Temperature Dependence Of Surface Tension Research Articles

Surface tension measurement and modeling for ternary aqueous solutions of N, N-diethylethanolamine + 2-amino-2-methyl-1-propanol/piperazine + water at T = (293.15 to 318.15) K

The surface tensions of ternary aqueous mixtures composed of N, N-diethylethanolamine (DEEA) (1), 2-amino-2-methyl-1-propanol (AMP) or piperazine (PZ) (2) and H2O (3) was measured at temperatures ranging from (293.15 to 318.15) K and 101 kPa. The systems with mass fractions of w1 = (0.20, 0.25, 0.30 and 0.35) DEEA, and w2 = (0.02 to 0.10) AMP/PZ were investigated. According to the experimental data, the surface tension deviation (Δγ) was obtained and the values were negative under the studied condition. Δγ values were fitted using a polynomial based on the Scatchard model with the average absolute deviation (AAD) ＜ 0.099 mN∙m−1 and the average relative deviations (ARD) ＜ 0.31 %. Moreover, the surface tension values were fitted using Fu-Li-Wang (FLW) and the extended Wilson models. The results revealed that both models can well correlate the surface tension as a function of temperature and composition. FLW model exhibited better fitting results with smaller AAD of less than 0.24 mN∙m−1 and ARD less than 0.68 %, respectively. Additionally, surface enthalpy (Hγ) and surface entropy (Sγ) were estimated based on the temperature dependence of surface tension.

Characterization and Application of Cyrene as a Biomass-Based Solvent for Homogeneous Heck-Coupling Reaction.

Cyrene, a renewable, non-toxic substance having negligible vapor pressure, even at high temperatures, was proposed as a reaction medium for homogeneous Pd-catalyzed Heck-coupling reactions. It was first characterized by its temperature-dependent physicochemical properties, i.e., vapor pressure, density, surface tension, heat capacity, and viscosity, the key parameters of its reaction and process chemistry. Its refractive indices in the function of temperature were also determined. Hereafter, the effect of reaction parameters (Pd source, nature of the base, the water content of the reaction mixture, leaving group (-I, -Br, -Cl, and -OTf of aromatic substrates) on Pd-catalyzed Heck-coupling reaction was investigated using iodobenzene and styrene as model substrates. Subsequently, 4-substituted iodobenzene and styrene derivatives were applied to investigate the effect of electronic parameters on the reaction efficiency and functional group tolerance. To demonstrate the applicability of the system, thirteen stilbene derivatives were isolated with good to high yields and purity (> 95%) using 0.2 mol% of Pd, 1.5 eq. of Et3N as a base, in 1 mL of Cyrene for 2 h at 100 °C.

Development of Cholinium-Based API Ionic Liquids with Enhanced Drug Solubility: Biological Evaluation and Interfacial Properties.

We report an efficient sustainable two-step anion exchange synthetic procedure for the preparation of choline API ionic liquids (Cho-API-ILs) that contain active pharmaceutical ingredients (APIs) as anions combined with choline-based cations. We have evaluated the in vitro cytotoxicity for the synthesized compounds using three different cells lines, namely, HEK293 (normal kidney cell line), SW480, and HCT 116 (colon carcinoma cells). The solubility of APIs and Cho-API-ILs was evaluated in water/buffer solutions and was found higher for Cho-API-ILs. Further, we have investigated the antimicrobial potential of the pure APIs, ILs, and Cho-API-ILs against clinically relevant microorganisms, and the results demonstrated the promise of Cho-API-ILs as potent antimicrobial agents to treat bacterial infections. Moreover, the aggregation and adsorption properties of the Cho-API-ILs were observed by using a surface tension technique. The aggregation behavior of these Cho-API-ILs was further supported by conductivity and pyrene probe fluorescence. The thermodynamics of aggregation for Cho-API-ILs has been assessed from the temperature dependence of surface tension. The micellar size and their stability have been studied by dynamic light scattering, transmission electron microscopy, and zeta potential. Therefore, the duality in the nature of Cho-API-ILs has been explored with the upgradation of their physical, chemical, and biopharmaceutical properties, which enhance the opportunities for advances in pharmaceutical sciences.

