Pub Date : 2025-12-07DOI: 10.1016/j.molliq.2025.129081
Zahra Arefi , Farshad Raji , Ahmad Rahbar-Kelishami
Microfluidic systems represent a cutting-edge approach for producing consistent spherical microparticles. In this process, microgels typically act as adsorbent materials capable of capturing pollutants from aqueous environments. In this study, alginate-based microgels were synthesized using a Y-shaped glass microchannel through water-in-oil droplet generation followed by ionic crosslinking in a calcium chloride bath. These microgels showed excellent adsorption performance for methylene blue (MB), confirmed by high removal efficiency and good fit with the Langmuir isotherm (R2 = 0.999) and pseudo-second-order kinetic model (R2 = 0.999), indicating monolayer uptake with strong physicochemical (electrostatic) interactions on a largely homogeneous surface. To better understand microgel formation, key dimensionless numbers (Re, Pe, Da, Sc, Sh) were analyzed. Laminar flow (low Re), convection-dominated mass transfer (high Pe, Sh), and Da < 1 suggested that gelation mainly occurred after channel exit. A reaction–diffusion model was also developed to predict gel front progression inside droplets, revealing that calcium diffusivity plays a dominant role in gelation kinetics. This combined experimental and modeling approach offers a strong foundation for optimizing microfluidic synthesis of adsorbents for water treatment.
{"title":"Integrating dimensionless analysis and reaction-diffusion modeling in the continuous synthesis of alginate microgels for dye removal","authors":"Zahra Arefi , Farshad Raji , Ahmad Rahbar-Kelishami","doi":"10.1016/j.molliq.2025.129081","DOIUrl":"10.1016/j.molliq.2025.129081","url":null,"abstract":"<div><div>Microfluidic systems represent a cutting-edge approach for producing consistent spherical microparticles. In this process, microgels typically act as adsorbent materials capable of capturing pollutants from aqueous environments. In this study, alginate-based microgels were synthesized using a Y-shaped glass microchannel through water-in-oil droplet generation followed by ionic crosslinking in a calcium chloride bath. These microgels showed excellent adsorption performance for methylene blue (MB), confirmed by high removal efficiency and good fit with the Langmuir isotherm (R<sup>2</sup> = 0.999) and pseudo-second-order kinetic model (R<sup>2</sup> = 0.999), indicating monolayer uptake with strong physicochemical (electrostatic) interactions on a largely homogeneous surface. To better understand microgel formation, key dimensionless numbers (<em>Re</em>, <em>Pe</em>, <em>Da</em>, <em>Sc</em>, <em>Sh</em>) were analyzed. Laminar flow (low <em>Re</em>), convection-dominated mass transfer (high <em>Pe</em>, <em>Sh</em>), and <em>Da</em> < 1 suggested that gelation mainly occurred after channel exit. A reaction–diffusion model was also developed to predict gel front progression inside droplets, revealing that calcium diffusivity plays a dominant role in gelation kinetics. This combined experimental and modeling approach offers a strong foundation for optimizing microfluidic synthesis of adsorbents for water treatment.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"442 ","pages":"Article 129081"},"PeriodicalIF":5.2,"publicationDate":"2025-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735944","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 : 2025-12-06DOI: 10.1016/j.molliq.2025.129102
Abdelkarim Ait Mansour , Saliha Loughmari , Hassan Haddouchy , Amina Amarray , Mouad Dahbi , Rachid Salghi , Abdelaziz El Bouadili , Hassan Laouane , Abdelilah Chtaini , Makayssi Abdelatif , Salah Eddine El Qouatli
E24 carbon steel, commonly used for general tool manufacturing, exhibits excellent machinability but is highly susceptible to corrosion in acidic environments such as those encountered during reactor cleaning. To address this issue, two new symmetrical vanillin derivatives: 3,6-bis(3,4-dimethoxyphenyl)-1,4,2,5-dioxadiazine (DVM) and 3,6-bis(4-ethoxy-3-methoxyphenyl)-1,4,2,5-dioxadiazine (DVE) were synthesized and their molecular structures confirmed by FT-IR, 1H NMR, and 13C NMR spectroscopy. Their corrosion inhibition performance for E24 steel in 1 M HCl was evaluated using electrochemical methods (PDP, EIS) and surface analyses (SEM/EDS). Both compounds exhibited high inhibition efficiencies of 87.07 % (DVM) and 89.09 % (DVE) at an optimal concentration of 10−3 M. DVE, showing the best performance, was further studied as a function of temperature (298–328 K) and immersion time (up to 24 h). The results revealed that DVE acts as a mixed-type inhibitor with predominant cathodic control and maintains strong protection under aggressive conditions. Thermodynamic analysis indicated spontaneous adsorption following the Langmuir isotherm. Theoretical studies (DFT, DFTB, and ESP mapping) supported strong electronic and steric interactions between DVE and the steel surface. Overall, DVM and DVE are efficient, eco-friendly corrosion inhibitors, with DVE demonstrating superior stability and adsorption strength in acidic media.
