Copper Surface Research Articles

Interfacial bonding and corrosion inhibition of 2-mercaptobenzimidazole organic films formed on copper surfaces under electrochemical control in acidic chloride solution

The interfacial bonding and the layered structure of 2-mercaptobenzimidazole (2-MBI) organic films adsorbed on electrochemically controlled copper surfaces and their corrosion inhibition effects in acidic chloride aqueous solution were investigated using an integrated approach of electrochemical methods and advanced surface analyses by X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry. It is shown that organic films formed on the copper surfaces are bi-layered with a chemisorbed inner layer and a physisorbed outer layer. In the chemisorbed inner layer, 2-MBI is bonded primarily by its nitrogen atoms with metallic and oxidized copper surfaces. Sulphur atoms are also involved in the bonding mechanism when metallic copper is directly accessible to the 2-MBI molecules. The initial presence of native copper oxides at the interface promotes the formation of Cu(I)-2-MBI metal-organic complexes in the chemisorbed inner layer using cathodic reduction to dissociate the oxide. Metal-organic complexes also form upon anodic polarisation due to Cu(I) ions generated by oxidation of the copper metal. 2-MBI effectively inhibits copper anodic dissolution in varying degrees, between 84% and 93%, depending on the pre-treatment used for the formation of the organic bi-layers. An enhanced protection of the substrate is obtained by adsorbing the 2-MBI inhibitor on an initially oxide-free surface, which is achieved by cathodic pre-treatment in absence of the inhibitor followed by 1 hour exposure to the inhibitor.

A novel device for investigating the anti-melting loss performance of Ni60A coating on coppery tuyere

Coppery tuyere is a core component in iron-making blast furnace, mainly used for supplying hot air and injecting pulverized coal. Due to the harsh service environment, tuyeres are prone to failure by wear and melting loss. Surface coatings can significantly improve the wear resistance of copper surface, but their anti-melting loss performance is still a research blank. This paper designed a novel device for testing the anti-melting loss performance of coatings. The device included plasma melting-drop, induction preheating and infrared temperature control systems, which can simulate the process of coating being corroded by molten iron under service conditions. Anti-melting loss test results of Ni60A coating indicated that the molten iron and the γ-(Cu, Fe, Ni) solid solution in the coating can form metallurgical bonding by element diffusion, thus adhering on the coating surface. The continuous accumulation of iron will worsen the heat-transfer capability of tuyere, making it more likely to cause melting loss. Adding ceramics in the Ni60A alloy or developing coating materials with higher melting points are expected to improve the anti-melting loss performance of coatings on coppery tuyere.

Condensed Fukui function and experimental evaluation of the corrosion inhibition properties of some antipyrinyl‐imidazotriazole and their derivatives for copper in an acidic environment

AbstractThe effectiveness of synthesized antipyrinyl‐imidazotriazole and its derivatives as inhibitors for the corrosion of copper alloy in 0.5 M H2SO4 solution was tested using weight loss, electrochemical impedance spectroscopy (EIS) and potentiodyanmic polarization techniques. The generated results confirmed that the tested compounds have strong inhibition efficiencies for the protection of the corrosion of copper alloy in 0.5 M H2SO4. Maximum inhibition efficiencies (IEs) evaluated from electrochemical measurements at inhibitor's concentrations of 0.040 g/L were 85% (5‐(4‐Antipyrinyl)‐3H‐imidazo[1,2‐b][1,2,4]triazole), 60% (6‐Antipyrinyl‐imidazo[2,1‐b]thiazole) and 72% (2‐Antipyrinyl‐7‐ethoxy‐imidazo[2,1‐b]benzothiazole). It was observed that the inhibition efficiency was strongly influenced by the flow rate of the solution and was reduced to 79 (5‐(4‐Antipyrinyl)‐3H‐imidazo[1,2‐b][1,2,4]triazole), 60% (6‐Antipyrinyl‐imidazo[2,1‐b]thiazole), and 44% (2‐Antipyrinyl‐7‐ethoxy‐imidazo[2,1‐b]benzothiazole) at an agitation speed of 400 rpm. EI from weight loss was comparable with those from PDP of mixed‐type inhibition style and EIS of diffusion model. The low inhibition efficiency for 6‐Antipyrinyl‐imidazo[2,1‐b]thiazole was significantly enhanced from 60% to 90% through a synergistic effect of 0.0001 M KI. The Temkin and Frumkin isotherms indicate the physical adsorption of inhibitors on copper surface. Condensed Fukui function calculations reveal a common center for electrophilic attacks in the three molecules: the nitrogen in the bridged pyrrole rings (labeled as N11).

