1
|
Mapile AN, Scatena LF. Bulking up: the impact of polymer sterics on emulsion stability. SOFT MATTER 2024; 20:7471-7483. [PMID: 39258873 DOI: 10.1039/d4sm00772g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2024]
Abstract
Encapsulation of hydrophobic active ingredients is critical for targeted drug delivery as water-insoluble drugs dominate the pharmaceutical marketplace. We previously demonstrated hexadecane-in-water emulsions stabilized with a pH-tunable polymer, poly(acrylic acid) (PAA), via a steric layer preventing particle aggregation. Using vibrational sum frequency scattering spectroscopy (VSFSS), here we probe the influence of steric hindrance on emulsion colloidal stability by tailoring the molecular weight of PAA and by adding an additional methyl group to the polymer backbone via poly(methacrylic acid) (PMAA) at pH 2, 4, and 6. At low polymer molecular weight (2 and 10 kDa), PAA adsorption is entropy driven and akin to surfactant-mediated stabilization. With 450 kDa PAA, the longer polymer chain emphasizes enthalpically favored polymer-oil interactions to initially coat the surface, and forms layers at increasing molecular weight (1000 and 4000 kDa). PMAA exhibits better oil-solubility than PAA at low concentrations but cannot accommodate the steric hindrance at higher concentrations leading to disorder. Finally, we connect our molecular-level understanding of PAA ordering with temperature-dependent dynamic light scattering experiments and observe that emulsions coated with PAA at pH 2 and 4 maintain colloidal stability from 0-90 °C, making PAA a promising polymer for hydrophobic drug delivery.
Collapse
Affiliation(s)
- Ashley N Mapile
- University of Oregon Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene, OR 97403, USA.
| | - Lawrence F Scatena
- University of Oregon Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene, OR 97403, USA.
| |
Collapse
|
2
|
Kaur S, Tomar D, Chaudhary M, Rana B, Kaur H, Nigam V, Jena KC. Interfacial molecular structure of phosphazene-based polymer electrolyte at the air-aqueous interface using sum frequency generation vibrational spectroscopy. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2023; 36:105001. [PMID: 37988750 DOI: 10.1088/1361-648x/ad0e94] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 11/21/2023] [Indexed: 11/23/2023]
Abstract
The change induced in the physicochemical properties of polymer while hosting ions provides a platform for studying its potential applications in electrochemical devices, water treatment plants, and materials engineering science. The ability to host ions is limited in very few polymers, which lack a detailed molecular-level understanding for showcasing the polymer-ion linkage behavior at the interfacial region. In the present manuscript, we have employed sum frequency generation (SFG) vibrational spectroscopy to investigate the interfacial structure of a new class phosphazene-based methoxyethoxyethoxyphosphazene (MEEP) polymer in the presence of lithium chloride salt at the air-aqueous interface. The interfacial aspects of the molecular system collected through SFG spectral signatures reveal enhanced water ordering and relative hydrogen bonding strength at the air-aqueous interface. The careful observation of the study finds a synchronous contribution of van der Waals and electrostatic forces in facilitating changes in the interfacial water structure that are susceptible to MEEP concentration in the presence of ions. The observation indicates that dilute MEEP concentrations support the role of electrostatic interaction, leading to an ordered water structure in proximity to diffused ions at the interfacial region. Conversely, higher MEEP concentrations promote the dominance of van der Waals interactions at the air-aqueous interface. Our study highlights the establishment of polymer electrolyte (PE) characteristics mediated by intermolecular interactions, as observed through the spectral signatures witnessed at the air-aqueous interface. The investigation illustrates the polymer-ion linkage adsorption effects at the interfacial region, which explains the macroscopic changes observed from the cyclic voltammetry studies. The fundamental findings from our studies can be helpful in the design and fine-tuning of better PE systems that can offer improved hydrophobic membranes and interface stability for use in electrochemical-based power sources.
