1
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Mayer S, Bergen A, Zhai Z, Trzeciak S, Chu J, Zahn D, Koller TM, Meyer K, Vogel N. Evolution of Surface Tension and Hansen Parameters of a Homologous Series of Imidazolium-Based Ionic Liquids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:9529-9542. [PMID: 38648374 DOI: 10.1021/acs.langmuir.4c00094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
In this study, we systematically analyze the surface tension and Hansen solubility parameters (HSPs) of imidazolium-based ionic liquids (ILs) with different anions ([NTf2]-, [PF6]-, [I]-, and [Br]-). These anions are combined with the classical 1-alkyl-3-methyl-substituted imidazolium cations ([CnC1Im]+) and a group of oligoether-functionalized imidazolium cations ([(mPEGn)2Im]+) based on methylated polyethylene glycol (mPEGn). In detail, the influences of the length of the alkyl- and the mPEGn-chain, the anion size, and the water content are investigated experimentally. For [CnC1Im]+-based ILs, the surface tension decreases with increasing alkyl chain length in all cases, but the magnitude of this decrease depends on the size of the anion ([NTf2]- < [PF6]- < [Br]- ≤ [I]-). Molecular dynamics (MD) simulations on [CnC1Im]+-based ILs indicate that these differences are caused by the interplay of charged and uncharged domains, in particular in the different anions, which affects the ability of the alkyl chains of the cation to orient toward the liquid-gas interface. An increase in the mPEGn-chain length of the [(mPEGn)2Im][A] ILs does not significantly influence the surface tension. These changes upon variation of the cation/anion combination do not correlate with the evolution of the HSPs for the two sets of ILs. Finally, our data suggest that significant water contents up to water mole fractions of x(H2O) = 0.25 do not significantly affect the surface tension of the studied binary IL-water mixtures.
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Affiliation(s)
- Sophie Mayer
- Institute of Particle Technology, Department of Chemical and Biological Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstr. 4, 91058 Erlangen, Germany
| | - Alexander Bergen
- Inorganic Chemistry, Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstr.1, 91058 Erlangen, Germany
| | - Ziwen Zhai
- Institute of Advanced Optical Technologies─Thermophysical Properties (AOT-TP), Department of Chemical and Biological Engineering and Erlangen Graduate School in Advanced Optical Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Paul-Gordan-Str. 8, 91052 Erlangen, Germany
| | - Simon Trzeciak
- Computer Chemistry Center/Theoretical Chemistry, Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Nägelsbachstr. 25, 91052 Erlangen, Germany
| | - Junyu Chu
- Inorganic Chemistry, Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstr.1, 91058 Erlangen, Germany
| | - Dirk Zahn
- Computer Chemistry Center/Theoretical Chemistry, Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Nägelsbachstr. 25, 91052 Erlangen, Germany
| | - Thomas M Koller
- Institute of Advanced Optical Technologies─Thermophysical Properties (AOT-TP), Department of Chemical and Biological Engineering and Erlangen Graduate School in Advanced Optical Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Paul-Gordan-Str. 8, 91052 Erlangen, Germany
| | - Karsten Meyer
- Inorganic Chemistry, Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstr.1, 91058 Erlangen, Germany
| | - Nicolas Vogel
- Institute of Particle Technology, Department of Chemical and Biological Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstr. 4, 91058 Erlangen, Germany
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2
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Carvalho RM, Santos LMNBF, Bastos M, Costa JCS. Carbon-Induced Changes in the Morphology and Wetting Behavior of Ionic Liquids on the Mesoscale. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024. [PMID: 38343280 PMCID: PMC10883047 DOI: 10.1021/acs.langmuir.4c00102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/25/2024]
Abstract
Thin films of ionic liquids (ILs) have gained significant attention due to their unique properties and broad applications. Extensive research has focused on studying the influence of ILs' chemical composition and substrate characteristics on the structure and morphology of IL films at the nano- and mesoscopic scales. This study explores the impact of carbon-coated surfaces on the morphology and wetting behavior of a series of alkylimidazolium-based ILs. Specifically, this work investigates the effect of carbon coating on the morphology and wetting behavior of short-chain ([C2C1im][NTf2] and [C2C1im][OTf]) and long-chain ([C8C1im][NTf2] and [C8C1im][OTf]) ILs deposited on indium tin oxide (ITO), silver (Ag), and gold (Au) substrates. A reproducible vapor deposition methodology was utilized for the deposition process. High-resolution scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy were used to analyze the morphological and structural characteristics of the substrates and obtained IL films. The experimental data revealed that the IL films deposited on carbon-coated Au substrates showed minor changes in their morphology compared to that of the films deposited on clean Au surfaces. However, the presence of carbon coatings on the ITO and Ag surfaces led to significant morphological alterations in the IL films. Specifically, for short-chain ILs, the carbon film surface induced 2D growth of the IL film, followed by subsequent island growth. In contrast, for long-chain ILs deposited on carbon surfaces, layer-by-layer growth occurred without island formation, resulting in highly uniform and coalesced IL films. The extent of morphological changes observed in the IL films was found to be influenced by two crucial factors: the thickness of the carbon film on the substrate surface and the amount of IL deposition.