Preparation of multicomponent rare earth based oxide charges

In this study we describe a relatively facile synthetic approach for the production of multicomponent oxide charges as the precursors of quaternary barium-rare earth-copper selenides BaRECuSe3, which, in turn, are of interest as promising thermoelectric materials. The starting reagents were initially prepared, including cleaning of the surface of elemental copper and annealing the rare earth oxides RE2O3 in a high-temperature furnace. A mixture of double, ternary and quaternary oxide charges was prepared by dissolving the stoichiometric ratios of the starting reagents RE2O3:2Cu:2Ba(NO3)2 (RE = La, Nd, Gd, Dy, Ho, Y, Er, Tm, Yb, Lu), CeO2:Cu:Ba(NO3)2, Pr6O11:6Cu:6Ba(NO3)2 or Tb4O7:4Cu:4Ba(NO3)2 in nitric acid. The Ce-based oxide charge was obtained in the presence of H2O2 as a reducing agent to improve solubility in nitric acid. Then, cocrystallization of crystalline hydrates, followed by their dehydration, and destruction of the resulting (oxo)nitrate salts, and dispersion of the final polycrystalline samples were performed. According to the powder X-ray diffraction data, topochemical reactions led to the formation of heterometallic oxides BaxREyCuzOn, BaREO3, BaCuO2 and RE2CuO4. The developed synthetic approach allows to obtain the target phase of orthorhombic selenides BaRECuSe3 of three structural types BaLaCuS3, Eu2CuS3 and KZrCuS3 with high yields in a relatively short period of time and at lower temperatures in comparison to the previously used synthetic methods.

Exploring sustainable corrosion inhibition of copper in saline environment: An examination of hydroquinazolinones via experimental and ab initio DFT simulations

Copper's potential in various applications is constrained due to environmental degradation, particularly in high-salinity environments, representing a sustainability concern. Herein, two novel hydroquinazolinones, namely 1-((4-hydroxynaphthalen-1-yl)methyl)-2-phenyl-2,3-dihydroquinazolin-4(1H)-one (DQ-H) and 1-((4-hydroxynaphthalen-1-yl)methyl)-2-(p-tolyl)-2,3-dihydroquinazolin-4(1H)-one (DQ-CH3), were analyzed for their ability to inhibit copper corrosion in a 3.5 % NaCl solution. The compounds, characterized by 1H and 13C NMR, were evaluated via potentiodynamic polarization curves, electrochemical impedance spectroscopy, and weight loss measurements. Comprehensive analyses utilizing scanning electron microscopy, Fourier Transform Infrared, and UV–vis spectroscopy have revealed insights into the surface morphology and the interactive nature of inhibitor molecules with the copper surface. Our findings highlight the formation of a strong, sustainable inhibitor film on the copper surface due to the addition of hydroquinazolinones, thereby exhibiting an enhanced polarization resistance and decreased double-layer capacitance. Both DQ-H and DQ-CH3 demonstrated a considerable inhibition effect, with efficiencies of 92 % and 94 % respectively, illustrating their potential for sustainable copper protection. Electrochemical impedance spectroscopy (EIS) results indicated a significant increase in polarization resistance from 605.7 (blank) to 9403 and 12861 Ω cm2, after the addition of DQ-H and DQ-CH3, respectively. Furthermore, the adsorption attributes of the compounds on the Cu(111) surface were examined using first-principles density functional theory simulation, revealing several covalent bonds formation. Our work aims to contribute to sustainability efforts in materials science by offering a corrosion-protective solution that is less harmful to the environment and more efficient in preserving copper's durability, particularly in saline environments.

Seeding the growth of femtosecond laser produced microstructures on copper with multi-layered materials

Femtosecond lasers can be used to create self-organized micro/nanostructures on the surface of most materials. However, on copper, these structures require significantly higher laser fluence when compared to other metals. We report a method to create self-organized structures on copper by clamping a foil of stainless steel on the copper surface prior to laser processing. All samples reported are processed using a peak fluence of 2.71 J/cm2, which is below the fluence threshold for self-organized micro/nanostructure formation on copper. When stainless steel is layered on copper, structures are created that consist of both stainless steel and copper at pulse counts of 998 and 1,197. With increased pulse count, the thickness of the stainless steel layer decreases. For pulse counts of 1,497 and higher, the permanent structures are completely composed of copper. Using these same parameters, but without the stainless steel foil on the copper, the laser processing formed agglomerations of nanoparticles on the surface regardless of pulse count. The structure morphology and chemistry of the surface features are characterized with surface and subsurface analysis to study the material make-up of the structures and investigate the pulse count necessary to fully remove the stainless steel, leaving a structured copper surface.

