Pub Date : 2026-02-03DOI: 10.1021/acs.langmuir.5c05586
Song Xu,Kangli Xiao,Lei Fang,Xiangjie Niu,Qiang Yuan,Ju Lin,Xiaojuan Jia
The ultraviolet-induced aging of cement-emulsified asphalt (CA) mortar in slab ballastless tracks progressively degrades its dynamic mechanical properties, compromising both ride comfort and operational safety. In order to investigate the ultraviolet (UV) aging of CA mortar, the changes in asphalt components and the degradation patterns of its dynamic mechanical properties were analyzed. Moreover, the linear rheological solid model with a fractional derivative, which accurately reflects the viscoelastic properties of CA mortar, was established to evaluate its UV aging degree. Results showed that CA mortar with an asphalt/cement (A/C) ratio of 0.9 exhibited greater aging sensitivity than that with a ratio of 0.3, with 33% higher increases in asphaltenes, 47% higher increases in dynamic modulus, and the peak loss factor also exhibited a greater decrease after 48 days of UV exposure. Cement enhances the UV-aging resistance of CA mortar by physically shielding asphalt through hydration products and by strengthening cement–asphalt interfacial adhesion at lower A/C ratios, which helps limit light fractions migration and volatilization. The linear rheological solid model demonstrated great fitting accuracy for the dynamic mechanical properties of CA mortar under UV aging, with the fractional order (α) serving as a reliable metric for quantifying the degree of aging.
{"title":"Assessment of Degradation in Dynamic Mechanical Properties and Aging Degree of Cement Emulsified Asphalt Mortar under Ultraviolet Aging","authors":"Song Xu,Kangli Xiao,Lei Fang,Xiangjie Niu,Qiang Yuan,Ju Lin,Xiaojuan Jia","doi":"10.1021/acs.langmuir.5c05586","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c05586","url":null,"abstract":"The ultraviolet-induced aging of cement-emulsified asphalt (CA) mortar in slab ballastless tracks progressively degrades its dynamic mechanical properties, compromising both ride comfort and operational safety. In order to investigate the ultraviolet (UV) aging of CA mortar, the changes in asphalt components and the degradation patterns of its dynamic mechanical properties were analyzed. Moreover, the linear rheological solid model with a fractional derivative, which accurately reflects the viscoelastic properties of CA mortar, was established to evaluate its UV aging degree. Results showed that CA mortar with an asphalt/cement (A/C) ratio of 0.9 exhibited greater aging sensitivity than that with a ratio of 0.3, with 33% higher increases in asphaltenes, 47% higher increases in dynamic modulus, and the peak loss factor also exhibited a greater decrease after 48 days of UV exposure. Cement enhances the UV-aging resistance of CA mortar by physically shielding asphalt through hydration products and by strengthening cement–asphalt interfacial adhesion at lower A/C ratios, which helps limit light fractions migration and volatilization. The linear rheological solid model demonstrated great fitting accuracy for the dynamic mechanical properties of CA mortar under UV aging, with the fractional order (α) serving as a reliable metric for quantifying the degree of aging.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"41 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146111285","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}
Achieving reliable hydrogen sensing at room temperature remains a critical challenge due to the limited carrier transport and unstable surface chemistry of conventional polycrystalline oxides. Here, we demonstrate that precise growth-mode control of epitaxial anatase TiO2 thin films via sputtering atmosphere engineering provides an effective route to overcoming these limitations. By systematically tuning the Ar/O2 ratio, the TiO2 growth mode transitions from a defective island-like mode to a layer-by-layer mode and finally to a stress-induced island. The film deposited at an 8/1 Ar/O2 ratio achieves an ideal combination of perfect crystallinity, an atomically flat surface, and a balanced oxygen vacancy concentration, yielding a clean and well-defined Pd-TiO2 interface upon catalyst deposition. The resulting Pd/TiO2 sensor exhibits exceptional room-temperature hydrogen sensing performance: a strong response of 11.34 to 100 ppm of H2, a low detection limit (5 ppm), excellent selectivity over other battery abuse gases, remarkable humidity resistance, and long-term stability. Comprehensive structural and mechanistic analyses reveal that the superior performance originates from an efficient interface-dominated sensing mechanism, rather than the conventional surface reaction pathway. This work establishes a “structure over stoichiometry” paradigm for developing advanced gas sensors and provides an effective route toward high-reliability, low-power hydrogen safety monitoring.
