1
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Yang P, Kumarasiri A, Hore D. Surface populations as a model for the distance-dependence of the interfacial refractive index. J Chem Phys 2024; 161:054703. [PMID: 39087546 DOI: 10.1063/5.0221234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Accepted: 07/16/2024] [Indexed: 08/02/2024] Open
Abstract
Vibrational sum frequency spectra provide information about interfaces that is sensitive to the orientation of molecules, their electronic environment, and the local electric fields. Here, we use molecular dynamics simulations in order to study a surfactant, para-cyanophenol, at the air-water interface. The volume fractions of water and the organic surfactant are considered at various points over the nanometer-scale region in a Lorentz-Lorenz model. We find that the calculated ratios of nonlinear susceptibility tensor elements are in agreement with experimental data only when this depth profile was considered. We also use these data to evaluate the ratio of the C-N hyperpolarizability tensor elements in the interfacial region.
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Affiliation(s)
- Peter Yang
- Department of Chemistry, University of Victoria, Victoria, British Columbia V8W 3V6, Canada
| | - Aruna Kumarasiri
- Department of Chemistry, University of Victoria, Victoria, British Columbia V8W 3V6, Canada
| | - Dennis Hore
- Department of Chemistry, University of Victoria, Victoria, British Columbia V8W 3V6, Canada
- Department of Computer Science, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
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2
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Dommer A, Wauer NA, Angle KJ, Davasam A, Rubio P, Luo M, Morris CK, Prather KA, Grassian VH, Amaro RE. Revealing the Impacts of Chemical Complexity on Submicrometer Sea Spray Aerosol Morphology. ACS CENTRAL SCIENCE 2023; 9:1088-1103. [PMID: 37396863 PMCID: PMC10311664 DOI: 10.1021/acscentsci.3c00184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Indexed: 07/04/2023]
Abstract
Sea spray aerosol (SSA) ejected through bursting bubbles at the ocean surface is a complex mixture of salts and organic species. Submicrometer SSA particles have long atmospheric lifetimes and play a critical role in the climate system. Composition impacts their ability to form marine clouds, yet their cloud-forming potential is difficult to study due to their small size. Here, we use large-scale molecular dynamics (MD) simulations as a "computational microscope" to provide never-before-seen views of 40 nm model aerosol particles and their molecular morphologies. We investigate how increasing chemical complexity impacts the distribution of organic material throughout individual particles for a range of organic constituents with varying chemical properties. Our simulations show that common organic marine surfactants readily partition between both the surface and interior of the aerosol, indicating that nascent SSA may be more heterogeneous than traditional morphological models suggest. We support our computational observations of SSA surface heterogeneity with Brewster angle microscopy on model interfaces. These observations indicate that increased chemical complexity in submicrometer SSA leads to a reduced surface coverage by marine organics, which may facilitate water uptake in the atmosphere. Our work thus establishes large-scale MD simulations as a novel technique for interrogating aerosols at the single-particle level.
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3
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Deal AM, Vaida V. Infrared Reflection–Absorption Spectroscopy of α-Hydroxyacids at the Water–Air Interface. J Phys Chem A 2022; 126:8280-8294. [DOI: 10.1021/acs.jpca.2c04462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alexandra M. Deal
- Department of Chemistry and Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Veronica Vaida
- Department of Chemistry and Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States
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4
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Staniscia F, Guzman HV, Kanduč M. Tuning Contact Angles of Aqueous Droplets on Hydrophilic and Hydrophobic Surfaces by Surfactants. J Phys Chem B 2022; 126:3374-3384. [PMID: 35468298 PMCID: PMC9082615 DOI: 10.1021/acs.jpcb.2c01599] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Adsorption of small
amphiphilic molecules occurs in various biological
and technological processes, sometimes desired while other times unwanted
(e.g., contamination). Surface-active molecules preferentially bind
to interfaces and affect their wetting properties. We use molecular
dynamics simulations to study the adsorption of short-chained alcohols
(simple surfactants) to the water–vapor interface and solid
surfaces of various polarities. With a theoretical analysis, we derive
an equation for the adsorption coefficient, which scales exponentially
with the molecular surface area and the surface wetting coefficient
and is in good agreement with the simulation results. We apply the
outcomes to aqueous sessile droplets containing surfactants, where
the competition of surfactant adsorptions to both interfaces alters
the contact angle in a nontrivial way. The influence of surfactants
is the strongest on very hydrophilic and hydrophobic surfaces, whereas
droplets on moderately hydrophilic surfaces are less affected.
