1
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Ariga K. Interface-Interactive Nanoarchitectonics: Solid and/or Liquid. Chemphyschem 2024:e202400596. [PMID: 38965042 DOI: 10.1002/cphc.202400596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 07/03/2024] [Accepted: 07/04/2024] [Indexed: 07/06/2024]
Abstract
The methodology of nanoarchitectonics is to construct functional materials using nanounits such as atoms, molecules, and nanoobjects, just like architecting buildings. Nanoarchitectonics pursues the ultimate concept of materials science through the integration of related fields. In this review paper, under the title of interface-interactive nanoarchitectonics, several examples of structure fabrication and function development at interfaces will be discussed, highlighting the importance of architecting materials with nanoscale considerations. Two sections provide some examples at the solid and liquid surfaces. In solid interfacial environments, molecular structures can be precisely observed and analyzed with theoretical calculations. Solid surfaces are a prime site for nanoarchitectonics at the molecular level. Nanoarchitectonics of solid surfaces has the potential to pave the way for cutting-edge functionality and science based on advanced observation and analysis. Liquid surfaces are more kinetic and dynamic than solid interfaces, and their high fluidity offers many possibilities for structure fabrications by nanoarchitectonics. The latter feature has advantages in terms of freedom of interaction and diversity of components, therefore, liquid surfaces may be more suitable environments for the development of functionalities. The final section then discusses what is needed for the future of material creation in nanoarchitectonics.
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Affiliation(s)
- Katsuhiko Ariga
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, 305-0044, Japan
- Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa, 277-8561, Japan
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2
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Fargher HA, Delmau LH, Bryantsev VS, Haley MM, Johnson DW, Moyer BA. Disrupting the Hofmeister bias in salt liquid-liquid extraction with an arylethynyl bisurea anion receptor. Chem Sci 2024; 15:5311-5318. [PMID: 38577371 PMCID: PMC10988605 DOI: 10.1039/d3sc05922g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 03/04/2024] [Indexed: 04/06/2024] Open
Abstract
Host-mediated liquid-liquid extraction is a convenient method for the separation of inorganic salts. However, selective extraction of an anion, regardless of its hydrophilicity or lipophilicity as qualitatively described by its place in the Hofmeister series, remains challenging. Herein we report the complete disruption of the Hofmeister-based ordering of anions in host-mediated extraction by a rigidified tweezer-type receptor possessing remarkably strong anion-binding affinity under the conditions examined. Experiments introduce a convenient new method for determination of anion binding using phosphorus inductively coupled plasma mass spectrometry (ICP-MS) to measure extraction of tetra-n-butylphosphonium (TBP+) salts from water into nitrobenzene, specifically examining the disrupting effect of the added arylethynyl bisurea anion receptor. In the absence of the receptor, the salt partitioning follows the expected Hofmeister-type ordering favoring the larger, less hydrated anions; the analysis yields the value -24 kJ mol-1 for the standard Gibbs energy of partitioning of TBP+ cation from water into nitrobenzene at 25 °C. Selectivity is markedly changed by the addition of receptor to the nitrobenzene and is concentration dependent, giving rise to three selectivity regimes. We then used SXLSQI liquid-liquid equilibrium analysis software developed at Oak Ridge National Laboratory to fit host-mediated extraction equilibria for TBP+ salts of Cl-, Br-, I-, and NO3- to the distribution data. While the reverse-Hofmeister 1 : 1 binding of the anions by the receptor effectively cancels the Hofmeister selectivity of the TBPX partitioning into nitrobenzene, formation of unexpected 2 : 1 receptor : anion complexes favoring Cl- and Br- dominates the selectivity at elevated receptor concentrations, producing the unusual order Br- > Cl- > NO3- > I- in anion distribution wherein a middle member of the series is selected and the most lipophilic anion is disfavored. Density functional theory calculations confirmed the likelihood of forming 2 : 1 complexes, where Cl- and Br- are encapsulated by two receptors adopting energetically competitive single or double helix structures. The calculations explain the rare non-Hofmeister preference for Br-. This example shows that anion receptors can be used to control the selectivity and efficiency of salt extraction regardless of the position of the anion in the Hofmeister series.