{"title":"Growth-Mode Engineering of Epitaxial TiO2 Thin Films for Room-Temperature Hydrogen Sensing and Battery Safety","authors":"Yuanyuan Fu,Hanwen Chi,Ni Tu,Jianing Mao,Juncheng Li,Zhizhen Ye,Liping Zhu,Jie Jiang","doi":"10.1021/acs.langmuir.5c06387","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c06387","url":null,"abstract":"Achieving reliable hydrogen sensing at room temperature remains a critical challenge due to the limited carrier transport and unstable surface chemistry of conventional polycrystalline oxides. Here, we demonstrate that precise growth-mode control of epitaxial anatase TiO2 thin films via sputtering atmosphere engineering provides an effective route to overcoming these limitations. By systematically tuning the Ar/O2 ratio, the TiO2 growth mode transitions from a defective island-like mode to a layer-by-layer mode and finally to a stress-induced island. The film deposited at an 8/1 Ar/O2 ratio achieves an ideal combination of perfect crystallinity, an atomically flat surface, and a balanced oxygen vacancy concentration, yielding a clean and well-defined Pd-TiO2 interface upon catalyst deposition. The resulting Pd/TiO2 sensor exhibits exceptional room-temperature hydrogen sensing performance: a strong response of 11.34 to 100 ppm of H2, a low detection limit (5 ppm), excellent selectivity over other battery abuse gases, remarkable humidity resistance, and long-term stability. Comprehensive structural and mechanistic analyses reveal that the superior performance originates from an efficient interface-dominated sensing mechanism, rather than the conventional surface reaction pathway. This work establishes a “structure over stoichiometry” paradigm for developing advanced gas sensors and provides an effective route toward high-reliability, low-power hydrogen safety monitoring.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"58 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146111099","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 : 2026-02-03DOI: 10.1021/acs.langmuir.5c05952
Chong Li,Jie Chen,Jian Zheng,Baojiang Liu,Chunyan Hu
Photothermal materials possess efficient light absorption and light-to-energy conversion capabilities, and have been widely applied in research on seawater desalination and sewage treatment. However, traditional solar desalination faces challenges such as poor salt resistance, low photothermal conversion efficiency, and the inability to effectively remove wastewater discharged from seawater. In this study, we designed a self-floating solar evaporator with a vertically arranged and porous structure. By employing a simple “impregnation-crosslinking-reduction” method, we induced cross-linking in balsa wood/MXene/MnO2 (MMW). Among them, MXene exhibits exceptionally Superior efficiency in photothermal energy conversion and is widely applied as a photothermal material in the field of seawater desalination. Meanwhile, MnO2 nanoflowers, rich in oxygen vacancies, can effectively activate peroxydisulfate (PDS), demonstrating efficient catalytic performance. Within the evaporator, they spontaneously establish a wet, porous internal structure and specialized water pathways. Under such conditions, The system demonstrates a maximum evaporation capacity of 1.90 kg m–2 h–1, along with an evaporation efficiency of 113.4%. Moreover, the evaporator demonstrates high degradation rates(94.09% for 50 mg L–1 methylene blue and 95.31% for 100 mg L–1 Rhodamine 6G). In addition, this evaporator enables salt to be expelled from its interior to the surface via convection,which can acquire freshwater efficiently and sustainably. Furthermore, we used the purified water collected from evaporation to irrigate mung beans, which were able to germinate and grow normally. This work provides a direction for the application of evaporators and offers an alternative approach to addressing water scarcity and enhancing water utilization.
