Nonpolar Fluids Research Articles

Electrohydrodynamic flow about a colloidal particle suspended in a non-polar fluid

Nonlinear electrokinetic phenomena, where electrically driven fluid flows depend nonlinearly on the applied voltage, are commonly encountered in aqueous suspensions of colloidal particles. A prime example is the induced-charge electro-osmosis, driven by an electric field acting on diffuse charge induced near a polarizable surface. Nonlinear electrohydrodynamic flows also occur in non-polar fluids, driven by the electric field acting on space charge induced by conductivity gradients. Here, we analyse the flows about a charge-neutral spherical solid particle in an applied uniform electric field that arise from conductivity dependence on local field intensity. The flow pattern varies with particle conductivity: while the flow about a conducting particle has a quadrupolar pattern similar to induced-charge electro-osmosis, albeit with opposite direction, the flow about an insulating particle has a more complex structure. We find that this flow induces a force on a particle near an electrode that varies non-trivially with particle conductivity: while it is repulsive for perfectly insulating particles and particles more conductive than the suspending medium, there exists a range of particle conductivities where the force is attractive. The force decays as the inverse square of the distance to the electrode and thus can dominate the dielectrophoretic attraction due to the image dipole, which falls off with the fourth power with the distance. This electrohydrodynamic lift opens new possibilities for colloidal manipulation and driven assembly by electric fields.

Optimization of Thermal and Rheological Performance in Non-Polar Binary Fluids Using Hybrid CuO Nanoparticles

Abstract Nanofluid is a novel type of technological fluid with numerous applications. Copper oxide (CuO) nanoparticles were dispersed in the binary fluids (Cyclohexane + Diethyl amine (DEA) and (1-4 dioxane + DEA) to create a nonpolar hybrid CuO nanofluid. The thermal conductivity (K) and viscosity (ῃ) of a nonpolar hybrid CuO nanofluid were determined at low concentrations (0.01M to 0.06M) and temperatures ranging from 298K to 318K. The transient hotwire approach is utilized for K measurements, while the viscometer is employed for viscosity measurements. As concentration increases, K drops, yet there is an increase owing to uniform variance in temperatures (T).ῃ changes with concentration and temperature. The results show that the hybrid CuO nanofluid has a phenomenal heat transfer improvement compared to the binary mixtures. The non-polar hybrid CuO nanofluid’s thermal conductivity increases by 15% to 20%, while its viscosity increases by 18% to 25%.

Non-Polar Chain-Enabled Suspension of Carbon Nanoparticles in Base Oil

The transition to electric vehicles (EVs) has introduced new challenges in lubrication, demanding innovative solutions to ensure consistent performance. One promising approach is the use of nanoparticle additives, which have the potential to improve lubrication performance significantly. However, achieving a stable suspension of these nanoparticles in lubricating oils remains a critical challenge, as suspension stability is essential for maintaining consistent performance and maximizing the benefits of these advanced additives. In this study, carbon nanoparticles (CNPs) were modified with dodecylamine (DDA) to achieve stable suspension in nonpolar fluids. The successful functionalization was confirmed by the FTIR results, which showed characteristic peaks of various bonding. The suspension stability tests demonstrated that DDA-CNPs remained suspended for over 60 days in the Polyalphaolefin (PAO) oil, whereas unmodified CNPs were sedimented within 3–7 days. The rheological behavior was measured under different shear rates and temperatures. Viscosity measurements indicated that DDA-CNPs maintained a lower value compared to base PAO. The lubricants’ friction coefficient (COF) was also determined under various speeds and loads. The addition of DDA-CNPs at a concentration of 0.05 wt.% resulted in a significant reduction in COF, with values decreasing by 26% compared to base PAO oil under a load of 1 N. Additionally, the COF for DDA-CNPs was consistently lower than that of PAO, with reductions ranging from 15% to 18% across all tested speeds. The Stribeck curve further highlighted the improved performance of DDA-CNPs across boundary, mixed, and hydrodynamic lubrication regimes. These findings suggest that DDA-CNPs significantly improve the lubrication performance of PAO oil, making them suitable for advanced lubrication applications in automotive and industrial systems.

