Article
Chemistry, Physical
Ruipeng Bai, Yuan Lin, Yuan Guo, Zhen Zhang
Summary: The interfacial structure of a super-concentration LiNO3 aqueous electrolyte was studied using non-resonant second harmonic generation (SHG) and heterodyne-detected SHG spectra. The increase in LiNO3 concentration led to the thickening of the interfacial water molecular layer, resulting in an expanded electrochemical stability window.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Martina Canton, Jessica Groppi, Lorenzo Casimiro, Stefano Corra, Massimo Baroncini, Serena Silvi, Alberto Credi
Summary: The research describes the modular design of a pseudorotaxane-based supramolecular pump and its photochemically driven autonomous nonequilibrium operation in a dissipative regime. These properties are a result of careful engineering of the energy maxima and minima along the threading coordinate and their light-triggered modulation, making this second-generation system amenable to functionalization for integration into more complex devices.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Engineering, Biomedical
Hongyan Wang, Haonan Yuan, Jinming Wang, Engui Zhang, Mingyun Bai, Yufeng Sun, Jianfeng Wang, Shijie Zhu, Yufeng Zheng, Shaokang Guan
Summary: The study systematically investigated the effect of second phase on protein adsorption on biodegradable Mg alloy surfaces using experimental methods and molecular dynamics simulations. Experimental results showed type-dependent effects on fibrinogen adsorption, while MD simulations revealed the mechanisms influencing protein adsorption, such as charge distribution, surface-protein interaction energy, and water molecule distribution. This work provides insights for designing Mg-based biomaterials with superior biocompatibility.
ACTA BIOMATERIALIA
(2021)
Article
Biochemistry & Molecular Biology
Baomei Xu, Jianhui Li, Shuai Zhang, Johar Zeb, Shunli Chen, Qunhui Yuan, Wei Gan
Summary: Subtle variations in lipid membrane structure and composition can greatly affect the transport of functional molecules and cell functions. This study compares the permeability of bilayers made of three lipids and reveals that the structural mismatch between saturated and unsaturated alkane chains leads to looser packing in lipid bilayers and better permeability. It also shows that surface curvature in certain vesicles disturbs the bilayer structure. This information provides clues for drug development and other medical and biological studies.
Article
Chemistry, Multidisciplinary
Yann Foucaud, Bertrand Siboulet, Magali Duvail, Alban Jonchere, Olivier Diat, Rodolphe Vuilleumier, Jean-Francois Dufreche
Summary: A breakthrough method has been developed to predict and interpret SHG signal at the atomic level, showing the significant impact of bulk quadrupole contribution in the SHG response. The experimental results are in unprecedented agreement with the simulated responses.
Article
Chemistry, Multidisciplinary
Bin Dong, Junjun Liu, Man Xue, Ziyue Ni, Yuan Guo, Zhifeng Huang, Zhen Zhang
Summary: The combination of SHG and linear dichroism, or SHG-LD, is used to study the chiroptical origin of silver chiral nanoparticles deposited by glancing angle deposition. The study reveals that the chiroptical activity of the silver CNPs is attributed to both structural chirality and one-fold anisotropy at the interface caused by substrate rotation during GLAD. This technique has great potential to provide valuable complementary information for studying the chiroptical properties of chiral metamaterials.