光热材料具有高效的光吸收和光能转换能力，在海水淡化和污水处理研究中得到了广泛的应用。然而，传统的太阳能脱盐面临着耐盐性差、光热转换效率低、无法有效去除海水排放废水等挑战。在本研究中，我们设计了一种垂直排列多孔结构的自漂浮式太阳能蒸发器。通过简单的“浸渍-交联-还原”方法，我们诱导了轻木/MXene/MnO2 （MMW）的交联。其中，MXene在光热能量转换方面表现出异常优异的效率，作为光热材料广泛应用于海水淡化领域。同时，MnO2纳米花富含氧空位，能有效活化过硫酸氢盐（PDS），表现出高效的催化性能。在蒸发器内部，它们自发地建立了一个潮湿的、多孔的内部结构和专门的水通道。在此条件下，系统的最大蒸发量为1.90 kg m-2 h-1，蒸发效率为113.4%。此外，蒸发器具有较高的降解率（对50 mg L-1亚甲基蓝的降解率为94.09%，对100 mg L-1罗丹明的降解率为95.31%）。此外，蒸发器使盐通过对流从其内部排出到表面，可以有效和可持续地获取淡水。此外，我们使用蒸发收集的纯化水来灌溉绿豆，绿豆能够正常发芽和生长。本研究为蒸发器的应用提供了方向，为解决水资源短缺和提高水资源利用率提供了另一种途径。
{"title":"A Self-Floating Balsa Wood Solar Evaporator: Simultaneously Achieving Seawater Desalination and Catalytic Degradation","authors":"Chong Li,Jie Chen,Jian Zheng,Baojiang Liu,Chunyan Hu","doi":"10.1021/acs.langmuir.5c05952","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c05952","url":null,"abstract":"Photothermal materials possess efficient light absorption and light-to-energy conversion capabilities, and have been widely applied in research on seawater desalination and sewage treatment. However, traditional solar desalination faces challenges such as poor salt resistance, low photothermal conversion efficiency, and the inability to effectively remove wastewater discharged from seawater. In this study, we designed a self-floating solar evaporator with a vertically arranged and porous structure. By employing a simple “impregnation-crosslinking-reduction” method, we induced cross-linking in balsa wood/MXene/MnO2 (MMW). Among them, MXene exhibits exceptionally Superior efficiency in photothermal energy conversion and is widely applied as a photothermal material in the field of seawater desalination. Meanwhile, MnO2 nanoflowers, rich in oxygen vacancies, can effectively activate peroxydisulfate (PDS), demonstrating efficient catalytic performance. Within the evaporator, they spontaneously establish a wet, porous internal structure and specialized water pathways. Under such conditions, The system demonstrates a maximum evaporation capacity of 1.90 kg m–2 h–1, along with an evaporation efficiency of 113.4%. Moreover, the evaporator demonstrates high degradation rates(94.09% for 50 mg L–1 methylene blue and 95.31% for 100 mg L–1 Rhodamine 6G). In addition, this evaporator enables salt to be expelled from its interior to the surface via convection,which can acquire freshwater efficiently and sustainably. Furthermore, we used the purified water collected from evaporation to irrigate mung beans, which were able to germinate and grow normally. This work provides a direction for the application of evaporators and offers an alternative approach to addressing water scarcity and enhancing water utilization.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"88 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146111103","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}
Layered double hydroxides (LDH), characterized by a unique layered structure with exchangeable interlayer anions, are an important class of inorganic functional materials. Their tunable composition and structure make them promising candidates as lubrication additives. However, LDH are limited in their long-term dispersibility and stability, and their compatibility with industrial lubrication mixtures has yet to be fully investigated, so their application in lubrication remains a major difficulty. This study involved the intercalation modification of LDH by alkyl alcohol amine phosphate ionic liquids (PIL) to ensure their stable distribution in water. The results showed that the use of ionic liquid intercalated double hydroxide (PIL-LDH) as an aqueous lubricant additive could significantly reduce friction and wear resistance and even reduce peak wear by 99.7%. PIL-LDH achieves self-lubrication and self-healing through interlayer slip and PIL release combined with chemisorbed and physically deposited layers.
