Liquid Layer Research Articles

Effect of Surface Chemistry on the Electrical Double Layer in a Long-Chain Ionic Liquid.

Room temperature ionic liquids (ILs) can create a strong accumulation of charges at solid interfaces by forming a very thin and dense electrical double layer (EDL). The structure of this EDL has important consequences in numerous applications involving ILs, for example, in supercapacitors, sensors, and lubricants, by impacting the interfacial capacitance, the charge carrier density of semiconductors, as well as the frictional properties of the interfaces. We have studied the interfacial structure of a long chain imidazolium-based IL (1-octyl-3-methylimidazolium dicyanamide) on several substrates: mica, silica, silicon, and molybdenum disulfide (MoS2), using atomic force microscopy (AFM) experiments and molecular dynamics (MD) simulations. We have observed 3 types of interfacial structures for the same IL, depending on the chemistry of the substrate and the water content, showing that the EDL structure is not an intrinsic property of the IL. We evidenced that at a low water content, neutral and apolar (thus hydrophobic) substrates promote a thin layer structure, where the ions are oriented parallel to the substrate and cations and anions are mixed in each layer. In contrast, a strongly charged (thus hydrophilic) substrate yields an extended structuration into several bilayers, while a heterogeneous layering with loose bilayer regions was observed on an intermediate polar and weakly charged substrate and on an apolar one at a high bulk water content. In the latter case, water contamination favors the formation of bilayer patches by promoting the segregation of the long chain IL into polar and apolar domains.

Effects of the wall temperature on the boiling process and the molecular dynamics behavior of the liquid hydrogen on a flat aluminum wall

Understanding the nucleation mechanism and boiling heat transfer characteristics of liquid hydrogen is a key issue in the development of liquid hydrogen storage systems. However, the current methods of experimental and mesoscopic or macroscopic scale continuous flow simulations suffer from the problems of large study scales and undetermined initial boundary conditions. The purpose of this study is to reveal the bubble nucleation mechanism and bubble development process of liquid hydrogen on the surface of heating plate at the molecular scale, and to investigate the effect of different heating plate temperature on bubble growth, during thin film boiling. In this research, molecular dynamics simulation is used to combine molecular position distribution with energy analysis and explain the molecular behavior. The effect of heating temperature on different phase transition stages of liquid hydrogen is also investigated by varying the heating surface temperature. In this study, the bubble nucleation, bubble development and merging of liquid hydrogen on the heating surface were successfully observed. It is shown that increasing the heating temperature has a small effect on the bubble growth rate and liquid layer thickness in the nucleation boiling stage, and mainly affects the gas film growth rate in the film boiling stage. The bubbles are extremely unstable at the initial stage of generation. Within 1 fs of the first appearance of bubbles, which are associated with random micro-pits caused by thermal motion of solid atoms, bubbles move on the surface of the heating plate. This study found a phenomenon that bubbles firstly generated and then disappeared. This paper provides a new idea for the nucleation mechanism and boiling heat transfer study of liquid hydrogen. Moreover, it provides a solution to the problems of liquid hydrogen phase change research.

Compressibility-induced destabilisation of falling liquid films: an integral approach

We revisit the classical 2D problem of a gravity-driven liquid layer down an inclined plate (Kapitza, 1948), relaxing the usual assumption of homogeneous fluid. We set out to answer three major issues. When the fluid density is allowed to vary, (i) how does this feature structurally affect the formulation of a low-dimensional depth-averaged model? (ii) To what extent and (iii) by virtue of which physical mechanism does compressibility participate in the long-wave interfacial instability? To provide the relevant answers, (i) we first make use of a second-order asymptotic expansion in the shallowness parameter to develop a weakly-compressible boundary-layer system: starting from a two-equation momentum-integrated model, an additional barotropic equation of state is required for closure purposes. In this respect, (ii) a temporal linear stability analysis is performed: it is revealed that compressibility plays a destabilising role whose magnitude is enhanced at intermediately tilted configurations, and the more the Reynolds number approaches the critical threshold in the incompressible limit. (iii) We finally interpret the ensuing dispersion relation under the convenient framework of two-wave hierarchy, initiated by Whitham (1974): the primary instability gets promoted by the flow compressibility as it contributes to deceleration of dynamic waves most significantly in the low-inertia regime. Indeed, compressibility locally acts as a further boost to the inertia-based mechanism of Kapitza instability by amplifying flow-rate variations within the liquid film.

