Young＇s equation is a fundamental equation in capillarity and wetting, which reflects the balance of the horizontal components of the three interracial tensions with the contact angle （CA）. However, it does not con...Young＇s equation is a fundamental equation in capillarity and wetting, which reflects the balance of the horizontal components of the three interracial tensions with the contact angle （CA）. However, it does not consider the vertical component of the liquid-vapor interracial tension （VCLVIT）. It is now well understood that the VCLVIT causes the elastic deformation of the solid substrate, which plays a significant role in the fabrication of the microfluidic devices because of the wide use of the soft materials. In this paper, the theoretical, experimental, and numerical aspects of the problem are reviewed. The effects of the VCLVIT-induced surface deformation on the wetting and spreading, the deflection of the microcantilever, and the elasto.capillarity and electro- elasto.capillarity are discussed. Besides a brief review on the historical development and the recent advances, some suggestions on the future research are also provided. Key words展开更多
Interfacial tension between liquid Al and molten fluoride salt was determined using sessile drop method combined with X-ray radiograph.A computer program of curve-fitting for coordination of configuration of sessile d...Interfacial tension between liquid Al and molten fluoride salt was determined using sessile drop method combined with X-ray radiograph.A computer program of curve-fitting for coordination of configuration of sessile drop was used in the picture processing of the sessile drop.Regressive equation were worked out to calculate the density of the molten salt.The in- fluence of mole ratio of NaF/AlF_3,content of Li_2CO_3 and rare-earth oxides in the molten salt on interfacial tension of Al-salt was discussed.The contact angles of liquid Al on the sur- face of graphite,graphitized carbon cathode and the graphite with coating of TiB_2 were de- termined.展开更多
The wetting phenomenon of water droplets coexisting with the ordered water monolayer termed an unexpected phenomenon of“water that does not wet a water monolayer”at room temperature has been found on several solid s...The wetting phenomenon of water droplets coexisting with the ordered water monolayer termed an unexpected phenomenon of“water that does not wet a water monolayer”at room temperature has been found on several solid surfaces.Although the hydrogen bond saturation inside the monolayer can qualitatively describe this phenomenon,whether the Young-Dupre equation still holds under this unconventional wetting framework is still not answered.In this work,we have´calculated the contact angle values of the droplets as well as the work of adhesion between the droplets and the monolayer based on an extended phantom-wall method.The results show that similar to the conventional solid-liquid interface,classical Young-Dupre equation is also applicable for the interface of liquid water and ordered water monolayer.展开更多
This study investigated experimentally the coupled effects of hydrophilic SiO_(2) nanoparticles(NPs)and low-salinity water(LSW)on the wettability of synthetic clay-free Berea sandstone.Capillary pressure,interfacial t...This study investigated experimentally the coupled effects of hydrophilic SiO_(2) nanoparticles(NPs)and low-salinity water(LSW)on the wettability of synthetic clay-free Berea sandstone.Capillary pressure,interfacial tension(IFT),contact angle,Zeta potential,and dynamic displacement measurements were performed at various NP mass fractions and brine salinities.The U.S.Bureau of Mines(USBM)index was used to quantify the wettability alteration.Furthermore,the NP stability and retention and the effect of enhanced oil recovery by nanofluid were examined.The results showed that LSW immiscible displacement with NPs altered the wettability toward more water wet.With the decreasing brine salinity and increasing NP mass fraction,the IFT and contact angle decreased.The wettability alteration intensified most as the brine salinity decreased to 4000 mg/L and the NP mass fraction increased to 0.075%.Under these conditions,the resulting incremental oil recovery factor was approximately 13 percentage points.When the brine salinity was 4000 mg/L and the NP mass fraction was 0.025%,the retention of NPs caused the minimum damage to permeability.展开更多
The determination of solid–liquid interfacial tension plays an important role in science and technology.Here,we propose a simple method to directly measure the contact angle between metal droplets and a graphite subs...The determination of solid–liquid interfacial tension plays an important role in science and technology.Here,we propose a simple method to directly measure the contact angle between metal droplets and a graphite substrate for the determination of metal–graphite interfacial tension.The proposed method involves the synthesis of micro-and nanosized metal droplets on graphite by arc melting.Owing to its small volume,the rapid cooling of the prepared metal droplets on the graphite substrate leads to the freezing of equilibrium contact confguration after solidifcation.We observe that the measured contact angle between micro-and nanosized Au(or Ag)particles and the graphite substrate is almost size independent,even though the size of the particles synthesized herein is 1–3 orders of magnitude smaller than that studied in previous works.In addition,the interfacial tensions of Au and Ag on the step edges(edge plane)of graphite are found to be larger than that on the(0001)plane(basal plane).The proposed method provides a simple approach to determine the solid–liquid interfacial tension and may be efective in the study of interface related science and technology.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 11002051)
