Pub Date : 2025-01-21DOI: 10.1021/acs.langmuir.4c03575
Timur S. Jakubov, Eduard S. Jakubov
In the proposed paper, a new result is presented, which is as follows: the point on the equilibrium excess adsorption isotherm at which the rate of increase of concentration of a component in the adsorption phase reaches its mean value is the point at which the curvature of the isotherm takes its extreme value. This regularity also holds in the case of the adsorption of gases. This result is confirmed and valid for isotherms of various types. This in turn allows us to directly find the limiting adsorption of the pure component and then the partial isotherm of absolute adsorption. Thus, this result demonstrates that the curvature of the excess adsorption isotherm holds crucial information about the adsorption system, enabling the calculation of absolute adsorption isotherms and several specific characteristics such as the volume of the adsorption space.
{"title":"Undescribed Hitherto Universal Properties of Isotherms of Excess Adsorption of Liquids and Gases. Connection of Peculiar Points of an Isotherm with Extremums of Its Curvature","authors":"Timur S. Jakubov, Eduard S. Jakubov","doi":"10.1021/acs.langmuir.4c03575","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c03575","url":null,"abstract":"In the proposed paper, a new result is presented, which is as follows: the point on the equilibrium excess adsorption isotherm at which the rate of increase of concentration of a component in the adsorption phase reaches its mean value is the point at which the curvature of the isotherm takes its extreme value. This regularity also holds in the case of the adsorption of gases. This result is confirmed and valid for isotherms of various types. This in turn allows us to directly find the limiting adsorption of the pure component and then the partial isotherm of absolute adsorption. Thus, this result demonstrates that the curvature of the excess adsorption isotherm holds crucial information about the adsorption system, enabling the calculation of absolute adsorption isotherms and several specific characteristics such as the volume of the adsorption space.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"58 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-21DOI: 10.1021/acs.langmuir.4c04938
Ling Gong
Thermoresponsive shape memory polymer (SMP) adhesives have demonstrated a high adhesion strength and large switching ratios on different substrates. However, a long response time to switch adhesion on or off is generally encountered. This study provides a fast adhesion switching method based on the temperature and rate dependence of adhesion within the glass-transition zone of an epoxy polymer. The epoxy polymer samples were prepared. The molecular structure and thermal and mechanical properties of samples were characterized. The adhesion of the epoxy polymer sample against a hemispherical glass indenter was measured. Effects of preset temperature and retraction speed on adhesion were investigated, and the switchable adhesion properties were evaluated. The results show that there exists a critical retraction speed (Vc) that makes the viscoelasticity and adhesion maximum at each preset temperature. The viscoelasticity and adhesion gradually enhance below Vc and gradually weaken above Vc with the increasing retraction speed, indicating that the effects of the temperature and retraction speed on adhesion originate from the viscoelastic difference of the epoxy polymer sample under different temperature and rate conditions. The pull-off force (Fpull-off) is verified to linearly depend on the dissipated energy ratio (r), work done during pulling off (U3), reduced modulus (Er), and contact radius apull–off, i.e., Fpull-off ∝ r√U3Erapull‐off. The epoxy polymer-based switchable adhesion demonstrates high adhesion strength (∼488 kPa), large switching ratio (approaching infinity), and short switching time (<100 ms) simultaneously based on the dual regulation strategy of temperature and rate. This study provides insights into fast adhesion switching and may activate the development and applications of relevant techniques and devices.