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Affiliation(s)
- Rita M Carvalho
- CIQUP, Institute of Molecular Sciences (IMS), Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre s/n, P4169-007 Porto, Portugal
| | - Luís M N B F Santos
- CIQUP, Institute of Molecular Sciences (IMS), Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre s/n, P4169-007 Porto, Portugal
| | - Margarida Bastos
- CIQUP, Institute of Molecular Sciences (IMS), Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre s/n, P4169-007 Porto, Portugal
| | - José C S Costa
- CIQUP, Institute of Molecular Sciences (IMS), Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre s/n, P4169-007 Porto, Portugal
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3
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Dynamic wetting of various liquids: Theoretical models, experiments, simulations and applications. Adv Colloid Interface Sci 2023; 313:102861. [PMID: 36842344 DOI: 10.1016/j.cis.2023.102861] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 02/12/2023] [Accepted: 02/13/2023] [Indexed: 02/23/2023]
Abstract
Dynamic wetting is a ubiquitous phenomenon and frequently observed in our daily life, as exemplified by the famous lotus effect. It is also an interfacial process of upmost importance involving many cutting-edge applications and has hence received significantly increasing academic and industrial attention for several decades. However, we are still far away to completely understand and predict wetting dynamics for a given system due to the complexity of this dynamic process. The physics of moving contact lines is mainly ascribed to the full coupling with the solid surface on which the liquids contact, the atmosphere surrounding the liquids, and the physico-chemical characteristics of the liquids involved (small-molecule liquids, metal liquids, polymer liquids, and simulated liquids). Therefore, to deepen the understanding and efficiently harness wetting dynamics, we propose to review the major advances in the available literature. After an introduction providing a concise and general background on dynamic wetting, the main theories are presented and critically compared. Next, the dynamic wetting of various liquids ranging from small-molecule liquids to simulated liquids are systematically summarized, in which the new physical concepts (such as surface segregation, contact line fluctuations, etc.) are particularly highlighted. Subsequently, the related emerging applications are briefly presented in this review. Finally, some tentative suggestions and challenges are proposed with the aim to guide future developments.