{"title":"Evaluation of the performance of dioxadiazine derivatives as corrosion inhibitors for E24 carbon steel in 1 M HCl medium: experimental approaches and theoretical simulations","authors":"Abdelkarim Ait Mansour , Saliha Loughmari , Hassan Haddouchy , Amina Amarray , Mouad Dahbi , Rachid Salghi , Abdelaziz El Bouadili , Hassan Laouane , Abdelilah Chtaini , Makayssi Abdelatif , Salah Eddine El Qouatli","doi":"10.1016/j.molliq.2025.129102","DOIUrl":"10.1016/j.molliq.2025.129102","url":null,"abstract":"<div><div>E24 carbon steel, commonly used for general tool manufacturing, exhibits excellent machinability but is highly susceptible to corrosion in acidic environments such as those encountered during reactor cleaning. To address this issue, two new symmetrical vanillin derivatives: 3,6-bis(3,4-dimethoxyphenyl)-1,4,2,5-dioxadiazine (DVM) and 3,6-bis(4-ethoxy-3-methoxyphenyl)-1,4,2,5-dioxadiazine (DVE) were synthesized and their molecular structures confirmed by FT-IR, <sup>1</sup>H NMR, and <sup>13</sup>C NMR spectroscopy. Their corrosion inhibition performance for E24 steel in 1 M HCl was evaluated using electrochemical methods (PDP, EIS) and surface analyses (SEM/EDS). Both compounds exhibited high inhibition efficiencies of 87.07 % (DVM) and 89.09 % (DVE) at an optimal concentration of 10<sup>−3</sup> M. DVE, showing the best performance, was further studied as a function of temperature (298–328 K) and immersion time (up to 24 h). The results revealed that DVE acts as a mixed-type inhibitor with predominant cathodic control and maintains strong protection under aggressive conditions. Thermodynamic analysis indicated spontaneous adsorption following the Langmuir isotherm. Theoretical studies (DFT, DFTB, and ESP mapping) supported strong electronic and steric interactions between DVE and the steel surface. Overall, DVM and DVE are efficient, eco-friendly corrosion inhibitors, with DVE demonstrating superior stability and adsorption strength in acidic media.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"442 ","pages":"Article 129102"},"PeriodicalIF":5.2,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735531","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 incorporation of iron (III) oxide (Fe2O3) on mesoporous aluminosilicate (MAS) derived from Lapindo volcanic mud was successfully achieved by synthesizing MAS via a sol–gel technique, followed by modification with varying amounts of Fe2O3 through a simple wet impregnation method. Incorporating iron (III) oxide on the MAS surface amounted to 5, 10 and 15 wt% by Fe. Comprehensive characterization including XRF, XRD, FTIR, SEM-EDX, HRTEM-SAED, N₂ adsorption–desorption, and FTIR-pyridine confirmed the successful transformation of LM into highly porous MAS and the effective incorporation of Fe2O3. Detailed analysis of the structural, textural, and surface properties of nanocomposites revealed substantial enhancements. XRF analysis revealed a SiO2/Al2O3 ratio of 6.18. XRD and FTIR results confirmed the successful incorporation of Fe2O3 into the MAS matrix, as evidenced by raised peak intensities of Fe2O3. Morphological observations from SEM and HRTEM showed progressive surface coverage of MAS with Fe₂O₃ as the loading increased. Intriguingly, incorporating Fe2O3 on the MAS improves the mesoporosity of nanocomposites. Each of them has a specific surface area of 170.16, 186.38, and 224.97 m2g−1 for the 5, 10, and 15 wt%, respectively. Incorporating Fe2O3 on MAS also improves the amount of acid sites of the nanocomposites. The highest Lewis acid degree is obtained by incorporating 15 wt% of Fe. The amount of Lewis acid sites of 15Fe2O3/MAS closely approaches that of pure Fe2O3, suggesting optimal dispersion of iron (III) oxide species on the MAS surface. These findings highlight the novel synthesis method and the enhanced physicochemical properties of Fe2O3/MAS nanocomposites, presenting potential material for advanced technological applications.