{"title":"Ionic Liquid Functionalized Layered Double Hydroxides Achieve Near-Zero Wear on Steel–Steel Contacts","authors":"Zhengkun Yao,Ru Liu,Zekun Kang,Huanchen Liu,Qingyu Li,Xia Zhang","doi":"10.1021/acs.langmuir.5c05736","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c05736","url":null,"abstract":"Layered double hydroxides (LDH), characterized by a unique layered structure with exchangeable interlayer anions, are an important class of inorganic functional materials. Their tunable composition and structure make them promising candidates as lubrication additives. However, LDH are limited in their long-term dispersibility and stability, and their compatibility with industrial lubrication mixtures has yet to be fully investigated, so their application in lubrication remains a major difficulty. This study involved the intercalation modification of LDH by alkyl alcohol amine phosphate ionic liquids (PIL) to ensure their stable distribution in water. The results showed that the use of ionic liquid intercalated double hydroxide (PIL-LDH) as an aqueous lubricant additive could significantly reduce friction and wear resistance and even reduce peak wear by 99.7%. PIL-LDH achieves self-lubrication and self-healing through interlayer slip and PIL release combined with chemisorbed and physically deposited layers.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"58 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146097831","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 : 2026-02-02DOI: 10.1021/acs.langmuir.5c06495
Die Ran,Cuiping Mao,Guanghui Zhu,Hongdan Zhang
Metal–organic frameworks (MOFs) and their composites have demonstrated efficient and selective capture of heavy metal ions from aqueous solutions. In this study, a novel AL@Fe-BTC (lignin in situ growth of iron-based metal–organic framework Fe-BTC) was prepared by a one-pot method to grow Fe-BTC (metal–organic framework) in situ with lignin as the main body. The resulting composite with a lignin-to-ligand ratio of 3:1 exhibited excellent adsorption capacity for Pb(II). Then the optimal adsorption conditions of AL@Fe-BTC were determined as follows: pH of 6.0, initial metal ion concentration of 400 mg/L, adsorbent dosage of 0.4 g/L, and adsorption time of 360 min, resulting in an equilibrium adsorption capacity of 144.1 mg/g Pb(II). Kinetic and isothermal models revealed that the adsorption process follows the pseudo-second-order kinetic model and conforms well to the Freundlich isotherm model. The adsorption thermodynamics showed that the adsorption of Pb(II) by AL@Fe-BTC was a feasible spontaneous heat-adsorbing process. In the presence of coexisting metal ions and interfering ions (K+, Ca2+, and Na+), AL@Fe-BTC also presented highly efficient and selective capture for Pb(II). Furthermore, AL@Fe-BTC also exhibited positive reusability with an adsorption capacity of Pb(II) after four cycles. The adsorption mechanism of Pb(II) involved the chelation interaction of Pb–O and ion-exchange interaction. This research focuses on the application of composites obtained by in situ growth of the MOF material Fe-BTC on lignin in heavy metal-contaminated wastewater, which provides a method for the preparation of green and simple biobased materials for the removal of heavy metals.
{"title":"Highly Efficient and Selective Capture of Pb(II) through Lignin-Decorated Metal Organic Frameworks","authors":"Die Ran,Cuiping Mao,Guanghui Zhu,Hongdan Zhang","doi":"10.1021/acs.langmuir.5c06495","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c06495","url":null,"abstract":"Metal–organic frameworks (MOFs) and their composites have demonstrated efficient and selective capture of heavy metal ions from aqueous solutions. In this study, a novel AL@Fe-BTC (lignin in situ growth of iron-based metal–organic framework Fe-BTC) was prepared by a one-pot method to grow Fe-BTC (metal–organic framework) in situ with lignin as the main body. The resulting composite with a lignin-to-ligand ratio of 3:1 exhibited excellent adsorption capacity for Pb(II). Then the optimal adsorption conditions of AL@Fe-BTC were determined as follows: pH of 6.0, initial metal ion concentration of 400 mg/L, adsorbent dosage of 0.4 g/L, and adsorption time of 360 min, resulting in an equilibrium adsorption capacity of 144.1 mg/g Pb(II). Kinetic and isothermal models revealed that the adsorption process follows the pseudo-second-order kinetic model and conforms well to the Freundlich isotherm model. The adsorption thermodynamics showed that the adsorption of Pb(II) by AL@Fe-BTC was a feasible spontaneous heat-adsorbing process. In the presence of coexisting metal ions and interfering ions (K+, Ca2+, and Na+), AL@Fe-BTC also presented highly efficient and selective capture for Pb(II). Furthermore, AL@Fe-BTC also exhibited positive reusability with an adsorption capacity of Pb(II) after four cycles. The adsorption mechanism of Pb(II) involved the chelation interaction of Pb–O and ion-exchange interaction. This research focuses on the application of composites obtained by in situ growth of the MOF material Fe-BTC on lignin in heavy metal-contaminated wastewater, which provides a method for the preparation of green and simple biobased materials for the removal of heavy metals.