Numerical simulation of solidification of boiler molten ash impinging on vertical wall based on Smoothed Particle Hydrodynamics method

In order to study the whole process of the high temperature liquid slag fly ash produced after the combustion of high alkali coal as power coal in the boiler furnace, which moves in the furnace and impinges on the water wall, the heat exchange occurs and then the cooling phase transformation deposits and slags, and the possible factors of slagging particles are studied by changing the environmental variables. In this paper, based on Smoothed Particle Hydrodynamics (SPH), the dynamic behavior of boiler molten ash impacting vertical wall is studied, and the flow spreading and solidification model of molten slag impacting vertical wall is established. Thus, the process of phase change deposition of slag particles against wall is simulated. By observing the phase distribution of slag and the change in spreading process, the complete process of the slag particles hitting the wall, spreading, shrinking and solidifying is analyzed. Based on the cohesive and repulsive surface force method, a temperature-dependent surface tension model is established to simulate the effect of surface tension on flow characteristics when molten ash impinges on low-temperature vertical walls. The influences of slag impact velocity, initial temperature and water wall temperature on deformation and solidification heat transfer are discussed. The results show that the initial velocity and initial temperature of slag particles affect the phase change deposition velocity and the final spreading factor of slag, while the temperature of the water wall has little effect on the deposition deformation and solidification process of slag.

Numerical modelling of high-power laser spot melting of thin stainless steel

Numerical modelling is an important scientific tool in laser materials processing to study different melting, evaporation, and solidification phenomena. It can assist in understanding why certain defects are formed, and thus may provide solution paths for how to decrease certain defects and to increase the quality of a product. Laser spot melting in heat conduction mode represents a simple case and is an excellent first step to build and test solvers prior to moving on to more complicated cases such as laser keyhole welding of thick plates. Modelling of laser spot melting requires only a limited computational domain and allows more complex physics to be added gradually. In this work, a thin 3.0 mm thick stainless steel plate was melted with high-power fiber laser and numerically simulated using a native and custom-build solver based on the VOF method within OpenFOAM. The process was captured with a high-speed imaging camera and simulation results are compared with the experimental results. It was found that temperature-dependent surface tension plays a vital role in controlling melt flow directions within melt pool.

Two-color thermal imaging of the melt pool in powder-blown laser-directed energy deposition

This work demonstrates an experimental technique to image melt pool temperature fields with a commercial color camera for laser-directed energy deposition (L-DED) processes. The technique relies on two-color thermography to construct spatially-resolved temperature fields and is demonstrated on 316L stainless steel (SS) melt pools from solidus to near-boiling temperatures. This two-color thermal imaging system negates the need for a priori knowledge of melt pool emissivity or the camera’s view factor and was validated with a calibrated tungsten filament lamp between temperatures of 1220 K and 2850 K. In-situ temperature measurements are combined with ex-situ cross-sectional geometry to determine the material’s effective absorptivity and coefficient of temperature-dependent surface tension, which is responsible for Marangoni convection, in a multi-physics computational fluid dynamics (CFD) model. Measured peak melt pool temperatures are important for understanding the molten convection within the melt pool, and measured cooling rates can be related to the resulting part microstructure. Peak temperatures from 1750 K to 3000 K show that below the boiling point, temperature increases with increasing laser power density and decreases with increasing scanning velocity. Thermal images are used to estimate cooling rates in the melt pool tail, which increase with the ratio of scanning velocity to power. Our thermal imaging strategy will advance measurement science in L-DED processes by validating multi-physics CFD models, quantifying cooling rates, providing real-time feedback control, and allowing process mapping of critical melt pool behaviors.

Temperature-dependent surface tension model in many-body dissipative particle dynamics with energy conservation

As a hybrid method, many-body dissipative particle dynamics with energy conservation (MDPDe), promises to simulate heat transport process with free surface fluids. However, the temperature-dependent surface tension cannot be modelled accurately in MDPDe so far, which greatly limits its further applications. In the present study, semi-empirical relationships between the attractive coefficient and temperature obtained by mapping with real liquids (i.e., water, ethylene glycol and benzaldehyde) are introduced into MDPDe. The simulation results are validated by comparing with the relevant experimental, theoretical and numerical results, respectively. The improved MDPDe model in the present work opens the door to study various thermocapillary phenomena with free surface fluids at mesoscopic scale.

