Thermophysical properties of stabilized copper oxide-polyaniline-palm oil based nanofluids

Nanofluids have attracted boundless attention among researchers due to their excellent heat transfer properties and have been proposed for various advanced heat transfer applications. However, the use of excessive nanoadditives could be costly and pose a threat to the environment due to the high toxicity of recent used nanoparticles. The advancement in technology has forced the search for advanced heat transfer fluid to replace the non-renewable conventional mineral oil base fluids. Therefore, to propose more ecologically and cost-effective nanofluids, the possibility of conducting polymer as nanoadditives in vegetable-based heat transfer fluids is proposed and investigated. Palm oil (a vegetable-based oil) has been the preferred fluid to substitute the centuries-old oil in the present work. In this research, the inexpensive and environmentally friendly polymers, PANI nanofibers, were synthesized and hybridized with CuO nanoparticles to serve as nanoadditives in RBDL for nanofluid formulation. The stability of formulated nanofluids was evaluated as stability plays a vital role in ensuring the behavior of the thermal system at a designed parameter. The formulated nanofluids' thermophysical properties were investigated in greater depth to reveal the possibility as advanced heat transfer fluid. Mathematical equations were developed at the final stage of the research for future properties prediction. The two-step approach was espoused to formulate CuORBDL, PANI-RBDL, and CuO-PANI-RBDL nanofluid with different volume concentrations ranging from 0.01-0.5%. The morphology and structure of the synthesized nanoadditives were analyzed using TEM, EDX, XRD, FT-IR, and TGA. Meanwhile, sedimentation observation, DLS, UV-Vis, FTIR, TGA are performed for stability evaluation. Thermophysical properties of formulated nanofluids such as density, rheology, and thermal conductivity were measured using density meter, rheometer, and thermal analyzer instruments. The mathematical model was developed using RSM for future prediction and validation via comparison study with the present data. Morphological and structural analysis performed using TEM, EDX, XRD, FTIR, and TGA analysis revealed that the PANI nanofibers had been successfully hybridized with CuO nanoparticles. Sedimentation observation noticed that the CuO-RBDL achieved stability only for a week, while PANI-RBDL and CuO-PANI-RBDL samples maintain their dispersion stability near a month. The stability observation findings were supported and further inveterate by DLS and UV-vis analysis. All PANI-RBDL and CuO-PANIRBDL nanofluids samples achieved an absorbance drop in the range of 4 to 12% in 30 days from the UV-Vis analysis. The FTIR spectrum and TGA curve for all the nanofluids indicate that the prepared nanofluids are chemically and thermally stable. The density of all nanofluids was found to increase with the volume concentration of nanoadditives but decrease with temperature. All nanofluids' rheology properties were found to have Newtonian flow behavior, and the viscosity increases with nanoparticle volume concentrations, but their properties diminish with temperature increment. The most outstanding thermal conductivity properties achieved by nanofluid were the 10wt% CuOPANI nanocomposites with 31.34% enhancement, while the least thermal conductivity acquired is for CuO-RBDL with 17.8% enhancement. The experimental results were compared with the predicted result obtained from the mathematical model. All the plotted data were found to have good agreement with the experimental data indicating the developed mathematical model's reliability for response estimation. In summary, the formulated nano-enhanced RBDL nanofluid evaluated properties expose the possibility of alternative advanced heat transfer fluid for industrial application due to their superior inherent qualities

Copper oxide/polyaniline nanocomposites-blended in palm oil hybrid nanofluid : Thermophysical behavior evaluation