Spectral control in the liquid crystal tunable filters

A liquid crystal is used as an electro-optical device with the advantages of low voltage driving, low power consumption, and thin flatness by utilizing its refractive index anisotropy (birefringence). In this research, a liquid crystal tunable filter (LCTF) with control of a main peak wavelength λ 0 and a full-width Δλ at half maximum is developed. The device contains two stacking liquid crystal layers with different wavelength dependences of birefringence Δn with their optical axes perpendicular to each other and controlling the light wavenumbers in a complementary manner (S-ECB).

IMMUNOSENSOR BASED ON SCREEN-PRINTED GRAPHITE ELECTRODES MODIFIED WITH GOLD NANOPARTICLES AND SYNTHETIC MEMBRANE-LIKE SUBSTANCE FOR THE DETERMINATION OF CHLORAMPHENICOL

An electrochemical immunosensor based on screen-printed graphite electrodes has been developed for the determination of the antibiotic chloramphenicol in water and milk samples. It has been shown that the immobilization of chloramphenicol-specific antibodies in a liquid crystal layer of a membrane-like didodecyldimethylammonium bromide preserves the mobility and accessibility of active centers of antibodies, and the addition of gold nanoparticles improves electron transfer from the electrode surface to the redox centers of horseradish peroxidase used as a label. The limit of detection of chloramphenicol in water was 0.02 μg/L, in milk - 0.04 μg/L. The method can be used to determine residual amounts of chloramphenicol in animal products.

Influence of water layer thickness on crater volume for nanosecond pulsed laser ablation of stainless steel

Under water laser ablation is a surface texturization method used to form micrometer-sized surface structures. Plasma confinement and cavitation bubble evolution play a critical role during the ablation process and their influence on material removal is strongly tied to liquid layer thickness. To influence the effects of these processes, such that material removal is at its maximum, an optimal layer thickness was found for various laser parameters. Specifically, for nanosecond pulsed laser ablation of stainless steel, however, the relation between layer thickness and volume removal is still unknown. Here, we show the relation between water layer thickness and removed material volume for a nanosecond pulsed laser. Results reveal that volume removal is at its maximum for a 1 mm water layer and drops by a factor of 2 when the layer thickness is increased to 2 mm. A further increase of layer thickness to 3 up to 10 mm shows a negligible effect on volume removal and removed volume amounts are shown to be similar to those obtained in ambient air in this water layer thickness range. This trend echo’s results obtained for nanosecond pulsed silicon ablation. The obtained results identify processing conditions which allow for faster and therefore more cost efficient texturization of stainless steel surfaces in the future.

Evaporation and heat exchange of a thin liquid layer under various heating methods: Advantages of local heating over uniform heating of the wall

Intensification of heat transfer and evaporation is widely used in modern technologies at limited dimensions of heat exchange surfaces and high energy density. To date, stationary heat transfer at uniform wall heating, has been most thoroughly investigated. Meanwhile, there is no comprehensive research providing a comparison of free convection, heat transfer and evaporation with different heating methods. The novelty of the work lies in the comparison of the heat transfer efficiency using one laser beam, two beams and homogeneous heating. When heated by a single laser beam, the average temperature of the layer interface is significantly lower than at homogeneous heating. However, due to the generation of intense Marangoni flow, a small heating spot provides more intense evaporation than homogeneous heating. The effectiveness of heat transfer is analyzed in terms of the total efficiency coefficient. If it is important to take into account power input, it is preferable to use a single laser beam. If it is not decisive, then two laser beams allow achieving maximum heat transfer and evaporation rate. Homogeneous heating is significantly inferior to local non-stationary heating in terms of all key criteria. The simple expressions serve to optimize the total efficiency coefficient.

Effect of irregular silicon carbide and tackifying phenolic resin on friction coefficients of rubber compounds