{"title":"Thermal- and Rate-Regulated Fast Switchable Adhesion within Glass Transition Zone of an Epoxy Polymer","authors":"Ling Gong","doi":"10.1021/acs.langmuir.4c04938","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04938","url":null,"abstract":"Thermoresponsive shape memory polymer (SMP) adhesives have demonstrated a high adhesion strength and large switching ratios on different substrates. However, a long response time to switch adhesion on or off is generally encountered. This study provides a fast adhesion switching method based on the temperature and rate dependence of adhesion within the glass-transition zone of an epoxy polymer. The epoxy polymer samples were prepared. The molecular structure and thermal and mechanical properties of samples were characterized. The adhesion of the epoxy polymer sample against a hemispherical glass indenter was measured. Effects of preset temperature and retraction speed on adhesion were investigated, and the switchable adhesion properties were evaluated. The results show that there exists a critical retraction speed (<i>V</i><sub>c</sub>) that makes the viscoelasticity and adhesion maximum at each preset temperature. The viscoelasticity and adhesion gradually enhance below <i>V</i><sub>c</sub> and gradually weaken above <i>V</i><sub>c</sub> with the increasing retraction speed, indicating that the effects of the temperature and retraction speed on adhesion originate from the viscoelastic difference of the epoxy polymer sample under different temperature and rate conditions. The pull-off force (<i>F</i><sub>pull-off</sub>) is verified to linearly depend on the dissipated energy ratio (<i>r</i>), work done during pulling off (<i>U</i><sub>3</sub>), reduced modulus (<i>E</i><sub>r</sub>), and contact radius <i>a</i><sub>pull–off</sub>, i.e., <i>F</i><sub>pull-off</sub> ∝ <i></i><span style=\"color: inherit;\"><span><span>r</span><span><span><span style=\"font-size: 169%; margin-top: 0.083em; margin-left: -0.055em;\">√</span></span><span><span style=\"border-top: 0.084em solid;\"></span><span><span><span><span style=\"margin-right: 0.05em;\"><span>U</span></span><span style=\"vertical-align: -0.4em;\"><span>3</span></span></span><span><span style=\"margin-right: 0.05em;\"><span>E</span></span><span style=\"vertical-align: -0.4em;\"><span>r</span></span></span><span><span style=\"margin-right: 0.05em;\"><span>a</span></span><span style=\"vertical-align: -0.4em;\"><span>pull‐off</span></span></span></span></span></span></span></span></span><span style=\"\" tabindex=\"0\"></span><script type=\"math/mml\"><math display=\"inline\"><mi>r</mi><msqrt><mrow><msub><mrow><mi>U</mi></mrow><mrow><mn>3</mn></mrow></msub><msub><mrow><mi>E</mi></mrow><mrow><mi mathvariant=\"normal\">r</mi></mrow></msub><msub><mrow><mi>a</mi></mrow><mrow><mi>pull‐off</mi></mrow></msub></mrow></msqrt></math></script>. The epoxy polymer-based switchable adhesion demonstrates high adhesion strength (∼488 kPa), large switching ratio (approaching infinity), and short switching time (<100 ms) simultaneously based on the dual regulation strategy of temperature and rate. This study provides insights into fast adhesion switching and may activate the development and applications of relevant techniques and devices.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"9 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-21DOI: 10.1021/acs.langmuir.4c04312
Angitha Francy, Ragi T. M, A. Peer Mohamed, Ananthakumar Solaiappan
Meso/microporous nano silica modified with macromolecular polymers produces attractive hybrids that repel water and have a hydrophobic surface, making them highly effective for targeting and eliminating organic contaminants in aquatic environments. In this study, nano silica was functionalized with silicone oil, an oligomeric siloxane derivative, to produce a hydrophobic silica nano hybrid characterized by a non-wetting water contact angle of 139°. This hydrophobic hybrid nano silica showed a sustainable floating nature on water even in turbulent streams. Due to such robust hydrophobic properties, the hybrid was explored for the separation of three different kinds of contaminants, such as (i) organic dyes, (ii) antibiotics, and (iii) nicotine. The concept of a floating sorbent has been innovatively introduced in this study through the application of silicone oil-modified nano silica. The adsorption experiments were systematically planned, and the data related to the percentage adsorption of contaminants with respect to dosage, pH, and concentration are reported. The results indicated an adsorption efficiency of >99% for cationic dyes with moderate adsorption observed for nicotine and antibiotics. The study highlights the significant potential of silicone oil-modified silica as a hydrophobic floating sorbent for environmental remediation. Buoyancy and strong water-repellent properties facilitate easy recovery and reuse, offering a sustainable and efficient method for the removal of diverse organic pollutants from water systems.
