX, and elemental mapping indicates a near-uniform distribution of reinforcement nanoparticles in the matrix. The relative density of the formed nanocomposite recorded a slight decreases than the extruded pure Al. Owing to the presence of the Al2O3 nanoparticles, the Al-15 wt. % Al2O3 hot extruded composite achieves a hardness of 136 and 132 measured on the cross and longitudinal sections, respectively, illustrating an improvement of around 109% over the extruded pure Al. The hot extruded Al/Al2O3 nanocomposites with 5, 10, and 15 wt. % content revealed compressive strength of 564, 579, and 763 MPa, respectively, with an enhancement of 97, 102, and 166% over those of the extruded pure Al.

Optimization and performance characteristics of diesel engine using green fuel blends with nanoparticles additives

The optimized experiment model is often developed to provide fewer costs, time consumed and error for experiment. Nanoparticles can be utilized as fuel additives to improve lubrication performance. Nevertheless, the concentration of nanoparticles is crucial for fuel lubricity. Thiswork describes the use of response surface methodology (RSM) based Box-Behnken design to optimize the tribological behaviour of several types of nanoparticles combined in tyre pyrolysis oil-biodiesel-diesel blended fuel using a four-ball tribometer. The study aims to identify the ideal values for applied load, rotation speed and nanoparticles concentration to enhance the fuel's tribological behaviour. The applied load, rotation speed and nanoparticles concentration range from 20 to 60 kg, 1000 to 1400 RPM and 0–0.2 wt%, respectively are used to determine the coefficient of friction (COF), wear scar diameter (WSD), and surface roughness (Ra). The result revealed that MgO, graphene and Al2O3 nano-fuel shows improvement in the tribological behaviour. MgO nano-fuel model, the optimum speed, load and concentration values were 1000 RPM, 26.99 kg and 0.0531 wt% for graphene nano-fuel model, the optimum speed, load and concentration values were 1161.73 RPM, 21.83 kg and 0.105 wt% and for Al2O3 nano-fuel model, the optimum speed, load and concentration values were 1109.3 RPM, 30.37 kg and 0.0107 wt% respectively. The investigation results demonstrated that the tribological behaviour of the nano fuels made of MgO, graphene and Al2O3 had been improved. In contrast to MgO and graphene nano fuel, the optimized Al2O3 nano fuel demonstrated the best tribological performance with the lowest concentration, price, load and speed.

Influencing mechanism of nano-Al2O3 on concrete performance based on multi-scale experiments

Multi-scale experiments were conducted to comprehensively explore the influencing mechanism of nano-Al2O3 (NA) on concrete performance. The experimental results indicated that the addition of 1% NA in concrete significantly improved its physical and mechanical properties and durability. Compared with the concrete without NA, this addition of 1% NA also made the internal structure denser, increased the early and late compressive strengths by 13.8% and 19.1%, respectively, and enhanced the ability to resist chloride ion penetration. However, with increasing NA content, the NA stabilized concrete gradually performed poorly in the workability and resistance to chloride ion penetration (RCP). Furthermore, it exhibited a decreased dry density and compressive strength, and an increased open porosity and water absorption. Through the mercury intrusion porosimetry (MIP) test, we found that the addition of NA effectively reduced the porosity and the most probable aperture of mortar in the concrete so that the proportion of gel micro-pores in the concrete increased and the proportion of capillary pores decreased. Moreover, NA had a pozzolanic effect and could react with calcium hydroxide (CH) to generate more nanofibers, which could fill pores and bond cracks to improve concrete performance under microscopic experiments.

Effect of nano Al2O3 addition on cycling performance of poly(ether block amide) based solid-state lithium metal batteries

A novel poly(ether block amide) (PEBA) based solid-state polymer electrolyte (SPE) was prepared using a casting method, in which 20wt% lithium (Li) bis-(trifluoromethanesulfonyl)imide (LiTFSI) and aluminum oxide (Al2O3) nanoparticles were used as the Li salt and solid plasticizer, respectively. In the case of addition of 3wt% Al2O3 nanoparticles, ion conductivity of the obtained PEBA 2533–20wt% LiTFSI-3wt% Al2O3 SPE was 3.57 × 10−5 S cm−1 at 25 °C. Furthermore, the Li symmetrical battery assembled with it showed excellent cycling stability (1000 h) at 0.1 mA cm−2. While, the assembled all-solid-state Li/PEBA 2533–20% LiTFSI-3wt% Al2O3/LiFePO4 (areal capacity: 0.15 mAh cm−2) battery maintained 94.9% of the maximal capacity (133.9 mAh g−1@0.1 mA cm−2) at 60 °C even after 650 cycles with a superior average coulombic efficiency (CE) of 99.84%. By using X-ray photoelectron spectroscope (XPS), self-aggregation layer (SAL) of polyamide 12 (PA12) of PEBA 2533 was discovered, which should contribute to promoting the robustness of lithium fluoride (LiF) enriched solid-electrolyte interphase (SEI) layer. In addition, it is considered that the state of interface between SPE and cathode should be the cause of voltage polarization of the full cell.

Fabrication and characterization of nano Al2O3 fiber-reinforced polymer composites

The current work focuses on a hand layup approach for the manufacture and characterization of Al2O3-fiber-reinforced polymer composites to understand the mechanical characteristics of an epoxy- and hardener-based E-glass (610-GSM) fiber-reinforced polymer composite. In order to create Al2O3 powder, high-energy ball milling is used. The testing samples are made in accordance with ASTM-D-638, ASTM-D-790, and ASTM-D-785 standards, utilising five layers of E-glass fibre for each laminate and varying volume percentages (0%, 0.5%, 1%, 1.5%, 2%, and 2.5%). These samples go through tensile, flexural (three-point bend), and hardness testing. For all the laminates, the findings are contrasted within the volume percentage range (0%, 0.5%, 1%, 1.5%, 2%, and 2.5%). The many benefits of E-glass fiber-reinforced polymer composites, including their great wear resistance and high strength-to-weight ratio, have led to a wide range of applications. Results of the composite's tensile strength, flexural strength, and hardness were compared.

CuO/water and Al2O3/water nanofluids as working fluid in an abandoned oil well to improve thermal performance in the seawater desalination process

BackgroundAbandoned Oil/gas wells could be employed as heat sources for various technical processes such as seawater desalination. MethodsIn this study, the thermal performance of an abandoned oil well is enhanced by the addition of nano Cu and Al2O3 particles into the working fluid (water) and by using two distinct thermal insulations in the coaxial double-pipe borehole heat exchanger to decrease heat losses of the heated working fluid. Diligent simulation of the process was carried out using the k-ω SST turbulence model and sweep meshing method. The effect of Cu/water and Al2O3/water nanofluid concentrations on extracted fluid temperature was investigated. Significant FindingThe results revealed that 0.5 wt.% of Cu/water and Al2O3/water as working fluid at a flow rate of 2 kg/s raised the extracted fluid temperature by 14% and 12.9% compared to pure water, respectively. Also, SiO2/GO composite thermal nano-insulation could improve heat loss by 7.4% compared to polystyrene thermal insulation. Furthermore, 806 m3/day of potable water was produced by a multi-effect distillation modified with flash-boxes desalination, where brines were reused as a secondary feed for potable water production. Noticeable increase achieved compared to conventional multi-effect distillation systems.