AbstractRubber compounds with high friction coefficients are widely used in safety shoes, functional shoes, etc. However, in the presence of a liquid lubrication layer, friction coefficients between rubber compounds and the opposing surface are generally very low. In this work, friction coefficients of rubber compounds are improved by a two‐pronged method. First, micron silicon carbides (SiC) with irregular shape and knife‐edge are selected as fillers to improve the plowing friction in dry state, and to improve the adhesive friction in wet state via piercing the liquid lubrication layer. Second, tackifying phenolic resin is added to increase the damping performance of rubber compounds, so as to improve the hysteresis friction in both dry and wet states. The results show that the comprehensive static and dynamic friction properties of rubber compounds are the best in both dry and wet states (0.5 wt% sodium dodecyl sulfate solution or 90 wt% glycerol solution), when SiC size is 7–14 μm and SiC content is 75–90 phr. Phenolic resin can increase the loss factor (tanδ) and loss modulus (E") of rubber compounds, and improve the static and dynamic friction coefficients in wet state (90 wt% glycerol solution). At the same time, it can improve the hardness of rubber compounds and reduce the relative content of SiC, thus reducing the static and dynamic friction coefficients of rubber compounds in dry and wet states (0.5 wt% sodium lauryl sulfate aqueous solution). In general, the optimal content of phenolic resin is 10–15 phr.Highlights Rubber friction coefficients improved via both adhesion and hysteresis friction. Irregular silicon carbides pierce liquid layer to improve adhesive friction of rubber. Phenolic resin increases hysteresis friction of rubber via damping property.

Optimization of leaching parameters for the extraction of copper from hematite-dominated copper ore using Response Surface Methodology (RSM)

The optimization of recovery of copper from Akiri hematite-dominated copper ore using hydrometallurgy was investigated in this study. The Akiri copper ore deposit hosts a high-grade copper mineral from which copper metal can be extracted. However, the ore is dominated by gangue minerals that need to be mechanically reduced for efficient copper recovery. The purpose of this study is to optimize the extraction of the metal from hematite-dominated copper ore. The experiments that were carried out in the course of this study include crushing, pulverization,mineralogical and chemical characterizations of the sample and sulpheric acid leaching. Response surface methodology was used to optimize the system parameters namely;temperature, concentration of the leachant and contact time so that an efficient method will be developed for the extraction of copper.Chalcopyrite, covellite and cuprite are the copper minerals while the gangues minerals were quartz ,mica, hematite,etc.on the characterization of the copper ore. The major oxides in the ore are hematite ,copper oxide and silica and revealed that the ore contains 4.61% copper and 65.8% iron. Effect of three independent factors like concentration ,temperature and contact time for copper extraction from the hematite-dominated copper ore was studied.Central composite design method was applied to the proposed quadratic model that connect the factors used for best copper extraction at the best process condition. The work shows that concentration of the acid was the best efficient factor for copper extraction compare to temperature and contact time. This may be as a result of high value of F-statistics for the concentration of the leachant, which effects to high level of copper extraction.Experimental and predicted values for weight loss from the copper ore were obtained as 39.10% and 39.03% at optimum conditions, respectively. The optimum conditions of 1.5M acid concentration, 90oC reaction temperature and 90minutes contact time were obtained and from which 6.64%Cu at recovery of 92.0% and 2.31%Fe was obtained without stirring. Also, the ore was subjected to leaching with stirring at 400rpm with the optimum conditions obtained to know the effect. The grade obtained was 7.84% Cu at recovery of 83.51% and iron content 5.47%. This shows that leaching without stirring is the best option against leaching with stirring to extract the copper and to reduce the iron and other gangues contents in the copper ore.The activation energies were estimated as 13.20kJ/mol and 22.67kJ/mol for liquid film diffusion and diffusion product layer respectively, the values indicate that the leaching rate is controlled by diffusion process.

Study of extinguishing a model fire of class "B" with bulk materials

The costs of components of the fire extinguishing system based on light loose materials for extinguishing a medium-sized class "B" model fire were experimentally determined. According to the results of preliminary studies on extinguishing a model fire of class "B" of small sizes, as components of such a system, granular foam glass with a granule size of 10–15 mm, expanded perlite with a granule size of 1,2±0,2 mm or vermiculite with a plate size of 1×2 mm and sprayed water. Styrofoam in such a system ensures its buoyancy and cooling of the surface layer of the burning liquid. The fine powder of expanded perlite improves the insulating properties of the fire extinguishing system. The water supplied to the upper layer of loose materials, in addition to increasing the insulating and cooling properties of the system, ensured the long-term absence of re-ignition. To increase the economic parameters of the fire extinguishing system, its composition was optimized according to the effect-cost parameter. It was established that the lowest economic costs for extinguishing gasoline are provided by the sequential supply of three components: crushed foam glass, dispersed expanded perlite and sprayed water with such specific surface costs – 6,7 kg/m2, 1,6 kg/m2 and 2,0 kg/m2 in accordance. For the optimized composition, a study was carried out on extinguishing a standard model fire 2"B", the results of which are close to the results obtained on model fires of small and medium sizes. It is shown that the proposed fire extinguishing system based on light loose materials has advantages in terms of economic and environmental parameters compared to existing and previously proposed means of extinguishing flammable liquids. Means of feeding light loose materials are proposed. The areas of work in the implementation of a fire extinguishing system based on light loose materials in the practice of fire extinguishing have been noted.