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"8 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098095","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 role of interfacial water interactions with photocatalyst surfaces is a critical yet elusive aspect of photocatalysis. In this work, we uncover how temperature-driven structural evolution in carbon nitride controls water–surface interactions and, in turn, photocatalytic activity. A series of carbon nitride (CN-x) photocatalysts were prepared by thermal polycondensation of melamine at 450–650 °C to elucidate the effect of calcination temperature on their structure and photocatalytic behavior. Systematic characterization (FTIR, XRD, XPS, SEM, UV–vis DRS, N2 sorption, and 1H NMR relaxation) revealed progressive polymerization and structural ordering with increasing temperature, accompanied by an enlarged pore size and narrowed band gap. The photocatalytic degradation of Congo Red (CR) displayed a distinct valley-shaped trend with temperature, with CN-450 showing the highest activity despite its relatively low surface area. Using NMR relaxation measurements, we establish a direct correlation between the T1/T2 ratio of adsorbed water and photocatalytic activity, revealing that an optimal water–surface interaction facilitates the generation of reactive oxygen species. Density functional theory (DFT) calculations confirmed that temperature-dependent structural evolution modulates the surface polarity and water adsorption energy, corroborating experimental findings. These results highlight the pivotal role of surface hydrophilicity in photocatalytic processes and demonstrate the value of NMR relaxation as an effective probe for understanding interfacial dynamics and guiding the rational design of photocatalysts.
{"title":"NMR Relaxation Unveils the Promoting Effect of Surface–Water Interactions on Photocatalytic Degradation over Carbon Nitride in Aqueous Solutions","authors":"Jiaye Shao,Heng Liu,Boyu Chen,Lan An,Carmine D’Agostino","doi":"10.1021/acs.langmuir.5c06245","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c06245","url":null,"abstract":"The role of interfacial water interactions with photocatalyst surfaces is a critical yet elusive aspect of photocatalysis. In this work, we uncover how temperature-driven structural evolution in carbon nitride controls water–surface interactions and, in turn, photocatalytic activity. A series of carbon nitride (CN-x) photocatalysts were prepared by thermal polycondensation of melamine at 450–650 °C to elucidate the effect of calcination temperature on their structure and photocatalytic behavior. Systematic characterization (FTIR, XRD, XPS, SEM, UV–vis DRS, N2 sorption, and 1H NMR relaxation) revealed progressive polymerization and structural ordering with increasing temperature, accompanied by an enlarged pore size and narrowed band gap. The photocatalytic degradation of Congo Red (CR) displayed a distinct valley-shaped trend with temperature, with CN-450 showing the highest activity despite its relatively low surface area. Using NMR relaxation measurements, we establish a direct correlation between the T1/T2 ratio of adsorbed water and photocatalytic activity, revealing that an optimal water–surface interaction facilitates the generation of reactive oxygen species. Density functional theory (DFT) calculations confirmed that temperature-dependent structural evolution modulates the surface polarity and water adsorption energy, corroborating experimental findings. These results highlight the pivotal role of surface hydrophilicity in photocatalytic processes and demonstrate the value of NMR relaxation as an effective probe for understanding interfacial dynamics and guiding the rational design of photocatalysts.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"145 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098098","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}
Differences in the physicochemical properties of titanium (Ti) and steel lead to complexity during solid-state bonding. In particular, the effect of carbon (C) in steel on elemental diffusion and interfacial reactions is still insufficiently understood. This study analyzed the interfacial morphology and the diffusion and reaction behavior of Ti, iron (Fe), and C diffusion-bonded couples, using commercial pure titanium (TA2) Ti and steels with different C contents (20#, 45#, and 85#) by diffusion bonding at 710, 870, and 960 °C, respectively. A continuous C-enriched layer formed on the Ti side of the interfaces, comprising nano- to sub-micrometer-scale face-centered cubic TiC grains, with the grain size increasing with the increasing distance from the interface. No Ti–Fe intermetallic was detected. The thickness of the C-enriched (TiC) layer increased with the increasing temperature and C content of steel, exceeding 2.5 μm in the TA2–85# joint bonded at 960 °C. During bonding, C atoms exhibited a faster diffusion rate and a stronger tendency to react with Ti, which led to preferential TiC formation at the Ti-side interface. Although Fe atoms also diffused toward the Ti side, the strong Ti–C reaction reduced the probability of Ti–Fe, and Fe was therefore mainly distributed along TiC grain boundaries. Ti atoms diffused more slowly and preferentially reacted with C, which prevented the formation of Ti-rich phases near the steel side. The activation energy of the Ti + C → TiC interfacial reaction decreased with increasing C content of steel. These findings address the research gap related to C diffusion in Ti-steel heterostructures and provide a scientific basis for controlling the detrimental diffusion of C during the fabrication.