Corrosion Inhibition of Expired Cefazolin Drug on Copper Metal in Dilute Hydrochloric Acid Solution: Practical and Theoretical Approaches.

In this work, we studied the corrosion of Cu metal in 0.5 mol L-1 HCl and the inhibition effect of the expired Cefazolin drug. The inhibition efficiency (IE) of Cefazolin varied according to its concentration in solution. As the Cefazolin concentration increased to 300 ppm, the IE increased to 87% at 298 K and decreased to 78% as the temperature increased to 318 K. The expired drug functioned as a mixed-type inhibitor. The adsorption of the drug on the copper surface followed Temkin's adsorption model. The magnitudes of the standard free energy change (ΔGoads) and adsorption equilibrium constant (Kads) indicated the spontaneous nature and exothermicity of the adsorption process. Energy dispersive X-ray (EDX) and scanning electron microscopy (SEM) techniques showed that the drug molecules were strongly attached to the Cu surface. The electrochemical frequency modulation (EFM), potentiodynamic polarization (PP), and electrochemical impedance spectroscopy (EIS) results were in good agreement with the results of the weight loss (WL) method. The density functional tight-binding (DFTB) and Monte Carlo (MC) simulation results indicated that the expired drug bound to the copper surface through the lone pair of electrons of the heteroatoms as well as the π-electrons of the tetrazole ring. The adsorption energy between the drug and copper metal was -459.38 kJ mol-1.

Investigating the corrosion inhibition of copper using DFT theoretical study with three organic molecules

A theoretical study of the inhibition efficiency of three organic heterocyclic molecules has been thoroughly probed using density functional theory B3LYP/6-31G(d) level. The calculated global quantities such as electrophilicity and nucleophilicity show that the three organic inhibitors are nucleophiles. The obtained values of charge transfer and energy of back-donation show that the 2-amino-4-(4-bromophenyl)thiophene-3-carbonitrile is the best inhibitor. Parr function indices have been calculated to determine the most preferred sites for the nucleophilic attacks towards the electrophilic transition metal surface of copper. The electrostatic surface potential has been mapped in order to explore the major regions of the molecules responsible of the inhibition. It is found that the zone surrounding the nitrogen atom and the -aromatic system of benzene are the one forming the protection layer. The theoretical results are in good commitment with the experimental results.

Heat transfer and behavior of ultra high temperature ceramic materials under exposure to supersonic carbon dioxide plasma with additional laser irradiation

The behavior of the ultra high temperature ceramic material HfB2-SiC-C(graphene) under exposure to a supersonic carbon dioxide plasma, with and without the addition of laser irradiation, has been studied. The material was heated to 1750 °C in an inductively coupled plasma jet without laser irradiation. A temperature jump to 2190 °C was observed when additional ytterbium laser irradiation was applied to the surface. The spectral emissivity of the heated surface at wavelengths of 0.65 and 0.9 μm was studied. It was found that the spectral emissivity decreases as the material oxidizes. The heat flux to the surface of the heated material was measured and compared to the heat flux to a cold copper surface under the same conditions. Analysis of the surface of HfB2-SiC-C(graphene) material after exposure was performed. Differences in microstructure were detected between specimens exposed to carbon dioxide plasma with and without additional laser irradiation.

Azobenzene isomerization on a reactive copper surface by efficient decoupling with bulky side groups

Azobenzene derivatives, an important class of molecular switches that undergo isomerization between trans and cis states, have been studied on various coinage metal surfaces in the past. However, on reactive copper surfaces switching turned out to be difficult. Here, we show that the use of bulky 2,6-dimethylphenyl side groups enables switching on a Cu(111) surface as studied by scanning tunneling microscopy. By applying voltage pulses from the STM tip, irreversible trans → cis isomerization of individual molecules can be induced where exactly one molecule within each unit cell is isomerized. The absence of backward cis → trans switching illustrates the importance of the adsorption structure on the potential energy landscape of azobenzene. Isomerization, which is activated by inelastic scattering of single tunneling electrons, happens in a very localized fashion, thus allowing to ‘write’ patterns of individual cis isomers into the homogeneous molecular layer. Our study demonstrates how the bulky spacer groups direct adsorption and self-assembly into close-packed structures, which are similar to three-dimensional molecular crystals, on the surface. In addition, they modulate the electronic coupling to the underlying substrate to maintain successful switching behavior even on the most reactive coinage metal surfaces.