A new method to calculate and predict thermodynamic properties of nonpolar, polar and quantum fluids at high temperatures

As the only known equation of state (EOS) with the rigid theoretical foundation, the virial equation of state (VEOS) can be reliable enough to describe real-gas imperfection for low-to-moderate densities when truncated after the second or third virial coefficient. In our previous work, on the basis of the corresponding state principle, the generalized second and third virial coefficient models were proposed for nonpolar, polar and quantum fluids in a wide temperature range. In this work, combined with the ideal heat capacities, the high-temperature performance of the truncated VEOSs was evaluated on derived thermodynamic properties including speed of sound, isobaric heat capacity, entropy and internal energy. The criterion for being “valid” is defined as 1% relative deviation from the multiparameter EOSs, and this work presents the valid density and pressure regions of the truncated VEOSs for the derived thermodynamic properties. The truncated VEOSs have valid densities of the saturated densities below the critical temperatures, and have valid densities that tend to be constant beyond the critical temperatures. The SRK EOS is chosen as the representative of generalized EOSs. By the comparisons with the SRK EOS, the truncated VEOSs show the advantage in stability and universality. The truncated VEOSs can give a reliable extrapolation with wide applicable pressure ranges at high temperatures for nonpolar, polar and quantum fluids. The applicable density regions of the truncated VEOSs for derived thermodynamic properties are recommended to be the valid density regions of the pvT property. The applicable temperature ranges of the truncated VEOSs for derived thermodynamic properties are determined by the temperature ranges of the available ideal heat capacity data.

New insights and novel perspectives in bileaflet mechanical heart valve prostheses thromboresistance

BackgroundAlthough well-known for their thromboresistance, bileaflet mechanical heart valves (BMHV) require lifelong anti-thrombotic therapy. This must be associated with a certain level of thrombogenicity. Since both thromboresistance and thrombogenicity are explained by the blood-artificial surface or liquid-solid interactions, the aim of the present study was to explore BMHV thromboresistance from new perspectives. The wettability of BMHV pyrolytic carbon (PyC) occluders was investigated in under-liquid conditions. The submerged BMHV wettability clarifies the mechanisms involved in the thromboresistance.MethodsThe PyC occluders of a SJM Regent™ BMHV were previously laser irradiated, to create a surface hierarchical nano-texture, featuring three nano-configurations. Additionally, four PyC occluders of standard BMHV (Carbomedics, SJM Regent™, Bicarbon™, On-X®), were investigated. All occluders were evaluated in under-liquid configuration, with silicon oil used as the working droplet, while water, simulating blood, was used as the surrounding liquid. The under-liquid droplet-substrate wetting interactions were analyzed using contact angle goniometry.ResultsAll the standard occluders showed very low contact angle, reflecting a pronounced affinity for non-polar molecules. No receding of the contact line could be observed for the untreated occluders. The smallest static contact angle of around 61° could be observed for On-X® valve (the only valve made of full PyC). The laser-treated occluders strongly repelled oil in underwater conditions. A drastic change in their wetting behaviour was observed depending on the surrounding fluid, displaying a hydrophobic behaviour in the presence of air (as the surrounding medium), and showing instead a hydrophilic nature, when surrounded by water.ConclusionsBMHV “fear” water and blood. The intrinsic affinity of BMHV for nonpolar fluids can be translated into a tendency to repel polar fluids, such as water and blood. The blood-artificial surface interaction in BMHV is minimized. The contact between blood and BMHV surface is drastically reduced by polar-nonpolar Van der Waals forces. The “hydro/bloodphobia” of BMHV is intrinsically related to their chemical composition and their surface energy, thus their material: PyC indeed. Pertaining to thromboresistance, the surface roughness does not play a significant role. Instead, the thromboresistance of BMHV lies in molecular interactions. BMHV wettability can be tuned by altering the surface interface, by means of nanotechnology.

Assessment of the acetylation process of wheat straw pulp as sustainable rheological modifier for non-polar fluids

The main aim of this work was to study the role of the acetylation process of wheat straw pulp on its ability to rheologically modify two of the most important non-polar engineering fluid: bitumen and oil. Pulp was produced by a pilot-scale kraft pulping process from local wheat straw. Pulp was functionalized with acetic anhydride and sulfuric acid as a catalyst by modifying (temperature, pulp/acetic anhydride mass ratio, and reaction time. Further, chemical, morphological and thermal changes induced by the acetylation process were properly assessed. Acetylated wheat straw pulp dispersions in oil showed gel-like behaviour, with a mechanical spectrum characterized by higher values of the storage modulus (G′) and a minimum in the loss modulus (G″) at intermediate frequencies. The complex modulus (G*) for bitumen dispersions formulated with acetylated samples was up to 4 times higher than neat bitumen, and the phase angle (δ) indicated an enhancement in the elastic behavior parameters. The rheological response of these systems was associated with the microstructural network formed by pulp fibers and the balance between the physical and chemical changes of wheat straw fibers. According to the experimental results obtained, it can be concluded that acetylation is a relevant chemical treatment to modulate the rheological properties of wheat straw pulp dispersions in non-polar fluids, improving the compatibility between pulp fibers and these engineering fluids. Accordingly, this study provides valuable insights into the development of sustainable multiphasic materials (bitumen binders and semi-solid lubricants) for industrial applications.