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Affiliation(s)
- Fabio Staniscia
- Department of Theoretical Physics, Jožef Stefan Institute, Ljubljana SI-1000, Slovenia
| | - Horacio V Guzman
- Department of Theoretical Physics, Jožef Stefan Institute, Ljubljana SI-1000, Slovenia
| | - Matej Kanduč
- Department of Theoretical Physics, Jožef Stefan Institute, Ljubljana SI-1000, Slovenia
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5
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Kappes K, Frandsen BN, Vaida V. Infrared spectroscopy of 2-oxo-octanoic acid in multiple phases. Phys Chem Chem Phys 2022; 24:6757-6768. [PMID: 35237773 DOI: 10.1039/d1cp05345k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Alpha-keto acids are environmentally and biologically relevant species whose chemistry has been shown to be influenced by their local environment. Vibrational spectroscopy provides useful ways to probe the potential inter- and intramolecular interactions available to them in several phases. We measure and compare the IR spectra of 2-oxo-octanoic acid (2OOA) in the gas phase, solid phase, and at the air-water interface. With theoretical support, we assign many of the vibrational modes in each of the spectra. In the gas phase, two types of conformers are identified and distinguished, with the intramolecularly H-bonded form being the dominant type, while the second conformer type identified does not have an intramolecular hydrogen bond. The van der Waals interactions between molecules in solid 2OOA manifest C-H and CO vibrations lower in energy than in the gas phase and we propose an intermolecular hydrogen bonding scheme for the solid phase. At the air-water interface the hydrocarbon tails of 2OOA do interact with each other while the carbonyls appear to interact with water in the subphase, but not with neighboring 2OOA as might be expected of a closely packed surfactant film.
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Affiliation(s)
- Keaten Kappes
- Department of Chemistry, University of Colorado-Boulder, UCB 215, Boulder, CO 80309, USA. .,Cooperative Institute for Research in Environmental Sciences, University of Colorado-Boulder, UCB 216, Boulder, CO 80309, USA
| | - Benjamin N Frandsen
- Department of Chemistry, University of Colorado-Boulder, UCB 215, Boulder, CO 80309, USA. .,Cooperative Institute for Research in Environmental Sciences, University of Colorado-Boulder, UCB 216, Boulder, CO 80309, USA
| | - Veronica Vaida
- Department of Chemistry, University of Colorado-Boulder, UCB 215, Boulder, CO 80309, USA. .,Cooperative Institute for Research in Environmental Sciences, University of Colorado-Boulder, UCB 216, Boulder, CO 80309, USA
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6
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Kalaycioglu GD, Yuksel D, Okmen B, Aydogan N. Interfacial properties and aggregates of novel redox-active surfactant to synthesize silver nanoparticles at the air/water interface. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.126759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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7
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Xu M, Tsona NT, Cheng S, Li J, Du L. Unraveling interfacial properties of organic-coated marine aerosol with lipase incorporation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 782:146893. [PMID: 33848860 DOI: 10.1016/j.scitotenv.2021.146893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/09/2021] [Accepted: 03/29/2021] [Indexed: 06/12/2023]
Abstract
Marine aerosols are believed to have an organic surface coating on which fatty acids act as an important component due to their high surface activity. In addition, various kinds of enzyme species are abundantly found in seawater, some of which have been identified to exist in marine aerosols. Herein, from the perspective of marine aerosol interface simulation, we investigate the effect of Burkholderia cepacia lipase on the surface properties of stearic acid (SA) monolayer at the air-water interface by using surface-sensitive techniques of Langmuir trough and Infrared reflection-absorption spectroscopy (IRRAS). Our findings indicate that the stearic acid film undergoes a significant expansion, especially when the lipase concentration is 500 nM, because of the incorporation of lipase as observed from the surface pressure-area (π-A) isotherms. IRRAS spectra also show reduced intensities and ordering in the methylene stretching vibration region of stearic acid as a result of low surface density and disordered packing as the enzyme concentration increases. In particular, when the concentration of lipase is 500 nM, the lowest Ias/Is values are shown on both pure water subphase and artificial seawater subphase, indicating more gauche conformations for SA. Furthermore, SA films with lipase incorporation were also studied at three different pH of subphase environment, considering the decrease of pH caused by the reaction with acidic gases during the aerosol aging process. The results reflect a more pronounced expansion of SA monolayer in acidic environment at pH 2.5, suggesting that hydrophobic interaction plays an important role in the disorder of the SA monolayer. In view of the coexistence of fatty acids and enzymes in the marine environment, this study provides a further understanding of the surface organization and behavior of organic-coated marine aerosols and deepen the knowledge of lipid-enzyme interfacial interactions occurring in the atmosphere.