Collapse
Affiliation(s)
- Sarabjeet Kaur
- Department of Physics, Indian Institute of Technology Ropar, Rupnagar 140001, Punjab, India
| | - Deepak Tomar
- Department of Physics, Indian Institute of Technology Ropar, Rupnagar 140001, Punjab, India
| | - Monika Chaudhary
- Department of Biomedical Engineering, Indian Institute of Technology Ropar, Rupnagar 140001, Punjab, India
| | - Bhawna Rana
- Department of Physics, Indian Institute of Technology Ropar, Rupnagar 140001, Punjab, India
| | - Harsharan Kaur
- Department of Biomedical Engineering, Indian Institute of Technology Ropar, Rupnagar 140001, Punjab, India
| | - Vineeta Nigam
- Defence Materials Stores Research and Development Establishment, Kanpur 208013, India
| | - Kailash C Jena
- Department of Physics, Indian Institute of Technology Ropar, Rupnagar 140001, Punjab, India
- Department of Biomedical Engineering, Indian Institute of Technology Ropar, Rupnagar 140001, Punjab, India
| |
Collapse
|
3
|
Kurapati R, Natarajan U. Tacticity and Ionization Effects on Adsorption Behavior of Poly(acrylic acid) and Poly(methacrylic acid) at the CCl 4–H 2O Interface Revealed by MD Simulations. Ind Eng Chem Res 2022. [DOI: 10.1021/acs.iecr.2c02416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Raviteja Kurapati
- Macromolecular Modeling and Simulation Laboratory, Department of Chemical Engineering, Indian Institute of Technology (IIT) Madras, Chennai600036, India
| | - Upendra Natarajan
- Macromolecular Modeling and Simulation Laboratory, Department of Chemical Engineering, Indian Institute of Technology (IIT) Madras, Chennai600036, India
| |
Collapse
|
4
|
Li X, Encheva M, Butt HJ, Backus EHG, Berger R. Adaptation and Recovery of A Styrene-Acrylic Acid Copolymer Surface to Water. Macromol Rapid Commun 2022; 43:e2100733. [PMID: 35338785 DOI: 10.1002/marc.202100733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 02/09/2022] [Indexed: 11/06/2022]
Abstract
Drops sliding down an adaptive surface lead to changes of the dynamic contact angles. Two adaptation processes play a role: (i) the adaptation of the surface upon bringing it into contact to the drop (wetting) and (ii) the adaptation of the surface after the drop passed (dewetting). In order to study both processes, we investigated samples made from random styrene (PS)/acrylic acid (PAA) copolymers, which are exposed to water. Sum-frequency generation spectroscopy (SFG) and tilted-plate measurements indicate that during wetting, the PS segments displace from the interface, while PAA segments are enriched. This structural adaptation of the PS/PAA random copolymer to water remains after dewetting. Annealing the adapted polymer induces reorientation of the PS segments to the surface. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Xiaomei Li
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz, 55128, Germany
| | - Mirela Encheva
- Department of Physical Chemistry, University of Vienna, Währinger Straße 42, Vienna, 1090, Austria
| | - Hans-Jürgen Butt
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz, 55128, Germany
| | - Ellen H G Backus
- Department of Physical Chemistry, University of Vienna, Währinger Straße 42, Vienna, 1090, Austria
| | - Rüdiger Berger
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz, 55128, Germany
| |
Collapse
|
5
|
Moll CJ, Giubertoni G, van Buren L, Versluis J, Koenderink GH, Bakker HJ. Molecular Structure and Surface Accumulation Dynamics of Hyaluronan at the Water-Air Interface. Macromolecules 2021; 54:8655-8663. [PMID: 34602653 PMCID: PMC8482758 DOI: 10.1021/acs.macromol.1c00366] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Indexed: 11/30/2022]
Abstract
![]()
Hyaluronan is a biopolymer
that is essential for many biological
processes in the human body, like the regulation of tissue lubrication
and inflammatory responses. Here, we study the behavior of hyaluronan
at aqueous surfaces using heterodyne-detected vibrational sum-frequency
generation spectroscopy (HD-VSFG). Low-molecular-weight hyaluronan
(∼150 kDa) gradually covers the water–air interface
within hours, leading to a negatively charged surface and a reorientation
of interfacial water molecules. The rate of surface accumulation strongly
increases when the bulk concentration of low-molecular-weight hyaluronan
is increased. In contrast, high-molecular-weight hyaluronan (>1
MDa)
cannot be detected at the surface, even hours after the addition of
the polymer to the aqueous solution. The strong dependence on the
polymer molecular weight can be explained by entanglements of the
hyaluronan polymers. We also find that for low-molecular-weight hyaluronan
the migration kinetics of hyaluronan in aqueous media shows an anomalous
dependence on the pH of the solution, which can be explained from
the interplay of hydrogen bonding and electrostatic interactions of
hyaluronan polymers.