Pool boiling heat transfer of Novec 649 on sandblasted surfaces

Pool boiling represents a potentially efficient mechanism for thermal management of power electronic components. The present study investigates pool boiling heat transfer using Novec 649 on copper substrates with varying surfaces. Sandblasting, which is a relatively simple surface modification technique, has been used to obtain different copper surface roughness levels ranging from 0.1 µm to 9 µm arithmetic mean surface roughness values. The effects of surface modifications and orientation on boiling heat transfer coefficient (HTC), and critical heat flux (CHF), of Novec 649 have been experimentally investigated by performing pool boiling experiments at atmospheric pressure and saturation pool temperature. The experimental results showed that the size and orientation of the boiling surface do not have a significant impact on the CHF, whilst the HTC improves in the nucleate boiling regime with vertical orientation. In addition, for the range of surface roughness investigated improvements of ∼3X and ∼1.5X in HTC and CHF, respectively, were found relative to the original smooth surface. The HTC in the film boiling regime relative to the nucleate boiling regime was also quantified and found to be ∼20X for our geometries.

Effect of laser welding strategy for reducing intermetallic compound formation and residual stress

Reductions in automobile weight and carbon dioxide emission are critical for the further development of the automobile industry. Aluminum is a lightweight material that can replace copper in automobile electronic equipment; therefore, laser welding of aluminum and copper is a subject of extensive research. This study investigates the influence of the laser strategy on the laser welding of aluminum and copper while preventing the formation of brittle Al–Cu intermetallic compounds. Aluminum and copper plates with a length of 20 mm and thickness of 0.3 and 1 mm, respectively, are used for the experiment. A continuous-wave laser with a power of 500 W and a spot beam radius of 150 μm is employed to irradiate the aluminum surface at different scan speeds. An electroless-plated nickel layer is used as a buffer between aluminum and copper, and the experimental results show that it can prevent copper surface damage and the formation of Al–Cu compounds during laser welding. In addition, the simulation and experimental results reveal that the residual thermal stress after laser welding can be reduced by heat treatment at different temperatures prior to laser irradiation.

Analysis and prevention of copper pipe corrosion

The failure of the locomotive heat exchanger due to pitting and corrosion of the T2 heat exchange copper tube is used as the engineering application background. The pitting corrosion and influencing factors of T2 copper tu were studied by weight loss method, SEM, and EDS. The optimal ratio of compound corrosion inhibitors (borax, sodium nitrite, sodium silicate, and benzotriazol) of T2 copper tube was obtained. The results show that the main reason for the pitting corrosion of T2 copper pipe is the local rupture of cuprous oxide protective film on the copper surface, resulting in the copper at the bottom of the pit as the anode and the Cu2O oxide film on the surface as the cathode to form a corrosion cell so that copper dissolves and pitting in the pit. The rupture of the Cu2O oxide film is related to excessive carbon-containing residue and the deposition of dirt (foreign matter) on the surface, mechanical attack, and defects of the material itself. The optimal ratio of compound corrosion inhibitor in 2 L pure aqueous solution is as follows: Borax content is 4.4 g, sodium silicate content is 4.23 g, sodium nitrite content is 4 g, and benzotriazole content is 0.2 g.

Electroless brassing of historical artefacts

Abstract The topic of this work was the investigation of an alternative brassing technique consisting of electroless zinc plating of a copper object in a strongly alkaline solution and subsequent annealing to achieve a characteristic brass appearance. Within the scope of the work was the determination of the mechanism of zinc deposition on the copper surface, the optimisation of the NaOH concentration (30 and 40 wt. %), time of deposition (5-120 min), as well as temperature (150 and 200 °C) and annealing time (15 – 60 min). Electrochemical methods (potentiodynamic curves and open-circuit potential), metallography, X-ray diffraction (XRD), and glow-discharge optical emission spectroscopy (GD-OES) were used to study the brassing mechanism. Electrochemical measurements have shown that zinc powder significantly decreases the surface potential of copper to the value of zinc itself and also acts as a reducing agent. The diffusion of zinc in copper was found to occur during the primary deposition of zinc with the formation of the γ phase (Cu5Zn8). The optimal NaOH concentration is 40 wt.% and the deposition time is 60 min. The optimal conditions of annealing are 200 °C and 60 min. The primary γ phase is transformed during the annealing process into β and α phases.