{"title":"Effect of Carbon Content on Titanium–Carbon Steel Heterostructure Interfacial Elemental Diffusion and Chemical Reaction","authors":"Sheng Zeng,Guoqiang You,Ruimin Huang,Min Hu,Cheng Gu,Bin Jiang","doi":"10.1021/acs.langmuir.5c06230","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c06230","url":null,"abstract":"Differences in the physicochemical properties of titanium (Ti) and steel lead to complexity during solid-state bonding. In particular, the effect of carbon (C) in steel on elemental diffusion and interfacial reactions is still insufficiently understood. This study analyzed the interfacial morphology and the diffusion and reaction behavior of Ti, iron (Fe), and C diffusion-bonded couples, using commercial pure titanium (TA2) Ti and steels with different C contents (20#, 45#, and 85#) by diffusion bonding at 710, 870, and 960 °C, respectively. A continuous C-enriched layer formed on the Ti side of the interfaces, comprising nano- to sub-micrometer-scale face-centered cubic TiC grains, with the grain size increasing with the increasing distance from the interface. No Ti–Fe intermetallic was detected. The thickness of the C-enriched (TiC) layer increased with the increasing temperature and C content of steel, exceeding 2.5 μm in the TA2–85# joint bonded at 960 °C. During bonding, C atoms exhibited a faster diffusion rate and a stronger tendency to react with Ti, which led to preferential TiC formation at the Ti-side interface. Although Fe atoms also diffused toward the Ti side, the strong Ti–C reaction reduced the probability of Ti–Fe, and Fe was therefore mainly distributed along TiC grain boundaries. Ti atoms diffused more slowly and preferentially reacted with C, which prevented the formation of Ti-rich phases near the steel side. The activation energy of the Ti + C → TiC interfacial reaction decreased with increasing C content of steel. These findings address the research gap related to C diffusion in Ti-steel heterostructures and provide a scientific basis for controlling the detrimental diffusion of C during the fabrication.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"80 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098099","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 : 2026-02-02DOI: 10.1021/acs.langmuir.5c05868
Jin Zhang,Jianhua Huang
Polymer conformation and dynamics are strongly influenced by the topology and chain rigidity. Understanding how these structural parameters influence the behavior of substrate-supported polymer films is of fundamental importance. Here, molecular dynamics simulations are performed to investigate semi-flexible linear and ring polymer films supported on attractive substrates, with a focus on comparing the effects of chain rigidity (kθ) on their adsorption, conformation, and diffusion. Simulation results show that the adsorption properties of ring polymers and the substrate’s suppression on their diffusion are weakly dependent on kθ. While the adsorbed linear polymers change from random adsorption at low kθ to fully adsorbed with localized ordered structure at high kθ. The diffusion of linear polymers is strongly dependent on kθ. At low kθ, nonadsorbed linear polymers show a reduced diffusion in the substrate region due to the interaction with adsorbed polymers; in contrast, their diffusion is accelerated at high kθ resulting from the formation of a dense adsorption layer, which screens the substrate’s attraction. However, nonadsorbed ring polymers consistently exhibit reduced diffusion in the substrate region, with stronger dynamic suppression compared to linear polymers. Conversely, the substrate’s influence propagates over a longer range in linear polymer films than in ring polymer films.