Collapse
Affiliation(s)
- Carolyn J Moll
- Amolf, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - Giulia Giubertoni
- Amolf, Science Park 104, 1098 XG Amsterdam, The Netherlands.,Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Lennard van Buren
- Amolf, Science Park 104, 1098 XG Amsterdam, The Netherlands.,Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Jan Versluis
- Amolf, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - Gijsje H Koenderink
- Amolf, Science Park 104, 1098 XG Amsterdam, The Netherlands.,Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Huib J Bakker
- Amolf, Science Park 104, 1098 XG Amsterdam, The Netherlands
| |
Collapse
|
6
|
Carter-Fenk KA, Dommer AC, Fiamingo ME, Kim J, Amaro RE, Allen HC. Calcium bridging drives polysaccharide co-adsorption to a proxy sea surface microlayer. Phys Chem Chem Phys 2021; 23:16401-16416. [PMID: 34318808 DOI: 10.1039/d1cp01407b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Saccharides comprise a significant mass fraction of organic carbon in sea spray aerosol (SSA), but the mechanisms through which saccharides are transferred from seawater to the ocean surface and eventually into SSA are unclear. It is hypothesized that saccharides cooperatively adsorb to other insoluble organic matter at the air/sea interface, known as the sea surface microlayer (SSML). Using a combination of surface-sensitive infrared reflection-absorption spectroscopy and all-atom molecular dynamics simulations, we demonstrate that the marine-relevant, anionic polysaccharide alginate co-adsorbs to an insoluble palmitic acid monolayer via divalent cationic bridging interactions. Ca2+ induces the greatest extent of alginate co-adsorption to the monolayer, evidenced by the ∼30% increase in surface coverage, whereas Mg2+ only facilitates one-third the extent of co-adsorption at seawater-relevant cation concentrations due to its strong hydration propensity. Na+ cations alone do not facilitate alginate co-adsorption, and palmitic acid protonation hinders the formation of divalent cationic bridges between the palmitate and alginate carboxylate moieties. Alginate co-adsorption is largely confined to the interfacial region beneath the monolayer headgroups, so surface pressure, and thus monolayer surface coverage, only changes the amount of alginate co-adsorption by less than 5%. Our results provide physical and molecular characterization of a potentially significant polysaccharide enrichment mechanism within the SSML.
Collapse
Affiliation(s)
- Kimberly A Carter-Fenk
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA.
| | | | | | | | | | | |
Collapse
|
7
|
David R, Tuladhar A, Zhang L, Arges C, Kumar R. Effect of Oxidation Level on the Interfacial Water at the Graphene Oxide-Water Interface: From Spectroscopic Signatures to Hydrogen-Bonding Environment. J Phys Chem B 2020; 124:8167-8178. [PMID: 32804501 PMCID: PMC7503515 DOI: 10.1021/acs.jpcb.0c05282] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
![]()
The interfacial region
of the graphene oxide (GO)-water system
is nonhomogenous due to the presence of two distinct domains: an oxygen-rich
surface and a graphene-like region. The experimental vibrational sum-frequency
generation (vSFG) spectra are distinctly different for the fully oxidized
GO-water interface as compared to the reduced GO-water case. Computational
investigations using ab initio molecular dynamics were performed to
determine the molecular origins of the different spectroscopic features.
The simulations were first validated by comparing the simulated vSFG
spectra to those from the experiment, and the contributions to the
spectra from different hydrogen bonding environments and interfacial
water orientations were determined as a function of the oxidation
level of the GO sheet. The ab initio simulations also revealed the
reactive nature of the GO-water interface.