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4
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Bhattacharjee S, Khan S. Quantification of the impact of water on the wetting behavior of hydrophilic ionic liquid: a molecular dynamics study. MOLECULAR SIMULATION 2023. [DOI: 10.1080/08927022.2023.2175171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Affiliation(s)
- Sanchari Bhattacharjee
- Department of Chemical & Biochemical Engineering, Indian Institute of Technology Patna, Patna, India
| | - Sandip Khan
- Department of Chemical & Biochemical Engineering, Indian Institute of Technology Patna, Patna, India
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5
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Aldhaleai A, Tsai PA. Dynamic Wetting of Ionic Liquid Drops on Hydrophobic Microstructures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:16073-16083. [PMID: 36516403 PMCID: PMC9799069 DOI: 10.1021/acs.langmuir.2c02694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/09/2022] [Indexed: 06/17/2023]
Abstract
Ionic liquids (ILs)─salts in a liquid state─play a crucial role in various applications, such as green solvents for chemical synthesis and catalysis, lubricants, especially for micro- and nanoelectromechanical systems, and electrolytes in solar cells. These applications critically rely on unique or tunable bulk properties of ionic liquids, such as viscosity, density, and surface tension. Furthermore, their interactions with different solid surfaces of various roughness and structures may uphold other promising applications, such as combustion, cooling, and coating. However, only a few systematic studies of IL wetting and interactions with solid surfaces exist. Here, we experimentally and theoretically investigate the dynamic wetting and contact angles (CA) of water and three kinds of ionic liquid droplets on hydrophobic microstructures of surface roughness (r = 2.61) and packing fraction (ϕ = 0.47) formed by micropillars arranged in a periodic pattern. The results show that, except for water, higher-viscosity ionic liquids have greater advancing and receding contact angles with increasing contact line velocity. Water drops initially form a gas-trapping, CB wetting state, whereas all three ionic liquid drops are in a Wenzel wetting state, where liquids penetrate and completely wet the microstructures. We find that an existing model comparing the global surface energies between a CB and a Wenzel state agrees well with the observed wetting states. In addition, a molecular dynamic model well predicts the experimental data and is used to explain the observed dynamic wetting for the ILs and superhydrophobic substrate. Our results further show that energy dissipation occurs more significantly in the three-phase contact line region than in the liquid bulk.
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Combining thermosensitive physical self-assembly and covalent cycloaddition chemistry as simultaneous dual cross-linking mechanisms for the preparation of injectable hydrogels with tuneable properties. Eur Polym J 2022. [DOI: 10.1016/j.eurpolymj.2022.111761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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7
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Mushtaq M, Butt FW, Akram S, Ashraf R, Ahmed D. Deep Eutectic Liquids as Tailorable Extraction Solvents: A Review of Opportunities and Challenges. Crit Rev Anal Chem 2022:1-27. [PMID: 36148704 DOI: 10.1080/10408347.2022.2125284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Deep Eutectic Liquids (DELs) fall among the rapidly evolving discoveries of the 21st century, and these liquids are considered as alternative solvents to toxic and volatile organic liquids. Nevertheless, the emerging trend regarding the use of DELs in every field of physical and biological sciences, a lot of ambiguities and misconceptions exist about their formation, mechanism, and efficiencies observed or projected. A review of available technical data makes it obvious that these liquids have the potential to revolutionize the underdeveloped areas of analytical chemistry particularly the extraction/enrichment of analytes. To ensure the green and sustainable use of DELs, the researchers need to have a thorough understanding of DELs, their classification, chemistry, the nature and strength of molecular entanglements, and their tailorable features. Many researchers have declared these liquids recyclable but more attentive trials are needed to develop an authentic and straightforward DELs recycling methodology. The present review covers sound background knowledge and expert opinions about the technical definition of DELs, their classification, formation, recyclability, and tailorable features for their application as extraction solvent/sorbent in analytical chemistry.