Self-healing liquid metal layer as high-capacity and long cycle life anode for Al-ion batteries

Rechargeable Al-ion batteries (AIBs) with high capacity and Earth-abundant metal resources are gaining attention. However, the anode side of AIBs has been overlooked, with most using pure Al foil as the anode. In this study, a simple brush painting technique using eutectic Ga-In (EGaIn) liquid metal (LM) creates a high-performance AIBs anode. The EGaIn@Mo anode allows uniform and reversible plating/stripping of Al for over 10,000 h at 10 mAh cm−2 with 99.6 % average Coulombic efficiency. It enables half-cell operation at an ultrahigh areal capacity of 50 mAh cm−2 for over 1200 h. A full cell with EGaIn@Mo anode and graphite cathode maintains a reversible capacity of 82.8 mAh g−1 after approximately 6000 cycles at a high rate of 2 A g−2, exhibiting an ultralow capacity fading rate of 0.00064 % per cycle. Moreover, an anode-free cell lasts over 800 cycles with a specific capacity of 75.9 mAh g−1. This work demonstrates the potential of EGaIn LM coating for high-capacity AIBs and LM anode application.

Critical analysis for evaluating maximum power point tracking strategy in photovoltaics and fuel cells using key performance metrics

This study performs detailed analyses to investigate and justify the utilization of maximum power point tracking (MPPT) algorithm in photovoltaics (PV) and fuel cells. Two devices are parallelly analyzed to establish a comparative and contrasting study on the performance of the two technologies at MPP regime for a given operational condition. Direct methanol fuel cell (DMFC) is chosen as a representative of the hydrogen fuel cells family. The operational variables affecting the electrical power in the devices, including temperature (for both devices), solar irradiance (for PV cells), and methanol concentration (for DMFC) are discussed, along with their similarities and differences. Voltage losses are addressed to gain insights into the electrical quality of each device at MPP regimes. Due to their pivotal role, fuel availability and cost, energy losses, overall efficiency, and cathode flooding are selected as crucial performance metrics to compare the two technologies at MPP. The results demonstrate that PV cells have a good voltage quality at MPP with an average retention of 87% from open-circuit voltage VOC, whereas DMFC performance deteriorates at MPP, resulting in a significant decline with a loss of 61% from VOC . Consistent with voltage loss results, fill factor analysis at MPP zones lead to the same conclusion wherein photovoltaics offer high fill factor of approximately 82%, whereas DMFC has lesser values that are below 40%. The maximum overall efficiency of PV cells is attained at the MPP zones, whereas optimal efficiencies do not match the MPP loci in fuel cells. Simulations show that DMFC is extremely prone to cathode flooding at MPP zones, where approximately 90% of pore spaces in the liquid distribution layer are occupied with water. Conversely, PV cells are completely free from such issues. Some recommendations for further advancement and investigation on the use of MPPT in both technologies are provided.

Thermographic analysis of topographically controlled Marangoni–Rayleigh–Bénard convection in a fluid with temperature-dependent properties

Thermal convection in a shallow layer of liquid with an array of metallic (aluminum) cubic elements evenly spaced along the bottom is investigated experimentally using a thermographic technique. The blocks protrude upwards and, although they are prevented from reaching the free surface, their vertical thickness, horizontal size and overall number can be varied parametrically. This configuration is used with the two-fold intention to produce a kind of obstruction or blockage in the flow and, at the same time, to feed thermal convection with heat directly injected into the fluid at a certain distance from the (hot) floor. It is shown that tuning of the physical topography at the bottom and the difference of temperature between the liquid and the external (gaseous) environment is instrumental in enabling internal feedback control over the spontaneous flow behavior. For a fixed geometry and temperature difference, variations in the emerging pattern can also be produced by changing the thickness of the liquid layer, which indirectly provides evidence for the additional degree of freedom represented by the relative importance of buoyancy and Marangoni effects. Overall, such results suggest a novel possible route to the realization of convective motions with complex (but surprisingly regular) organization, which have been rarely obtained in earlier attempts based on conventional setups.