Collapse
Affiliation(s)
- Rolf David
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Aashish Tuladhar
- Physical Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Le Zhang
- Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Christopher Arges
- Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Revati Kumar
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| |
Collapse
|
8
|
Senechal V, Saadaoui H, Vargas-Alfredo N, Rodriguez-Hernandez J, Drummond C. Weak polyelectrolyte brushes: re-entrant swelling and self-organization. SOFT MATTER 2020; 16:7727-7738. [PMID: 32735003 DOI: 10.1039/d0sm00810a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We have studied the combined influence of pH and ionic strength on the properties of brushes of a weak polyion, poly(acrylic acid), in conditions of grafting density close to the mushroom-brush crossover. By combining atomic force microscopy AFM and quartz crystal microbalance, we show that at low ionic strengths the conformational change of grafted polyions is non-monotonic with increasing pH due to the counterintuitive variation of the ionization degree. Thus, reentrant swelling of the polymer chains is observed with increasing pH. This effect is more important at low polymer grafting densities, when it is accompanied by in-plane heterogeneous distribution at intermediate pH values. In addition, we observed self-assembly on the polymer brush (formation of holes and islands) at pH values below pKa, due to the short-range attractive interaction between uncharged grafted chains. The sensitivity of the ionization of grafted chains to the physicochemical environment was also studied by measuring the interaction force between a silica tip and polymer brushes by atomic force microscopy. The dependence of the ionization of polyions on the presence of the tip points toward important charge regulation effects, in particular at pH values corresponding to partial ionization of the polyion.
Collapse
Affiliation(s)
- Vincent Senechal
- CNRS, Centre de Recherche Paul Pascal (CRPP), UMR 5031, F-33600 Pessac, France. and Université de Bordeaux, Centre de Recherche Paul Pascal, F-33600 Pessac, France
| | - Hassan Saadaoui
- CNRS, Centre de Recherche Paul Pascal (CRPP), UMR 5031, F-33600 Pessac, France. and Université de Bordeaux, Centre de Recherche Paul Pascal, F-33600 Pessac, France
| | - Nelson Vargas-Alfredo
- Instituto de Ciencia y Tecnología de Polímeros, CSIC, Juan de la Cierva 3, 28006, Madrid, Spain
| | | | - Carlos Drummond
- CNRS, Centre de Recherche Paul Pascal (CRPP), UMR 5031, F-33600 Pessac, France. and Université de Bordeaux, Centre de Recherche Paul Pascal, F-33600 Pessac, France
| |
Collapse
|
9
|
Myalitsin A, Ghosh S, Urashima SH, Nihonyanagi S, Yamaguchi S, Aoki T, Tahara T. Structure of water and polymer at the buried polymer/water interface unveiled using heterodyne-detected vibrational sum frequency generation. Phys Chem Chem Phys 2020; 22:16527-16531. [DOI: 10.1039/d0cp02618b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Heterodyne-detected vibrational sum frequency generation reveals the molecular-level structure of the polymer/water interface that is different from what has been argued.
