ACS Earth and Space Chemistry最新文献

{"title":"Molecular Structure and Rotational Dynamics in the Acetonitrile:Acetylene (1:2) Plastic Co-crystal at Titan Conditions","authors":"Atul C. Thakur,&nbsp; and ,&nbsp;Richard C. Remsing*,&nbsp;","doi":"10.1021/acsearthspacechem.4c0015710.1021/acsearthspacechem.4c00157","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00157https://doi.org/10.1021/acsearthspacechem.4c00157","url":null,"abstract":"<p >The surface of Saturn’s moon Titan is coated with small-molecule organic solids termed cryominerals. Cryominerals play an analogous role to minerals on Earth in Titan’s surface geology and geochemistry. To develop a predictive understanding of Titan’s surface geochemistry, we need to characterize the structure and dynamics of cryominerals at the molecular scale. We use <i>ab initio</i> molecular dynamics simulations to quantify the structure and dynamics of the acetonitrile:acetylene (1:2) co-crystal at Titan surface conditions. We suggest that acetonitrile:acetylene is in a plastic phase, in which acetonitrile molecules are dynamically disordered about the N–C–C axis on sub-picosecond timescales, and that this rotational, plastic disorder persists at least to temperatures of 30 K. We anticipate that many cryominerals may have plastic phases at or near Titan surface conditions, and understanding this disorder will be crucial to predicting chemistry on Titan’s surface.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141984333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural Composition and Molecular Weight Distribution of Dissolved Organic Matter in Bituminous Oil Sand from Okitipupa, Southern Nigeria","authors":"Gbenga Aladekoyi, Emmanuel G. Olumayede, Samuel O. Olusanya, Patricia A. Heiden, Simeon K. Schum","doi":"10.1021/acsearthspacechem.4c00062","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00062","url":null,"abstract":"The structural and exact molecular weight composition of the dissolved organic matter present in the oil sand from Okitipupa was investigated. Microscopic and spectroscopic methods were employed to determine the mineral composition and molecular structure of the compounds detected in the extracted bitumen. The extracted composite (dichloromethane/toluene solvent (<i>D</i>:<i>T</i>) ratio was 1:1 (50 mL each) and the sample-to-solvent ratio was 1:2.5 at 60 °C and 300 r/min. Elemental quantification of the oil sand from P1 (Loda) and P2 (Idiopopo) indicated a vast interaction of bitumen with clay minerals through their forms and compositions. The highest extractive quality of the compounds was obtained from P1 using 50:50 <i>D</i>:<i>T</i> extraction. P1 indicated an appreciable percentage of organic compounds with a maximum number of asphaltenes and aromatics as major components of bitumen, saturates, and resin. In P1, high concentrations of heteroatoms like nitrogen, oxygen, sulfur, and metals contributed to an increase in the viscosity and bonding of bitumen with embedded minerals compared to others. Oil sand in this region consists of complex heteroatomic compounds. Meanwhile, the van Krevelen plot revealed that the majority of formulas are in the regions H/C 0.5–2.5 <i>m</i>/<i>z</i> and O/C 0.1–0.5 <i>m</i>/<i>z</i>, which confirmed the diversity in the distribution of mass formulas for the samples. This revealed an important suggestion for understanding the geochemistry and exploitation of bitumen.","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141944259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural Composition and Molecular Weight Distribution of Dissolved Organic Matter in Bituminous Oil Sand from Okitipupa, Southern Nigeria","authors":"Gbenga Aladekoyi*,&nbsp;Emmanuel G. Olumayede,&nbsp;Samuel O. Olusanya,&nbsp;Patricia A. Heiden and Simeon K. Schum,&nbsp;","doi":"10.1021/acsearthspacechem.4c0006210.1021/acsearthspacechem.4c00062","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00062https://doi.org/10.1021/acsearthspacechem.4c00062","url":null,"abstract":"<p >The structural and exact molecular weight composition of the dissolved organic matter present in the oil sand from Okitipupa was investigated. Microscopic and spectroscopic methods were employed to determine the mineral composition and molecular structure of the compounds detected in the extracted bitumen. The extracted composite (dichloromethane/toluene solvent (<i>D</i>:<i>T</i>) ratio was 1:1 (50 mL each) and the sample-to-solvent ratio was 1:2.5 at 60 °C and 300 r/min. Elemental quantification of the oil sand from P1 (Loda) and P2 (Idiopopo) indicated a vast interaction of bitumen with clay minerals through