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Affiliation(s)
- Muhammad Mushtaq
- Department of Chemistry, Government College University, Lahore, Pakistan
| | - Faizan Waseem Butt
- Department of Chemistry, Government College University, Lahore, Pakistan
| | - Sumia Akram
- Division of Science and Technology, University of Education Lahore, Lahore, Pakistan
| | - Rizwan Ashraf
- Department of Chemistry, University of Agriculture, Faisalabad, Pakistan
| | - Dildar Ahmed
- Department of Chemistry, Forman Christian College University Lahore, Lahore, Pakistan
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8
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Nucleation, Coalescence, and Thin-Film Growth of Triflate-Based Ionic Liquids on ITO, Ag, and Au Surfaces. COLLOIDS AND INTERFACES 2022. [DOI: 10.3390/colloids6030046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study investigates the nucleation and growth of micro-/nanodroplets of triflate-based ionic liquids (ILs) fabricated by vapor deposition on different surfaces: indium tin oxide (ITO); silver (Ag); gold (Au). The ILs studied are constituted by the alkylimidazolium cation and the triflate anion—[CnC1im][OTF] series. One of the key issues that determine the potential applications of ILs is the wettability of surfaces. Herein, the wetting behavior was evaluated by changing the cation alkyl chain length (C2 to C10). A reproducible control of the deposition rate was conducted employing Knudsen cells, and the thin-film morphology was evaluated by high-resolution scanning electron microscopy (SEM). The study reported here for the [CnC1im][OTF] series agrees with recent data for the [CnC1im][NTf2] congeners, highlighting the higher wettability of the solid substrates to long-chain alkylimidazolium cations. Compared to [NTf2], the [OTF] series evidenced an even more pronounced wetting ability on Au and coalescence processes of droplets highly intense on ITO. Higher homogeneity and film cohesion were found for cationic groups associated with larger alkyl side chains. An island growth was observed on both Ag and ITO substrates independently of the cation alkyl chain length. The Ag surface promoted the formation of smaller-size droplets. A quantitative analysis of the number of microdroplets formed on Ag and ITO revealed a trend shift around [C6C1im][OTF], emphasizing the effect of the nanostructuration intensification due to the formation of nonpolar continuous domains.
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Costa JCS, Alves A, Bastos M, Santos LMNBF. The impact of the cation alkyl chain length on the wettability of alkylimidazolium-based ionic liquids at the nanoscale. Phys Chem Chem Phys 2022; 24:13343-13355. [PMID: 35608141 DOI: 10.1039/d2cp01868c] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ionic liquids (ILs) have been widely used for energy storage and conversion devices due to their negligible vapor pressure, high thermal stability, and outstanding interfacial properties. Notably, the interfacial nanostructure and the wettability of thin ionic liquid films on solid surfaces are of utmost relevance in nanosurface science and technology. Herein, a reproducible physical vapor deposition methodology was used to fabricate thin films of four alkylimidazolium bis(trifluoromethylsulfonyl)imide ILs. The effect of the cation alkyl chain length on the wettability of ILs was explored on different surfaces: gold (Au); silver (Ag); indium-tin oxide (ITO). High-resolution scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to evaluate the morphology of the produced micro- and nanodroplets and films. SEM and AFM results revealed an island growth for all the ILs deposited on ITO and Ag surfaces, with a lower minimum free area to promote nucleation (MFAN) in Ag and higher wettability for ILs having larger non-polar domains. The low wettability of ITO by the studied ILs was highlighted. For long-chain ILs, nucleation and growth mechanisms were strongly conditioned by coalescence processes. The results also supported the higher affinity of the ILs to the Au surface. The increase in the length of the cation alkyl chain was found to promote a better film adhesion inducing a 2D growth and higher wetting ability.
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Affiliation(s)
- José C S Costa
- CIQUP, Institute of Molecular Sciences (IMS), Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, P4169-007, Porto, Portugal.
| | - Alexandre Alves
- CIQUP, Institute of Molecular Sciences (IMS), Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, P4169-007, Porto, Portugal.
| | - Margarida Bastos
- CIQUP, Institute of Molecular Sciences (IMS), Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, P4169-007, Porto, Portugal.
| | - Luís M N B F Santos
- CIQUP, Institute of Molecular Sciences (IMS), Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, P4169-007, Porto, Portugal.