{"title":"Comparative Study of Adsorption, Conformations, and Dynamics of Semi-Flexible Linear and Ring Polymers in Substrate-Supported Films","authors":"Jin Zhang,Jianhua Huang","doi":"10.1021/acs.langmuir.5c05868","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c05868","url":null,"abstract":"Polymer conformation and dynamics are strongly influenced by the topology and chain rigidity. Understanding how these structural parameters influence the behavior of substrate-supported polymer films is of fundamental importance. Here, molecular dynamics simulations are performed to investigate semi-flexible linear and ring polymer films supported on attractive substrates, with a focus on comparing the effects of chain rigidity (kθ) on their adsorption, conformation, and diffusion. Simulation results show that the adsorption properties of ring polymers and the substrate’s suppression on their diffusion are weakly dependent on kθ. While the adsorbed linear polymers change from random adsorption at low kθ to fully adsorbed with localized ordered structure at high kθ. The diffusion of linear polymers is strongly dependent on kθ. At low kθ, nonadsorbed linear polymers show a reduced diffusion in the substrate region due to the interaction with adsorbed polymers; in contrast, their diffusion is accelerated at high kθ resulting from the formation of a dense adsorption layer, which screens the substrate’s attraction. However, nonadsorbed ring polymers consistently exhibit reduced diffusion in the substrate region, with stronger dynamic suppression compared to linear polymers. Conversely, the substrate’s influence propagates over a longer range in linear polymer films than in ring polymer films.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"42 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098102","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}
Although high-performance protective coatings have been realized, the impact of self-assembled arrays or superstructures obtained from copolymers on surface and interfacial properties remains poorly understood. Thus, a detailed investigation of assembled micelle-surface/interface properties is needed. Herein, we report a copolymer-based micelle-induced self-assembled film-forming mechanism for fabricating high-performance protective coatings. Diblock copolymers of polydimethylsiloxane-block-poly(glycidyl methacrylate) (PDMS-b-PGMA) were synthesized using the atom transfer radical polymerization method. The macromonomer (bromine-functionalized PDMS) initiated GMA polymerization. The copolymer formed PGMA-core-PDMS-shell nanowires (up to a micrometer in length) through a typical time-dependent shape evolution from spherical micelles in chloroform (CHCl3). Uniform spherical micelles with a PDMS core and PGMA shell were detected in acetone, while irregular micelles with a PGMA-core and PDMS-shell were detected in dioxane and N,N-dimethylformamide, indicating the critical dictating role of the solvent in the self-assembled pattern. The assembled nanowires of PDMS-b-PGMA in CHCl3 were stable, regardless of the PGMA block length and concentration. The CHCl3-derived nanowire-based coating exhibited better hydrophobic properties and adhesive strength than the acetone-derived spherical micelle-based coating. Thus, we propose a micelle-induced self-assembled film-forming mechanism by regulating the migration and arrangement of PDMS and the solvent evaporation rate. Nanowires comprising PDMS shells exhibited greater curvature, which is highly conducive to the PDMS group migrating to the surface during the film-forming process. The PDMS-b-PGMA micelle-induced coating effectively improved hydrophobicity for protecting sandstones. This study provides a solution by regulating micelle-induced self-assembled film formation for fabricating high-performance protective coatings with wide application prospects.