{"title":"Silicone Oil-Functionalized Hydrophobic Nano Silica: A Floating Sorbent for Organic Pollutant Removal in Aquatic Systems","authors":"Angitha Francy, Ragi T. M, A. Peer Mohamed, Ananthakumar Solaiappan","doi":"10.1021/acs.langmuir.4c04312","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04312","url":null,"abstract":"Meso/microporous nano silica modified with macromolecular polymers produces attractive hybrids that repel water and have a hydrophobic surface, making them highly effective for targeting and eliminating organic contaminants in aquatic environments. In this study, nano silica was functionalized with silicone oil, an oligomeric siloxane derivative, to produce a hydrophobic silica nano hybrid characterized by a non-wetting water contact angle of 139°. This hydrophobic hybrid nano silica showed a sustainable floating nature on water even in turbulent streams. Due to such robust hydrophobic properties, the hybrid was explored for the separation of three different kinds of contaminants, such as (i) organic dyes, (ii) antibiotics, and (iii) nicotine. The concept of a floating sorbent has been innovatively introduced in this study through the application of silicone oil-modified nano silica. The adsorption experiments were systematically planned, and the data related to the percentage adsorption of contaminants with respect to dosage, pH, and concentration are reported. The results indicated an adsorption efficiency of >99% for cationic dyes with moderate adsorption observed for nicotine and antibiotics. The study highlights the significant potential of silicone oil-modified silica as a hydrophobic floating sorbent for environmental remediation. Buoyancy and strong water-repellent properties facilitate easy recovery and reuse, offering a sustainable and efficient method for the removal of diverse organic pollutants from water systems.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"8 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Titanium alloy plates are often used for fixation to bone. However, the plates often need to be removed due to infection and adverse inflammation. To avoid these problems, we immobilized copper, which has antibacterial effects and low cytotoxicity, on titanium plates by immersing the titanium in copper-tris(hydroxymethyl)aminomethane complex solutions. The amount of copper immobilized on the titanium alloy surface was dependent on the amount of tris(hydroxymethyl)aminomethane and the pH of the solutions. The maximum amount of copper immobilized on the titanium alloy surface was about 20 atomic%, without any change in the surface morphological characteristics. The obtained titanium alloy with immobilized copper exhibited antibacterial and anti-inflammation properties without cytotoxicity.
{"title":"Antibacterial and Anti-Inflammation Activity of Titanium Alloy by Efficient Copper Immobilization","authors":"Miki Morinobu, Akira Tsuchiya, Masaya Shimabukuro, Masafumi Moriyama, Kunio Ishikawa","doi":"10.1021/acs.langmuir.4c04782","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04782","url":null,"abstract":"Titanium alloy plates are often used for fixation to bone. However, the plates often need to be removed due to infection and adverse inflammation. To avoid these problems, we immobilized copper, which has antibacterial effects and low cytotoxicity, on titanium plates by immersing the titanium in copper-tris(hydroxymethyl)aminomethane complex solutions. The amount of copper immobilized on the titanium alloy surface was dependent on the amount of tris(hydroxymethyl)aminomethane and the pH of the solutions. The maximum amount of copper immobilized on the titanium alloy surface was about 20 atomic%, without any change in the surface morphological characteristics. The obtained titanium alloy with immobilized copper exhibited antibacterial and anti-inflammation properties without cytotoxicity.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"84 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-20DOI: 10.1021/acs.langmuir.4c03586
Ekta Sharma, Hitesh Rawate, Rochish M. Thaokar, Vinay Anant Juvekar
Water-in-oil emulsions are critical in various fields, including food, agriculture, personal care, and pharmaceuticals. In some situations, spontaneous emulsification occurs in emulsions with high concentrations of oil-soluble surfactants, in which the parent water drops fragment into finer droplets, forming a network near the interface, which exhibits interfacial elasticity. This study investigates this phenomenon using a water/Span 80-paraffin oil system. We measured interfacial shear elasticity and used microscopy to capture the dynamics. The time of onset of the network depends on the contact time between the two liquid phases and the Span 80 concentration, scaling inversely with the square of the bulk concentration of Span 80. Beyond the time of onset of network formation, different trends are observed, depending on the concentration of Span 80. At higher concentrations, the interfacial elasticity shows a maximum, followed by a minimum. This oscillatory trend in the interfacial elasticity is an outcome of the formation of multiple layers of water droplets at the interface. The existence of multiple layers is also observed through an optical microscope. In a more viscous paraffin oil, both the emulsification rate and the elasticity peak are reduced. No spontaneous emulsification is observed when the paraffin oil is replaced with silicone oil. Moreover, spontaneous emulsification is suppressed by the addition of a salt. On the contrary, the addition of Tween 80 in water increases the rate of spontaneous emulsion, resulting in larger droplets and a denser emulsion layer. However, the drops form a very weak network, as indicated by a negligibly small interfacial elasticity.