{"title":"Incorporating Iron (III) oxide on mesoporous Aluminosilicate derived from Lapindo mud: Structural, textural, and surface properties","authors":"Qurrota A'yuni , Alfa Akustia Widati , Hartati Hartati , Hikmat Hikmat , Riki Subagyo , Ni'matur Rahmah , Ika Fitri Ulfindrayani , Mohamad Afiq Mohamed Huri","doi":"10.1016/j.molliq.2025.129105","DOIUrl":"10.1016/j.molliq.2025.129105","url":null,"abstract":"<div><div>The incorporation of iron (III) oxide (Fe<sub>2</sub>O<sub>3</sub>) on mesoporous aluminosilicate (MAS) derived from Lapindo volcanic mud was successfully achieved by synthesizing MAS via a sol–gel technique, followed by modification with varying amounts of Fe<sub>2</sub>O<sub>3</sub> through a simple wet impregnation method. Incorporating iron (III) oxide on the MAS surface amounted to 5, 10 and 15 wt% by Fe. Comprehensive characterization including XRF, XRD, FTIR, SEM-EDX, HRTEM-SAED, N₂ adsorption–desorption, and FTIR-pyridine confirmed the successful transformation of LM into highly porous MAS and the effective incorporation of Fe<sub>2</sub>O<sub>3</sub>. Detailed analysis of the structural, textural, and surface properties of nanocomposites revealed substantial enhancements. XRF analysis revealed a SiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> ratio of 6.18. XRD and FTIR results confirmed the successful incorporation of Fe<sub>2</sub>O<sub>3</sub> into the MAS matrix, as evidenced by raised peak intensities of Fe<sub>2</sub>O<sub>3</sub>. Morphological observations from SEM and HRTEM showed progressive surface coverage of MAS with Fe₂O₃ as the loading increased. Intriguingly, incorporating Fe<sub>2</sub>O<sub>3</sub> on the MAS improves the mesoporosity of nanocomposites. Each of them has a specific surface area of 170.16, 186.38, and 224.97 m<sup>2</sup>g<sup>−1</sup> for the 5, 10, and 15 wt%, respectively. Incorporating Fe<sub>2</sub>O<sub>3</sub> on MAS also improves the amount of acid sites of the nanocomposites. The highest Lewis acid degree is obtained by incorporating 15 wt% of Fe. The amount of Lewis acid sites of 15Fe<sub>2</sub>O<sub>3</sub>/MAS closely approaches that of pure Fe<sub>2</sub>O<sub>3</sub>, suggesting optimal dispersion of iron (III) oxide species on the MAS surface. These findings highlight the novel synthesis method and the enhanced physicochemical properties of Fe<sub>2</sub>O<sub>3</sub>/MAS nanocomposites, presenting potential material for advanced technological applications.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"442 ","pages":"Article 129105"},"PeriodicalIF":5.2,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145736000","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 : 2025-12-06DOI: 10.1016/j.molliq.2025.129085
Abraha Gebremeskel Bairu , Xin Huang , Yifu Zhang , Mingyu Chen , Ting Wang , Na Wang , Hongxun Hao
The dissolution behavior of solid compounds plays a crucial role in the design and optimization of crystallization processes. In this work, a comprehensive investigation of the solubility of 2-hydroxynicotinic acid (2-HNA) in pure and binary solvent systems was carried out using experimental gravimetric measurements, thermodynamic modeling, and molecular simulations. Solubility was determined in ten pure solvents (methanol, ethanol, isopropanol, ethyl acetate, n-butyl acetate, acetone, acetonitrile, water, n-butanol, and 2-butanol) and in methanol-ethyl acetate binary mixtures over the temperature range of 293.15–333.15 K. The solubility of 2-HNA increased with rising temperature in all systems, and a synergistic co-solvency effect was observed in the binary mixtures. Four thermodynamic models were employed to correlate the experimental solubility data, among which the modified Apelblat model exhibited the best agreement. Thermodynamic analysis revealed that the dissolution process of 2-HNA in all solvents systems is spontaneous, endothermic, and entropy-dominated. Furthermore, molecular simulations, including Hirshfeld surface (HS) analysis, molecular electrostatic potential (MEP) mapping, radial distribution function (RDF) analysis, and mean square displacement (MSD) calculations, consistently elucidated the molecular basis of solubility. These integrated findings provide a molecular-to-macroscopic understanding that can guide solvent selection and the optimization of crystallization process for 2-HNA.