{"title":"Fabrication of Polydimethylsiloxane-Based Nanowire-Shaped Micelles as a Highly Hydrophobic and Adhesive Coating for Protecting Sandstone Cultural Relics.","authors":"Shengying Huang, Xiaoqin Ma, Hengjian Mou, Heqiang Niu, Chengyu Shi, Ling He, Aizhao Pan","doi":"10.1021/acs.langmuir.5c05742","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c05742","url":null,"abstract":"<p><p>Although high-performance protective coatings have been realized, the impact of self-assembled arrays or superstructures obtained from copolymers on surface and interfacial properties remains poorly understood. Thus, a detailed investigation of assembled micelle-surface/interface properties is needed. Herein, we report a copolymer-based micelle-induced self-assembled film-forming mechanism for fabricating high-performance protective coatings. Diblock copolymers of polydimethylsiloxane-<i>block</i>-poly(glycidyl methacrylate) (PDMS-<i>b</i>-PGMA) were synthesized using the atom transfer radical polymerization method. The macromonomer (bromine-functionalized PDMS) initiated GMA polymerization. The copolymer formed PGMA-core-PDMS-shell nanowires (up to a micrometer in length) through a typical time-dependent shape evolution from spherical micelles in chloroform (CHCl<sub>3</sub>). Uniform spherical micelles with a PDMS core and PGMA shell were detected in acetone, while irregular micelles with a PGMA-core and PDMS-shell were detected in dioxane and <i>N</i>,<i>N</i>-dimethylformamide, indicating the critical dictating role of the solvent in the self-assembled pattern. The assembled nanowires of PDMS-<i>b</i>-PGMA in CHCl<sub>3</sub> were stable, regardless of the PGMA block length and concentration. The CHCl<sub>3</sub>-derived nanowire-based coating exhibited better hydrophobic properties and adhesive strength than the acetone-derived spherical micelle-based coating. Thus, we propose a micelle-induced self-assembled film-forming mechanism by regulating the migration and arrangement of PDMS and the solvent evaporation rate. Nanowires comprising PDMS shells exhibited greater curvature, which is highly conducive to the PDMS group migrating to the surface during the film-forming process. The PDMS-<i>b</i>-PGMA micelle-induced coating effectively improved hydrophobicity for protecting sandstones. This study provides a solution by regulating micelle-induced self-assembled film formation for fabricating high-performance protective coatings with wide application prospects.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146103049","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}
Microparticles abundant in marine and aquatic environments can readily deposit on surfaces and influence the biofouling development there. So far, the impacts of micrometer scale particles on bacterial adhesion, including most sediments and cellular debris, remain unclear. By using digital holographic microscopy for real-time 3D bacterial tracking, we have investigated the interaction of Pseudomonas aeruginosa (PAO1) near surface deposited with particles having diameter of 0.5 to 8.0 μm sparsely distributed on the glass substrate. It reveals that the bacterial adhesion is reduced for all the particle-decorated surfaces compared with flat surface and shows size dependence with minimum adhesion on surfaces deposited with 5.0 μm particle. In addition, the near-surface motions of PAO1 are greatly changed by the microparticles. PAO1 speeds up with more continuous climbing and leveling as it approaches the particle. Flow simulation demonstrates that a deposited particle alters the local flow depending on its size, where a 5.0 μm particle has the shortest-range flow disruption. Anyhow, the hydrodynamic interaction between particles and bacteria is responsible for the near-surface bacterial motions. The present study provides a basis for designing marine antifouling materials.
{"title":"Obstacle of Surface-Deposited Microparticles to Bacterial Motility and Adhesion","authors":"Xiaolong Zhu,Weixiong Zhang,Pu Feng,Xiangjun Gong,Guangzhao Zhang","doi":"10.1021/acs.langmuir.5c05997","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c05997","url":null,"abstract":"Microparticles abundant in marine and aquatic environments can readily deposit on surfaces and influence the biofouling development there. So far, the impacts of micrometer scale particles on bacterial adhesion, including most sediments and cellular debris, remain unclear. By using digital holographic microscopy for real-time 3D bacterial tracking, we have investigated the interaction of Pseudomonas aeruginosa (PAO1) near surface deposited with particles having diameter of 0.5 to 8.0 μm sparsely distributed on the glass substrate. It reveals that the bacterial adhesion is reduced for all the particle-decorated surfaces compared with flat surface and shows size dependence with minimum adhesion on surfaces deposited with 5.0 μm particle. In addition, the near-surface motions of PAO1 are greatly changed by the microparticles. PAO1 speeds up with more continuous climbing and leveling as it approaches the particle. Flow simulation demonstrates that a deposited particle alters the local flow depending on its size, where a 5.0 μm particle has the shortest-range flow disruption. Anyhow, the hydrodynamic interaction between particles and bacteria is responsible for the near-surface bacterial motions. The present study provides a basis for designing marine antifouling materials.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"12 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098100","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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