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Affiliation(s)
- Minglan Xu
- Environment Research Institute, Shandong University, Binhai Road 72, Qingdao 266237, China
| | - Narcisse T Tsona
- Environment Research Institute, Shandong University, Binhai Road 72, Qingdao 266237, China
| | - Shumin Cheng
- Environment Research Institute, Shandong University, Binhai Road 72, Qingdao 266237, China
| | - Jianlong Li
- Environment Research Institute, Shandong University, Binhai Road 72, Qingdao 266237, China
| | - Lin Du
- Environment Research Institute, Shandong University, Binhai Road 72, Qingdao 266237, China.
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8
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Yu Y, Chen H, Zhao Q, Mou Q, Dong L, Wang R, Shi Z, Gao Y. Impact of Gas-Liquid Interface on Photochemical Vapor Generation. Anal Chem 2021; 93:3343-3352. [PMID: 33566589 DOI: 10.1021/acs.analchem.9b05634] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Interfacial effect has attracted increasing interest as the inherent asymmetric environment of a gas-liquid interface leads to different chemical and physical properties between this region and the bulk phase, resulting in enhanced chemical processes, specific reactions, and mass transfer at the interface. Photochemical vapor generation (PVG) is regarded as a simple and green sample introduction method in atomic spectrometry. However, the photochemical behavior of elements with the interface is not known. Herein, we report the PVG of elements at the gas-liquid interface along with a possible mechanism investigated for the first time. Enhancement and/or suppression effects from the gas-liquid interface were observed on the PVG of 17 elements, which was correlated with the properties of analytes and the generated intermediate substances/products of PVG and the applied conditions. Enhancement from 1.1- to 7.3-fold in analytical sensitivity was found for 12 elements in the system with gas-liquid interface(s) compared to the results obtained in previous reports of PVG using traditional flow injection with inductively coupled plasma mass spectrometry measurement. The introduction of gas-liquid interface(s) and the resultant elevated temperature inside the PVG reactor likely facilitated the generation of radicals, the subsequent radical-based reactions, and the separation/transport/detection of volatile species of elements. In contrast, intermediate substances/products generated in PVG with poor thermostability will readily decompose at elevated temperatures, leading to a decreased signal response of analytes. The finding is helpful to understand the transport of elements under UV irradiation in the environment and has potential for analysis of trace elements in environmental and biological samples.
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Affiliation(s)
- Ying Yu
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Earth Sciences, Chengdu University of Technology, Chengdu, Sichuan 610059, China
| | - Hanjiao Chen
- Analytical & Testing Center, Sichuan University, Chengdu, Sichuan 610064, China
| | - Qian Zhao
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Earth Sciences, Chengdu University of Technology, Chengdu, Sichuan 610059, China
| | - Qing Mou
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Earth Sciences, Chengdu University of Technology, Chengdu, Sichuan 610059, China
| | - Liang Dong
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Earth Sciences, Chengdu University of Technology, Chengdu, Sichuan 610059, China
| | - Ruilin Wang
- College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu, Sichuan 610059, China
| | - Zeming Shi
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Earth Sciences, Chengdu University of Technology, Chengdu, Sichuan 610059, China
| | - Ying Gao
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Earth Sciences, Chengdu University of Technology, Chengdu, Sichuan 610059, China
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9
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Gordon BP, Lindquist GA, Crawford ML, Wren SN, Moore FG, Scatena LF, Richmond GL. Diol it up: The influence of NaCl on methylglyoxal surface adsorption and hydration state at the air–water interface. J Chem Phys 2020; 153:164705. [DOI: 10.1063/5.0017803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Brittany P. Gordon
- Department of Chemistry, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, USA
- Department of Chemistry, University of California, Irvine, 1214 Natural Sciences II, Irvine, California 92697, USA
| | - Grace A. Lindquist
- Department of Chemistry, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, USA
| | - Michael L. Crawford
- Department of Chemistry, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, USA
| | - Sumi N. Wren
- Department of Chemistry, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, USA