Temperature- and curvature-dependent surface tensions and Tolman lengths for real fluids: A mesoscopic investigation

The curvature and temperature dependency of the liquid-vapor surface tension has a significant influence on the accurate prediction of the nanobubble/nanodrop nucleation process. In this work, a mesoscopic approach combining the pseudo-potential multiphase lattice Boltzmann method (LBM), the principle of dynamic similarity, and the van der Waals theory of corresponding states is adopted to quantitatively investigate the curvature and temperature dependency of the surface tension and Tolman length for real fluids (water and R134a). By Tolman length, we mean the distance from the surface of tension to the equimolar surface, which measures the extent by which the surface tension of a nanodrop/nanobubble deviates from the corresponding flat interface limit. We show that the Tolman lengths for flat liquid-vapor interfaces (δF) increase with the increase of temperature and are proportional to (1−Tr)−1.044. Equations for predicting surface tensions of water and R134a with effects of temperature and curvature radius taken into consideration are proposed. We demonstrate that the surface tensions increase while the Tolman lengths (δB) decrease with the increase of curvature for nanobubbles. For nanodroplets, however, the surface tensions decrease while the Tolman lengths (δD) increase with the increase of curvature. Effects of the equation of state for real fluids, which determines the interparticle interaction force in the pseudo-potential LBM, are also discussed. This mesoscopic approach can quantify the curvature dependency of liquid-vapor surface tensions for various real fluids in a wide temperature range with low computation costs, providing a new avenue for the accurate prediction of nucleation processes in micro-/nanoscale phase change heat transfer with applications to boiling, evaporation, and condensation.

The Role of Thermoviscous and Thermocapillary Effects in the Cooling and Gravity-Driven Draining of Molten Free Liquid Films

We theoretically considered two-dimensional flow in a vertically aligned thick molten liquid film to investigate the competition between cooling and gravity-driven draining, which is relevant in the formation of metallic foams. Molten liquid in films cools as it drains, losing its heat to the surrounding colder air and substrate. We extended our previous model to include non-isothermal effects, resulting in coupled non-linear evolution equations for the film’s thickness, extensional flow speed and temperature. The coupling between the flow and cooling effect was via a constitutive relationship for temperature-dependent viscosity and surface tension. This model was parameterized by the heat transfer coefficients at the film–air free surface and film–substrate interface, the Péclet number, the viscosity–temperature coupling parameter and the slope of the linear surface tension–temperature relationship. A systematic exploration of the parameter space revealed that at low Péclet numbers, increasing the heat transfer coefficient and gradually reducing the viscosity with temperature was conducive to cooling and could slow down the draining and thinning of the film. The effect of increasing the slope of the surface tension–temperature relationship on the draining and thinning of the film was observed to be more effective at lower Péclet numbers, where surface tension gradients in the lamella region opposed the gravity-driven flow. At higher Péclet numbers, though, the surface tension gradients tended to enhance the draining flow in the lamella region, resulting in the dramatic thinning of the film in the later stages.

Evidence for Ion Association at the Gas-Liquid Interface of the Mixture of 1-Butyl-3-methylimidazolium Hexafluorophosphate and Benzonitrile: A Sum Frequency Generation Spectroscopy and Surface Tension Study.

The gas-liquid interface for the mixtures of [BMIM][PF6] and benzonitrile is studied by sum frequency generation (SFG) spectroscopy and surface tension measurements as an important solute to reduce the viscosity of ionic liquids. Solvation of ionic compounds in bulk solvent is not necessarily the same as that at the surface due to the lower dielectric medium at the air/liquid interface. The results from the temperature-dependent SFG spectroscopy and surface tension study suggest that the ionic liquid in a benzonitrile solvent is associated as ion pairs at the surface rather than as dissociated─solvated─ions in the bulk solution. The influence of ionic liquids on the surface structure of benzonitrile is investigated from 0 to 1.0 mole fraction of benzonitrile. The CH stretching mode of vibration of benzonitrile in the SFG spectrum begins from a 0.2 mole fraction (x) of benzonitrile, and the intensity of the peak constantly increases on increasing the concentration of benzonitrile. However, the addition of benzonitrile does not result in extra peaks or shifting of the peak frequency to the spectra of [BMIM][PF6]. The surface tension measurements further support the presence of benzonitrile at the gas-liquid interface. The surface tension data of the mixture smoothly decrease as the benzonitrile concentration increases. The apparent tilt angle of the terminal methyl group of the cation of [BMIM][PF6] is calculated from SFG polarization spectra and shows an apparent lowering with the addition of benzonitrile. The effect of temperature on the surface structure of the binary mixture is also reported at four different temperatures between -15 and 40 °C for both the SFG spectroscopy and surface tension study. Benzonitrile shows different behavior in the mixture at higher temperatures than pure benzonitrile, as observed in the SFG spectra. In contrast, it does not show any CN peak in the mixture below 0.9 mole fraction. The temperature dependence of the interfacial tension is used to evaluate thermodynamic functions such as surface entropy and surface enthalpy. Both were found to be lowered with the increasing concentration of benzonitrile. Both spectroscopic and thermodynamic analyses indicate that the ionic liquid is highly associated as ion pairs and the benzonitrile is more ordered at the surface at concentration <0.4×.