Vertical Light Non-Aqueous Phase Liquid (LNAPL) distribution by Rn prospecting in monitoring wells.

In the frame of a collaboration between the Italian National Research Council (CNR) and Mares s.r.l., a study, about the possibility of determining radon vertical distribution at different soil depths in order to trace light non-aqueous phase liquid (LNAPL) contaminations, was developed. The radon deficit technique, based on the preferential solubility of soil gas radon into non-polar fluids, such as refined hydrocarbons, has been investigated by various theoretical and applied research so far. According to international scientific literature, radon deficit can be used both for geochemical prospection of the spatial irregular NAPL dispersion and for monitoring of remediation activities. Even though it is well known that this type of pollutants can be distributed along the vertical soil profile-firstly due to their density in comparison to water density, and secondly due to fluctuations of shallow aquifers, soil pore size, aging of contamination, and so on-the vertical localization of the plume still represents a scientific challenge. In this article, a method to determine the radon vertical profile is tested and applied to assess the potential use of the radon deficit technique in the vertical detection of pollutant presence for the first time in a fuelling station. Two LNAPL-contaminated sites were selected for a pilot test. Experimental findings seem to support the use of vertical radon geochemical prospection to delimit the depth range of a LNAPL pollution directly. Systematic data collection and modeling may lead to a 3D reconstruction of the dispersion of contaminant in different soil levels.

Influence of non-linear slip dependent zeta potential on the bi-layered electrohydrodynamic flow in an electrically actuated microsystem

In this paper, the electro-osmotic flow (EOF) of two immiscible fluids through an electrically actuated micro-slit with a non-linear slip-dependent zeta potential is considered. The main objective of this work is to enhance the EOF velocity of non-polar fluid with an intensive flow variation in micro-confinements. We present the comparison between the Poisson–Nernst–Planck (P–N–P) and the Poisson–Boltzmann model and illustrate the impact of different parameters, such as Debye–Hückel parameter, slip coefficient, and interfacial potential drop, on the ionic concentration and the induced potential in detail. In this study, the interface between two immiscible fluids is considered to be planar, and a potential drop is observed close to the interface due to the development of back-to-back diffuse layers. At the interface between two layers, the continuity of the velocity and total stresses (Maxwell stress and shear stress) are taken into account to investigate the flow field in the system of immiscible electrolytes. The P–N–P model, linked with the ion transport equation and the Poisson equation, is employed to describe the motion of electrolyte solutions. The non-linear governing equations are numerically computed using a pressure-correction-based finite volume technique based on a staggered grid algorithm. Closed-form analytical solutions are derived for both steady and unsteady EOF field of two immiscible fluids for the low wall zeta potential and non-overlapping electrical double layer. The analytical solutions are well validated with our numerical results under suitable assumptions. It is also observed that the slip-dependent zeta potential successfully provides a considerable enhancement in EOF velocity over a broad range of parameters such as zeta potential, Debye–Hückel parameter, as well as boundary slip parameter. The results for both layers are highly affected by unequal wall potential, and the ion concentrations are highly actuated by the external electric field.

Innovative integration of porous materials and membranes: Achieving optimized pore orientation for enhanced performance