- Environment and Climate Change Canada (ECCC), Air Quality Research Division, 4905 Dufferin Street, Toronto, Ontario M3H 5T4, Canada
| | - Frederick G. Moore
- Department of Physics, Whitman College, Walla Walla, Washington 99362, USA
| | - Lawrence F. Scatena
- Department of Chemistry, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, USA
| | - Geraldine L. Richmond
- Department of Chemistry, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, USA
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10
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Jia F, Wu K, Che Y, Zhang Y, Zeng F, Luo Q, Yu X, Zhu Z, Zhao Y, Wang F. ToF‐SIMS analysis of chemical composition of atmospheric aerosols in Beijing. SURF INTERFACE ANAL 2019. [DOI: 10.1002/sia.6710] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Feifei Jia
- Beijing National Laboratory for Molecular Sciences; CAS Research/Education Center for Excellence in Molecular Sciences; CAS Key Laboratory of Analytical Chemistry for Living Biosystems; National Centre for Mass Spectrometry in Beijing; Institute of ChemistryChinese Academy of Sciences Beijing China
| | - Kui Wu
- Beijing National Laboratory for Molecular Sciences; CAS Research/Education Center for Excellence in Molecular Sciences; CAS Key Laboratory of Analytical Chemistry for Living Biosystems; National Centre for Mass Spectrometry in Beijing; Institute of ChemistryChinese Academy of Sciences Beijing China
- Key Laboratory of Hubei Province for Coal Conversion and New Carbon Materials; School of Chemistry and Chemical EngineeringWuhan University of Science and Technology Wuhan China
| | - Yanli Che
- Beijing National Laboratory for Molecular Sciences; CAS Research/Education Center for Excellence in Molecular Sciences; CAS Key Laboratory of Analytical Chemistry for Living Biosystems; National Centre for Mass Spectrometry in Beijing; Institute of ChemistryChinese Academy of Sciences Beijing China
- School of Environment and Natural ResourcesRenmin University of China Beijing China
| | - Yanyan Zhang
- Beijing National Laboratory for Molecular Sciences; CAS Research/Education Center for Excellence in Molecular Sciences; CAS Key Laboratory of Analytical Chemistry for Living Biosystems; National Centre for Mass Spectrometry in Beijing; Institute of ChemistryChinese Academy of Sciences Beijing China
| | - Fangang Zeng
- School of Environment and Natural ResourcesRenmin University of China Beijing China
| | - Qun Luo
- Beijing National Laboratory for Molecular Sciences; CAS Research/Education Center for Excellence in Molecular Sciences; CAS Key Laboratory of Analytical Chemistry for Living Biosystems; National Centre for Mass Spectrometry in Beijing; Institute of ChemistryChinese Academy of Sciences Beijing China
| | - Xiao‐Ying Yu
- Energy and Environment DirectoratePacific Northwest National Laboratory Richland Washington
| | - Zihua Zhu
- Environmental Molecular Sciences LaboratoryPacific Northwest National Laboratory Richland Washington
| | - Yao Zhao
- Beijing National Laboratory for Molecular Sciences; CAS Research/Education Center for Excellence in Molecular Sciences; CAS Key Laboratory of Analytical Chemistry for Living Biosystems; National Centre for Mass Spectrometry in Beijing; Institute of ChemistryChinese Academy of Sciences Beijing China
| | - Fuyi Wang
- Beijing National Laboratory for Molecular Sciences; CAS Research/Education Center for Excellence in Molecular Sciences; CAS Key Laboratory of Analytical Chemistry for Living Biosystems; National Centre for Mass Spectrometry in Beijing; Institute of ChemistryChinese Academy of Sciences Beijing China
- University of Chinese Academy of Sciences Beijing China
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11
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Blanco YS, Topel Ö, Bajnóczi ÉG, Werner J, Björneholm O, Persson I. Chemical equilibria of aqueous ammonium-carboxylate systems in aqueous bulk, close to and at the water-air interface. Phys Chem Chem Phys 2019; 21:12434-12445. [PMID: 31143906 DOI: 10.1039/c9cp02449b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Previous studies have shown that the water-air interface and a number of water molecule layers just below it, the surface region, have significantly different physico-chemical properties, such as lower relative permittivity and density, than bulk water. The properties in the surface region of water favor weakly hydrated species as neutral molecules, while ions requiring strong hydration and shielding of their charge are disfavored. In this study the equilibria NH4+(aq) + RCOO-(aq) ⇌ NH3(aq) + RCOOH(aq) are investigated for R = CnH2n+1, n = 0-8, as open systems, where ammonia and small carboxylic acids in the gas phase above the water surface are removed from the system by a gentle controlled flow of nitrogen to mimic the transport of volatile compounds from water droplets into air. It is shown that this non-equilibrium