Surface Tension of Organophosphorus Compounds: Sarin and its Surrogates

While the production and stockpiling of organophosphorus chemical warfare agents (CWAs), such as sarin, was banned three decades ago, CWAs have remained a threat. New approaches for decontamination and destruction of CWAs require detailed knowledge of their various physicochemical properties. In particular, surface tension is needed to describe the formation and evolution of hazardous aerosols when CWA liquids are dispersed in the air. Due to the extreme toxicity of sarin, most experimental studies are carried out using its surrogates─organophosphorus compounds which, while having similar structures, are much less toxic, e.g., dimethyl methylphosphonate (DMMP) and diisopropyl methylphosphonate (DIMP). However, not only for sarin, but also for its surrogates, literature data on the surface tension are scarce. Here we present experimental measurements and computational predictions of the surface tension of DMMP and DIMP. Classical molecular dynamics simulations using the Transferable Potentials for Phase Equilibria (TraPPE) force field produced an excellent agreement with the experimental results in the temperature range from 3 to 60 °C, validating the predictive capability of TraPPE. Consequently, we applied the TraPPE force field to sarin. Our modeled values for the sarin surface tension cover the range of temperatures from 0 to 85 °C, and the four experimental data points from the literature measured between 20 and 35 °C agree perfectly with our predictions. The temperature-dependent surface tension values for sarin and its surrogates obtained in our study can be used in models predicting the formation and evolution of aerosols made of these chemicals. Furthermore, our results justify the use of the TraPPE force field to derive the thermodynamic properties of other organophosphorus compounds with structures similar to the ones studied here.

A numerical study on the levitation system for droplet preparation in a fuel-coolant interaction experiment

The MISTEE facility at KTH was designed to investigate the process and phenomena of a molten droplet falling into a water pool that may be encountered in fuel-coolant interactions (FCI) during a severe accident of light water reactors. An aerodynamic levitation mechanism is proposed to hold the molten droplet during its preparation (melting and heating up to a prescribed temperature) in an induction furnace. The crucible is flushed with argon through an injection nozzle at the bottom to prevent the droplet from falling out of the crucible. A numerical simulation of the aerodynamic levitation system is performed in the present study with the objective of determining and optimizing the design. The problem was simplified as an isothermal two-phase flow in an axisymmetric geometry. The simulation is realized through ANSYS Fluent v17 platform, which employs the VOF method to track interfaces between two phases and the SST k-omega model to describe turbulence flow of argon gas. The numerical model is validated against tests performed in the MISTEE facility after mesh sensitivity study. It is then applied to investigate the impacts of various parameters on the facility levitation capability and the droplet stability. According to the simulation results, stable molten droplets can be obtained in the designed experimental setup. The simulation also provides the appropriate values of argon inlet velocity and sample mass at which a stable droplet can be obtained inside the crucible before its discharge. Either higher or lower inlet velocity will destabilize the formation of the droplet. Considering the temperature-dependent melt properties, both surface tension and viscosity affect the movement and deformation of the molten droplet. The wettability of melt on the crucible wall is critical to droplet formation, and it is found that a poor wettability can ensure the levitation of droplet.

Melt flow and ripple formation induced by continuous wave laser irradiating of copper foil at 10 Pa

Continuous wave laser (CW laser) ablation morphology of copper foil in low pressure environment is very different from that in atmospheric environment. In low pressure environment, there are few splashes on the surface of molten region. Ring ripples are also observed on the surfaces of molten region after laser irradiation. A 2D axisymmetric model considering temperature dependent surface tension and condensation coefficient is established to investigate the molten flow behavior in molten pool during laser ablation in the environment of 10 Pa. The results show that Marangoni effect caused by temperature gradient is the main driver of fluid flow during laser irradiation. Ring ripples are formed by Marangoni effect and capillary force during cooling process. Compared with those in atmospheric environment, the recoil pressure in 101 Pa environment is smaller and the evaporation rate is higher at the same temperature. For foils with different thicknesses, the differences in temperature gradient make the distribution of ripples different. The mechanisms of the ripple formation on metal foil induced by CW laser irradiation are revealed for the first time.