Incorporating inorganic porous materials into polymer membranes presents a promising strategy to rectify their inherent imperfections. Nonetheless, achieving peak efficiency necessitates pores oriented perpendicular to the membrane surface, a feat that remains challenging due to orientation control complexities. In this study, a novel synthesis approach for two-dimensional (2D) mesoporous silica nanoparticles (MSN) featuring high aspect ratios and vertical pore channels is presented. These channels, oriented perpendicular to the membrane surface, optimize water permeability. This unique orientation is meticulously achieved via cetyltrimethylammonium bromide (CTAB) acting as a surfactant at the nexus of polar and non-polar fluids, guaranteeing interface evenness. Intriguingly, the resultant mesoporous compound harbors both micro and mesopores—a phenomenon attributed to surfactant non-polar segment expansion within non-polar solvents or the distinct U-shaped interface upon contact with hydrophilic mesoporous entities. After depositing a tannic acid (TA) coating on a polyvinylidene fluoride (PVDF) base membrane, 2D MSN was fixed on the membrane surface using polyethyleneimine (PEI) as a linker through strong hydrogen bonding. Thanks to the asymmetric structure of the mesoporous separation layer combining micro and mesopores, the perpendicular pore channels with superhydrophilic features, water can permeate through the separation membrane with the shortest distance and lowest resistance, achieving an ultra-high pure water permeation volume of 394.5 L−1h−1bar−1. The uniform pore channels of 2D MSN show a rejection rate of over 97% for large molecular dyes such as Evans blue (EB), Congo red (CR), and Rose Bengal sodium (RB). This work not only advances the synthesis of two-dimensional materials with vertical pore channels but also underscores their potential in membrane separation applications.

Ultrasonic study of water adsorbed in nanoporous glasses.

Thermodynamic properties of fluids confined in nanopores differ from those observed in the bulk. To investigate the effect of nanoconfinement on water compressibility, we perform water sorption experiments on two nanoporous glass samples while concomitantly measuring the speed of longitudinal and shear ultrasonic waves in these samples. These measurements yield the longitudinal and shear moduli of the water-laden nanoporous glass as a function of relative humidity that we utilize in the Gassmann theory to infer the bulk modulus of the confined water. This analysis shows that the bulk modulus (inverse of compressibility) of confined water is noticeably higher than that of the bulk water at the same temperature. Moreover, the modulus exhibits a linear dependence on the Laplace pressure. The results for water, which is a polar fluid, agree with previous experimental and numerical data reported for nonpolar fluids. This similarity suggests that irrespective of intermolecular forces, confined fluids are stiffer than bulk fluids. Accounting for fluid stiffening in nanopores may be important for accurate interpretation of wave propagation measurements in fluid-filled nanoporous media, including in petrophysics, catalysis, and other applications, such as in porous materials characterization.

Silica Nanoparticle-Infused Omniphobic Polyurethane Foam with Bacterial Anti-Adhesion and Antifouling Properties for Hygiene Purposes.

In this study, a method for preventing cross-infection through the surface coating treatment of polyurethane (PU) foam using functionalized silica nanoparticles was developed. Experimental results confirmed that the fabricated PU foam exhibited omniphobic characteristics, demonstrating strong resistance to both polar and nonpolar contaminants. Additionally, quantitative analysis using the pour plate method and direct counting with a scanning electron microscope determined that the treated material exhibited anti-adhesion properties against bacteria. The fabricated PU foam also demonstrated a high level of resistance to the absorption of liquids commonly found in medical facilities, including blood, 0.9% sodium chloride solution, and 50% glycerol. Mechanical durability and stability were verified through repeated compression tests and chemical leaching tests, respectively. The proposed coated PU foam is highly effective at preventing fouling from polar and nonpolar fluids as well as bacteria, making it well-suited for use in a range of fields requiring strict hygiene standards, including the medical, food, and environmental industries.

Influence of Liquid CO2 Extraction and Dissolution on Coal Adsorption Characteristics

Liquid CO2 is a non-polar fluid, and the injection of CO2 fluid into a coal seam causes a strong water–rock interaction between the inorganic minerals and organic matter in the coal and acidic fluid. The minerals in the coal are thereby corroded and precipitated to different degrees, and the organic matter is dissolved and extracted, which further changes the physical and chemical properties of the coal and rock. Three kinds of coal samples with different metamorphic degrees were selected as the research objects, and the research methods of theoretical analysis and experimental testing were used to carry out the related research on the modification of coal by liquid CO2 extraction and dissolution. After the three kinds of coal samples were extracted by liquid CO2, the pore specific surface area decreased and the CO2 adsorption decreased with the increase in extraction pressure. The reduction in anthracite adsorption was greater than that of bituminous coal and lignite; after being corroded by different CO2 pressures, the adsorption capacity of bituminous coal gradually increased with the increase in corrosion pressure, and the increase in adsorption capacity of bituminous coal was larger than that of anthracite and lignite. After corrosion, bituminous coal was suitable for CO2 geological storage.