{"title":"Interfacial Rheology as a Tool to Characterize the Dynamics of Spontaneous Emulsification","authors":"Ekta Sharma, Hitesh Rawate, Rochish M. Thaokar, Vinay Anant Juvekar","doi":"10.1021/acs.langmuir.4c03586","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c03586","url":null,"abstract":"Water-in-oil emulsions are critical in various fields, including food, agriculture, personal care, and pharmaceuticals. In some situations, spontaneous emulsification occurs in emulsions with high concentrations of oil-soluble surfactants, in which the parent water drops fragment into finer droplets, forming a network near the interface, which exhibits interfacial elasticity. This study investigates this phenomenon using a water/Span 80-paraffin oil system. We measured interfacial shear elasticity and used microscopy to capture the dynamics. The time of onset of the network depends on the contact time between the two liquid phases and the Span 80 concentration, scaling inversely with the square of the bulk concentration of Span 80. Beyond the time of onset of network formation, different trends are observed, depending on the concentration of Span 80. At higher concentrations, the interfacial elasticity shows a maximum, followed by a minimum. This oscillatory trend in the interfacial elasticity is an outcome of the formation of multiple layers of water droplets at the interface. The existence of multiple layers is also observed through an optical microscope. In a more viscous paraffin oil, both the emulsification rate and the elasticity peak are reduced. No spontaneous emulsification is observed when the paraffin oil is replaced with silicone oil. Moreover, spontaneous emulsification is suppressed by the addition of a salt. On the contrary, the addition of Tween 80 in water increases the rate of spontaneous emulsion, resulting in larger droplets and a denser emulsion layer. However, the drops form a very weak network, as indicated by a negligibly small interfacial elasticity.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"15 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-20DOI: 10.1021/acs.langmuir.4c04363
Jiaming Xu, Stephen Adepoju, Simran Pandey, Jimena Pérez Tetuán, Mary Williams, Rudolf G. Abdelmessih, Debra T. Auguste, Francisco R. Hung
We performed all-atom and coarse-grained simulations of lipid bilayer mixtures of the unsaturated lipid DOPC, with saturated lipids having the same 18-carbon acyl tails and different headgroups, to understand their mechanical properties. The secondary lipids were DSPG, DSPA, DSPS, DSPC, and DSPE. The DOPC:DSPG system with 65:35 molar ratio was the softest, with area compressibility modulus KA ∼ 22% smaller than the pure DOPC value. Raising the mole % of DOPC leads to increases in KA, yet at any given composition the KA trend is DSPG < DSPA < DSPS < DSPC < DSPE. Lipid–lipid interactions are weaker in DOPC:DSPG mixtures and stronger in DSPE systems. The head and phosphate groups of the secondary lipids DSPG, DSPA, and DSPS interact strongly with salt ions. Adding secondary lipids leads to DOPC having more ordered acyl tails relative to pure DOPC systems. No evidence of phase separation or inhomogeneities was observed in our simulations. We synthesized three liposomal formulations, L-DOPC (pure DOPC) and L-DOPC/DSPG and L-DOPC/DSPA, both with 15 mol % of secondary lipid. L-DOPC/DSPA had approximately 3- and 2-times higher in vitro internalization by normal epithelial (EpH4-Ev) and metastatic breast cancer (4T1) cells, compared with L-DOPC. The uptake of L-DOPC/DSPG by EpH4-Ev cells was almost 2-fold compared to L-DOPC, but both liposomes had similar uptakes by cancer cells. As L-DOPC/DSPG and L-DOPC/DSPA have similar KA values, we presumed that the mechanical properties, possibly in combination with the higher negative surface charges in L-DOPC/DSPA and differences in effective liposome diameters and diffusivities, contributed to these observations.