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Affiliation(s)
- Hazel A Fargher
- Department of Chemistry and Biochemistry, Materials Science Institute, University of Oregon Eugene OR 97403-1253 USA
| | - Lætitia H Delmau
- Radioisotope Science and Technology Division, Oak Ridge National Laboratory Oak Ridge TN 37831-6384 USA
| | | | - Michael M Haley
- Department of Chemistry and Biochemistry, Materials Science Institute, University of Oregon Eugene OR 97403-1253 USA
| | - Darren W Johnson
- Department of Chemistry and Biochemistry, Materials Science Institute, University of Oregon Eugene OR 97403-1253 USA
| | - Bruce A Moyer
- Chemical Sciences Division, Oak Ridge National Laboratory Oak Ridge TN 37831-6119 USA
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3
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Olson AL, Alghamdi AO, Geiger FM. NaCl, MgCl 2, and AlCl 3 Surface Coverages on Fused Silica and Adsorption Free Energies at pH 4 from Nonlinear Optics. J Phys Chem A 2024; 128:2162-2168. [PMID: 38470438 DOI: 10.1021/acs.jpca.4c00514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
We employ amplitude- and phase-resolved second harmonic generation experiments to probe interactions of fused silica:aqueous interfaces with Al3+, Mg2+, and Na+ cations at pH 4 and as a function of metal cation concentration. We quantify the second-order nonlinear susceptibility and the total interfacial potential in the presence and absence of a 10 mM screening electrolyte to understand the influence of charge screening on cation adsorption. Strong cation:surface interactions are observed in the absence of the screening electrolyte. The total potential is then employed to estimate the total number of absorbed cations cm-2. The contributions to the total potential from the bound and mobile charges were separated using Gouy-Chapman-Stern model estimates. All three cations bind fully reversibly, indicating physisorption as the mode of interaction. Of the isotherm models tested, the Kd adsorption model fits the data with binding constants of 3-30 and ∼300 mol-1 for the low (<0.1 mM) and high (0.1-3 mM) concentration regimes, corresponding to adsorption free energies of -13 to -18 and -24 kJ mol-1 at room temperature, respectively. The maximum surface coverages are around 1013 cations cm-2, matching the number of deprotonated silanol groups on silica at pH 4. Clear signs of decoupled Stern and diffuse layer nonlinear optical responses are observed and found to be cation-specific.
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Affiliation(s)
- Alyssa L Olson
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60202, United States
| | - Amani O Alghamdi
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60202, United States
| | - Franz M Geiger
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60202, United States
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4
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Banning DH, Kuhl GM, Howell MM, Johnson DW. Evaluating impacts of bambusuril pocket size and sterics on anion binding trends using ChemFET sensors. Org Biomol Chem 2024; 22:269-273. [PMID: 37982641 DOI: 10.1039/d3ob01781h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
Chemically-sensitive Field Effect Transistors (ChemFETs) are a useful tool to evaluate aqueous anion affinity of hydrophobic supramolecular scaffolds. More specifically, ChemFETs can be used to probe impacts of receptor modification to aqueous anion affinity. In this study, ChemFETs are used to evaluate the anion affinity of both dodeca-n-butyl bambus[6]uril and dodecabenzyl bambus[6]uril to assess steric effects in the chemical selectivity of the sensor membrane. The ChemFETs were evaluated through a series of common anions in the Hofmeister series in order to ascertain the difference in detection limit imparted by the specific functionalization of the bambus[6]uril macrocycles, which are quite sensitive to modest steric effects. Significant improvements to perchlorate and nitrate detection limits were observed via n-butyl bambusuril-containing sensor membranes over detection limits recorded with benzyl bambusuril sensors.