Article
Chemistry, Physical
XiangYu Hong, Hao Yu, HengYu Xu, XiaoQi Wang, Xu Jin, HengAn Wu, FengChao Wang
Summary: This study investigates the competitive adsorption of asphaltene and n-heptane on quartz surfaces using molecular dynamics simulations. The results show that asphaltene exhibits stronger adsorption ability than n-heptane, leading to a significant decrease in the transport flux of n-heptane in nanopores caused by asphaltene deposition. The presence of surface hydroxyl groups on the quartz substrates has a prominent impact on asphaltene adsorption, resulting in an enhancement of oil flux through SiO2 nanopores.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Physical
Asela S. Dikkumbura, Prakash Hamal, Min Chen, Daniel A. Babayode, Jeewan C. Ranasinghe, Kenneth Lopata, Louis H. Haber
Summary: The growth dynamics of colloidal silver-gold core-shell nanoparticles in water were monitored using time-dependent SHG and extinction spectroscopy in a stepwise synthesis approach. Sequential additions of chloroauric acid, sodium citrate, and hydroquinone were used to grow a gold shell around a silver core, with changes in surface morphology and thickness observed using transmission electron microscopy. Comparison of extinction spectra with FDTD calculations showed deviations for the first and second additions, but general agreement after the third addition reached equilibrium, providing detailed insights for investigating complex nanoparticle growth mechanisms and dynamics.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Materials Science, Multidisciplinary
Fan Yang, Cristian Ciraci
Summary: We present a theoretical study on second-harmonic generation from a singular metasurface, which strongly interacts with incident light and generates intense surface polarization, resulting in the generation of second-harmonic field. By using transformation optics, the calculation of nonlinear optical response is simplified, and the dependence on the incident angle is weak, making it potentially useful for all-angle harmonic generation. Furthermore, we investigate the symmetry dependence of second-harmonic generation in the far field and demonstrate an enhanced conversion efficiency under normal incidence by breaking the surface inversion symmetry.
Article
Metallurgy & Metallurgical Engineering
Hongyan Wang, Mingyun Bai, Haonan Yuan, Yachen Hou, Yihao Liu, Zhe Fang, Yufeng Sun, Jianfeng Wang, Shijie Zhu, Shaokang Guan
Summary: The study systematically investigated the effect of Zn content on the adsorption behavior of fibrinogen (Fg) in Mg-Zn binary alloy. It was found that low Zn content promoted Fg adsorption, while high Zn content hindered stable Fg adsorption.
JOURNAL OF MAGNESIUM AND ALLOYS
(2021)
Article
Multidisciplinary Sciences
Shingo Toyoda, Manfred Fiebig, Taka-hisa Arima, Yoshinori Tokura, Naoki Ogawa
Summary: Mirror symmetries play a crucial role in fundamental properties and conservation laws, with potential magnetoelectric cross-coupling when both spatial inversion and time reversal are broken. The giant nonreciprocal optical response observed in SHG of CuB2O4 is due to interference between magnetic-dipole and electric-dipole contributions, showing the potential for nonreciprocal nonlinear optical functionalities in multiferroics and magnetoelectrics. Resonantly enhanced magnetic-dipole transitions contribute significantly to the nonreciprocity, maximizing the effect despite the inherently weaker nature compared to electric-dipole transitions.
Article
Chemistry, Analytical
Chuansheng Xia, Jianli Sun, Qiong Wang, Jinping Chen, Tianjie Wang, Wenxiong Xu, He Zhang, Yuanyuan Li, Jianhua Chang, Zengliang Shi, Chunxiang Xu, Qiannan Cui
Summary: This study reports a label-free real-time sensing technique using strong optical second harmonic generation of monolayer 2D semiconductors to observe the dynamics of molecular adsorption and desorption at interfaces. The proposed detection scheme is both interface specific and widely applicable, enabling nanometer-scale spatial resolution across interfaces.
Article
Multidisciplinary Sciences
Shivangi Shree, Delphine Lagarde, Laurent Lombez, Cedric Robert, Andrea Balocchi, Kenji Watanabe, Takashi Taniguchi, Xavier Marie, Iann C. Gerber, Mikhail M. Glazov, Leonid E. Golub, Bernhard Urbaszek, Ioannis Paradisanos
Summary: Efficient second-harmonic generation (SHG) occurs for crystals with broken inversion symmetry, such as transition metal dichalcogenide monolayers. Here the authors show SHG tuning in bilayer MoS2 - an inversion-symmetric crystal - mediated by interlayer excitons.
NATURE COMMUNICATIONS
(2021)
Article
Engineering, Chemical
Gonzalo R. Quezada, Roberto E. Rozas, Pedro G. Toledo
Summary: The adsorption of partially hydrolyzed polyacrylamide (HPAM) on quartz surfaces is influenced by salts and surface charge under conditions of high salt and wide pH range, primarily achieved via salt bridges.