Vapor-liquid equilibria of binary mixtures containing Stockmayer-type model fluids from Monte-Carlo simulations

In this contribution, the vapor-liquid equilibria (VLE) of binary mixtures containing Lennard-Jones (LJ), Stockmayer (LJ + point dipole, ST), and shifted Stockmayer (sST) fluids are investigated with molecular simulations. The LJ and ST fluids are commonly used nonpolar and polar model fluids, respectively. The sST fluid differs from the ST fluid in that the dipole is shifted away from the dispersive center, which results in the sST fluid exhibiting H-bonding-like behavior. By varying the dispersion energy of the LJ fluid and the dipole moments of the ST and sST fluids, and the dipole shift of the sST fluids, different mixtures are generated, which are investigated at several temperatures and concentrations. Differences in the phase behavior between mixtures containing ST and sST fluids are quantified and linked to differences in fluid structure. The reported data include the VLE envelopes, coexisting densities, activity coefficients, and enthalpies for liquid and vapor phases, as well as structural information on the fluids’ intermolecular orientations.

A Reference Equation of State with an Associating Term for the Thermodynamic Properties of Ammonia

Fluid ammonia is highly associated because of strong intermolecular hydrogen bonding. This causes different behavior of thermophysical properties from nonpolar fluids, as reflected, for example, in the heat capacity. In this work, a new equation of state explicit in the Helmholtz energy with independent variables of temperature and density was developed, which includes a new associating term. Its uncertainties in density, vapor pressure, saturated liquid and vapor densities, and caloric properties were estimated by comparisons with experimental data. The new equation of state is valid from the triple-point temperature (195.49 K) to 725 K at pressures up to 1000 MPa and densities up to 53.13 mol dm−3. Physically correct behavior within the region of validity and at extremely high temperatures and pressures, and at temperatures far below the triple-point temperature, was obtained by applying constraints on various properties. The unique physical behavior of ammonia shown in some thermodynamic properties is described in detail, which will provide a preliminary template for developing equations of state for other associating fluids.

Superancillary Equations for Nonpolar Pure Fluids Modeled with the PC-SAFT Equation of State

Superancillary equations are presented for the PC-SAFT equation of state of Gross and Sadowski for nonpolar pure fluids. The equations cover the range of a number of segments from 1 to 64. These equations, formed as nested sets of Chebyshev expansions, represent the densities for vapor–liquid equilibria better than can be achieved by iterative calculations in double precision arithmetic. Furthermore, the expressions are more than 16 times faster to evaluate than the iterative calculations from the fastest thermodynamic property library. By their construction, the superancillary equations are guaranteed to be reliable over the entire temperature range. For user-friendliness, the functions have been packaged into a Python package available on PYPI.

Orientation order of a nonpolar molecular fluid compressed into a nanosmall space.

The ordering structures of non-polar carbon tetrachloride liquid compressed to nano-scales between parallel substrates is studied in this work. The theoretical considerations show that the potential well formed by the confined parallel substrates induces orientational ordering of non-polar molecules. Through molecular dynamic (MD) simulations, the relations between various ordered structures of a non-polar liquid (carbon tetrachloride) and the confined gap size are demonstrated. The density distribution shows that the confinement does affect the ordering modes and induces an orientational ordering of molecules at the solid-liquid interface under extreme confinement conditions. This molecular orientation suggested from the theoretical model and MD simulation is directly supported by the experimental studies for the first time. The X-ray reflectivity data reveal a strong layering effect with splitting of the density profile in C and Cl-rich sublayers. The investigation shows that the liquid structure factor in confinement has a characteristic length similar to the short-range ordering in bulk, but the confined structure is strongly influenced by the surface potential and the interface properties. This introduces preferred molecular orientation and ordering which are not favorable in the bulk phase. As the orientational ordering is closely related to crystallization, our results provide a new perspective to control the crystallization in nano-confined space by compression.

Role of Nanoparticles in Acoustical and Dielectric Measurements using Binary Non-Polar Fluid

In this work, the experimental values of dielectric constant and acoustical parameters for binary mixture (benzene + diethylamine) and hybrid CuO nanofluid (CuO + diethylamine + benzene) were studied for various molar fraction from 0.01 to 0.06 M with different temperatures ranging from 298 to 318 K. Molecular interaction depends on the concentration, inclusion of CuO nanoparticles and temperature. FTIR analyses also revealed that despite the rise in temperature, no bond breakdown between the molecules is found. The results demonstrate that the weak interaction due to van der Waals forces exist between the unlike molecules due to dipole-induced dipole interactions.