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Affiliation(s)
- Douglas H Banning
- Department of Chemistry & Biochemistry and Materials Science Institute, University of Oregon, 97403-1253 Eugene, OR, USA.
| | - Grace M Kuhl
- Department of Chemistry & Biochemistry and Materials Science Institute, University of Oregon, 97403-1253 Eugene, OR, USA.
| | - Madeline M Howell
- Department of Chemistry & Biochemistry and Materials Science Institute, University of Oregon, 97403-1253 Eugene, OR, USA.
| | - Darren W Johnson
- Department of Chemistry & Biochemistry and Materials Science Institute, University of Oregon, 97403-1253 Eugene, OR, USA.
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5
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Uysal A. Aqueous Interfaces in Chemical Separations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023. [PMID: 37917551 DOI: 10.1021/acs.langmuir.3c02170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
Chemical separations play a vital role in refinery and reprocessing of critical materials, such as platinum group metals, rare earths, and actinides. The choice of separation system─whether it is liquid-liquid extraction (LLE), sorbents, or membranes─depends on specific needs and applications. In almost all separation processes, the desired metal ions adsorb or transfer across an aqueous interface, such as the solid/liquid interface in sorbents or oil/water interfaces in LLE. Despite these separation technologies being extensively used for decades, our understanding of the molecular-scale mechanisms governing ion adsorption and transport at interfaces remains limited. This knowledge gap presents a significant challenge in meeting the increasing demands for these critical materials due to their growing use in advanced technologies. Fortunately, recent advancements in surface-specific experimental and computational techniques offer promising avenues to bridge this gap and facilitate the development of next-generation separation systems. Interestingly, unanswered questions regarding interfacial phenomena in chemical separations hold great relevance to various fields, including energy storage, geochemistry, and atmospheric chemistry. Therefore, the model interfacial systems developed for studying chemical separations, such as amphiphilic molecules assembled at a solid/water, air/water, or oil/water interface, may have far-reaching implications, extending beyond separations and opening doors to addressing a wide range of scientific inquiries. This perspective discusses recent interfacial studies elucidating amphiphile-ion interactions in chemical separations of metal ions. These studies provide direct, molecular-scale information about solute and solvent behavior at aqueous interfaces, including multivalent and complex ions in highly concentrated solutions, which play key roles in LLE of critical materials.
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Affiliation(s)
- Ahmet Uysal
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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6
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Kuhl GM, Banning DH, Fargher HA, Davis WA, Howell MM, Zakharov LN, Pluth MD, Johnson DW. Benchmarking the placement of hydrosulfide in the Hofmeister series using a bambus[6]uril-based ChemFET sensor. Chem Sci 2023; 14:10273-10279. [PMID: 37772108 PMCID: PMC10530170 DOI: 10.1039/d3sc03616b] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/02/2023] [Indexed: 09/30/2023] Open
Abstract
Hydrosulfide (HS-) is the conjugate base of gasotransmitter hydrogen sulfide (H2S) and is a physiologically-relevant small molecule of great interest in the anion sensing community. However, selective sensing and molecular recognition of HS- in water remains difficult because, in addition to the diffuse charge and high solvation energy of anions, HS- is highly nucleophilic and readily oxidizes into other reactive sulfur species. Moreover, the direct placement of HS- in the Hofmeister series remains unclear. Supramolecular host-guest interactions provide a promising platform on which to recognize and bind hydrosulfide, and characterizing the placement of HS- in the Hofmeister series would facilitate the future design of selective receptors for this challenging anion. Few examples of supramolecular HS- binding have been reported, but the Sindelar group reported HS- binding in water using bambus[6]uril macrocycles in 2018. We used this HS- binding platform as a starting point to develop a chemically-sensitive field effect transistor (ChemFET) to facilitate assigning HS- to a specific place in the Hofmeister series. Specifically, we prepared dodeca-n-butyl bambus[6]uril and incorporated it into a ChemFET as the HS- receptor motif. The resultant device provided an amperometric response to HS-, and we used this device to measure the response of other anions, including SO42-, F-, Cl-, Br-, NO3-, ClO4-, and I-. Using this response data, we were able to experimentally determine that HS- lies between Cl- and Br- in the Hofmeister series, which matches recent theoretical computational work that predicted a similar placement. Taken together, these results highlight the potential of using molecular recognition coupled with ChemFET architectures to develop new approaches for direct and reversible HS- detection and measurement in water and further advance our understanding of different recognition approaches for this challenging anion.