{"title":"Multiscale investigation of 2-HNA solubility in pure and binary solvent systems: integrating experimental, thermodynamic modeling, and molecular simulation approaches","authors":"Abraha Gebremeskel Bairu , Xin Huang , Yifu Zhang , Mingyu Chen , Ting Wang , Na Wang , Hongxun Hao","doi":"10.1016/j.molliq.2025.129085","DOIUrl":"10.1016/j.molliq.2025.129085","url":null,"abstract":"<div><div>The dissolution behavior of solid compounds plays a crucial role in the design and optimization of crystallization processes. In this work, a comprehensive investigation of the solubility of 2-hydroxynicotinic acid (2-HNA) in pure and binary solvent systems was carried out using experimental gravimetric measurements, thermodynamic modeling, and molecular simulations. Solubility was determined in ten pure solvents (methanol, ethanol, isopropanol, ethyl acetate, n-butyl acetate, acetone, acetonitrile, water, n-butanol, and 2-butanol) and in methanol-ethyl acetate binary mixtures over the temperature range of 293.15–333.15 K. The solubility of 2-HNA increased with rising temperature in all systems, and a synergistic co-solvency effect was observed in the binary mixtures. Four thermodynamic models were employed to correlate the experimental solubility data, among which the modified Apelblat model exhibited the best agreement. Thermodynamic analysis revealed that the dissolution process of 2-HNA in all solvents systems is spontaneous, endothermic, and entropy-dominated. Furthermore, molecular simulations, including Hirshfeld surface (HS) analysis, molecular electrostatic potential (MEP) mapping, radial distribution function (RDF) analysis, and mean square displacement (MSD) calculations, consistently elucidated the molecular basis of solubility. These integrated findings provide a molecular-to-macroscopic understanding that can guide solvent selection and the optimization of crystallization process for 2-HNA.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"442 ","pages":"Article 129085"},"PeriodicalIF":5.2,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735943","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 : 2025-12-06DOI: 10.1016/j.molliq.2025.129104
Abduallah Nabil , Maha M. Khaled , Mohamed A. Ismail , Hesham S. Abdel-Samad , Ayman A. Abdel-Shafi
This study investigates the photophysical properties of two simple structured analogous of push-pull fluorophores in a range of solvents. Both compounds feature a 3-(5-phenylthiophen-2-yl)pyridine π-bridge and a methoxy electron-donating group (MP) and trimethoxy group (TMP) with a cyano electron-withdrawing group in both compounds. The photophysical behavior was characterized using steady-state absorption, fluorescence emission, and time-resolved fluorescence spectroscopy across a range of solvents. Time-dependent density functional theory (TD-DFT) calculations were performed in select solvents, with theoretical results systematically compared to experimental data. Ground-state geometries were found to be non-planar, whereas excited-state geometries adopted a planar conformation. Compound MP exhibited fluorescence emission maxima ranging from 460 nm in cyclohexane (CHX) to 512 nm in water (H₂O), while TMP displayed a bathochromic shift of 7–37 nm, depending on solvent polarity, with the largest shift observed in dimethyl sulfoxide (DMSO). The small bathochromic shift observed in TMP compared to MP in water is attributed to the strong hydrogen bonding interactions in TMP than in MP. The fluorescence quantum yields of MP and TMP were highly solvent-dependent. For MP, the yield approached unity in most solvents, except for water and methanol. In contrast, TMP exhibited a broader range of values, influenced by both solvent acidity and polarity. This combination of a near-unity yield for MP and a tunable yield for TMP makes them ideal reference standards for quantum yield determinations, particularly in nonpolar aprotic solvents. Their strong absorption near 365 nm and broad emission across 400–650 nm further enhance their utility, as this spectral range is uncommon among high-performance standards. Fluorescence decay kinetics followed a mono-exponential trend in all solvents except water, which required a bi-exponential fit. Lifetimes were longer in polar solvents than in non-polar media. Correlations between photophysical properties and solvent polarity (ε) confirmed intramolecular charge transfer (ICT) characteristics in both ground and excited states. Analysis using the solvent polarity parameter () revealed distinct trends for aprotic versus protic solvents. To further elucidate solvent effects, four-parameter linear solvation energy relationships (LSERs) were applied using Catalán and Laurence models.