{"title":"Effects of Lipid Headgroups on the Mechanical Properties and In Vitro Cellular Internalization of Liposomes","authors":"Jiaming Xu, Stephen Adepoju, Simran Pandey, Jimena Pérez Tetuán, Mary Williams, Rudolf G. Abdelmessih, Debra T. Auguste, Francisco R. Hung","doi":"10.1021/acs.langmuir.4c04363","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04363","url":null,"abstract":"We performed all-atom and coarse-grained simulations of lipid bilayer mixtures of the unsaturated lipid DOPC, with saturated lipids having the same 18-carbon acyl tails and different headgroups, to understand their mechanical properties. The secondary lipids were DSPG, DSPA, DSPS, DSPC, and DSPE. The DOPC:DSPG system with 65:35 molar ratio was the softest, with area compressibility modulus <i>K</i><sub><i>A</i></sub> ∼ 22% smaller than the pure DOPC value. Raising the mole % of DOPC leads to increases in <i>K</i><sub><i>A</i></sub>, yet at any given composition the <i>K</i><sub><i>A</i></sub> trend is DSPG < DSPA < DSPS < DSPC < DSPE. Lipid–lipid interactions are weaker in DOPC:DSPG mixtures and stronger in DSPE systems. The head and phosphate groups of the secondary lipids DSPG, DSPA, and DSPS interact strongly with salt ions. Adding secondary lipids leads to DOPC having more ordered acyl tails relative to pure DOPC systems. No evidence of phase separation or inhomogeneities was observed in our simulations. We synthesized three liposomal formulations, L-DOPC (pure DOPC) and L-DOPC/DSPG and L-DOPC/DSPA, both with 15 mol % of secondary lipid. L-DOPC/DSPA had approximately 3- and 2-times higher in vitro internalization by normal epithelial (EpH4-Ev) and metastatic breast cancer (4T1) cells, compared with L-DOPC. The uptake of L-DOPC/DSPG by EpH4-Ev cells was almost 2-fold compared to L-DOPC, but both liposomes had similar uptakes by cancer cells. As L-DOPC/DSPG and L-DOPC/DSPA have similar <i>K</i><sub><i>A</i></sub> values, we presumed that the mechanical properties, possibly in combination with the higher negative surface charges in L-DOPC/DSPA and differences in effective liposome diameters and diffusivities, contributed to these observations.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"32 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Adsorbents with high selectivity and adsorption capacity are of significant interest for the removal of dye pollutants. Herein, we report a facile low-temperature solvothermal synthesis of clew-like Cu2O/CuO microspheres by using cupric acetate monohydrate as the copper resource and ethylene glycol as the solvent and morphology modulator. The synthesized Cu2O/CuO microspheres showed high selective adsorption to anionic dyes (e.g., methyl orange (MO) and Reactive Red 2 (RR2)) rather than to cationic dyes (e.g., methylene blue (MB), Rhodamine B (RhB)). MO was then selected to evaluate the parameters of adsorption due to the adsorbent exhibiting the highest adsorption capacity for MO. We demonstrate that the adsorption of MO by Cu2O/CuO microspheres has a good correlation with the pseudo-second-order model and Langmuir isotherm with a maximum adsorption capacity of 826.45 mg/g, which is higher than that of previously reported metal oxide material adsorbents. The excellent adsorption ability of clew-like Cu2O/CuO microspheres to MO may be attributed to the synergistic effects of electrostatic attraction, unique hierarchical structure, and crystal defects of the prepared Cu2O/CuO microspheres. We believe our work provides new insight into the synthesis of high-performance adsorbents.