transport of chemicals can be sufficiently large to cause a change of the chemical content of the aqueous bulk. Furthermore, X-ray photoelectron spectroscopy (XPS) has been used to determine the relative concentration of alkyl carboxylic acids and their conjugated alkyl carboxylates in aqueous surfaces using a micro-jet. These studies confirm that neutral alkyl carboxylic acids are accumulated in the surface region, while charged species, as alkyl carboxylates, are depleted. The XPS studies show also that the hydrophobic alkyl chains are oriented upwards into regions with lower relative permittivity and density, thus perpendicular to the aqueous surface. These combined results show that there are several chemical equilibria between the aqueous bulk and the surface region. The analytical studies show that the release of mainly ammonia is dependent on its concentration in the surface region, as long as the solubility of the carboxylic acid in the surface region is sufficiently high to avoid a precipitation in/on the water-air interface. However, for n-octyl- and n-nonylcarboxylic acid the solubility is sufficiently low to cause precipitation. The combined analytical and surface speciation studies in this work show that the equilibria involving the surface region are fast. The results from this study increase the knowledge about the distribution of chemical species in the surface region at and close to the water-air interface, and the transport of chemicals from water to air in open systems.
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Affiliation(s)
- Yina Salamanca Blanco
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden.
| | - Önder Topel
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden.
| | - Éva G Bajnóczi
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden.
| | - Josephina Werner
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden. and Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
| | - Olle Björneholm
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
| | - Ingmar Persson
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden.
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12
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Zhang H, Wang W, Pi S, Liu L, Li H, Chen Y, Zhang Y, Zhang X, Li Z. Gas phase transformation from organic acid to organic sulfuric anhydride: Possibility and atmospheric fate in the initial new particle formation. CHEMOSPHERE 2018; 212:504-512. [PMID: 30165277 DOI: 10.1016/j.chemosphere.2018.08.074] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 08/09/2018] [Accepted: 08/15/2018] [Indexed: 06/08/2023]
Abstract
New particle formation (NPF) process has been observed frequently in various environments and produces a large fraction of atmospheric aerosols. However, the chemical species participating in the nucleation as well as the corresponding nucleation mechanism in the atmosphere still remain ambiguous. Recent research by Leopold et al. shows that cycloaddition reaction of SO3 to carboxylic acids could contribute to the formation of organic sulfuric anhydride which would have lower vapor pressure compared with the corresponding carboxylic acid and hence kick-start new particle formation in the gas phase. In the present study, energy profile for the formation of 3-methyl-1,2,3-butanetricarboxylic sulfuric anhydride (MBTCSA) through the cycloaddition of SO3 to 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA) has been investigated using computational methods. As a result, such a process would be effectively barrierless for one of the terminal carboxy group and has very low energy barriers for the other two carboxy groups (0.6 and 2.8 kcal/mol, respectively), indicating the whole process is a plausible gas phase pathway to MBTCSA formation. Furthermore, by evaluating the stability of the generated atmospheric clusters through topological and kinetic analysis, interaction between atmospheric nucleation precursor with MBTCSA is found to be more thermodynamically favourable and stronger than those with sulfuric acid and MBTCA which is identified from further-generation oxidation of a-pinene. Hence MBTCSA is speculated to be a potential participator in the initial new particle formation and the further particles growth.
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Affiliation(s)
- Haijie Zhang
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Wei Wang
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Shuangqi Pi
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Ling Liu
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Hao Li
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Yu Chen
- School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Yunhong Zhang
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Xiuhui Zhang
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China.
| | - Zesheng Li
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China.