{"title":"New fluorescence quantum yield standards: Highly fluorescent push-pull chromophores based on 3-(5-Phenylthiophen-2-yl)pyridine derivatives","authors":"Abduallah Nabil , Maha M. Khaled , Mohamed A. Ismail , Hesham S. Abdel-Samad , Ayman A. Abdel-Shafi","doi":"10.1016/j.molliq.2025.129104","DOIUrl":"10.1016/j.molliq.2025.129104","url":null,"abstract":"<div><div>This study investigates the photophysical properties of two simple structured analogous of push-pull fluorophores in a range of solvents. Both compounds feature a 3-(5-phenylthiophen-2-yl)pyridine π-bridge and a methoxy electron-donating group (MP) and trimethoxy group (TMP) with a cyano electron-withdrawing group in both compounds. The photophysical behavior was characterized using steady-state absorption, fluorescence emission, and time-resolved fluorescence spectroscopy across a range of solvents. Time-dependent density functional theory (TD-DFT) calculations were performed in select solvents, with theoretical results systematically compared to experimental data. Ground-state geometries were found to be non-planar, whereas excited-state geometries adopted a planar conformation. Compound MP exhibited fluorescence emission maxima ranging from 460 nm in cyclohexane (CHX) to 512 nm in water (H₂O), while TMP displayed a bathochromic shift of 7–37 nm, depending on solvent polarity, with the largest shift observed in dimethyl sulfoxide (DMSO). The small bathochromic shift observed in TMP compared to MP in water is attributed to the strong hydrogen bonding interactions in TMP than in MP. The fluorescence quantum yields of MP and TMP were highly solvent-dependent. For MP, the yield approached unity in most solvents, except for water and methanol. In contrast, TMP exhibited a broader range of values, influenced by both solvent acidity and polarity. This combination of a near-unity yield for MP and a tunable yield for TMP makes them ideal reference standards for quantum yield determinations, particularly in nonpolar aprotic solvents. Their strong absorption near 365 nm and broad emission across 400–650 nm further enhance their utility, as this spectral range is uncommon among high-performance standards. Fluorescence decay kinetics followed a mono-exponential trend in all solvents except water, which required a bi-exponential fit. Lifetimes were longer in polar solvents than in non-polar media. Correlations between photophysical properties and solvent polarity (ε) confirmed intramolecular charge transfer (ICT) characteristics in both ground and excited states. Analysis using the solvent polarity parameter (<span><math><msubsup><mi>E</mi><mi>T</mi><mi>N</mi></msubsup></math></span>) revealed distinct trends for aprotic versus protic solvents. To further elucidate solvent effects, four-parameter linear solvation energy relationships (LSERs) were applied using Catalán and Laurence models.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"442 ","pages":"Article 129104"},"PeriodicalIF":5.2,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735939","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 curing behavior of epoxy resin/polyurethane (ER/PU)-modified asphalt strongly affects its structural evolution and mechanical performance. However, the interaction between dual crosslinking reactions and network formation is not fully understood, limiting the design of high-performance modified asphalt. To address this gap, we developed a dual-crosslinking model integrating atomic-scale molecular dynamics (MD) simulations with experimental validation to reveal the curing mechanism and performance evolution of ER/PU-modified asphalt. Key molecular parameters were analyzed to characterize network compactness and component compatibility. Results show that ER rapidly forms a dense three-dimensional network, while PU, restricted by slower reaction kinetics, introduces early-stage phase heterogeneity. Molecular analysis indicates that both ER and PU exhibit increasing radius of gyration (Rg) during curing, reflecting enhanced spatial coordination as crosslinking progresses. A marked reduction in diffusion coefficient and solubility parameter (δ) was observed near a critical ER/PU composition, suggesting a transition to a more compact and compatible network structure. Fluorescence microscopy and Fourier transform infrared spectroscopy confirmed the evolution from dispersed microdomains to an interpenetrating polymer network. Simulated viscosities agreed with experimental measurements, and tensile tests validated that higher crosslinking enhances stiffness but induces a ductile-to-brittle transition. These findings show that the dual-crosslinking model effectively captures molecular interactions, structural evolution, and mechanical behavior, providing molecular-level guidance for optimizing strength–toughness balance in ER/PU-modified asphalt.
{"title":"Experimental studies and molecular dynamics simulations on the curing mechanism and performance of epoxy resin/polyurethane dual-crosslinked asphalt system","authors":"Wei Liao, Sheng Li, Haitao Zhang, Yaru Liu, Yu Sun, Miao Wang","doi":"10.1016/j.molliq.2025.129093","DOIUrl":"10.1016/j.molliq.2025.129093","url":null,"abstract":"<div><div>The curing behavior of epoxy resin/polyurethane (ER/PU)-modified asphalt strongly affects its structural evolution and mechanical performance. However, the interaction between dual crosslinking reactions and network formation is not fully understood, limiting the design of high-performance modified asphalt. To address this gap, we developed a dual-crosslinking model integrating atomic-scale molecular dynamics (MD) simulations with experimental validation to reveal the curing mechanism and performance evolution of ER/PU-modified asphalt. Key molecular parameters were analyzed to characterize network compactness and component compatibility. Results show that ER rapidly forms a dense three-dimensional network, while PU, restricted by slower reaction kinetics, introduces early-stage phase heterogeneity. Molecular analysis indicates that both ER and PU exhibit increasing radius of gyration (Rg) during curing, reflecting enhanced spatial coordination as crosslinking progresses. A marked reduction in diffusion coefficient and solubility parameter (δ) was observed near a critical ER/PU composition, suggesting a transition to a more compact and compatible network structure. Fluorescence microscopy and Fourier transform infrared spectroscopy confirmed the evolution from dispersed microdomains to an interpenetrating polymer network. Simulated viscosities agreed with experimental measurements, and tensile tests validated that higher crosslinking enhances stiffness but induces a ductile-to-brittle transition. These findings show that the dual-crosslinking model effectively captures molecular interactions, structural evolution, and mechanical behavior, providing molecular-level guidance for optimizing strength–toughness balance in ER/PU-modified asphalt.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"442 ","pages":"Article 129093"},"PeriodicalIF":5.2,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145736001","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 : 2025-12-05DOI: 10.1016/j.molliq.2025.129080
Omar A. Arrieta-Guerrero, Daniela N. Díaz-Zepeda, H. Mercado-Uribe, José R. Guzmán-Sepúlveda, J.C. Ruiz-Suárez
Cooling water below 0 C under constant volume (isochoric) conditions is experimentally straightforward. However, we found that the dynamic response of the constrained cooled liquid is far from trivial. First, after a slight supercooled state, normal ice (Ih) forms heterogeneously on the walls of the container, causing, as a result of its inherent expansion, a sudden increase in pressure. Second, being a fragile and brittle solid, the formed ice cannot withstand such pressure and breaks into countless fragments of varying sizes, some of them colloidal ones. Third, as it cools further, bulk water enters a second supercooled state, becomes denser, and eventually forms Ice III. The dynamics of these fascinating behaviors were analyzed by conducting joint thermodynamic and optical experiments based on coherent-gated light scattering.