Investigating the Impact of Final Finishes on the Insertion Loss in As Received and After Aging

The task of the final finish on the printed circuit board is to protect the copper surface and at the same time keep it active for the subsequent assembly steps. In high frequency applications, additionally the impact on the signal loss becomes of interest. Typically, the choice of the final finish is defined by the target application. The demands on solderability and bondability need to be considered and the acceptable price level needs to be defined. For the use in high frequency applications the signal integrity becomes of interest and adds on the reliability criteria such as solder joint reliability or corrosion resistance. In this study various surface finishes were tested towards their performance on insertion loss at high frequency. In contrast to earlier studies the frequency range was investigated up to 150 GHz and the impact of thermal or humid aging of the final finish was evaluated. Overall, seven different finishes have been selected including EPAG (Electroless palladium/Autocatalytic gold), I-Sn (Immersion tin), I-Ag (immersion silver), DIG (direct immersion gold), Au/Pd/Au (Gold/Palladium/Gold), ENIG (Electroless Nickel/Immersion Gold) with high and medium phosphorous Nickel and ENEPIG (Electroless Nickel/Electroless Palladium/Immersion Gold). The paper compiles the data for insertion loss versus frequency for the different final finishes at layer thicknesses as commonly used in the PCB industry. The results in the insertion loss performance are correlated to other properties of the different final finishes such as reliability and assembly performance to identify the best candidates for high frequency applications.

Interfacial reaction of Sn-1.5Ag-2.0Zn low-silver lead-free solder with oriented copper

High density packaging technology reduces the pad size and the number of grains contained in the pad. When the polycrystalline pad turns into a single crystal pad, the grain orientation has an important impact on the formation of the intermetallic compound (IMC) at the interface. The growth of IMC at the interface between the solder and the single-crystal copper substrate is investigated by selecting the prospective Sn-1.5Ag–2Zn as the solder alloy. Sn-1.5Ag-2.0Zn lead-free solder joints soldered with single crystal (111) copper substrate and polycrystalline red copper substrate are reflowed at 250 °C for 5 min. Samples are subsequently aged at 160 °C. The uneven scallop like Cu6Sn5 IMC layer grows rapidly when the alloy solder contacts with the copper substrate. The Cu6Sn5 grain size formed on the surface of single crystal copper is larger than that of polycrystalline copper. Single crystal copper has no grain boundary to block atomic diffusion, which affects grain nucleation and growth. The growth rate of Cu6Sn5 formed by alloy solder and the single crystal (111) copper solder joint after aging treatment at 160 °C for 20 h is about twice that of the polycrystalline copper solder joint. Then it grows slowly with the increase of aging treatment time. The thick layer Cu6Sn5 breaks due to crack diffusion after 600 h of aging treatment, and the thickness of IMC remains at 3.5 μm. Cu5Zn8 generated at the solder and polycrystalline copper solder joint during aging treatment acts as a barrier layer, preventing the solder from contacting the copper substrate and inhibiting the formation of Cu6Sn5. Cu5Zn8 is broken and decomposed after 300 h of aging treatment, and Cu6Sn5 grows rapidly after the barrier layer disappeared. The thickness of Cu6Sn5 is about 2.8 μm. The thickness of IMC of solder joint on single crystal copper is 0.7 μm more than that on polycrystalline copper. After aging treatment, the IMC formed at the interface between alloy solder and single crystal copper has better compactness and basically no pores, while there are obvious pores between IMC grains at the interface between alloy solder and polycrystalline copper, which can predict that the soldering quality of the interface between alloy solder and single crystal copper is better. This will provide application prospects for solder joint interface reliability research.

Accelerated Lignocellulosic Molecule Adsorption Structure Determination.