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13
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Li J, Li S, Cheng S, Tsona NT, Du L. Emerging investigator series: exploring the surface properties of aqueous aerosols coated with mixed surfactants. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2018; 20:1500-1511. [PMID: 30371711 DOI: 10.1039/c8em00419f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Mixed Langmuir monolayers of cholesterol with both saturated and unsaturated fatty acids, stearic acid (SA), and oleic acid (OA) spread at the air-seawater surface were studied. The phase behavior, molecular interaction, and conformational order of the monolayers were investigated by surface pressure-area (π-A) isotherms and infrared reflection-absorption spectroscopy (IRRAS) measurements. The thermodynamic parameters of the mixed films, including excess molecular area and excess Gibbs free energy were calculated by using the isotherm data. The interaction between SA (or OA) and cholesterol varied with the molar fraction of the fatty acids and surface pressure. OA/chol monolayers showed the characteristics of miscibility, but they acted as nonideal systems. Cholesterol has been observed to have a stabilizing effect on OA monolayers. The negative values of the excess Gibbs free energy in the entire composition range demonstrated that mixed OA/chol monolayers were thermodynamically stable. IRRAS spectra showed that mixing with cholesterol changes the ordering of fatty acid monolayers at the air-seawater surface. The findings provide general information regarding the structural changes in the monolayer induced by lateral packing. These results help in the understanding of the mixing behavior of fatty acids and cholesterol and provide insights into the fate of the mixed-monolayer-coated sea salt aerosol in the ocean environment.
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Affiliation(s)
- Junyao Li
- Environment Research Institute, Shandong University, Binhai Road 72, Qingdao, 266237, China.
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14
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Li S, Du L, Zhang Q, Wang W. Stabilizing mixed fatty acid and phthalate ester monolayer on artificial seawater. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 242:626-633. [PMID: 30014940 DOI: 10.1016/j.envpol.2018.07.043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 07/09/2018] [Accepted: 07/10/2018] [Indexed: 06/08/2023]
Abstract
Phthalate esters which are widely used as industrial chemicals have become widespread contaminants in the marine environment. However, little information is available on the interfacial behavior of phthalate esters in the seawater, where contaminants generally occur at elevated concentrations and have the potential to transfer into the atmosphere through wave breaking on sea surface. We used artificial seawater coated with fatty acids to simulate sea surface microlayer in a Langmuir trough. The interactions of saturated fatty acids (stearic acid (SA) and palmitic acid (PA)) with one of the most abundant phthalate esters (di-(2-ethylhexyl) phthalate (DEHP)), were investigated under artificial seawater and pure water conditions. Pure DEHP monolayer was not stable, while more stable mixed monolayers were formed by SA and DEHP on the artificial seawater at relatively low surface pressure. Sea salts in the subphase can lower the excess Gibbs free energy to form more stable mixed monolayer. Among the ten components in the sea salts, Ca2+ ions played the major role in condensation of mixed monolayer. The condensed characteristic of the mixed SA (or PA)/DEHP monolayers suggested that the hydrocarbon chains were ordered on artificial seawater. By means of infrared reflection-absorption spectroscopy (IRRAS), we found that multiple sea salt mixtures induced deprotonated forms of fatty acids at the air-water interface. Sea salts can improve the stability and lifetime of mixed fatty acid and phthalate ester monolayer on aqueous droplets in the atmosphere. Interfacial properties of mixed fatty acid and phthalate ester monolayers at the air-ocean interface are important to help understand their behavior and fate in the marine environment.
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Affiliation(s)
- Siyang Li
- Environment Research Institute, Shandong University, Binhai Road 72, Qingdao, 266237, China
| | - Lin Du
- Environment Research Institute, Shandong University, Binhai Road 72, Qingdao, 266237, China.
| | - Qingzhu Zhang
- Environment Research Institute, Shandong University, Binhai Road 72, Qingdao, 266237, China
| | - Wenxing Wang
- Environment Research Institute, Shandong University, Binhai Road 72, Qingdao, 266237, China
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Jarisz T, Roy S, Hore DK. Surface Water as a Mediator and Reporter of Adhesion at Aqueous Interfaces. Acc Chem Res 2018; 51:2287-2295. [PMID: 30152686 DOI: 10.1021/acs.accounts.8b00258] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Understanding the adsorption of molecules onto surfaces is integral to a wide variety of fields with scientific, engineering, and industrial applications. The surface-adsorbed structure is governed by the nature of the molecule, surface characteristics, and solution environment. There are therefore three critical interactions that govern adhesion: solvent-analyte, substrate-analyte, and substrate-solvent. The last two interactions require a surface-specific probe restricted to a few nanometers or less. This is particularly true of efforts to probe polymer surface structure without being overwhelmed by bulk polymer signal or interfacial water