their forms and compositions. The highest extractive quality of the compounds was obtained from P1 using 50:50 <i>D</i>:<i>T</i> extraction. P1 indicated an appreciable percentage of organic compounds with a maximum number of asphaltenes and aromatics as major components of bitumen, saturates, and resin. In P1, high concentrations of heteroatoms like nitrogen, oxygen, sulfur, and metals contributed to an increase in the viscosity and bonding of bitumen with embedded minerals compared to others. Oil sand in this region consists of complex heteroatomic compounds. Meanwhile, the van Krevelen plot revealed that the majority of formulas are in the regions H/C 0.5–2.5 <i>m</i>/<i>z</i> and O/C 0.1–0.5 <i>m</i>/<i>z</i>, which confirmed the diversity in the distribution of mass formulas for the samples. This revealed an important suggestion for understanding the geochemistry and exploitation of bitumen.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141984468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics of Cenomanian–Turonian Oceanic Anoxic Event 2 and its Impact on Organic Carbon Accumulation in the Abu Roash (F) Organic-Rich Carbonate Rocks in the Abu Gharadig Field, Egypt","authors":"Tamer E. Hamed,&nbsp;Mohammed Hail Hakimi*,&nbsp;Naira M. Lotfy,&nbsp;Mohammad Alqudah,&nbsp;Ali Y. Kahal,&nbsp;Afikah Rahim and Emad A. Eysa,&nbsp;","doi":"10.1021/acsearthspacechem.4c0000210.1021/acsearthspacechem.4c00002","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00002https://doi.org/10.1021/acsearthspacechem.4c00002","url":null,"abstract":"<p >The Cenomanian–Turonian was a period of climatic perturbations associated with extraordinary marine production of organic carbon during the redox conditions in the southern Neo-Tethys Ocean. The Abu Roash-F carbonates in the northwestern desert of Egypt were deposited during this period. This work revealed some organic and inorganic geochemical results combined with microscopic examinations of the carbonate rocks of the mid-Cretaceous Abu Roash-F Member from two exploration wells in the Abu Gharadig Basin, Egypt. This work was designed to understand the paleoenvironmental conditions during Cenomanian–Turonian oceanic anoxic event 2 (OAE2) and its impact on the organic carbon-rich accumulation in Abu Roash (F) carbonates. Geochemical proxies indicated that AR-F contains total organic matter and sulfur contents in the ranges of 0.89–3.32 and 0.30–2.73 wt %, respectively, confirming the marine environment for the studied samples. The presence of a marine environment, ranging from deep sea to slope and deep shelf, was also inferred by the large quantities of planktic forams and other marine skeletal assemblages, including bivalves and echinoderms, with rare ostracods. The Ni and V geochemical proxies, together with their ratios and enrichment factors, confirmed that these facies were mainly found in low oxygen environments, ranging from dysoxic to anoxic nonsulfidic conditions, thereby contributing to the preservation of organic matter. An Rb/Sr ratio of less than 0.1 indicated that the facies were accumulated in warm and humid climates, thereby resulting in an intensity of subaerial weathering. The dominant presence of warm-water plankton species (i.e., Globigerinoides sp.) together with a large number of primary producers (i.e., algae and dinocysts) in the Cenomanian–Turonian AR-F carbonate facies further suggested that warm climatic conditions occurred during OAE2. These warm climatic conditions can be the source of a mass influx of nutrients into the basins, which could be attributed to increased productivity of the water column. The high productivity was further supported by the presence of the shelf nannofossil taxon <i>Zeugrhabdotus erectus</i>. Such conditions resulted in high productivity and preservation of organic matter during OAE2, and thus, organic carbon-rich accumulation in the carbonate-rich sediments within the AR-F Member.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141984432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-Analyte Concentration Analysis of Marine Samples through Regression-Based Machine Learning","authors":"Nicole M. North, Jessica B. Clark, Abigail A. A. Enders, Alex J. Grooms, Salmika G. Wairegi, Kezia A. Duah, Efthimia I. Palassis-Naziri, Abraham Badu-Tawiah, Heather C. Allen","doi":"10.1021/acsearthspacechem.4c00018","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00018","url":null,"abstract":"Marine systems are incredibly chemically complex. An understanding of the chemical compounds that make up the chemical diversity in marine samples is critical to understanding