{"title":"Water becomes a supercooled complex fluid below freezing temperatures under isochoric conditions","authors":"Omar A. Arrieta-Guerrero, Daniela N. Díaz-Zepeda, H. Mercado-Uribe, José R. Guzmán-Sepúlveda, J.C. Ruiz-Suárez","doi":"10.1016/j.molliq.2025.129080","DOIUrl":"10.1016/j.molliq.2025.129080","url":null,"abstract":"<div><div>Cooling water below 0 <span><math><msup><mspace></mspace><mrow><mo>∘</mo></mrow></msup></math></span>C under constant volume (isochoric) conditions is experimentally straightforward. However, we found that the dynamic response of the constrained cooled liquid is far from trivial. First, after a slight supercooled state, normal ice (Ih) forms heterogeneously on the walls of the container, causing, as a result of its inherent expansion, a sudden increase in pressure. Second, being a fragile and brittle solid, the formed ice cannot withstand such pressure and breaks into countless fragments of varying sizes, some of them colloidal ones. Third, as it cools further, bulk water enters a second supercooled state, becomes denser, and eventually forms Ice III. The dynamics of these fascinating behaviors were analyzed by conducting joint thermodynamic and optical experiments based on coherent-gated light scattering.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"442 ","pages":"Article 129080"},"PeriodicalIF":5.2,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735992","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 : 2025-12-05DOI: 10.1016/j.molliq.2025.129096
Nikita A. Shekhovtsov, Mark B. Bushuev
The intrinsic photostability of DNA is a unique feature that enables it to dissipate high-energy UV radiation through non-radiative, non-reactive pathways, thereby preserving the integrity of the genetic code and preventing mutations. In this work, we investigate how solvent polarity influences the excited-state relaxation mechanism of the guanine-cytosine Watson-Crick base pair – a fundamental unit of DNA – using non-adiabatic dynamics simulations with ML-MCTDH method. Our results confirm an ultrafast deactivation of initially excited bright states on a timescale of ca. 100 fs across all studied environments, underpinning DNA's general photostability. However, the specific relaxation pathway was found to be highly sensitive to the polarity of the media. In low-polarity media, the exciton population transfers rapidly from the G (ππ*2) state to the guanine-to-cytosine charge transfer (CT) and C (ππ*1) states, facilitating the intermolecular proton transfer due to the excess of electron density on the cytosine moiety. In contrast, in highly polar solvents, relaxation is confined to an internal conversion within the guanine moiety, i.e. from G (ππ*2) to G (ππ*1), shutting down the CT and proton transfer channels. This study elucidates the critical environmental dependence of DNA's photophysical mechanisms, providing key insights for understanding its stability across diverse biological contexts.