Collapse
Affiliation(s)
- Anton Myalitsin
- Molecular Spectroscopy Laboratory
- RIKEN
- Saitama 351-0198
- Japan
- Nissan ARC, Ltd
| | - Sanat Ghosh
- Molecular Spectroscopy Laboratory
- RIKEN
- Saitama 351-0198
- Japan
| | | | - Satoshi Nihonyanagi
- Molecular Spectroscopy Laboratory
- RIKEN
- Saitama 351-0198
- Japan
- Ultrafast Spectroscopy Research Team
| | - Shoichi Yamaguchi
- Department of Applied Chemistry
- Graduate School of Science and Technology
- Saitama University
- Saitama 338-8570
- Japan
| | - Takashi Aoki
- Department of Biobased Materials Science
- Graduate School of Science and Technology
- Kyoto Institute of Technology
- Kyoto 606-8585
- Japan
| | - Tahei Tahara
- Molecular Spectroscopy Laboratory
- RIKEN
- Saitama 351-0198
- Japan
- Ultrafast Spectroscopy Research Team
| |
Collapse
|
10
|
Moll CJ, Meister K, Kirschner J, Bakker HJ. Surface Structure of Solutions of Poly(vinyl alcohol) in Water. J Phys Chem B 2018; 122:10722-10727. [PMID: 30372078 DOI: 10.1021/acs.jpcb.8b08374] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We use surface-specific heterodyne-detected vibrational sum-frequency generation spectroscopy (HD-VSFG) and surface tension measurements to investigate the molecular structure of the surface of aqueous solutions of poly(vinyl alcohol) (PVA) polymers with average molecular weights of 10000 and 125000 g/mol. We find that the interfacial water molecules have a preferred orientation with their hydrogen-bonded O-H groups pointing away from the bulk, for both PVA10000 and PVA125000. This observation is explained from the ongoing hydrolysis of the acetyl impurities on the PVA polymer chains. This hydrolysis yields negatively charged acetate ions that have a relatively high surface propensity. For both PVA10000 and PVA125000 the strong positive signal vanishes when the pH is decreased, due to the neutralization of the acetate ions. For solutions with a high concentration of PVA10000 the interfacial water signal becomes very small, indicating that the surface gets completely covered with a disordered PVA polymer film. In contrast, for high concentrations of PVA125000, the strong positive water signal persists at high pH, which shows that the water surface does not get completely covered. The HD-VSFG data combined with surface tension data indicate that concentrated PVA125000 solutions form a structured surface layer with pores containing a high density of interfacial water.
Collapse
Affiliation(s)
- C J Moll
- AMOLF , Science Park 104 , 1098XG Amsterdam , The Netherlands
| | - K Meister
- AMOLF , Science Park 104 , 1098XG Amsterdam , The Netherlands.,Max-Planck Institute for Polymer Research , Ackermanweg 10 , D-55128 Mainz , Germany
| | | | - H J Bakker
- AMOLF , Science Park 104 , 1098XG Amsterdam , The Netherlands
| |
Collapse
|
11
|
Schulze-Zachau F, Bachmann S, Braunschweig B. Effects of Ca 2+ Ion Condensation on the Molecular Structure of Polystyrene Sulfonate at Air-Water Interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:11714-11722. [PMID: 30188134 PMCID: PMC6170951 DOI: 10.1021/acs.langmuir.8b02631] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/05/2018] [Indexed: 06/02/2023]
Abstract
The structure of poly(sodium 4-styrenesulfonate) (NaPSS) polyelectrolytes at air-water interfaces was investigated with tensiometry, ellipsometry, and vibrational sum-frequency generation (SFG) in the presence of low and high CaCl2 concentrations. In addition, we have studied the foaming behavior of 20 mM NaPSS solutions to relate the PSS molecular structure at air-water interfaces to foam properties. PSS polyelectrolytes without additional salt exhibited significant surface activity, which can be tuned further by additions of CaCl2. The hydrophobicity of the backbone due to incomplete sulfonation during synthesis is one origin, whereas the effective charge of the polyelectrolyte chain is shown to play another major role. At low salt concentrations, we propose that the polyelectrolyte is forming a layered structure. The hydrophobic parts are likely to be located directly at the interface in loops, whereas the hydrophilic parts are at low concentrations stretched out into near-interface regions in tails. Increasing the Ca2+ concentration leads to ion condensation, a collapse of the tails, and likely to Ca2+ intra- and intermolecular bridges between polyelectrolytes at the interface. The increase in both surface excess and foam stability originates from changes in the polyelectrolyte's hydrophobicity due to Ca2+ condensation onto the PSS polyanions. Consequently, charge screening at the interface is enhanced and repulsive electrostatic interactions are reduced. Furthermore, SFG spectra of O-H stretching bands reveal a decrease in intensity of the low-frequency branch when c(Ca2+) is increased whereas the high-frequency branch of O-H stretching modes persists even for 1 M CaCl2. This originates from the remaining net charge of the PSS polyanions at the air-water interface that is not fully compensated by condensation of Ca2+ ions and leads to electric-field-induced contributions to the SFG spectra of interfacial H2O. A charge reversal of the PSS net charge at the air-water interface is not observed and is consistent with bulk electrophoretic mobility measurements.