Grain Boundary Wetting Transition in the Mg-Based ZEK 100 Alloy

Modern magnesium-based alloys are broadly used in various industries as well as for biodegradable medical implants due to their exceptional combination of light weight, strength, and plasticity. The studied ZEK100 alloy had a nominal composition of 1 wt.% zinc, 0.1 wt.% zirconium, and 0.1 wt.% rare earth metals (REMs) such as Y, Ce, Nd, and La, with the remainder being Mg. It has been observed that between the solidus (Ts = 529.5 ± 0.5 °C) and liquidus temperature (Tl = 645 ± 5 °C), the Mg/Mg grain boundaries can contain either the droplets of a melt (incomplete or partial wetting) or the continuous liquid layers separating the abutting Mg grains (complete wetting). With the temperature increasing from Ts to Tl, the transformation proceeds from incomplete to complete grain boundary wetting. Below 565 °C, all grain boundaries are partially wetted by the melt. Above 565 °C, the completely wetted Mg/Mg grain boundaries appear. Their portion grows quickly with an increasing temperature until reaching 100% at 622 °C. Above 622 °C, all the solid Mg grains are completely surrounded by the melt. After rapid solidification, the REM-rich melt forms brittle intermetallic compounds. The compression strength as well as the compression yield strength parameter σ02 strongly depend on the morphology of the grain boundary layers. If the hard and brittle intermetallic phase has the shape of separated particles (partial wetting), the overall compression strength is about 341 MPa and σ02 = 101 MPa. If the polycrystal contains the continous intergarnular layers of the brittle intermetallic phase (complete wetting), the overall compression strength drops to 247 Mpa and σ02 to 40 Mpa. We for the first time observed, therefore, that the grain boundary wetting phenomena can strongly influence the mechanical properties of a polycrystal. Therefore, grain boundary wetting can be used for tailoring the behavior of materials.

Edge-driven collapse of fluid holes

We study the stability and collapse of holes at the wall in liquid layers on circular bounded containers with various wettabilities. Three distinct wetting modes of the hole are observed, which are related to the wettability of the container: when the substrate and the inner wall of the container are superhydrophobic, a stable hole remains as the liquid volume is continuously increased until the liquid layer covers the entire substrate; when the substrate and the inner wall are hydrophobic, an eye-shaped hole remains stable as the projected area of the hole exceeds a critical value $A_c$ , however, the hole collapses if the liquid volume is further increased; when the substrate is superhydrophobic but the wall is hydrophilic, on increasing the liquid volume, the hole suddenly transfers into a circular hole and is pushed against the wall, leaving the hole dwelling around the centre of the container. Theoretical analyses and numerical simulations are conducted to establish the phase diagram for different wetting modes. It is found that, in the second mode, $A_c$ increases with the size of the container but decreases with the contact angle of the substrate and the wall. Furthermore, we experimentally investigate the dynamics of the hole. The time evolution of the area of the hole obeys a scaling relationship $A \sim (t_0 - t)^{1.1}$ after the hole collapses at time $t_0$ .

Discharge in electrospraying of highly conductive aqueous solution coated with outer ionic liquid

Discharge in electrospraying can be applied in water decontamination, dental sterilization, and spectrometry of biological samples. The discharge in electrospraying of a single liquid like the aqueous solution or the ionic liquid has been investigated, which presents different discharge characteristics such as patterns, currents and frequencies. This paper puts forward a way to actively control the discharge characteristics of liquids electrospray beyond the limitation of their own physical properties, which was accomplished by utilizing the technique of coaxial electrospray to coat the concentrated sodium chloride (NaCl) aqueous solution with a layer of ionic liquid. Previously we used this method to suppress the discharge of NaCl solution and stably electrosprayed the NaCl solution. The discharge characteristics of coaxial electrospray and the effect of the applied voltage and the flow rates of both liquids on the discharge was investigated in detail. When being electrosprayed, the NaCl solution alone discharged with pre-onset mode, pulseless corona discharge mode and streamer discharge mode, while the ionic liquid and the coaxial electrospray only discharged with the streamer discharge mode with a conical liquid shape, and less droplets were formed during the transient cone-jet emission. After being coated with the outer ionic liquid, the current, frequency and onset voltage of the discharge of the inner aqueous solution all increased. The current and frequency of the discharge of the coaxial electrospray all increased as the applied voltage increased. In addition, a numerical simulation has been conducted, which confirmed that the inner aqueous solution was strongly shielded from the external electric field by the outer ionic liquid layer. Therefore, it is plausible to actively control the discharge characteristics of the liquids through adjusting the flow rates of both liquids, the applied voltage and choosing the suitable outer liquid.