ecological and ocean health metrics. Using Raman spectroscopy in tandem with machine learning combines a low-cost, highly transportable analytical technique with a powerful and rapid computational approach that can aid in marine analysis. Here, we use Raman spectroscopy and machine learning to identify mM concentrations of three chemically relevant compounds in three distinct classes in a complex aqueous matrix. Saccharides are represented by glucose, fatty acids by butyric acid, and proteins by an amino acid proxy through glycine. Eight classical machine learning models (gradient boosted regressors, random forests, histogram gradient boosted regressors, decision trees, k-nearest neighbors, support vector regression, multi-layer perceptrons, and multivariate linear regression) were tested for their accuracy in identifying the concentrations of glycine, glucose, and butyric acid in marine samples, which were benchmarked through a mass spectrometric method. Support vector regression was able to best identify all three concentrations of glycine, butyric acid, and glucose. Butyric acid was similarly well described through gradient boosted regression and histogram gradient boosted regression. The described spectroscopy and machine learning methodology has the potential to significantly advance rapid field analysis of marine samples.","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141865469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-Analyte Concentration Analysis of Marine Samples through Regression-Based Machine Learning","authors":"Nicole M. North,&nbsp;Jessica B. Clark,&nbsp;Abigail A. A. Enders,&nbsp;Alex J. Grooms,&nbsp;Salmika G. Wairegi,&nbsp;Kezia A. Duah,&nbsp;Efthimia I. Palassis-Naziri,&nbsp;Abraham Badu-Tawiah and Heather C. Allen*,&nbsp;","doi":"10.1021/acsearthspacechem.4c0001810.1021/acsearthspacechem.4c00018","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00018https://doi.org/10.1021/acsearthspacechem.4c00018","url":null,"abstract":"<p >Marine systems are incredibly chemically complex. An understanding of the chemical compounds that make up the chemical diversity in marine samples is critical to understanding ecological and ocean health metrics. Using Raman spectroscopy in tandem with machine learning combines a low-cost, highly transportable analytical technique with a powerful and rapid computational approach that can aid in marine analysis. Here, we use Raman spectroscopy and machine learning to identify mM concentrations of three chemically relevant compounds in three distinct classes in a complex aqueous matrix. Saccharides are represented by glucose, fatty acids by butyric acid, and proteins by an amino acid proxy through glycine. Eight classical machine learning models (gradient boosted regressors, random forests, histogram gradient boosted regressors, decision trees, k-nearest neighbors, support vector regression, multi-layer perceptrons, and multivariate linear regression) were tested for their accuracy in identifying the concentrations of glycine, glucose, and butyric acid in marine samples, which were benchmarked through a mass spectrometric method. Support vector regression was able to best identify all three concentrations of glycine, butyric acid, and glucose. Butyric acid was similarly well described through gradient boosted regression and histogram gradient boosted regression. The described spectroscopy and machine learning methodology has the potential to significantly advance rapid field analysis of marine samples.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141984433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics of Cenomanian–Turonian Oceanic Anoxic Event 2 and its Impact on Organic Carbon Accumulation in the Abu Roash (F) Organic-Rich Carbonate Rocks in the Abu Gharadig Field, Egypt","authors":"Tamer E. Hamed, Mohammed Hail Hakimi, Naira M. Lotfy, Mohammad Alqudah, Ali Y. Kahal, Afikah Rahim, Emad A. Eysa","doi":"10.1021/acsearthspacechem.4c00002","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00002","url":null,"abstract":"The Cenomanian–Turonian was a period of climatic perturbations associated with extraordinary marine production of organic carbon during the redox conditions in the southern Neo-Tethys Ocean. The Abu Roash-F carbonates in the northwestern desert of Egypt were deposited during this period. This work revealed some organic and inorganic geochemical results combined with microscopic examinations of the carbonate rocks of the mid-Cretaceous Abu Roash-F Member from two exploration wells in the Abu Gharadig Basin, Egypt. This work was designed to understand the paleoenvironmental conditions