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Affiliation(s)
- Grace M Kuhl
- Department of Chemistry & Biochemistry, Materials Science Institute, University of Oregon 97403-1253 Eugene OR USA https://www.dwjlab.com/
| | - Douglas H Banning
- Department of Chemistry & Biochemistry, Materials Science Institute, University of Oregon 97403-1253 Eugene OR USA https://www.dwjlab.com/
| | - Hazel A Fargher
- Department of Chemistry & Biochemistry, Materials Science Institute, University of Oregon 97403-1253 Eugene OR USA https://www.dwjlab.com/
| | - Willow A Davis
- Department of Chemistry & Biochemistry, Materials Science Institute, University of Oregon 97403-1253 Eugene OR USA https://www.dwjlab.com/
| | - Madeline M Howell
- Department of Chemistry & Biochemistry, Materials Science Institute, University of Oregon 97403-1253 Eugene OR USA https://www.dwjlab.com/
| | - Lev N Zakharov
- Department of Chemistry & Biochemistry, Materials Science Institute, University of Oregon 97403-1253 Eugene OR USA https://www.dwjlab.com/
| | - Michael D Pluth
- Department of Chemistry & Biochemistry, Materials Science Institute, University of Oregon 97403-1253 Eugene OR USA https://www.dwjlab.com/
| | - Darren W Johnson
- Department of Chemistry & Biochemistry, Materials Science Institute, University of Oregon 97403-1253 Eugene OR USA https://www.dwjlab.com/
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7
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Rana B, Fairhurst DJ, Jena KC. Ion-Specific Water-Macromolecule Interactions at the Air/Aqueous Interface: An Insight into Hofmeister Effect. J Am Chem Soc 2023; 145:9646-9654. [PMID: 37094217 DOI: 10.1021/jacs.3c00701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2023]
Abstract
The specificity of ions in inducing conformational changes in macromolecules is introduced as the Hofmeister series; however, the detailed underlying mechanism is not comprehensible yet. We utilized surface-specific sum frequency generation (SFG) vibrational spectroscopy to explore the Hofmeister effect at the air/polyvinylpyrrolidone (PVP)/water interface. The spectral signature observed from the ssp polarization scheme reveals ion-specific ordering of water molecules following the Hofmeister series attributed to the ion-macromolecule interactions. Along with this, the presence of ions does not reflect any significant influence on the structure of the PVP macromolecule. However, the ppp-SFG spectra in the CH-stretch region reveal the impact of ions on the orientation angle of vinyl chain CH2-groups, which follows the Hofmeister series: SO42- > Cl- > NO3- > Br- > ClO4- > SCN-. The minimal orientation angle of CH2-groups indicates significant reordering in PVP vinyl chains in the presence of chaotropic anions ClO4-, and SCN-. The observation is attributed to the ion-specific water-macromolecule interactions at the air/aqueous interface. It is compelling to observe the signature of spectral blue shifts in the OH-stretch region in the ppp configuration in the presence of chaotropic anions. The origin of spectral blue shifts has been ascribed to the existence of weaker interactions between the interfacial water molecules and the backbone CH- and CH2-moieties of the PVP macromolecules. The ion-specific modulation in water-macromolecule interactions is endorsed by the relative propensity of anion's adsorption toward the air/aqueous interface. The experimental findings highlight the existence and cooperative participation of ion-specific water-macromolecule interactions in the mechanism of the Hofmeister effect, along with the illustrious ion-water and ion-macromolecule interactions.