In the present work, Copper Oxide-Polyaniline (CuO/PANI) nanocomposites-blended in palm oil hybrid nanofluid have been prepared via a two-step method and investigated as potential heat transfer hybrid nanofluids for the first time. Initially, CuO/PANI nanocomposites are synthesized via oxidative polymerization by varying the weight percentage of CuO nanoparticles (1, 5, and 10 wt%) and characterized using TEM, EDX, XRD, FTIR, and TGA analysis. The findings revealed a successful fusion of nanocomposite composed of spherical CuO nanoparticles embedded in flake-like PANI. The formulated CuO/PANI-palm oil hybrid nanofluids are prepared at a volume concentration between 0.01% and 0.5% and stabilized using an ultrasonication process without any surfactant. UV–vis and sedimentation observation revealed that all nanofluids remain stable for up to a month. FTIR analysis reveals that all formulated nanofluids are chemically stable as no formation of new peaks obtained with the dispersion of nano additives. The TGA analysis affirmed better thermal stability in all nanofluids compared to base fluids. Density evaluation of formulated nanofluids shows a linear relationship between density and volume concentration of nanocomposites but decreased with temperature. Rheology study indicates that palm oil exhibits viscous flow behavior similar to Newtonian behavior. Nanofluid containing 10 wt% CuO/PANI nanocomposites displayed having the highest viscosity and thermal conductivity properties (31.34% enhancement) compared to the rest prepared nanofluids. Mathematical equations were developed at the final stage of the research for future properties prediction

A Brief Review on Thermal Behaviour of PANI as Additive in Heat Transfer Fluid

Since a decade ago, investigation on nanofluids has grown significantly owing to its enhanced thermal properties compared to conventional heat transfer fluids. This engineered nanofluid has been widely used in the thermal engineering system to improve their energy consumption by improving the thermal efficiency of the system. The addition of nano-size particles as additives dispersed in the base fluids proved to significantly either improve or diminish the behaviour of the base fluids. The behaviour of the base fluid highly depends on the properties of the additives material, such as morphology, size, and volume fraction. Among the variety of nanoparticles studied, the conducting polymers have been subject of high interest due to its high environmental stability, good electrical conductivity, antimicrobial, anti-corrosion property and significantly cheap compared to other nanoparticles. As such, the main objective of the present review is to provide an overview of the work performed on thermal properties performance of conducting polymers based nanofluids

Template Synthesis of Ni Nanowires: Characterization and Modelling

Template-assisted electrochemical deposition is a straight forward approach for the synthesis of 1D nanostructures (e.g., nanowire, nanorod, and nanobelt) with controllable morphology. This approach is suitable for mass production as it works at ambient pressure and temperature with the properties of synthesized 1D nanostructures being influenced by synthesis conditions during the electrochemical deposition process. This work aims to investigate the influence of stabilizing agent concentration and heating temperature towards the physical behavior of Nickel (Ni) nanowires synthesized via a template-assisted electrochemical deposition approach. In this research, the electrolyte bath was prepared in three different concentrations of the stabilizing agent (6 g/L, 40 g/L and 70 g/L), and the deposition bath temperature used was 30°C, 70°C, and 110°C respectively. The elemental composition was determined using Energy Dispersive X-ray (EDX) analysis to investigate the percentage of pure Ni element in the synthesized nanowires. The diameter, surface texture, and growth length of the synthesized Ni nanowires were characterized using Field Emission Scanning Electron Microscope (FESEM). X-ray diffractions (XRD) was used for crystal size and crystal orientation analysis. Additionally, the mechanical properties of Ni nanowires were extracted via molecular dynamic simulation. Growth length of Ni nanowires found to be significantly improved as the heating temperature increased, but it decreased when stabilizer agent concentration is high. The diffraction patterns for all synthesis conditions exhibited the synthesis Ni nanowires are polycrystalline as the crystalline planes with Miller indices of 111, 200, and 220. All the investigated nanowires showed ductile failure behavior, a typical behavior at larger length scales of Ni

Energizing the thermal conductivity and optical performance of salt hydrate phase change material using copper (II) oxide nano additives for sustainable thermal energy storage