Direct Correlation of Surface Tension and Surface Composition of Ionic Liquid Mixtures—A Combined Vacuum Pendant Drop and Angle-Resolved X-ray Photoelectron Spectroscopy Study

We investigated the surface tension and surface composition of various mixtures of the two ionic liquids (ILs) 1-methyl-3-octyl-imidazolium hexafluorophosphate [C8C1Im][PF6] and 1,3-bis(polyethylene glycol)imidazolium iodide [(mPEG2)2Im]I in the temperature range from 230 to 370 K under ultraclean vacuum conditions. The surface tension was measured using a newly developed apparatus, and the surface composition was determined by angle-resolved X-ray photoelectron spectroscopy (ARXPS). In the pure ILs, the alkyl chains of [C8C1Im][PF6] and the PEG chains of [(mPEG2)2Im]I are enriched at the IL/vacuum interface. In the mixtures, a strong selective surface enrichment of the alkyl chains occurs, which is most pronounced at low [C8C1Im][PF6] contents. For the surface tension, strong deviations from an ideal mixing behaviour take place. By applying a simple approach based on the surface composition of the mixtures as deduced from ARXPS, we are able to predict and reproduce the experimentally measured temperature-dependent surface tension values with astonishingly high accuracy.

A versatile SPH modeling framework for coupled microfluid-powder dynamics in additive manufacturing: binder jetting, material jetting, directed energy deposition and powder bed fusion

Many additive manufacturing (AM) technologies rely on powder feedstock, which is fused to form the final part either by melting or by chemical binding with subsequent sintering. In both cases, process stability and resulting part quality depend on dynamic interactions between powder particles and a fluid phase, i.e., molten metal or liquid binder. The present work proposes a versatile computational modeling framework for simulating such coupled microfluid-powder dynamics problems involving thermo-capillary flow and reversible phase transitions. In particular, a liquid and a gas phase are interacting with a solid phase that consists of a substrate and mobile powder particles while simultaneously considering temperature-dependent surface tension and wetting effects. In case of laser–metal interactions, the effect of rapid evaporation is incorporated through additional mechanical and thermal interface fluxes. All phase domains are spatially discretized using smoothed particle hydrodynamics. The method’s Lagrangian nature is beneficial in the context of dynamically changing interface topologies due to phase transitions and coupled microfluid-powder dynamics. Special care is taken in the formulation of phase transitions, which is crucial for the robustness of the computational scheme. While the underlying model equations are of a very general nature, the proposed framework is especially suitable for the mesoscale modeling of various AM processes. To this end, the generality and robustness of the computational modeling framework is demonstrated by several application-motivated examples representing the specific AM processes binder jetting, material jetting, directed energy deposition, and powder bed fusion. Among others, it is shown how the dynamic impact of droplets in binder jetting or the evaporation-induced recoil pressure in powder bed fusion leads to powder motion, distortion of the powder packing structure, and powder particle ejection.

An improved recoil pressure boundary condition for the simulation of deep penetration laser beam welding using the SPH method

Deep penetration laser beam welding is simulated using the mesh-free Lagrangian Smoothed Particle Hydrodynamics (SPH) method. The physical phenomena modeled are the elastic material behavior of the solid phase, the fluid dynamics of the liquid phase including temperature-dependent surface tension, heat transfer by heat conduction, and the phase transitions melting, solidification, and evaporation. The energy input of the laser beam is determined by a ray-tracing scheme that calculates the absorbed irradiance distribution in the capillary. Based on the locally absorbed irradiance, an improved recoil pressure model is introduced and compared with a temperature-dependent model frequently used in the literature. To transfer the momentum of the recoil pressure to the surrounding melt, two boundary conditions based on either dynamically detected boundary particles or surface forces are presented and validated using simple examples. The results show that the recoil pressure is a key factor for the formation of a deep capillary and the acceleration of the melt around the capillary. Comparison of capillary geometry and melt pool size from simulation and experiment shows good agreement for the irradiance-dependent recoil pressure model.