{"title":"Solvent-polarity-dependent ultrafast excited state decay in guanine-cytosine base pair: a non-adiabatic dynamics study","authors":"Nikita A. Shekhovtsov, Mark B. Bushuev","doi":"10.1016/j.molliq.2025.129096","DOIUrl":"10.1016/j.molliq.2025.129096","url":null,"abstract":"<div><div>The intrinsic photostability of DNA is a unique feature that enables it to dissipate high-energy UV radiation through non-radiative, non-reactive pathways, thereby preserving the integrity of the genetic code and preventing mutations. In this work, we investigate how solvent polarity influences the excited-state relaxation mechanism of the guanine-cytosine Watson-Crick base pair – a fundamental unit of DNA – using non-adiabatic dynamics simulations with ML-MCTDH method. Our results confirm an ultrafast deactivation of initially excited bright states on a timescale of <em>ca.</em> 100 fs across all studied environments, underpinning DNA's general photostability. However, the specific relaxation pathway was found to be highly sensitive to the polarity of the media. In low-polarity media, the exciton population transfers rapidly from the G (ππ*2) state to the guanine-to-cytosine charge transfer (CT) and C (ππ*1) states, facilitating the intermolecular proton transfer due to the excess of electron density on the cytosine moiety. In contrast, in highly polar solvents, relaxation is confined to an internal conversion within the guanine moiety, <em>i.e.</em> from G (ππ*2) to G (ππ*1), shutting down the CT and proton transfer channels. This study elucidates the critical environmental dependence of DNA's photophysical mechanisms, providing key insights for understanding its stability across diverse biological contexts.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"442 ","pages":"Article 129096"},"PeriodicalIF":5.2,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735534","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 : 2025-12-05DOI: 10.1016/j.molliq.2025.129079
Pham Ngoc Huyen , Nguyen Thi Hai , Dang Van Thanh , Nguyen Quang Tinh , Duc Dung Nguyen , Pham Thi Trang , Vo Thi Hai Le , Nguyen Vu Huyen Ngoc , Cao Thanh Hai , Khieu Thi Tam
Zinc oxide nanoparticles (ZnO NPs) have attracted increasing attention due to their fascinating properties and broad applications in biomedicine and environmental remediation. However, despite significant progress, there is an increasing demand to develop a more efficient, scalable, and environmentally sustainable synthetic approach to fully harness their multifunctional properties. The objective of study was to develop enviromentally benign ZnO NPs and evaluate their antibacterial, antioxidant, and photocatalytic activities. In this study, a one-pot green synthesis approach was developed using Elsholtzia citilia extract to synthesize ZnO NPs with potent antibacterial, antioxidant, and photocatalytic activities. The Elsholtzia citilia mediated synthesized ZnO (EC-ZnO) NPs were characterized using UV–Vis DRS, FT-IR, XRD, SEM, TEM, and BET analyses to confirm their optical, structural, morphological properites. The EC-ZnO NPs possessed a hexagonal wurtzite crystal structure, spherical morphology with an average particle size of 9.18 ± 0.23 nm, and a band gap of 3.14 eV. Bioactive studies demonstrated that EC-ZnO NPs showed notable antioxidant activity, achieving 66.68 ± 2.28 % 2,2-diphenyl-1-picrylhydrazyl radical scavenging at a concentration of 100 μg/mL. Moreover, the NPs exhibited strong antibacterial activities against E. coli, P. aeruginosa, K. pneumoniae, and S. aureus with minimum inhibitory concentration values ranging from 10.42 to 20.83 μg/mL. Photocatalytic studies revealed efficient degradation of reactive red 120 (RR120) dye under visible light irradiation, and potential degradation pathways were also investigated. These findings show the promising use of the plant-mediated ZnO NPs as a multifunctional agent for biomedical and environmental applications.
{"title":"Photocatalytic, antibacterial, and antioxidant properties of green synthesized EC-ZnO nanoparticles from Elsholtzia ciliata leaf extract","authors":"Pham Ngoc Huyen , Nguyen Thi Hai , Dang Van Thanh , Nguyen Quang Tinh , Duc Dung Nguyen , Pham Thi Trang , Vo Thi Hai Le , Nguyen Vu Huyen Ngoc , Cao Thanh Hai , Khieu Thi Tam","doi":"10.1016/j.molliq.2025.129079","DOIUrl":"10.1016/j.molliq.2025.129079","url":null,"abstract":"<div><div>Zinc oxide nanoparticles (ZnO NPs) have attracted increasing attention due to their fascinating properties and broad applications in biomedicine and environmental remediation. However, despite significant progress, there is an increasing demand to develop a more efficient, scalable, and environmentally sustainable synthetic approach to fully harness their multifunctional properties. The objective of study was to develop enviromentally benign ZnO NPs and evaluate their antibacterial, antioxidant, and photocatalytic activities. In this study, a one-pot green synthesis approach was developed using <em>Elsholtzia citilia</em> extract to synthesize ZnO NPs with potent antibacterial, antioxidant, and photocatalytic activities. The <em>Elsholtzia citilia</em> mediated synthesized ZnO (EC-ZnO) NPs were characterized using UV–Vis DRS, FT-IR, XRD, SEM, TEM, and