Due to intermittent nature of solar energy, scientists and researchers are working to develop thermal energy storage (TES) systems for effectively use the solar energy. One promising avenue involves utilizing phase change materials (PCMs), but primary challenge lies in their limited thermal conductivity, which results in slower heat transfer rate and lower thermal energy storage density. The present research work demonstrates, to develop and explore a PCM composite by embedding salt hydrate and coper (II) oxide to enhance the heat transfer mechanism for potential utilization of TES material. The optical behavior, and thermal conductivity were analyzed by using Ultraviolet visible spectrum, and thermal property analyzer. The developed copper oxide dispersed PCM composite displayed the thermal conductivity was energized up to 71.5 % without affecting the other properties. Also, the optical absorptance was remarkably enhanced and the transmittance reduced to 87 %. Increasing the concentration of copper oxide nanoparticles in the salt hydrate PCM improves the optical absorptivity and heat conductivity. With these extraordinary abilities the nanocomposite could play a significant role in progress of sustainable TES with significance to contribute towards sustainable development goal of affordable and clean energy and climate change

Electrochemical Deposited Nickel Nanowires: Influence of Deposition Bath Temperature on the Morphology and Physical Properties

This paper investigates the influence of the electrolytic bath temperature on the morphology and physical properties of nickel (Ni) nanowires electrochemically deposited into the anodic alumina oxide porous membrane (AAO). The synthesis was performed using nickel sulfate hexahydrate (NiSO4.6H2O) and boric acid (H3BO3) as an electrolytic bath for the electrochemical deposition of Ni nanowires. During the experiment, the electrolyte bath temperature varied from 40°C, 80°C, and 120°C. After the electrochemical deposition process, AAO templates cleaned with distilled water preceding to dissolution in sodium hydroxide (NaOH) solution to obtain free-standing Ni nanowires. Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDX) and X-ray Diffraction (XRD) analysis were employed to characterize the morphology and physical properties of the synthesized Ni nanowires. Finding reveals the electrodeposition bath temperature significantly influences the morphology and physical properties of the synthesized Ni nanowires. Rougher surface texture, larger crystal size, and longer Ni nanowires obtained as the deposition bath temperature increased

Harnessing nature’s ingenuity: A comprehensive exploration of nanocellulose from production to cutting-edge applications in engineering and sciences

Primary material supply is the heart of engineering and sciences. The depletion of natural resources and an increase in the human population by a billion in 13 to 15 years pose a critical concern regarding the sustainability of these materials; therefore, functionalizing renewable materials, such as nanocellulose, by possibly exploiting their properties for various practical applications, has been undertaken worldwide. Nanocellulose has emerged as a dominant green natural material with attractive and tailorable physicochemical properties, is renewable and sustainable, and shows biocompatibility and tunable surface properties. Nanocellulose is derived from cellulose, the most abundant polymer in nature with the remarkable properties of nanomaterials. This article provides a comprehensive overview of the methods used for nanocellulose preparation, structure–property and structure–property correlations, and the application of nanocellulose and its nanocomposite materials. This article differentiates the classification of nanocellulose, provides a brief account of the production methods that have been developed for isolating nanocellulose, highlights a range of unique properties of nanocellulose that have been extracted from different kinds of experiments and studies, and elaborates on nanocellulose potential applications in various areas. The present review is anticipated to provide the readers with the progress and knowledge related to nanocellulose. Pushing the boundaries of nanocellulose further into cutting-edge applications will be of particular interest in the future, especially as cost-effective commercial sources of nanocellulose continue to emerge

Potential coolants for fuel cell application: Multi-objective optimization of thermophysical properties and PPF calculation of hybrid palm oil nanofluids