Collapse
Affiliation(s)
- Felix Schulze-Zachau
- Institute
of Physical Chemistry and Center for Soft Nanoscience, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, 48149 Münster, Germany
| | - Silvia Bachmann
- Institute
of Particle Technology (LFG), Friedrich-Alexander-Universität
Erlangen-Nürnberg (FAU), Cauerstraße 4, 91058 Erlangen, Germany
| | - Björn Braunschweig
- Institute
of Physical Chemistry and Center for Soft Nanoscience, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, 48149 Münster, Germany
| |
Collapse
|
12
|
Liang Y, Zhang S, Wu W, Yang F, Gan W, Jia H, Chen S, Zhu X, Yuan Q. Lyophobicity may not be the main driving force for long chain surfactants from the bulk phase to the interface. Phys Chem Chem Phys 2018; 20:10165-10172. [PMID: 29589842 DOI: 10.1039/c7cp07322d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
According to the Traube rule, a surfactant with a longer alkane chain is more hydrophobic so its tendency to be driven from a polar solvent to a less polar interface is higher. In this work, we revisited this topic by studying the adsorption of quaternary ammonium salts and carboxylic acids with various alkane chain lengths at the hexadecane-water interface. The adsorption free energies of the surfactants at this oil-water interface from the polar (aqueous solution) or nonpolar phase (hexadecane) were estimated from second harmonic generation measurements. The variation of the free energies per methylene group in the bulk phase, at the oil-water interface and at the air-water interface revealed that there are different interactions between the alkane chains of the surfactants in different environments. The chain-chain interaction at the hexadecane-water interface is lower than that at the air-water interface. The driving force for the alkane chains to adsorb at the oil-water interface from the oil phase is close to that from the aqueous phase. This observation reveals that the chain-chain interaction rather than the lyophobicity of the solute with respect to the solvent is the main contributor to the adsorption free energy. This is the first experimental comparison of the free energies of the alkane chains in oil, in water, at the air-water interface and at the oil-water interface. These results provide information for studying the interactions of hydrophobic species in different environments. This work also provides a method for estimating the solvation energy of some head groups in surfactants.
Collapse
Affiliation(s)
- Yuanzhen Liang
- Laboratory of Environmental Science and Technology, Xinjiang Technical Institute of Physics & Chemistry, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011, China.
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Kusaka R, Watanabe M. The structure of a lanthanide complex at an extractant/water interface studied using heterodyne-detected vibrational sum frequency generation. Phys Chem Chem Phys 2018; 20:2809-2813. [DOI: 10.1039/c7cp06758e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Eu3+ at an extractant/water interface is bound to extractants from the upper side and to water molecules from the lower side, and forms a unique interfacial complex.
Collapse
Affiliation(s)
- Ryoji Kusaka
- Nuclear Science and Engineering Center
- Japan Atomic Energy Agency (JAEA)
- 2-4 Shirakata
- Tokai
- Japan
| | - Masayuki Watanabe
- Nuclear Science and Engineering Center
- Japan Atomic Energy Agency (JAEA)
- 2-4 Shirakata
- Tokai
- Japan
| |
Collapse
|
14
|
Kusaka R, Ishiyama T, Nihonyanagi S, Morita A, Tahara T. Structure at the air/water interface in the presence of phenol: a study using heterodyne-detected vibrational sum frequency generation and molecular dynamics simulation. Phys Chem Chem Phys 2018; 20:3002-3009. [DOI: 10.1039/c7cp05150f] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A simple, neutral organic molecule, phenol, forms a specific hydrogen-bonding structure with water at the air/water interface.