Temperature-dependent wall slip of Newtonian lubricants

We discuss (i) the measurement, (ii) interpretation and (iii) technical impact of temperature-dependent wall slip and its activation energy for polar and non-polar hydrocarbon Newtonian fluids moving relative to machined metal surfaces. A newly developed apparatus, the slip length tribometer (SLT), overcomes the drawbacks of existing measurement devices in terms of characterising relevant rough surfaces by measuring the slip length at different temperatures over a sufficiently large wetted area. The experimental data show that the bulk viscosity and slip length at the fluid–metal interface is independent of the shear rate up to $10^5\,\mathrm {s}^{-1}$ , being consistent with recent results from molecular dynamics simulations by Mehrnia & Pelz (J. Mol. Liq., vol. 336, 2021, 116589). Furthermore, the activation energies for wall slip and bulk shear determined by means of the SLT differ by a factor of two, i.e. $E_{\lambda }\approx 0.5 E_\mu$ for non-polar hydrocarbon molecules sliding relative to metal walls. This difference is explained by a generalised Eyring model applied to wall slip. The paper closes with the impact of wall slip on Sommerfeld's similarity theory of tribology and the resulting Stribeck curve (Sommerfeld, Z. Math. Phys., vol. 50, 1904, pp. 97–155; Z. Tech. Phys., vol. 2. Jahrg., 1921; Mechanik der deformierbaren Medien, 1944, Akademische Verlagsgesellschaft Becker & Erler). For this purpose, Reynolds’ equation generalised for wall slip is solved in combination with the experimentally determined constitutive relations for bulk shear and wall slip to predict typical characteristics of journal bearings. The results show that, for a typical journal bearing, where the ratio of slip length to average bearing clearance is of the order of $10^{-2}$ , the influence of wall slip on both load-carrying capacity and dissipation is not negligible. This work combines nanofluidics and tribology in order to provide methods and knowledge for e.g. tailor-made fluids and interfaces.

Electrostatic field treatment as a novel and efficient method for refining crude canola oil

Traditional vegetable oil refining strategies are energy-intensive and can result in substantial oil loss. In metalworking and machine shops, electrostatic “oil cleaners” are used to remove particulate matter (e.g., wear particles, soot, vanish, and dust) from non-polar working fluids with low dielectric constants (e.g., lubricating oil and hydraulic oil). Vegetable oils are also non-polar fluids. Polar contaminants (e.g., phospholipids, free fatty acids, peroxides) can be present in unrefined vegetable oils. The effects of electrostatic field (E-field) applied using a commercial electrostatic “oil cleaner” on crude canola oils were studied. E-field treatments of crude canola oils reduced suspended particles and the contents of phospholipids (reduction of 74.9%), free fatty acids (reduction of 53.2%), and peroxides (reduction of 47.0%). These treatments did not significantly alter either carotenoid content or fatty acid composition. Furthermore, oil loss was negligible (0.37%) during E-field treatment. Therefore, E-field can provide an economical, sustainable, and environmentally friendly alternative to conventional refining methods with minimal oil loss.

Comparative molecular dynamics simulations of thermal conductivities of aqueous and hydrocarbon nanofluids.

The addition of metal oxide nanoparticles to fluids has been used as a means of enhancing the thermal conductive properties of base fluids. This method formulates a heterogeneous fluid conferred by nanoparticles and can be used for high-end fluid heat-transfer applications, such as phase-change materials and fluids for internal combustion engines. These nanoparticles can enhance the properties of both polar and nonpolar fluids. In the current paper, dispersions of nanoparticles were carried out in hydrocarbon and aqueous-based fluids using molecular dynamic simulations (MDS). The MDS results have been validated using the autocorrelation function and previous experimental data. Highly concurrent trends were achieved for the obtained results. According to the obtained results of MDS, adding CuO nanoparticles increased the thermal conductivity of water by 25% (from 0.6 to 0.75 W·m−1·K−1). However, by adding these nanoparticles to hydrocarbon-based fluids (i.e., alkane) the thermal conductivity was increased three times (from 0.1 to 0.4 W·m−1·K−1). This approach to determine the thermal conductivity of metal oxide nanoparticles in aqueous and nonaqueous fluids using visual molecular dynamics and interactive autocorrelations demonstrate a great tool to quantify thermophysical properties of nanofluids using a simulation environment. Moreover, this comparison introduces data on aqueous and nonaqueous suspensions in one study.