The role of plate geometry and boundary type in global plate ductility and mantle convection

This paper tracks the role of plates in plate tectonics and mantle convection. Geometric and morphologic plate analyses are based on paleoreconstructions, beginning at 200 Ma, large-scale volcanic events, APWPs, and geoid data. Plates organize themselves to form a space-fitting geometry with a minimum perimeter/area (P/A) ratio (i.e., SA/V in three-dimensions) and a coordination number close to 5. Plates are either broken and subducted in order to remove plates with high P/A ratios or combined with other plates to reduce the total perimeter in the lithospheric plate mosaic. Various permutations of breaking and/or combining of high P/A plates are applied throughout earth's history to reduce the global P/A ratio. During this process, plates change their shape and/or size, which aids plate mobility to ultimately reach a stable geometry. Plates can only move with a suitable geometry and the global pattern keeps adjusting to reach a stable geometry. The lithospheric plates follow a pattern of ‘punctuated steady state’, where the global geometry cycles between ‘ductile’ periods, when the plates are moving to reach a new steady state geometry, to more static, or stable, periods, when the plates are relatively immobile and connected by a stable network of compressional stresses. Here, the Bénard-Marangoni theory is used to explain plate patterns in terms of surface tension because it allows for convection to be driven by temperature dependent surface tension. Mantle flow drives the temperature gradient at the surface, which results in a surface tension gradient. So, temperature dependent buoyancy and surface tension both play a role in convection. This suggests that there is feedback between the plates and the mantle, so neither is entirely passive.

Cattaneo\u2013Christov heat flow model for copper\u2013water nanofluid heat transfer under Marangoni convection and slip conditions

This report is devoted to the study of the flow of MHD nanofluids through a vertical porous plate with a temperature-dependent surface tension using the Cattaneo–Christov heat flow model. The energy equation was formulated using the Cattaneo–Christov heat flux model instead of Fourier’s law of heat conduction. The Tiwari–Das model was used to take into account the concentration of nanoparticles when constructing the momentum equation. The problem is described mathematically using the boundary layer approach as a PDE, which is then converted into an ODE with the help of the transformation process. The solution finding process was completed by running the bvp4c code in MATLAB. A quantitative analysis of the influence of some newly occurring parameters on physical quantities was carried out using graphics. The addition of nanoparticles to the base fluid leads to an increase in both skin friction and thermal conductivity. The increase in thermal conductivity is the advantage, while the increase in skin friction is the disadvantage of the nanoparticle concentration. Marangoni convection has proven to be one of the most cost-effective tools available that can reduce skin friction. Marangoni convection improves the heat transfer coefficient during suction but decreases the heat transfer coefficient during the injection.

Temperature and composition dependent surface tension of binary liquid alloys

Surface tension is a fundamental parameter of binary liquid alloys (BLAs) for controlling the casting and welding processes. In this study, starting from the broken-bond rules, a theoretical model for the temperature-dependent surface tension (TDST) of BLAs was developed. Then combined with the classical ideal solution model, a surface tension model of BLAs related to temperature and composition was established. The model predictions are in good agreement with the available experimental data, which shows the rationality of our model. This research offers a simple method for the prediction of surface tension of BLAs with different component concentrations in a wide temperature range only by inputting the surface tension of pure components at a reference temperature and some basic thermodynamic data.

Effects of wall temperature and temperature-dependent viscosity on maximum spreading of water-in-oil emulsion droplet

The study is focused on the spreading dynamics of the droplets of n-decane and water-in-oil emulsions based on n-decane and isoparaffinic oil stabilized by different nonionic surfactants. The droplets fall on a solid glass surface heated up to 70–390 °C at Weber numbers of 100–500 and Ohnesorge numbers of 0.001–0.008. Five hydrodynamic outcomes of the droplet impact on a heated surface are experimentally identified, including deposition, bouncing, contact splashing, film splashing, and rebound. The maximum spreading of droplets of the liquids is quantified given their temperature-dependent dynamic viscosity. As a result, a universal empirical model for maximum droplet spreading diameter, βmax=(T*WeOhT–1)1/8 + 0.15, is proposed, taking into account the overall effects of temperature-dependent dynamic viscosity, surface tension, and explicit impact surface temperature term. The model has been successfully tested using the experimental data on the maximum droplet spreading diameters for pure hydrocarbons, commercial hydrocarbon liquid fuels, and biofuel at Weber numbers of 60–900, Ohnesorge numbers of 0.002–0.015, and impact surface temperature of 25–210 °C. The values of the maximum droplet spreading diameter predicted by the model are compared with those determined by the empirical expression by Bhat et al. (2019) for single- and multi-component liquid fuels, also involving an explicit surface temperature term. The model by Bhat et al. (2019) is modified by introducing the temperature-dependent viscosity leading to the significant decrease in the relative mean error between the experimental and predicted values of the maximum droplet spreading diameter. The findings related to the no-slip condition for the viscous liquids are critically important in modeling the conjugate problems of fluid mechanics and heat mass transfer used in the fuel-air mixture formation in combustion chambers.