during Cenomanian–Turonian oceanic anoxic event 2 (OAE2) and its impact on the organic carbon-rich accumulation in Abu Roash (F) carbonates. Geochemical proxies indicated that AR-F contains total organic matter and sulfur contents in the ranges of 0.89–3.32 and 0.30–2.73 wt %, respectively, confirming the marine environment for the studied samples. The presence of a marine environment, ranging from deep sea to slope and deep shelf, was also inferred by the large quantities of planktic forams and other marine skeletal assemblages, including bivalves and echinoderms, with rare ostracods. The Ni and V geochemical proxies, together with their ratios and enrichment factors, confirmed that these facies were mainly found in low oxygen environments, ranging from dysoxic to anoxic nonsulfidic conditions, thereby contributing to the preservation of organic matter. An Rb/Sr ratio of less than 0.1 indicated that the facies were accumulated in warm and humid climates, thereby resulting in an intensity of subaerial weathering. The dominant presence of warm-water plankton species (i.e., Globigerinoides sp.) together with a large number of primary producers (i.e., algae and dinocysts) in the Cenomanian–Turonian AR-F carbonate facies further suggested that warm climatic conditions occurred during OAE2. These warm climatic conditions can be the source of a mass influx of nutrients into the basins, which could be attributed to increased productivity of the water column. The high productivity was further supported by the presence of the shelf nannofossil taxon <i>Zeugrhabdotus erectus</i>. Such conditions resulted in high productivity and preservation of organic matter during OAE2, and thus, organic carbon-rich accumulation in the carbonate-rich sediments within the AR-F Member.","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141865473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formation of S-Bearing Complex Organic Molecules in Interstellar Clouds via Ice Reactions with C2H2, HS, and Atomic H","authors":"Julia C. Santos*,&nbsp;Joan Enrique-Romero,&nbsp;Thanja Lamberts,&nbsp;Harold Linnartz and Ko-Ju Chuang,&nbsp;","doi":"10.1021/acsearthspacechem.4c0015010.1021/acsearthspacechem.4c00150","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00150https://doi.org/10.1021/acsearthspacechem.4c00150","url":null,"abstract":"<p >The chemical network governing interstellar sulfur has been the topic of unrelenting discussion for the past few decades due to the conspicuous discrepancy between its expected and observed abundances in different interstellar environments. More recently, the astronomical detections of CH₃CH₂SH and CH₂CS highlighted the importance of interstellar formation routes for sulfur-bearing organic molecules with two carbon atoms. In this work, we perform a laboratory investigation of the solid-state chemistry resulting from the interaction between C₂H₂ molecules and SH radicals─both thought to be present in interstellar icy mantles─at 10 K. Reflection absorption infrared spectroscopy and quadrupole mass spectrometry combined with temperature-programmed desorption experiments are employed as analytical techniques. We confirm that SH radicals can kick-start a sulfur reaction network under interstellar cloud conditions and identify at least six sulfurated products: CH₃CH₂SH, CH₂CHSH, HSCH₂CH₂SH, H₂S₂, and tentatively CH₃CHS and CH₂CS. Complementarily, we utilize computational calculations to pinpoint the reaction routes that play a role in the chemical network behind our experimental results. The main sulfur-bearing organic molecule formed under our experimental conditions is CH₃CH₂SH, and its formation yield increases with the ratios of H to other reactants. It serves as a sink to the sulfur budget within the network, being formed at the expense of the other unsaturated products. The astrophysical implications of the chemical network proposed here are discussed.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsearthspacechem.4c00150","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141984414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formation of S-Bearing Complex Organic Molecules in Interstellar Clouds via Ice Reactions with C2H2, HS, and Atomic H","authors":"Julia C. Santos, Joan Enrique-Romero, Thanja Lamberts, Harold Linnartz, Ko-Ju Chuang","doi":"10.1021/acsearthspacechem.4c00150","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00150","url":null,"abstract":"The chemical network governing interstellar sulfur has been the topic of unrelenting discussion for the past few decades due to the conspicuous discrepancy between its expected and observed