Water Activation in Solar-Powered Vapor Generation.

Solar-powered vapor evaporation (SVG), based on the liquid-gas phase conversion concept using solar energy, has been given close attention as a promising technology to address the global water shortage. At molecular level, water molecules escaping from liquid water should overcome the attraction of the molecules on the liquid surface layer to evaporate. For this reason, it is better to reduce the energy required for evaporation by breaking a smaller number of hydrogen bonds or forming weak hydrogen bonds to ensure efficient and convenient vapor production. Many novel evaporator materials and effective water activation strategies have been proposed to stimulate rapid steam production and surpass the theoretical thermal limit. However, an in-depth understanding of the phase/enthalpy change process of water evaporation is unclear. In this review, a summary of theoretical analyses of vaporization enthalpy, general calculations, and characterization methods is provided. Various water activation mechanisms are also outlined to reduce evaporation enthalpy in evaporators. Moreover, unsolved issues associated with water activation are critically discussed to provide a direction for future research. Meanwhile, significant pioneering developments made in SVG are highlighted, hoping to provide a relatively entire chain for more scholars who are just stepping into this field.

Effect of aging on mechanical properties of 3D printed samples using stereolitography

This paper focuses on stereolithography (an additive manufacturing technology working on the principle of curing liquid resins layer by layer using ultraviolet radiation) and the effect of aging on the mechanical properties of the material and printed samples. The aging of the material could be a problem for its subsequent use as the stability of the mechanical properties would not be maintained and unwanted deterioration of the material could occur. As part of the research, sets of samples were printed and subjected to different aging methods and subsequently subjected to quasi-static and dynamic uni-axial load tests. From the data obtained, the basic mechanical properties of the material were calculated and compared with each other. The aim of this paper was to investigate whether aging process causes significant changes in the mechanical properties of the materials used, which could have a consequential impact on their use in different industries.

Mucosa-Inspired Electro-Responsive Lubricating Supramolecular-Covalent Hydrogel.

Enabling the living capability of secreting liquids dynamically triggered by external stimuli while maintaining the bulk frame is a significant challenge for mucosa-inspired hydrogels. A mucosa-inspired electro-responsive hydrogel is developed in this study using the synergy between electro-responsive silk supramolecular non-covalent networks and covalent polyacrylamide and polyvinyl alcohol polymer networks. The formed supramolecular-covalent hydrogel exhibits a partial gel-sol transition upon the application of an electric field, and the liquid layer on the hydrogel surface near the cathode is used to mimic the mucus-secreting capability to regulate lubrication. The electro-responsive lubricating process can operate under a safe voltage and exhibits good reversibility. It is also a universal strategy is to construct an electro-responsive hydrogel by introducing an electro-responsive supramolecular network into the polymer network. This mucosa-inspired electro-responsive supramolecular-covalent hydrogel offers a promising method for designing soft actuators or robots that can regulate lubrication using an electric strategy. This article is protected by copyright. All rights reserved.

Molecular dynamics study of bubble nucleation on trigonometric nanostructured surfaces

Nanostructures have a crucial impact on bubble nucleation. In this paper, different nano-grooved surfaces are constructed using complex trigonometric functions, and the nucleation process of liquid argon on the surfaces is investigated using molecular dynamics simulations. The nanostructures affect the bubble nucleation location, and the results show that the bubble nucleation always occurs in the groove region during the boiling process. In contrast, the bubbles on the flat surface appear randomly. In addition, bubble growth is also affected by the nanostructure. Increasing nanostructure size can reduce the bubble nucleation time and enhance the bubble growth rate. The nanostructure increases the solid-liquid interface area, which enhances the heat transfer between solid and liquid. Finally, the reasons for bubble nucleation on different nanostructured surfaces are analyzed. The heat transfer between solid and liquid is the leading factor for bubble nucleation when the difference in liquid atoms’ potential energy is slight. As the nanostructure size increases, the substrate attracts more argon atoms to form a non-evaporating liquid layer, improving heat transfer and promoting bubble nucleation.