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Affiliation(s)
- Bhawna Rana
- Department of Physics, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001, India
| | - David J Fairhurst
- Department of Physics and Mathematics, School of Science and Technology, Nottingham Trent University, Clifton Campus, Nottingham NG11 8NS, U.K
| | - Kailash C Jena
- Department of Physics, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001, India
- Department of Biomedical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001, India
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8
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Sam S, Sung S, Krem S, Park S, Hwang DS, Kim D. Sum-Frequency Vibrational Spectroscopic Study of the Cation-π Interaction: Amine and Guanidine. J Phys Chem B 2022; 126:7621-7626. [PMID: 36166344 DOI: 10.1021/acs.jpcb.2c05709] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The cation-π interaction is an interaction between a positively charged cation and π electrons in an aromatic group of a molecule. It is considered to play key roles in signal transduction, stabilization of the protein structure, enzyme catalysis in biology, and wet adhesion and biomolecular condensation. In this study, octadecylguanidine hydrochloride (ODG) and octadecylamine (ODA) having guanidine and amine headgroups, respectively, are found to interact with π molecules (phenol or indole) as investigated by sum-frequency vibrational spectroscopy. ODG is unstable and does not form a neat monolayer on the water surface. However, after adding π molecules into subphase water, it becomes more stable against dissolution as evidenced by the appearance of its CHx peaks and a CH peak of the aromatic ring in the sum-frequency spectrum. Unlike ODG, ODA forms a stable monolayer on the water surface at a neutral pH. After adding π molecules into the solution, the amine-π interaction promotes the protonation of the amine headgroup and the penetration of the π molecules makes the ODA monolayer more disordered. Indole is found to be more effective in binding with the ODG as compared to phenol.
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Affiliation(s)
- Sokhuoy Sam
- Department of Physics, Sogang University, 35, Baekbeom-ro, Mapo-gu, Seoul 04107, Korea
| | - Siheon Sung
- Department of Physics, Sogang University, 35, Baekbeom-ro, Mapo-gu, Seoul 04107, Korea
| | - Sona Krem
- Department of Physics, Sogang University, 35, Baekbeom-ro, Mapo-gu, Seoul 04107, Korea
| | - Sohee Park
- Division of Environmental Science and Engineering (DESE), Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Namgu, Pohang 37673, Korea
| | - Dong Soo Hwang
- Division of Environmental Science and Engineering (DESE), Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Namgu, Pohang 37673, Korea
| | - Doseok Kim
- Department of Physics, Sogang University, 35, Baekbeom-ro, Mapo-gu, Seoul 04107, Korea
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9
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Yan L, Saha A, Zhao W, Neal JF, Chen Y, Flood AH, Allen HC. Recognition competes with hydration in anion-triggered monolayer formation of cyanostar supra-amphiphiles at aqueous interfaces. Chem Sci 2022; 13:4283-4294. [PMID: 35509460 PMCID: PMC9006960 DOI: 10.1039/d2sc00986b] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 03/14/2022] [Indexed: 11/21/2022] Open
Abstract
The triggered self-assembly of surfactants into organized layers at aqueous interfaces is important for creating adaptive nanosystems and understanding selective ion extraction. While these transformations require molecular recognition, the underlying driving forces are modified by the local environment in ways that are not well understood. Herein, we investigate the role of ion binding and ion hydration using cyanosurf, which is composed of the cyanostar macrocycle, and its binding to anions that are either size-matched or mis-matched and either weakly or highly hydrated. We utilize the supra-amphiphile concept where anion binding converts cyanosurf into a charged and amphiphilic complex triggering its self-organization into monolayers at the air-water interface. Initially, cyanosurf forms aggregates at the surface of a pure water solution. When the weakly hydrated and size-matched hexafluorophosphate (PF6 -) and perchlorate (ClO4 -) anions are added, the macrocycles form distinct monolayer architectures. Surface-pressure isotherms reveal significant reorganization of the surface-active molecules upon anion binding while infrared reflection absorption spectroscopy show the ion-bound complexes are well ordered at the interface. Vibrational sum frequency generation spectroscopy shows the water molecules in the interfacial region are highly ordered in response to the charged monolayer of cyanosurf complexes. Consistent with the importance of recognition, we find the smaller mis-matched chloride does not trigger the transformation. However, the size-matched phosphate (H2PO4 -) also does not trigger monolayer formation indicating hydration inhibits its interfacial binding. These studies reveal how anion-selective recognition and hydration both control the binding and thus the switching of a responsive molecular interface.