In this study, Response Surface Methodology (RSM) is being used to optimize density, viscosity, and thermal conductivity in CuO-polyaniline/palm oil hybrid nanofluids. Using a Central Composite Design (CCD) within RSM, researchers are systematically exploring the impact of temperature (ranging from 30 to 60 °C), volume concentration of nanoadditives (varying from 0.1 to 0.5 vol%) and CuO composition (ranging from 1 to 10 wt%) on the thermophysical properties of these nanofluids. This research is pioneering in its evaluation of the price performance factor (PPF) for these nanofluids. To ensure model reliability, Analysis of Variance (ANOVA) is being applied. The findings showcase robust models, as indicated by a 45° angle line within the predicted vs. actual data graph. The models exhibit impressive R2 values: 98.66 % for density, 99.93 % for viscosity, and 99.91 % for thermal conductivity, underscoring the agreement between predicted and actual data. Optimal values for density, viscosity, and thermal conductivity are being obtained: 0.901532 g/mL, 37.1229 mPa s, and 0.356891 W/mK, respectively. These correspond to critical parameters of 53.92 °C for temperature, 0.038 vol% for volume concentration of nanoadditives and 2.90 wt% for CuO composition. Moreover, the price performance factor (PPF) assessment reveals that higher thermal conductivity doesn't necessarily equate to greater cost-effectiveness

Progress in research and technological developments of phase change materials integrated photovoltaic thermal systems : The allied problems and their mitigation strategies

The efficiency of solar cells and photovoltaic (PV) panels are lacking significantly due to its surface overheating by the incident solar radiation. Indeed, the generated heat energy is harnessed by integrating a thermal system into PV panel, which introduces a photovoltaic thermal (PVT) system. Phase change materials (PCM)s are a class of energy material that is intended to facilitate thermal regulations of photovoltaic (PV) panel. Despite, PVT systems are allied with numerous problems like, integration technique, increase in overall weight of the system, dust accumulation, complication of tracking etc., which are of utmost importance to be resolved. The foremost aim of the review is to analyze the current technologies and allied problems of PVT system, the impact of the overall weight of the system on the PVT systems, detailed assessment of recent advancements in soil mitigation techniques, and the economic benefit of the PVT systems. Also, this review article is specifically intended to discuss on a) concerns allied with PV and PVT system integrated with PCM for thermal regulation; b) framework intimidating the performance of PCM-integrated PVT system; and c) mitigation techniques to resolve the problems and enhanced the performance of PCM integrated PVT system. A elaborative technical exploration on common issues associated with both PV and PVT systems in terms of surface cleaning towards dust mitigation via advanced mechanisms and futuristic technologies is comprehensively presented. A new possible sustainable solution towards enhancing the performance of PV and PVT systems is also provided. A summary of numerous research works conducted on enhancing the performance of PVT system integrated with PCM at different global locations is summarized. Furthermore, this review also discusses the economic analysis of PVT system integrated with PCM along with a summary of technical challenges and future outlook of PCM integrated PVT system to boost sustainable development

Energizing the thermophysical properties of phase change material using carbon-based nano additives for sustainable thermal energy storage application in photovoltaic thermal systems

As solar energy are intermittent in nature and not predictable, researchers and scientists are actively developing efficient thermal energy storage (TES) systems intending to maximize the utilization of solar energy. Phase change materials (PCM) are potential materials that are largely accessed towards TES. However, the notable drawback of PCM is their lower thermal conductivity, leading to slower heat transfer rates and reduced thermal energy storage density. Thus, the current study focuses on developing and exploring a PCM composite by embedding paraffin wax and graphene to enhance the heat transfer mechanisms, making it a promising option for TES applications. Various aspects of the composite's performance were examined, including its microstructural behaviour, chemical stability, thermal stability, thermal conductivity, thermal reliability, and heat transfer characteristics. The findings revealed that the inclusion of graphene led to a substantial increase of up to 75.09 % in thermal conductivity while preserving the melting enthalpy of the material. The newly developed nanocomposite also demonstrated chemically and thermally stable up to a temperature of 210 °C, and the thermal stability was slightly enhanced by adding nanoparticles. This nanocomposite also exhibited improved optical absorptance and reduced transmittance, enhancing its potential for solar energy absorption. It further demonstrated durability, maintaining stability even after undergoing 500 thermal cycles. Notably, the overall efficiency of the nano-enhanced PCM integrated photovoltaic-thermal system (PVT) enhanced by 29 % and 49 % greater than the PVT system and conventional PV system. Given these exceptional characteristics and performance enhancements, this nanocomposite material holds promise for significantly advancing future sustainable TES technologies