MINERALS ENGINEERING
(2021)
Article
Chemistry, Physical
Dan Su, Lei Zhang, Jianying Guo, Shengyu Liu, Bao Li
Summary: This study employed molecular dynamics simulations to clarify the mechanism of adsorption and accumulation of gas on rough surfaces during flotation, revealing that van der Waals force plays a leading role throughout the entire adsorption process. The findings contribute to a better understanding of the gas-liquid-solid interaction mechanism in the flotation process.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Physical
Ke Li, Visal Subasinghege Don, Chris S. Gupta, Rolf David, Revati Kumar
Summary: The differences in ion association and charge transport between NaOTf and NaTFSI at different salt concentrations in glymes with increasing chain length were studied using molecular simulations. The results showed similar trends in ion association behavior as a function of salt concentration for both NaOTf and NaTFSI, but the dominant solvation structures were distinctly different in different glyme concentrations. Conductivity was affected by ion association behavior and non-vehicular transport of anions in these electrolytes systems.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
D. I. I. Senadheera, Neepa M. K. Kuruppu Arachchige, Visal Subasinghege Don, Revati Kumar, Jayne C. Garno
Summary: Water plays a crucial role in initiating hydrosilation reactions of trifunctional organosilanes and directing molecular placement on surfaces. The wettability nature of substrates affects the formation of organosilane films by vapor-phase reactions. By mapping the areas where water is deposited on surfaces using organosilanes as markers, researchers were able to indirectly observe the competition between hydrophobic and hydrophilic domains for water adsorption and coalescence. Molecular dynamics simulations and electronic structure calculations provided insight into the mechanism for surface binding and the factors influencing the association and placement of silane molecules on surfaces.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Prakash Hamal, Visal Subasinghege Don, Huy Nguyenhuu, Jeewan C. Ranasinghe, Julia A. Nauman, Robin L. McCarley, Revati Kumar, Louis H. Haber
Summary: A fundamental understanding of the kinetics and thermodynamics of chemical interactions at the phospholipid bilayer interface is crucial for developing potential drug-delivery applications. Molecular dynamics simulations and surface-sensitive second harmonic generation spectroscopy were used to study the molecular adsorption and transport of malachite green at the surface of liposomes in water at different temperatures. The adsorption process is exothermic, leading to increased overall entropy, and molecular transport kinetics are more rapid at higher temperatures, with excellent agreement between experimental and simulation results.
JOURNAL OF PHYSICAL CHEMISTRY B
(2021)
Article
Chemistry, Physical
Raju R. Kumal, Srikanth Nayak, Wei Bu, Ahmet Uysal
Summary: Ion adsorption and transfer at charged interfaces are crucial in industrial and environmental processes. This study investigates SeCN- adsorption on a floating charged monolayer, revealing that the orientation and coverage of SeCN- ions change with increasing KSeCN concentration. The reorganization of interfacial ions and water is important for chemical separations of heavy metals.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Raju R. Kumal, Michael J. Servis, Pubudu N. Wimalasiri, Ahmet Uysal
Summary: Anions play important roles in the separation of lanthanides and actinides, but their behavior at aqueous interfaces is not well understood. This study used simulations to investigate the interfacial structure and behavior of thiocyanate anions at a charged interface, and found the emergence of a new population of thiocyanate ions at high concentrations.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Electrochemistry
Matthew L. Jordan, Tanmay Kulkarni, Dodangodage Ishara Senadheera, Revati Kumar, Yupo J. Lin, Christopher G. Arges
Summary: This study investigates the use of tethered benzyl 1-methyl imidazolium cations in polysulfone anion exchange membranes (AEMs) for ionic separations. The results demonstrate that these alternative cation moieties significantly enhance lactate conductivity and anion flux compared to traditional quaternary benzyl ammonium AEMs. Molecular dynamics and NMR experiments suggest that the closer binding of lactate anions to the imidazolium cations is responsible for the improved flux values.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Srikanth Nayak, Raju R. Kumal, Ahmet Uysal
Summary: This article investigates the ion-dependent reaction transformation process in rare earth metal separation technology. It is found that the introduction of specific ions can lead to the transformation of a monolayer into an inverted bilayer, providing insights for the development of new separation technologies. The study also reveals that temperature and the nature of background anions affect the transformation kinetics.