Collapse
Affiliation(s)
- Ryoji Kusaka
- Molecular Spectroscopy Laboratory, RIKEN
- Wako 351-0198
- Japan
| | - Tatsuya Ishiyama
- Department of Applied Chemistry, Graduate School of Science and Engineering, University of Toyama
- Toyama 930-8555
- Japan
| | - Satoshi Nihonyanagi
- Molecular Spectroscopy Laboratory, RIKEN
- Wako 351-0198
- Japan
- Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP)
- Wako 351-0198
| | - Akihiro Morita
- Department of Chemistry, Graduate School of Science, Tohoku University
- Sendai 980-8578
- Japan
- Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University
- Kyoto 615-8520
| | - Tahei Tahara
- Molecular Spectroscopy Laboratory, RIKEN
- Wako 351-0198
- Japan
- Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP)
- Wako 351-0198
| |
Collapse
|
15
|
Heath MS, Horsell DW. Multi-frequency sound production and mixing in graphene. Sci Rep 2017; 7:1363. [PMID: 28465601 PMCID: PMC5430977 DOI: 10.1038/s41598-017-01467-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 03/28/2017] [Indexed: 11/11/2022] Open
Abstract
The ability to generate, amplify, mix and modulate sound in one simple electronic device would open up a new world in acoustics. Here we show how to build such a device. It generates sound thermoacoustically by Joule heating in graphene. A rich sonic palette is created by controlling the composition and flow of the electric current through the graphene. This includes frequency mixing (heterodyning), which results exclusively from the Joule mechanism. It also includes shaping of the sound spectrum by a dc current and modulating its amplitude with a transistor gate. We show that particular sounds are indicators of nonlinearity and can be used to quantify nonlinear contributions to the conduction. From our work, we expect to see novel uses of acoustics in metrology, sensing and signal processing. Together with the optical qualities of graphene, its acoustic capabilities should inspire the development of the first combined audio-visual nanotechnologies.
Collapse
Affiliation(s)
- M S Heath
- School of Physics and Astronomy, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK
| | - D W Horsell
- School of Physics and Astronomy, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK.
| |
Collapse
|
16
|
Roy S, Freiberg S, Leblanc C, Hore DK. Surface Structure of Acrylate Polymer Adhesives. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:1763-1768. [PMID: 28134525 DOI: 10.1021/acs.langmuir.6b03875] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Total internal reflection infrared (IR) absorption and visible-IR sum-frequency spectroscopies were used to study the role of acrylic acid in the evolution of surface structure in a poly(butyl acrylate)-based pressure-sensitive adhesive during the drying process. By monitoring these spectral responses and calculating the heterospectral correlation coefficients, we established that acrylic acid alters the nature of the molecular interactions at the surface. In the absence of acrylic acid, butyl acrylate orientation is driven by the packing of the polymer as the water evaporates. When acrylic acid is present, a rapid ordering of the copolymer takes place as a result of favorable hydrogen-bonding interactions with the surface.
Collapse
Affiliation(s)
- Sandra Roy
- Department of Chemistry, University of Victoria , Victoria, British Columbia V8W 3V6, Canada
| | - Stephan Freiberg
- Mapei Inc. , 2900 Avenue Francis-Hughes, Laval, Quebec H7L 3J5, Canada
| | - Claude Leblanc
- Mapei Inc. , 2900 Avenue Francis-Hughes, Laval, Quebec H7L 3J5, Canada
| | - Dennis K Hore
- Department of Chemistry, University of Victoria , Victoria, British Columbia V8W 3V6, Canada
| |
Collapse
|
17
|
Lu X, Zhang C, Ulrich N, Xiao M, Ma YH, Chen Z. Studying Polymer Surfaces and Interfaces with Sum Frequency Generation Vibrational Spectroscopy. Anal Chem 2016; 89:466-489. [DOI: 10.1021/acs.analchem.6b04320] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Xiaolin Lu
- State
Key Laboratory of Bioelectronics, School of Biological Science and
Medical Engineering, Southeast University, Nanjing 210096, Jiangsu Province, P. R. China
| | - Chi Zhang
- Department
of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Nathan Ulrich
- Department
of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Minyu Xiao
- Department
of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Yong-Hao Ma
- State
Key Laboratory of Bioelectronics, School of Biological Science and
Medical Engineering, Southeast University, Nanjing 210096, Jiangsu Province, P. R. China
| | - Zhan Chen
- Department
of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| |
Collapse
|