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Affiliation(s)
- Liwei Yan
- Department of Chemistry and Biochemistry, The Ohio State University Columbus Ohio 43210 USA +1-614-292-1685 +1-614-292-4707
| | - Ankur Saha
- Department of Chemistry and Biochemistry, The Ohio State University Columbus Ohio 43210 USA +1-614-292-1685 +1-614-292-4707
| | - Wei Zhao
- Department of Chemistry, Indiana University Bloomington Indiana 47405 USA +1-812-855-8300 +1-812-856-3642
| | - Jennifer F Neal
- Department of Chemistry and Biochemistry, The Ohio State University Columbus Ohio 43210 USA +1-614-292-1685 +1-614-292-4707
| | - Yusheng Chen
- Department of Chemistry, Indiana University Bloomington Indiana 47405 USA +1-812-855-8300 +1-812-856-3642
| | - Amar H Flood
- Department of Chemistry, Indiana University Bloomington Indiana 47405 USA +1-812-855-8300 +1-812-856-3642
| | - Heather C Allen
- Department of Chemistry and Biochemistry, The Ohio State University Columbus Ohio 43210 USA +1-614-292-1685 +1-614-292-4707
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10
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de Souza RM, Romeu FC, Ribeiro MCC, Karttunen M, Dias LG. Osmotic Method for Calculating Surface Pressure of Monolayers in Molecular Dynamics Simulations. J Chem Theory Comput 2022; 18:2042-2046. [PMID: 35254819 DOI: 10.1021/acs.jctc.2c00109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Surface pressure is a fundamental thermodynamic property related to the activity of molecules at interfaces. In molecular simulations, it is typically calculated from its definition: the difference between the surface tension of the air-water and air-surfactant interfaces. In this Letter, we show how to connect the surface pressure with a two-dimensional osmotic pressure and how to take advantage of this analogy to obtain a practical method of calculating surface pressure-area isotherms in molecular simulation. As a proof-of-concept, compression curves of zwitterionic and ionic surfactant monolayers were obtained using the osmotic approach and the curves were compared with the ones from the traditional pressure tensor-based scheme. The results shown an excellent agreement between both alternatives. Advantageously, the osmotic approach is simple to use and allows to obtain the surface pressure-area isotherm on the fly with a single simulation using equilibration stages.
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Affiliation(s)
- Rafael Maglia de Souza
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Avenida Professor Lineu Prestes 748, 05508-000, São Paulo, SP,Brasil
| | - Fábio Cavalcante Romeu
- Departamento de Química, FFCLRP, Universidade de São Paulo, Avenida Bandeirantes 3900, 14040-901, Ribeirão Preto, SP,Brasil
| | - Mauro Carlos Costa Ribeiro
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Avenida Professor Lineu Prestes 748, 05508-000, São Paulo, SP,Brasil
| | - Mikko Karttunen
- Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario Canada, N6A 5B7.,Department of Physics and Astronomy, The University of Western Ontario, 1151 Richmond Street, London, Ontario, Canada N6A 3K7.,Centre for Advanced Materials and Biomaterials Research, The University of Western Ontario, 1151 Richmond Street, London, Ontario Canada, N6A 5B7
| | - Luís Gustavo Dias
- Departamento de Química, FFCLRP, Universidade de São Paulo, Avenida Bandeirantes 3900, 14040-901, Ribeirão Preto, SP,Brasil
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11
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Sun P, Binter EA, Liang Z, Brown MA, Gelis AV, Benjamin I, Bera MK, Lin B, Bu W, Schlossman ML. Antagonistic Role of Aqueous Complexation in the Solvent Extraction and Separation of Rare Earth Ions. ACS CENTRAL SCIENCE 2021; 7:1908-1918. [PMID: 34841061 PMCID: PMC8614105 DOI: 10.1021/acscentsci.1c00960] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Indexed: 05/28/2023]
Abstract
Solvent extraction is used widely for chemical separations and environmental remediation. Although the kinetics and efficiency of this process rely upon the formation of ion-extractant complexes, it has proven challenging to identify the location of ion-extractant complexation within the solution and its impact on the separation. Here, we use tensiometry and X-ray scattering to characterize the surface of aqueous solutions of lanthanide chlorides and the water-soluble extractant bis(2-ethylhexyl) phosphoric acid (HDEHP), in the absence of a coexisting organic solvent. These studies restrict ion-extractant interactions to the aqueous phase and its liquid-vapor interface, allowing us to explore the consequences that one or the other is the location of ion-extractant complexation. Unexpectedly, we find that light lanthanides preferentially occupy the liquid-vapor interface. This contradicts our expectation that heavy lanthanides should have a higher interfacial density since they are preferentially extracted by HDEHP in solvent extraction processes. These results reveal the antagonistic role played by ion-extractant complexation within the aqueous phase and clarify the advantages of complexation at the interface. Extractants in common use are often soluble in water, in addition to their organic phase solubility, and similar effects to those described here are expected to be relevant to a variety of separations processes.