Article
Chemistry, Physical
Amanda J. Carr, Raju R. Kumal, Wei Bu, Ahmet Uysal
Summary: This study investigates the distribution of metal ions and water near graphene oxide films using interface-specific techniques. The results reveal that trivalent yttrium ions preferentially adsorb to graphene oxide and affect its structure, while divalent strontium and monovalent cesium ions have different effects. These findings provide fundamental information about the organization of ions and water at the interface and have relevance for improving graphene oxide membranes and applications downstream.
Article
Polymer Science
Erin Tsai, Hishara Keshani Gallage Dona, Xinjie Tong, Pu Du, Brian Novak, Rolf David, Steven W. Rick, Donghui Zhang, Revati Kumar
Summary: In this study, the internal structure and noncovalent interactions of polypeptoid micelles were investigated using a combination of molecular dynamics simulations and experimental data. The position of charged moieties was found to influence the shape of the micelles, offering the possibility for tailoring their shape. Additionally, micelles with triple-charged moieties exhibited stronger electrostatic repulsion and their shape was difficult to predict.
Article
Nanoscience & Nanotechnology
Amanda J. Carr, Seung Eun Lee, Raju R. Kumal, Wei Bu, Ahmet Uysal
Summary: Graphene oxide (GO) membranes are excellent candidates for separation applications, and understanding the interaction between water, ions, and the GO interface is critical. Experimental results show that solution conditions significantly impact water organization and lanthanide adsorption, which is connected to GO membrane performance.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Matthew L. Jordan, Grzegorz Kokoszka, Hishara Keshani Gallage Dona, Dodangodage Ishara Senadheera, Revati Kumar, Yupo J. Lin, Christopher G. Arges
Summary: In this study, a new membrane wafer assembly (MWA) was developed for the separation of p-coumaric acid in electrodeionization (EDI) process. The MWA showed improved capture efficiency for p-coumaric acid and reduced energy consumption and cost.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Chemistry, Physical
Visal Subasinghege Don, Lukas Kim, Rolf David, Julia A. Nauman, Revati Kumar
Summary: The adsorption of organic aromatic molecule, aniline, onto graphene oxide was investigated using molecular simulations. The effects of oxidation level and two different halide salts, sodium chloride and sodium iodide, were examined. The results showed that aniline molecule had a higher affinity for the graphene oxide-water interface in the more-reduced graphene oxide case compared to the oxidized form, and the presence of iodide ion increased the affinity in the reduced case but had the opposite effect in the more-oxidized form. The impact of oxidation and added salt on the interfacial water layer was also examined.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Srikanth Nayak, Raju R. Kumal, Seung Eun Lee, Ahmet Uysal
Summary: We investigated the adsorption of trivalent neodymium on floating arachidic acid films using two surface specific probes, sum frequency generation spectroscopy and X-ray fluorescence near total reflection. Our findings showed that neodymium ions can compensate for the surface charge of the arachidic acid film without charge reversal. However, changes in the bulk concentration of neodymium ions affected the interfacial water structure. Additionally, the presence of a high concentration of NaCl led to overcharging at a certain Nd3+ concentration.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Mario. V. V. Ramos-Garces, Dodangodage Ishara Senadheera, Karthik Arunagiri, Polyxeni. P. P. Angelopoulou, Georgios Sakellariou, Ke Li, Bryan. D. D. Vogt, Revati Kumar, Christopher. G. G. Arges
Summary: Ion-exchange membranes (IEMs) are widely used in various applications in electrochemical systems. The chemical composition and macromolecular architecture of ion-conducting polymers play a crucial role in ion and water transport. This study focuses on the preparation of different microphase separated block copolymer electrolytes (BCEs) with distinct side chain chemistries. The results show that the more hydrophobic alkyl side chains exhibit significantly higher ionic conductivity compared to alkoxy and zwitterionic side chains.
MATERIALS ADVANCES
(2023)
Article
Chemistry, Multidisciplinary
Rolf David, Revati Kumar
Summary: Graphene oxide displays interesting reactive behavior at its interface with water, influenced by the level of oxidation. Fully oxidized sheets make the interfacial water acidic and negatively charged, while reduced sheets can form long-lived carbocations.
CHEMICAL COMMUNICATIONS
(2021)