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10
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Yan J, Gundsambuu B, Krasowska M, Platts K, Facal Marina P, Gerber C, Barry SC, Blencowe A. Injectable Diels-Alder cycloaddition hydrogels with tuneable gelation, stiffness and degradation for the sustained release of T-lymphocytes. J Mater Chem B 2022; 10:3329-3343. [PMID: 35380575 DOI: 10.1039/d2tb00274d] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Engineered T-cell therapies have proven highly efficacious for the treatment of haematological cancers, but translation of this success to solid tumours has been limited, in part, due to difficulties in maintaining high doses at specific target sites. Hydrogel delivery systems that provide a sustained release of T-cells at the target site are emerging as a promising strategy. Therefore, in this study we aimed to develop an injectable hydrogel that gels in situ via efficient Diels-Alder cycloaddition (DAC) chemistry and provides a sustained release of T-cells through gradual hydrolysis of the hydrogel matrix. Hydrogels were prepared via the DAC between fulvene and maleimide functionalised poly(ethylene glycol) (PEG) derivatives. By adjusting the concentration and molecular weight of the functionalised PEGs in the hydrogel formulation the in vitro gelation time (Tgel), initial Young's modulus (E) and degradation time (Td) could be tailored from 15-150 min, 5-179 kPa and 7-114 h, respectively. Prior to gelation, the formulations could be readily injected through narrow gauge (26 G) needles with the working time correlating closely with the Tgel. A 5 wt% hydrogel formation with conjugated cyclic RGD motif was found to be optimal for the encapsulation and release of CD3+ T-cells with a near linear release profile and >70% cell viability over the first 4 d and release continuing out to 7 d. With their tuneable Tgel, Td and stiffness, the DAC hydrogels provide the opportunity to control the release period and profile of encapsulated cells.
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Affiliation(s)
- Jie Yan
- Applied Chemistry and Translational Biomaterials (ACTB) Group, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia 5000, Australia.
| | - Batjargal Gundsambuu
- Molecular Immunology, Robinson Research Institute, University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Marta Krasowska
- Surface Interaction and Soft Matter (SISM) Group, Future Industries Institute (FII), UniSA STEM, University of South Australia, Mawson Lakes, South Australia 5095, Australia
| | - Kirsten Platts
- Applied Chemistry and Translational Biomaterials (ACTB) Group, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia 5000, Australia.
| | - Paula Facal Marina
- Applied Chemistry and Translational Biomaterials (ACTB) Group, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia 5000, Australia.
| | - Cobus Gerber
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia 5000, Australia
| | - Simon C Barry
- Molecular Immunology, Robinson Research Institute, University of Adelaide, Adelaide, South Australia 5005, Australia.,Department of Gastroenterology, Women's and Children's Hospital, SA Health, Adelaide, South Australia 5006, Australia
| | - Anton Blencowe
- Applied Chemistry and Translational Biomaterials (ACTB) Group, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia 5000, Australia.
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11
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Ivanova N, Esenbaev T. Wetting and dewetting behaviour of hygroscopic liquids: Recent advancements. Curr Opin Colloid Interface Sci 2021. [DOI: 10.1016/j.cocis.2020.101399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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12
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Bhattacharjee S, Chakraborty D, Khan S. Wetting behavior of aqueous 1-alkyl-3-methylimidazolium tetrafluoroborate {[Cn MIM][BF4] (n = 2, 4, 6)} on graphite surface. Chem Eng Sci 2021. [DOI: 10.1016/j.ces.2020.116078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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13
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Hansen BB, Spittle S, Chen B, Poe D, Zhang Y, Klein JM, Horton A, Adhikari L, Zelovich T, Doherty BW, Gurkan B, Maginn EJ, Ragauskas A, Dadmun M, Zawodzinski TA, Baker GA, Tuckerman ME, Savinell RF, Sangoro JR. Deep Eutectic Solvents: A Review of Fundamentals and Applications. Chem Rev 2020; 121:1232-1285. [PMID: 33315380 DOI: 10.1021/acs.chemrev.0c00385] [Citation(s) in RCA: 702] [Impact Index Per Article: 175.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Deep eutectic solvents (DESs) are an emerging class of mixtures characterized by significant depressions in melting points compared to those of the neat constituent components. These materials are promising for applications as inexpensive "designer" solvents exhibiting a host of tunable physicochemical properties. A detailed review of the current literature reveals the lack of predictive understanding of the microscopic mechanisms that govern the structure-property relationships in this class of solvents. Complex hydrogen bonding is postulated as the root cause of their melting point depressions and physicochemical properties; to understand these hydrogen bonded networks, it is imperative to study these systems as dynamic entities using both simulations and experiments. This review emphasizes recent research efforts in order to elucidate the next steps needed to develop a fundamental framework needed for a deeper understanding of DESs. It covers recent developments in DES research, frames outstanding scientific questions, and identifies promising research thrusts aligned with the advancement of the field toward predictive models and fundamental understanding of these solvents.