{"title":"Clew-like Cu2O/CuO Microsphere Adsorbents for Highly Efficient Anionic Dye Removal","authors":"Shuyu Wang, Xiaohui Wu, Lijuan Ren, Xian Pei, Hui Fang, Ping Lv, Ning Nan, Xianwei Lv, Xianming Zheng, Feihe Ma, Yun Wu, Yuping Liu, Linqi Shi","doi":"10.1021/acs.langmuir.4c04019","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04019","url":null,"abstract":"Adsorbents with high selectivity and adsorption capacity are of significant interest for the removal of dye pollutants. Herein, we report a facile low-temperature solvothermal synthesis of clew-like Cu<sub>2</sub>O/CuO microspheres by using cupric acetate monohydrate as the copper resource and ethylene glycol as the solvent and morphology modulator. The synthesized Cu<sub>2</sub>O/CuO microspheres showed high selective adsorption to anionic dyes (e.g., methyl orange (MO) and Reactive Red 2 (RR2)) rather than to cationic dyes (e.g., methylene blue (MB), Rhodamine B (RhB)). MO was then selected to evaluate the parameters of adsorption due to the adsorbent exhibiting the highest adsorption capacity for MO. We demonstrate that the adsorption of MO by Cu<sub>2</sub>O/CuO microspheres has a good correlation with the pseudo-second-order model and Langmuir isotherm with a maximum adsorption capacity of 826.45 mg/g, which is higher than that of previously reported metal oxide material adsorbents. The excellent adsorption ability of clew-like Cu<sub>2</sub>O/CuO microspheres to MO may be attributed to the synergistic effects of electrostatic attraction, unique hierarchical structure, and crystal defects of the prepared Cu<sub>2</sub>O/CuO microspheres. We believe our work provides new insight into the synthesis of high-performance adsorbents.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"57 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The anionic species of antimony(V) and phosphate(V) are commonly found in the contaminated soil of mining areas, exerting a significant influence on the sorption of heavy metals and thus affecting their migration. This study quantitatively discussed the sorption mechanism of Sb and P in promoting the sorption of Cd or Cu on goethite through a series of extraction methods. In the single sorption system, the majority of Cu (87–98%) is adsorbed on goethite in the form of EDTA-extractable Cu (EF Cu, possibly inner-sphere complexes) under pH conditions of 3.5–6.5. Cadmium is primarily adsorbed in the form of EDTA-extractable Cd (49–71%), with a considerable amount of Mg(NO3)2 extractable Cd (MF Cd, possibly outer-sphere complexes) also present (25–51%), within the pH range of 4.5–7.5. The presence of either Sb or P greatly enhances the sorption of Cd and Cu on goethite, although the mechanisms differ significantly. Sb enhances the sorption of Cu mainly by increasing the amount of EF Cu (61.7–68.1% of total Cu enhancement), with less significant effects on MF Cu. Furthermore, Sb shows similar enhancing effects on both MF Cd and EF Cd. As the pH increases, the enhancing effects of Sb on various forms of Cu and Cd decrease. Phosphate mainly promotes the formation of MF Cu and MF Cd, accounting for 53.9– 80.8% (Cu) and 78.0–94.9% (Cd) of total enhancement at different pH levels. ΔMF and ΔEF Cu increase with increasing pH when P is present, while ΔMF/ΔEF Cd remains essentially constant. Based on the extracted results and characterization analysis, the main mechanism of synergistic sorption between elements was discussed, and the connection modes of elements at the goethite interface were preliminarily speculated. The results indicate that the promotion of oxyanions on the fixation of heavy metal cations is more complex than expected, making it difficult to describe using only one mechanism.