Here, we present a study combining Bayesian optimization structural inference with the machine learning interatomic potential Neural Equivariant Interatomic Potential (NequIP) to accelerate and enable the study of the adsorption of the conformationally flexible lignocellulosic molecules β-d-xylose and 1,4-β-d-xylotetraose on a copper surface. The number of structure evaluations needed to map out the relevant potential energy surfaces are reduced by Bayesian optimization, while NequIP minimizes the time spent on each evaluation, ultimately resulting in cost-efficient and reliable sampling of large systems and configurational spaces. Although the applicability of Bayesian optimization for the conformational analysis of the more flexible xylotetraose molecule is restricted by the sample complexity bottleneck, the latter can be effectively bypassed with external conformer search tools, such as the Conformer-Rotamer Ensemble Sampling Tool, facilitating the subsequent lower-dimensional global minimum adsorption structure determination. Finally, we demonstrate the applicability of the described approach to find adsorption structures practically equivalent to the density functional theory counterparts at a fraction of the computational cost.

Effect of Cross Nanowall Surface on the Onset Time of Explosive Boiling: A Molecular Dynamics Study

Explosive boiling is a fast-phase transition from an ultra-thin liquid film to vapor under an extremely high heat flux, which typically has been studied using the molecular dynamics simulation (MDS) method. The present MDS study investigated the explosive boiling of a liquid argon nanofilm over different solid copper surfaces with different nanowall patterns, including parallel and cross nanowalls. For each surface, atomic motion trajectories, the number of liquid and vapor argon atoms, heat flux, and, mainly, the onset time of explosive boiling were investigated. The simulation results indicated that explosive boiling occurs earlier on parallel and cross nanowall surfaces than on an ideally smooth surface, regardless of the topology and configuration of the nanowalls. Moreover, the results revealed that by using the cross nanowall surfaces, the onset time of explosive boiling decreased by 0.7–4% compared to the parallel nanowall surfaces. In addition, it was found that the onset time of explosive boiling strongly depends on the potential energy barrier and the movement space between nanowalls for both parallel and cross nanowall surfaces. Furthermore, the simulation findings showed that even though increasing the height of cross nanowalls increases the heat flux and temperature of the fluid argon domain, it does not necessarily result in a shorter onset time for explosive boiling. These findings demonstrate the capability of cross nanowall surfaces for explosive boiling, thereby being utilized in future surface design for thermal management applications.

Orientation-dependent plastic flow in nanoscratching of copper surfaces

The characterization of frictional behavior in ductile metals is a crucial aspect of materials science, as it relates to the plastic deformation of the material. However, due to the intricate dislocation evolution at the submicron/nanometer scale, the isolation of the basic plastic mechanisms remains challenging. In this study, nanoscratching technology is employed to investigate submicron/nanometer-level plastic deformation in individual grains of polycrystalline copper. To achieve this, a crystal plastic constitutive model for copper materials is developed by incorporating geometrically necessary dislocation effects. The calibration of the constitutive model is conducted with great precision and specificity, leveraging mechanical responses, surface accumulation morphology, and indentation size effects from nanoindentation experiments of 110-oriented single crystal copper. Through the combination of crystal plastic finite element simulation and nanoscratching experiments, the plastic flow of the material is thoroughly analyzed. The results demonstrate that the anisotropic scratching behavior is influenced by different orientations of individual grains, taking into account both statistical storage dislocations and geometrically necessary dislocations. The insights gleaned from this study offer a valuable contribution to our understanding of the plastic mechanisms of metals at a small scale, enhancing the design and performance of advanced materials for a wide range of applications.

Boiling heat transfer characteristics of self-rewetting fluid based on the bi-porous sintered surface

Enhancing boiling heat transfer by changing the working fluid or surface modification is an effective and simple method. In order to investigate the effect of the coupling characteristics of porous sintered surfaces with self-rewetting fluid, pool boiling experiments were carried out on the polished copper surface (PCS) and the bi-porous sintered surface (BPS) with n-heptanol aqueous solution as the working fluid. The experimental results showed that, for the PCS cases, the self-rewetting fluid enhanced the heat transfer coefficient (HTC), while reduced the critical heat flux (CHF). This is because while self-rewetting fluid promoted the generation and detachment of bubbles, it also caused gas–liquid conflict, resulting in the surface was covered by a layer of vapor film. As for the boiling experiments on the BPS, the self-rewetting fluid not only enhanced the HTC but also enhanced the CHF. The Marangoni effect, generated by the self-rewetting fluid, replenished the BPS and coupled with its stronger capillary force. That led to surface wetting and reduced conflict between gas and liquid flow. Consequently, under this coupling effect, the heat transfer coefficient (HTC) of 0.1 wt% n-heptanol aqueous solution was 178.7 % higher than that of deionized water with PCS.