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Affiliation(s)
- Benworth B Hansen
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee37996-2200, United States
| | - Stephanie Spittle
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee37996-2200, United States
| | - Brian Chen
- Department of Chemical and Biomolecular Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Derrick Poe
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Yong Zhang
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Jeffrey M Klein
- Department of Chemical and Biomolecular Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Alexandre Horton
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee37996-2200, United States
| | - Laxmi Adhikari
- Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211, United States
| | - Tamar Zelovich
- Department of Chemistry, New York University, New York, New York 10003, United States
| | - Brian W Doherty
- Department of Chemistry, New York University, New York, New York 10003, United States
| | - Burcu Gurkan
- Department of Chemical and Biomolecular Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Edward J Maginn
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Arthur Ragauskas
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee37996-2200, United States
| | - Mark Dadmun
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37916, United States
| | - Thomas A Zawodzinski
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee37996-2200, United States
| | - Gary A Baker
- Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211, United States
| | - Mark E Tuckerman
- Department of Chemistry, New York University, New York, New York 10003, United States
| | - Robert F Savinell
- Department of Chemical and Biomolecular Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Joshua R Sangoro
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee37996-2200, United States
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14
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Wang YL, Li B, Sarman S, Mocci F, Lu ZY, Yuan J, Laaksonen A, Fayer MD. Microstructural and Dynamical Heterogeneities in Ionic Liquids. Chem Rev 2020; 120:5798-5877. [PMID: 32292036 PMCID: PMC7349628 DOI: 10.1021/acs.chemrev.9b00693] [Citation(s) in RCA: 183] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Indexed: 12/11/2022]
Abstract
Ionic liquids (ILs) are a special category of molten salts solely composed of ions with varied molecular symmetry and charge delocalization. The versatility in combining varied cation-anion moieties and in functionalizing ions with different atoms and molecular groups contributes to their peculiar interactions ranging from weak isotropic associations to strong, specific, and anisotropic forces. A delicate interplay among intra- and intermolecular interactions facilitates the formation of heterogeneous microstructures and liquid morphologies, which further contributes to their striking dynamical properties. Microstructural and dynamical heterogeneities of ILs lead to their multifaceted properties described by an inherent designer feature, which makes ILs important candidates for novel solvents, electrolytes, and functional materials in academia and industrial applications. Due to a massive number of combinations of ion pairs with ion species having distinct molecular structures and IL mixtures containing varied molecular solvents, a comprehensive understanding of their hierarchical structural and dynamical quantities is of great significance for a rational selection of ILs with appropriate properties and thereafter advancing their macroscopic functionalities in applications. In this review, we comprehensively trace recent advances in understanding delicate interplay of strong and weak interactions that underpin their complex phase behaviors with a particular emphasis on understanding heterogeneous microstructures and dynamics of ILs in bulk liquids, in mixtures with cosolvents, and in interfacial regions.