abundances in different interstellar environments. More recently, the astronomical detections of CH₃CH₂SH and CH₂CS highlighted the importance of interstellar formation routes for sulfur-bearing organic molecules with two carbon atoms. In this work, we perform a laboratory investigation of the solid-state chemistry resulting from the interaction between C₂H₂ molecules and SH radicals─both thought to be present in interstellar icy mantles─at 10 K. Reflection absorption infrared spectroscopy and quadrupole mass spectrometry combined with temperature-programmed desorption experiments are employed as analytical techniques. We confirm that SH radicals can kick-start a sulfur reaction network under interstellar cloud conditions and identify at least six sulfurated products: CH₃CH₂SH, CH₂CHSH, HSCH₂CH₂SH, H₂S₂, and tentatively CH₃CHS and CH₂CS. Complementarily, we utilize computational calculations to pinpoint the reaction routes that play a role in the chemical network behind our experimental results. The main sulfur-bearing organic molecule formed under our experimental conditions is CH₃CH₂SH, and its formation yield increases with the ratios of H to other reactants. It serves as a sink to the sulfur budget within the network, being formed at the expense of the other unsaturated products. The astrophysical implications of the chemical network proposed here are discussed.","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Role of Organic Vapor in the Water Uptake of Organic Aerosols","authors":"Kotiba A. Malek, Nahin Ferdousi-Rokib, Dewansh Rastogi, Akua A. Asa-Awuku","doi":"10.1021/acsearthspacechem.4c00017","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00017","url":null,"abstract":"Organic solvents are ubiquitous in the atmosphere and can readily form a coated layer around the particles. While their presence has been widely reported, their effects on cloud droplet formation have been poorly understood. This study elucidated the effect of a prominent organic solvent on the water uptake of organic aerosols under the relevant environmental conditions. Specifically, we investigated the water uptake efficiencies of aerosols obtained from three organic isomers of different solubilities, namely, phthalic acid (PTA; high solubility), isophthalic acid (IPTA; partial solubility), and terephthalic acid (TPTA; low solubility) in the presence of aqueous-phase and gas-phase ethanol (EtOH). Using laboratory-based measurements, the water uptake properties were investigated under supersaturated and subsaturated conditions by using a cloud condensation nuclei counter (CCNC) and a hygroscopicity tandem differential mobility analyzer (H-TDMA), respectively. Under supersaturated conditions (0.86%), the critical diameter (<i>D</i>_d) of each system was reported and compared relative to the pure compounds. Under a supersaturated environment, the presence of EtOH was shown to increase the water uptake efficiency of partial and low solubility particles, IPTA and TPTA, but not the water-soluble PTA particles. In supersaturated environments, the intrinsic solubility of aerosol particles governs its water uptake behavior. Since PTA exhibits a high-water solubility, the presence of EtOH exerted little to no influence on the dissolution of PTA particles. Hence, EtOH had no impact on the water uptake of PTA particles. This is signified by the minimal change in critical diameter (∼0.1–2 nm) between the PTA systems that contained EtOH compared with the pure PTA particles. Conversely, the addition of EtOH to IPTA and TPTA aerosols enhanced the dissolution of these partial/low-water solubility particles, as a result, increasing their water uptake affinity. The addition of ethanol to IPTA and TPTA particles resulted in a decrease in critical diameter by ∼6–8.2 and ∼16–20.1 nm, respectively. Our subsaturated results show that EtOH has the opposite effect relative to our supersaturated results. Under a subsaturated environment, the water uptake affinity of PTA particles was enhanced by the presence of EtOH and diminished for IPTA and TPTA particles. The water uptake of PTA was enhanced with the presence of aqueous ethanol (<i>G</i>_f increased from ∼1.02 to ∼1.23), while IPTA and TPTA particles showed reduction in size (<i>G</i>_f decreased from ∼1.01 to ∼0.95). This is attributed to the morphological properties of the particles supported by TEM images and shape factor measurements. Hence, atmospheric organic solvents can readily coat aerosol particles and play a major role in the water uptake properties under sub- and super-saturated conditions.","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}