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Affiliation(s)
- Pan Sun
- NSF’s
ChemMatCARS, Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Erik A. Binter
- Department
of Physics, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Zhu Liang
- Department
of Physics, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - M. Alex Brown
- Chemical
and Fuel Cycle Technologies Division, Argonne
National Laboratory, Lemont, Illinois 60439, United States
| | - Artem V. Gelis
- Radiochemistry
Program, Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, Nevada 89141, United States
| | - Ilan Benjamin
- Department
of Chemistry and Biochemistry, University
of California, Santa Cruz, California 95064, United States
| | - Mrinal K. Bera
- NSF’s
ChemMatCARS, Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Binhua Lin
- NSF’s
ChemMatCARS, Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Wei Bu
- NSF’s
ChemMatCARS, Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Mark L. Schlossman
- Department
of Physics, University of Illinois at Chicago, Chicago, Illinois 60607, United States
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12
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Lin L, Chowdhury AU, Ma YZ, Sacci RL, Katsaras J, Hong K, Collier CP, Carrillo JMY, Doughty B. Ion Pairing Mediates Molecular Organization Across Liquid/Liquid Interfaces. ACS APPLIED MATERIALS & INTERFACES 2021; 13:33734-33743. [PMID: 34235915 DOI: 10.1021/acsami.1c09763] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Liquid/liquid interfaces play a central role in scientific fields ranging from nanomaterial synthesis and soft matter electronics to nuclear waste remediation and chemical separations. This diversity of functions arises from an interface's ability to respond to changing conditions in its neighboring bulk phases. Understanding what drives this interfacial flexibility can provide novel avenues for designing new functional interfaces. However, limiting this progress is an inadequate understanding of the subtle intermolecular and interphase interactions taking place at the molecular level. Here, we use surface-specific vibrational sum frequency generation spectroscopy combined with atomistic molecular dynamics simulations to investigate the self-assembly and structure of model ionic oligomers consisting of an oligodimethylsiloxane (ODMS) tail covalently attached to a positively charged methyl imidazolium (MIM+) head group at buried oil/aqueous interfaces. We show how the presence of seemingly innocuous salts can impart dramatic changes to the ODMS tail conformations in the oil phase via specific ion effects and ion-pairing interactions taking place in the aqueous phase. These specific ion interactions are shown to drive enhanced amphiphile adsorption, induce morphological changes, and disrupt emergent hydrogen-bonding structures at the interface. Tuning these interactions allows for independent control over the oligomer structure in the oil phase versus interfacial population changes and represents key mechanistic insight that is needed to control chemical reactions at liquid/liquid interfaces.
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Affiliation(s)
- Lu Lin
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Azhad U Chowdhury
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Ying-Zhong Ma
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Robert L Sacci
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - John Katsaras
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Shull Wollan Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Kunlun Hong
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - C Patrick Collier
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Jan-Michael Y Carrillo
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Benjamin Doughty
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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