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Affiliation(s)
- Yong-Lei Wang
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Bin Li
- School
of Chemical Engineering and Technology, Sun Yat-sen University, Zhuhai 519082, P. R. China
| | - Sten Sarman
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Francesca Mocci
- Department
of Chemical and Geological Sciences, University
of Cagliari, I-09042 Monserrato, Italy
| | - Zhong-Yuan Lu
- State
Key Laboratory of Supramolecular Structure and Materials, Institute
of Theoretical Chemistry, Jilin University, Changchun 130021, P. R. China
| | - Jiayin Yuan
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Aatto Laaksonen
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
- State
Key Laboratory of Materials-Oriented and Chemical Engineering, Nanjing Tech University, Nanjing 210009, P. R. China
- Centre of
Advanced Research in Bionanoconjugates and Biopolymers, Petru Poni Institute of Macromolecular Chemistry Aleea Grigore Ghica-Voda, 41A, 700487 Iasi, Romania
- Department
of Engineering Sciences and Mathematics, Division of Energy Science, Luleå University of Technology, SE-97187 Luleå, Sweden
| | - Michael D. Fayer
- Department
of Chemistry, Stanford University, Stanford, California 94305, United States
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Bhattacharjee S, Khan S. The wetting behavior of aqueous imidazolium based ionic liquids: a molecular dynamics study. Phys Chem Chem Phys 2020; 22:8595-8605. [PMID: 32255456 DOI: 10.1039/d0cp00143k] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aqueous ionic liquids are of particular interest due to their tunability of physical and chemical properties and a deeper understanding of their structure-property relationship is desired. Molecular dynamics (MD) simulations were conducted to study the wetting behavior of aqueous imidazolium-based ionic liquids (ILs), consisting of a 1-ethyl-3-methylimidazolium [EMIM]+ cation and either a hydrophilic boron tetrafluoride [BF4]- or a hydrophobic bis(trifluoromethylsulfonyl)imide [NTF2]- anion mixed in water. To understand the effect of anion and concentration of ILs at the graphite solid-liquid interface, wettability studies were performed with IL concentrations from 0-50 wt%. The contact angle of aqueous IL droplets decreases with increasing IL concentration. Droplet characteristics near the surface were investigated by profiling the density perpendicular (z-direction) and horizontal (r-direction) to the graphite sheet; this was further quantified by an orientation order parameter. Due to the preferred adsorption of ILs, water depletes near the surface as IL concentration increases. The hydrophobic [NTF2]- anion forces the IL toward the interface from the bulk, whereas the hydrophilic [BF4]- anion causes the IL to remain in the bulk of the droplet. Differences in water-anion hydrogen bonding, the nature of the anions, and their interfacial tensions are crucial factors in the wetting behavior of aqueous ionic liquids.
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Affiliation(s)
- Sanchari Bhattacharjee
- Department of Chemical and Biochemical Engineering, Indian Institute of Technology Patna, 801103, India.
| | - Sandip Khan
- Department of Chemical and Biochemical Engineering, Indian Institute of Technology Patna, 801103, India.
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Lexow M, Massicot S, Maier F, Steinrück HP. Stability and Exchange Processes in Ionic Liquid/Porphyrin Composite Films on Metal Surfaces. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2019; 123:29708-29721. [PMID: 31867088 PMCID: PMC6913898 DOI: 10.1021/acs.jpcc.9b08531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 11/12/2019] [Indexed: 06/10/2023]
Abstract
In light of increasing interest in the development of organic-organic multicomponent heterostructures on metals, this molecular-scale study investigates prototypical composite systems of ultrathin porphyrin and ionic liquid (IL) films on metallic supports under well-defined ultrahigh vacuum conditions. By means of angle-resolved X-ray photoelectron spectroscopy, we investigated the adsorption, stability, and thermal exchange of the resulting films after sequential physical vapor deposition of the free-base porphyrin 5,10,15,20-tetraphenylporphyrin, 2H-TPP, and the IL 1-methyl-3-octylimidazolium hexafluorophosphate, [C8C1Im][PF6], on Ag(111) and Au(111). 2H-TPP shows two-dimensional growth of up to two closed molecular layers on Ag(111) and Au(111) and three-dimensional island growth for thicker films. IL films on top of a monolayer of 2H-TPP exhibit Stranski-Krastanov-like growth and are stable up to 385 K. The 2H-TPP layer leads to destabilization of the IL films, compared to the IL in direct contact with the bare metals, by inhibiting the specific adsorption of the ions on the metal surfaces. When the porphyrin is deposited on top of [C8C1Im][PF6] at low temperature, the 2H-TPP molecules adsorb on top of the IL film at first but replace the IL at the IL/metal interfaces upon heating above 240 K. This exchange process is most likely driven by the higher adsorption energy of 2H-TPP on Ag(111) and Au(111) surfaces, as compared to the IL. The behavior observed on Ag(111) and Au(111) is identical. The results are highly relevant for the stability of porphyrin/IL-based thin film catalyst systems and molecular devices, and more generally, stacked organic multilayer architectures.
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