{"title":"Compositional Differences of Various Sorption States of Cu and Cd on Goethite in the Presence of Oxyanions: A Quantitative Study","authors":"Chao Xue, Feng Jiang, Yuebei Yang, Hua Yin, Xiaoyun Yi, Zhi Dang","doi":"10.1021/acs.langmuir.4c04316","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04316","url":null,"abstract":"The anionic species of antimony(V) and phosphate(V) are commonly found in the contaminated soil of mining areas, exerting a significant influence on the sorption of heavy metals and thus affecting their migration. This study quantitatively discussed the sorption mechanism of Sb and P in promoting the sorption of Cd or Cu on goethite through a series of extraction methods. In the single sorption system, the majority of Cu (87–98%) is adsorbed on goethite in the form of EDTA-extractable Cu (EF Cu, possibly inner-sphere complexes) under pH conditions of 3.5–6.5. Cadmium is primarily adsorbed in the form of EDTA-extractable Cd (49–71%), with a considerable amount of Mg(NO<sub>3</sub>)<sub>2</sub> extractable Cd (MF Cd, possibly outer-sphere complexes) also present (25–51%), within the pH range of 4.5–7.5. The presence of either Sb or P greatly enhances the sorption of Cd and Cu on goethite, although the mechanisms differ significantly. Sb enhances the sorption of Cu mainly by increasing the amount of EF Cu (61.7–68.1% of total Cu enhancement), with less significant effects on MF Cu. Furthermore, Sb shows similar enhancing effects on both MF Cd and EF Cd. As the pH increases, the enhancing effects of Sb on various forms of Cu and Cd decrease. Phosphate mainly promotes the formation of MF Cu and MF Cd, accounting for 53.9– 80.8% (Cu) and 78.0–94.9% (Cd) of total enhancement at different pH levels. ΔMF and ΔEF Cu increase with increasing pH when P is present, while ΔMF/ΔEF Cd remains essentially constant. Based on the extracted results and characterization analysis, the main mechanism of synergistic sorption between elements was discussed, and the connection modes of elements at the goethite interface were preliminarily speculated. The results indicate that the promotion of oxyanions on the fixation of heavy metal cations is more complex than expected, making it difficult to describe using only one mechanism.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"8 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-20DOI: 10.1021/acs.langmuir.4c04323
Chen Li, Yichun Li, Jiayu Weng, Jiafeng Chen, Xiaoyong Cao, Chunlei Wei, Nan Xu, Yi He
In area-selective atomic layer deposition (AS-ALD), small molecule inhibitors (SMIs) play a critical role in directing surface selectivity, preventing unwanted deposition on non-growth surfaces, and enabling precise thin-film formation essential for semiconductor and advanced manufacturing processes. This study utilizes grand canonical Monte Carlo (GCMC) simulations to investigate the competitive adsorption characteristics of three SMIs─aniline, 3-hexyne, and propanethiol (PT)─alongside trimethylaluminum (TMA) precursors on a Cu(111) surface. Single-component adsorption analyses reveal that aniline attains the highest coverage among the SMIs, attributed to its strong interaction with the Cu surface; however, this coverage decreases by approximately 42% in the presence of TMA, underscoring its susceptibility to competitive adsorption effects. By contrast, 3-hexyne displays minimal alteration in adsorption when it is in competition with TMA, effectively inhibiting TMA adsorption and indicating its suitability as a robust SMI for AS-ALD. PT also demonstrates moderate inhibitory capability against TMA, although it is less effective than 3-hexyne in this regard. These findings highlight the importance of intermolecular forces and adsorption energies in determining SMI effectiveness in blocking TMA on non-growth surfaces. Mechanistic insights from this study reveal the nuanced influence of specific SMI–precursor interactions, emphasizing the necessity of selecting SMIs tailored to precursor characteristics and surface interactions. This work provides essential contributions to the rational design of SMIs in AS-ALD, with implications for improving deposition precision and optimizing AS-ALD parameters in nanomanufacturing applications.