文摘Young＇s equation is a fundamental equation in capillarity and wetting, which reflects the balance of the horizontal components of the three interracial tensions with the contact angle （CA）. However, it does not consider the vertical component of the liquid-vapor interracial tension （VCLVIT）. It is now well understood that the VCLVIT causes the elastic deformation of the solid substrate, which plays a significant role in the fabrication of the microfluidic devices because of the wide use of the soft materials. In this paper, the theoretical, experimental, and numerical aspects of the problem are reviewed. The effects of the VCLVIT-induced surface deformation on the wetting and spreading, the deflection of the microcantilever, and the elasto.capillarity and electro- elasto.capillarity are discussed. Besides a brief review on the historical development and the recent advances, some suggestions on the future research are also provided. Key words
文摘Interfacial tension between liquid Al and molten fluoride salt was determined using sessile drop method combined with X-ray radiograph.A computer program of curve-fitting for coordination of configuration of sessile drop was used in the picture processing of the sessile drop.Regressive equation were worked out to calculate the density of the molten salt.The in- fluence of mole ratio of NaF/AlF_3,content of Li_2CO_3 and rare-earth oxides in the molten salt on interfacial tension of Al-salt was discussed.The contact angles of liquid Al on the sur- face of graphite,graphitized carbon cathode and the graphite with coating of TiB_2 were de- termined.
基金supported by the National Natural Science Foundation of China(Grant Nos.12022508 and 12074394)Sichuan Science and Technology Program(Grant No.2017YJ0174).
文摘The wetting phenomenon of water droplets coexisting with the ordered water monolayer termed an unexpected phenomenon of“water that does not wet a water monolayer”at room temperature has been found on several solid surfaces.Although the hydrogen bond saturation inside the monolayer can qualitatively describe this phenomenon,whether the Young-Dupre equation still holds under this unconventional wetting framework is still not answered.In this work,we have´calculated the contact angle values of the droplets as well as the work of adhesion between the droplets and the monolayer based on an extended phantom-wall method.The results show that similar to the conventional solid-liquid interface,classical Young-Dupre equation is also applicable for the interface of liquid water and ordered water monolayer.
基金Kuwait University General Research Facilities (GE01/17,GE01/07,and GS03/01)for their support in conducting the necessary experimental work of this study。
文摘This study investigated experimentally the coupled effects of hydrophilic SiO_(2) nanoparticles(NPs)and low-salinity water(LSW)on the wettability of synthetic clay-free Berea sandstone.Capillary pressure,interfacial tension(IFT),contact angle,Zeta potential,and dynamic displacement measurements were performed at various NP mass fractions and brine salinities.The U.S.Bureau of Mines(USBM)index was used to quantify the wettability alteration.Furthermore,the NP stability and retention and the effect of enhanced oil recovery by nanofluid were examined.The results showed that LSW immiscible displacement with NPs altered the wettability toward more water wet.With the decreasing brine salinity and increasing NP mass fraction,the IFT and contact angle decreased.The wettability alteration intensified most as the brine salinity decreased to 4000 mg/L and the NP mass fraction increased to 0.075%.Under these conditions,the resulting incremental oil recovery factor was approximately 13 percentage points.When the brine salinity was 4000 mg/L and the NP mass fraction was 0.025%,the retention of NPs caused the minimum damage to permeability.
基金supported by the Key Research and Development Program of Hubei Province(Grant No.2021BAA192)the Fundamental Research Funds for the Central Universities(Grant No.2042023kf0233)the National Natural Science Foundation of China(Grant Nos.12172260 and 11802210).
文摘The determination of solid–liquid interfacial tension plays an important role in science and technology.Here,we propose a simple method to directly measure the contact angle between metal droplets and a graphite substrate for the determination of metal–graphite interfacial tension.The proposed method involves the synthesis of micro-and nanosized metal droplets on graphite by arc melting.Owing to its small volume,the rapid cooling of the prepared metal droplets on the graphite substrate leads to the freezing of equilibrium contact confguration after solidifcation.We observe that the measured contact angle between micro-and nanosized Au(or Ag)particles and the graphite substrate is almost size independent,even though the size of the particles synthesized herein is 1–3 orders of magnitude smaller than that studied in previous works.In addition,the interfacial tensions of Au and Ag on the step edges(edge plane)of graphite are found to be larger than that on the(0001)plane(basal plane).The proposed method provides a simple approach to determine the solid–liquid interfacial tension and may be efective in the study of interface related science and technology.