structure in the presence of bulk water. Second-order nonlinear optical techniques are ideal probes of such interactions, as their reporting depth is determined by the polar arrangement of molecules (a break in the macroscopic inversion symmetry) rather than the penetration of the optical fields. This Account begins with an introduction of surface water structure from the perspective of a nonlinear probe. Details about the unique view of the water orientation distribution are discussed and contrasted with information obtained from conventional vibrational techniques. The salient features of water next to model hydrophobic and hydrophilic surfaces are discussed, in preparation for a discussion of solute interactions that follows. We then present three examples using a combination of linear and nonlinear vibrational spectroscopy and molecular dynamics simulations to illustrate how water is both a mediator and a marker of adhesion. The first is a study of amphipathic peptide adhesion onto hydrophobic and hydrophilic surfaces, characterizing the adsorbed structure in relation to the water surrounding the molecule and trapped near the surface. Water is found to be especially important in mediating adhesion to hydrophilic surfaces, where it aids in solvating the peptide as well as facilitating interactions with the surface. In the second example, we look at adhesion of a multicomponent polymer adhesive using surface-bulk heterospectral correlation analysis, in which surface vibrational spectroscopy is combined with bulk infrared absorption to determine interfacial structure development during the evaporation of water. When acrylic acid is added to the polymer, there is a change in orientation of the polymer before an increase in population. This is opposite to what is observed when no additive is present. In our third example, we show how interfacial water provides a unique window into the surface microenvironment during bacterial adhesion, highlighting the role of solution conditions at the surface in cell attachment and biofilm growth. Changes in the nonlinear vibrational response of interfacial water reflect changes occurring in the pH and ionic strength only at the surface, due to the presence of polymeric adhesives secreted by the bacteria. These studies underline the importance of surface water in governing the structure of adhered molecules and in mediating changes in the interfacial environment as a result of adhesion and provide insight into a nanoscale region that is otherwise difficult to query. They also illustrate the importance of combining surface-sensitive and bulk spectroscopic probes with computer modeling to gain a better understanding of the interplay between water and adsorbate structure.
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Affiliation(s)
- Tasha Jarisz
- Department of Chemistry, University of Victoria, Victoria, British Columbia V8W 3V6, Canada
| | - Sandra Roy
- Department of Chemistry, University of Victoria, Victoria, British Columbia V8W 3V6, Canada
| | - Dennis K. Hore
- Department of Chemistry, University of Victoria, Victoria, British Columbia V8W 3V6, Canada
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Shrestha M, Luo M, Li Y, Xiang B, Xiong W, Grassian VH. Let there be light: stability of palmitic acid monolayers at the air/salt water interface in the presence and absence of simulated solar light and a photosensitizer. Chem Sci 2018; 9:5716-5723. [PMID: 30079180 PMCID: PMC6050592 DOI: 10.1039/c8sc01957f] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 06/04/2018] [Indexed: 01/13/2023] Open
Abstract
Long-chain fatty acid monolayers are known surfactants present at air/water interfaces. However, little is known about the stability of these long-chain fatty acid monolayers in the presence of solar radiation. Here we have investigated, for the first time, the stability of palmitic acid monolayers on salt water interfaces in the presence and absence of simulated solar light with and without a photosensitizer in the underlying salt subphase. Using surface sensitive probes to measure changes in the properties of these monolayers upon irradiation, we found that the monolayers become less stable in the presence of light and a photosensitizer, in this case humic acid, in the salt solution. The presence of the photosensitizer is essential in significantly reducing the stability of the monolayer upon irradiation. The mechanism for this loss of stability is due to interfacial photochemistry involving electronically excited humic acid and molecular oxygen reacting with palmitic acid at the interface to form more oxygenated and less surface-active species. These oxygenated species can then more readily partition into the underlying solution.
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Affiliation(s)
- Mona Shrestha
- Department of Chemistry & Biochemistry , University of California , La Jolla , San Diego , CA 92093 , USA .
| | - Man Luo
- Department of Chemistry & Biochemistry , University of California , La Jolla , San Diego , CA 92093 , USA .
| | - Yingmin Li
- Materials Science and Engineering Program , University of California , La Jolla , San Diego , CA 92093 , USA
| | - Bo Xiang
- Materials Science and Engineering Program , University of California , La Jolla , San Diego , CA 92093 , USA
| | - Wei Xiong
- Department of Chemistry & Biochemistry , University of California , La Jolla , San Diego , CA 92093 , USA .
- Materials Science and Engineering Program , University of California , La Jolla , San Diego , CA 92093 , USA
| | - Vicki H Grassian
- Department of Chemistry & Biochemistry , University of California , La Jolla , San Diego , CA 92093 , USA .