{"title":"Competitive Adsorption of Small Molecule Inhibitors and Trimethylaluminum Precursors on the Cu(111) Surface during Area-Selective Atomic Layer Deposition: A GCMC Study","authors":"Chen Li, Yichun Li, Jiayu Weng, Jiafeng Chen, Xiaoyong Cao, Chunlei Wei, Nan Xu, Yi He","doi":"10.1021/acs.langmuir.4c04323","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04323","url":null,"abstract":"In area-selective atomic layer deposition (AS-ALD), small molecule inhibitors (SMIs) play a critical role in directing surface selectivity, preventing unwanted deposition on non-growth surfaces, and enabling precise thin-film formation essential for semiconductor and advanced manufacturing processes. This study utilizes grand canonical Monte Carlo (GCMC) simulations to investigate the competitive adsorption characteristics of three SMIs─aniline, 3-hexyne, and propanethiol (PT)─alongside trimethylaluminum (TMA) precursors on a Cu(111) surface. Single-component adsorption analyses reveal that aniline attains the highest coverage among the SMIs, attributed to its strong interaction with the Cu surface; however, this coverage decreases by approximately 42% in the presence of TMA, underscoring its susceptibility to competitive adsorption effects. By contrast, 3-hexyne displays minimal alteration in adsorption when it is in competition with TMA, effectively inhibiting TMA adsorption and indicating its suitability as a robust SMI for AS-ALD. PT also demonstrates moderate inhibitory capability against TMA, although it is less effective than 3-hexyne in this regard. These findings highlight the importance of intermolecular forces and adsorption energies in determining SMI effectiveness in blocking TMA on non-growth surfaces. Mechanistic insights from this study reveal the nuanced influence of specific SMI–precursor interactions, emphasizing the necessity of selecting SMIs tailored to precursor characteristics and surface interactions. This work provides essential contributions to the rational design of SMIs in AS-ALD, with implications for improving deposition precision and optimizing AS-ALD parameters in nanomanufacturing applications.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"9 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-20DOI: 10.1021/acs.langmuir.4c04543
Timofei V. Golubitchenko, Kirill A. Emelyanenko, Vladimir G. Krasovsky, Alexandre M. Emelyanenko, Ludmila B. Boinovich
The results of an investigation of an impact of the structure of recently synthesized bis(trifluoromethylsulfonyl)imide mono- and dicationic ionic liquids on their properties and behavior as lubricants for slippery liquid infused superhydrophobic coatings are presented for a wide temperature range. In this study, a new approach based on monitoring the surface tension of a liquid sessile droplet on top of a coating was exploited for the analysis of the evolution of the coating properties in prolonged contact with the liquid. It was found that the continuous contact with water flow results in slippery property degradation according to two different scenarios. In the first one, the washing out of lubricant eventually led to the transition from water droplets sliding to them rolling with the establishment of a superhydrophobic state. The second scenario was revealed in di- and monocationic ILs with a siloxane linker or both siloxane tails through the continuous lubricant depletion from the texture, increase in sliding angle value, loss of slippery properties, and establishing of a homogeneous wetting regime by aqueous droplets with the contact angle around 140°. The obtained experimental data allowed concluding that, among studied ILs, the monocationic bis(trifluoromethylsulfonyl)imide ionic liquids with alkyl or mixed alkylene/siloxane tails are better suitable for application as lubricants for slippery, regularly refilled surfaces.
{"title":"Are the Imidazole Ionic Liquids Suitable Lubricants for Slippery Coatings?","authors":"Timofei V. Golubitchenko, Kirill A. Emelyanenko, Vladimir G. Krasovsky, Alexandre M. Emelyanenko, Ludmila B. Boinovich","doi":"10.1021/acs.langmuir.4c04543","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04543","url":null,"abstract":"The results of an investigation of an impact of the structure of recently synthesized bis(trifluoromethylsulfonyl)imide mono- and dicationic ionic liquids on their properties and behavior as lubricants for slippery liquid infused superhydrophobic coatings are presented for a wide temperature range. In this study, a new approach based on monitoring the surface tension of a liquid sessile droplet on top of a coating was exploited for the analysis of the evolution of the coating properties in prolonged contact with the liquid. It was found that the continuous contact with water flow results in slippery property degradation according to two different scenarios. In the first one, the washing out of lubricant eventually led to the transition from water droplets sliding to them rolling with the establishment of a superhydrophobic state. The second scenario was revealed in di- and monocationic ILs with a siloxane linker or both siloxane tails through the continuous lubricant depletion from the texture, increase in sliding angle value, loss of slippery properties, and establishing of a homogeneous wetting regime by aqueous droplets with the contact angle around 140°. The obtained experimental data allowed concluding that, among studied ILs, the monocationic bis(trifluoromethylsulfonyl)imide ionic liquids with alkyl or mixed alkylene/siloxane tails are better suitable for application as lubricants for slippery, regularly refilled surfaces.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"37 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：