BET analyses to confirm their optical, structural, morphological properites. The EC-ZnO NPs possessed a hexagonal wurtzite crystal structure, spherical morphology with an average particle size of 9.18 ± 0.23 nm, and a band gap of 3.14 eV. Bioactive studies demonstrated that EC-ZnO NPs showed notable antioxidant activity, achieving 66.68 ± 2.28 % 2,2-diphenyl-1-picrylhydrazyl radical scavenging at a concentration of 100 μg/mL. Moreover, the NPs exhibited strong antibacterial activities against <em>E. coli</em>, <em>P. aeruginosa</em>, <em>K. pneumoniae</em>, and <em>S. aureus</em> with minimum inhibitory concentration values ranging from 10.42 to 20.83 μg/mL. Photocatalytic studies revealed efficient degradation of reactive red 120 (RR120) dye under visible light irradiation, and potential degradation pathways were also investigated. These findings show the promising use of the plant-mediated ZnO NPs as a multifunctional agent for biomedical and environmental applications.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"441 ","pages":"Article 129079"},"PeriodicalIF":5.2,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145691811","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 : 2025-12-05DOI: 10.1016/j.molliq.2025.129098
Shulin Li , Xiaoli Ji , Di Sun , Na Zhang , Xia Xin , Xingwei Luo
Metal nanoclusters (NCs), particularly those with atomic precision, exhibit distinct photonic and electrical characteristics, excellent catalysis, and favorable biological safety, rendering them a compelling candidate for diverse optoelectronics and biomedical applications. Silver nanoclusters (Ag NCs) exhibit promising optical properties but suffer from solid-state quenching due to uncontrolled aggregation. Herein, we report a supramolecular assembly strategy to overcome this limitation using water-soluble, pseudo-chiral (NH4)9 [Ag9 (mba)9] nanoclusters (Ag9 NCs, where H2mba = 2-mercaptobenzoic acid) as building blocks. Through controlled introduction of Ca2+ ions, we successfully achieve the hierarchical chiral self-assembly of Ag9 NCs into precisely organized helical architectures. Ca2+-mediated assembly forms a rigid fibrous network that effectively suppresses non-radiative decay pathways by restricting intramolecular motion (RIM) of the mba ligands, which induce aggregation-induced emission (AIE). This precise structural control leads to yielding a 240 nm Stokes shift, 380-fold lifetime elongation (1248.11 ns), and phosphorescence emission. Furthermore, the asymmetric coordination environment created by Ca2+ induces supramolecular chirality. In addition, the assembly exhibits sensitive temperature responsiveness (113–293 K), providing the possibility for the development of new temperature sensors. This study opens up new avenues for breaking through the bottleneck of solid-state luminescence of silver clusters and constructing multifunctional nano-assembly materials.
{"title":"Ca2+-induced assembly of silver nanoclusters towards multifunctional aggregation-induced emission materials with supramolecular chirality and thermoresponsive fluorescence","authors":"Shulin Li , Xiaoli Ji , Di Sun , Na Zhang , Xia Xin , Xingwei Luo","doi":"10.1016/j.molliq.2025.129098","DOIUrl":"10.1016/j.molliq.2025.129098","url":null,"abstract":"<div><div>Metal nanoclusters (NCs), particularly those with atomic precision, exhibit distinct photonic and electrical characteristics, excellent catalysis, and favorable biological safety, rendering them a compelling candidate for diverse optoelectronics and biomedical applications. Silver nanoclusters (Ag NCs) exhibit promising optical properties but suffer from solid-state quenching due to uncontrolled aggregation. Herein, we report a supramolecular assembly strategy to overcome this limitation using water-soluble, pseudo-chiral (NH<sub>4</sub>)<sub>9</sub> [Ag<sub>9</sub> (mba)<sub>9</sub>] nanoclusters (Ag<sub>9</sub> NCs, where H<sub>2</sub>mba = 2-mercaptobenzoic acid) as building blocks. Through controlled introduction of Ca<sup>2+</sup> ions, we successfully achieve the hierarchical chiral self-assembly of Ag<sub>9</sub> NCs into precisely organized helical architectures. Ca<sup>2+</sup>-mediated assembly forms a rigid fibrous network that effectively suppresses non-radiative decay pathways by restricting intramolecular motion (RIM) of the mba ligands, which induce aggregation-induced emission (AIE). This precise structural control leads to yielding a 240 nm Stokes shift, 380-fold lifetime elongation (1248.11 ns), and phosphorescence emission. Furthermore, the asymmetric coordination environment created by Ca<sup>2+</sup> induces supramolecular chirality. In addition, the assembly exhibits sensitive temperature responsiveness (113–293 K), providing the possibility for the development of new temperature sensors. This study opens up new avenues for breaking through the bottleneck of solid-state luminescence of silver clusters and constructing multifunctional nano-assembly materials.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"442 ","pages":"Article 129098"},"PeriodicalIF":5.2,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735945","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}
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