- Scripps Institution of Oceanography , University of California , La Jolla , San Diego , CA 92093 , USA
- Department of Nanoengineering , University of California , La Jolla , San Diego , CA 92093 , USA
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Zhang H, Li H, Liu L, Zhang Y, Zhang X, Li Z. The potential role of malonic acid in the atmospheric sulfuric acid - Ammonia clusters formation. CHEMOSPHERE 2018; 203:26-33. [PMID: 29604427 DOI: 10.1016/j.chemosphere.2018.03.154] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 06/08/2023]
Abstract
Malonic acid (MOA), one of the major dicarboxylic acids (DCAs) in aerosols, has been identified experimentally and computationally to be a strong acid. However, its potential role in the atmospheric clusters formation is still ambiguous. Hence, the participant mechanism of MOA on the formation of atmospheric sulfuric acid (SA)- ammonia (A) clusters was investigated by combining computational methods with atmospheric cluster dynamics code (ACDC). The most stable molecular structures obtained at the M06-2X/6-311++G(3df,3pd) level of theory shows that the added MOA molecule in the SA-A-based clusters presents a promotion on the interactions between SA and A molecules. ACDC simulations indicate directly an obvious enhancement strength RMOA on the clusters formation rates at 218 K and the concentration of MOA ([MOA]) larger than 108 molecules cm-3, up to five orders of magnitude. Meanwhile, enhancement strength of MOA is compared with that of glycolic acid, and as expected, MOA presents a superior enhancement strength. Both RMOA and the compared enhancement strength (rcom) present a positive dependency on [MOA] and a negative dependency on [SA]. With the increase of [A], both RMOA and rcom (except at [SA] = 104 molecules cm-3) first increase, reaching the maximum value and then decrease. Finally, a catalytic participant mechanism of MOA where MOA acts as a mediate bridge for the formation of pure SA-A-based clusters has been identified by tracing the main growth pathways of the system.
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Affiliation(s)
- Haijie Zhang
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Hao Li
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Ling Liu
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Yunhong Zhang
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Xiuhui Zhang
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China.
| | - Zesheng Li
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China.
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18
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Self-Assembled Composite Langmuir Films via Fluorine-Containing Bola-Type Derivative with Metal Ions. COATINGS 2018. [DOI: 10.3390/coatings8040141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Li S, Du L, Tsona NT, Wang W. The interaction of trace heavy metal with lipid monolayer in the sea surface microlayer. CHEMOSPHERE 2018; 196:323-330. [PMID: 29310068 DOI: 10.1016/j.chemosphere.2017.12.157] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 12/17/2017] [Accepted: 12/22/2017] [Indexed: 06/07/2023]
Abstract
Lipid molecules and trace heavy metals are enriched in sea surface microlayer and can be transferred into the sea spray aerosol. To better understand their impact on marine aerosol generation and evolution, we investigated the interaction of trace heavy metals including Fe3+, Pb2+, Zn2+, Cu2+, Ni2+, Cr3+, Cd2+, and Co2+, with dipalmitoylphosphatidylcholine (DPPC) monolayers at the air-water interface. Phase behavior of the DPPC monolayer on heavy metal solutions was probed with surface pressure-area (π-A) isotherms. The conformation order and orientation of DPPC alkyl chains were characterized by infrared reflection-absorption spectroscopy (IRRAS). The π-A isotherms show that Zn2+ and Fe3+ strongly interact with DPPC molecules, and induce condensation of the monolayers in a concentration-dependent manner. IRRAS spectra show that the formation of cation-DPPC complex gives rise to conformational changes and immobilization of the headgroups. The current results suggest that the enrichment of Zn2+ in sea spray aerosols is due to strong binding to the DPPC film. The interaction of Fe3+ with DPPC monolayers can significantly influence their surface organizations through the formation of lipid-coated particles. These results suggest that the sea surface microlayer is capable of accumulating much higher amounts of these metals than the subsurface water. The organic and metal pollutants may transfer into the atmosphere by this interaction.
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Affiliation(s)
- Siyang Li
- Environment Research Institute, Shandong University, Shanda South Road 27, 250100 Shandong, China
| | - Lin Du
- Environment Research Institute, Shandong University, Shanda South Road 27, 250100 Shandong, China.
| | - Narcisse T Tsona
- Environment Research Institute, Shandong University, Shanda South Road 27, 250100 Shandong, China
| | - Wenxing Wang
- Environment Research Institute, Shandong University, Shanda South Road 27, 250100 Shandong, China
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