51
|
Chen M, Li L, Zhu R, Zhu J, He H. Intrinsic water layering next to soft, solid, hydrophobic, and hydrophilic substrates. J Chem Phys 2020; 153:224702. [DOI: 10.1063/5.0030021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- Meng Chen
- CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Institutions of Earth Science, Chinese Academy of Sciences (CAS), Guangzhou 510640, China
| | - Lin Li
- CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Institutions of Earth Science, Chinese Academy of Sciences (CAS), Guangzhou 510640, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Runliang Zhu
- CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Institutions of Earth Science, Chinese Academy of Sciences (CAS), Guangzhou 510640, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianxi Zhu
- CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Institutions of Earth Science, Chinese Academy of Sciences (CAS), Guangzhou 510640, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hongping He
- CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Institutions of Earth Science, Chinese Academy of Sciences (CAS), Guangzhou 510640, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
52
|
Ding Y, Zhang Q, Rui K, Xu F, Lin H, Yan Y, Li H, Zhu J, Huang W. Ultrafast Microwave Activating Polarized Electron for Scalable Porous Al toward High-Energy-Density Batteries. NANO LETTERS 2020; 20:8818-8824. [PMID: 33231472 DOI: 10.1021/acs.nanolett.0c03762] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Chemical etching of metals generally brings about undesirable surface damage accompanied by deteriorated performance. However, new possibilities in view of structured interfaces and functional surfaces can be explored by wisely incorporating corrosion chemistry. Here, an ultrafast route to scalable Al foils with desired porous structures originating from Fe(III)-induced oxidation etching was presented. Coupling with efficient electron polarization involving microwave interaction, straightforward surface engineering is well established on various commercial Al foils within minutes, which can be successfully extended to bulk Al alloys. As a proof-of-concept demonstration, the well-defined porous Al foils featuring regulated surface energy, demonstrate great potential as current collectors in promoting cycling stability, for example, 85.2% reversible capacity sustained after 550 cycles (comparable to commercial Al/C foils), and energy density, that is, approximately 3 times of that by using pristine Al foils for LiFePO4-Li half cells.
Collapse
Affiliation(s)
- Ying Ding
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
| | - Qiao Zhang
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
| | - Kun Rui
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
| | - Feng Xu
- Institute of Flexible Electronics (IFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, China
| | - Huijuan Lin
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
| | - Yan Yan
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
| | - Hai Li
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
| | - Jixin Zhu
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
| | - Wei Huang
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
- Institute of Flexible Electronics (IFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, China
| |
Collapse
|
53
|
Abstract
The preparation methods of hydrophobic materials such as zeolites, modified silicas and polymers has been reviewed. Particular attention has been paid to the characterization methods classified according to the surface and bulk composition, on one hand, and to the measure of interactions with water or organic solvents, on the other. Some selected applications are analyzed in order to understand the relevance of the reactants/products adsorption to address activity and selectivity of the reaction. Thus, absorption of a non-polar reactant or desorption of a hydrophilic product are much easier on a hydrophobic surface and can effectively boost the catalytic activity.
Collapse
|
54
|
Liang D, Dahal U, Zhang YK, Lochbaum C, Ray D, Hamers RJ, Pedersen JA, Cui Q. Interfacial water and ion distribution determine ζ potential and binding affinity of nanoparticles to biomolecules. NANOSCALE 2020; 12:18106-18123. [PMID: 32852025 DOI: 10.1039/d0nr03792c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The molecular features that dictate interactions between functionalized nanoparticles and biomolecules are not well understood. This is in part because for highly charged nanoparticles in solution, establishing a clear connection between the molecular features of surface ligands and common experimental observables such as ζ potential requires going beyond the classical models based on continuum and mean field models. Motivated by these considerations, molecular dynamics simulations are used to probe the electrostatic properties of functionalized gold nanoparticles and their interaction with a charged peptide in salt solutions. Counterions are observed to screen the bare ligand charge to a significant degree even at the moderate salt concentration of 50 mM. As a result, the apparent charge density and ζ potential are largely insensitive to the bare ligand charge densities, which fall in the range of ligand densities typically measured experimentally for gold nanoparticles. While this screening effect was predicted by classical models such as the Manning condensation theory, the magnitudes of the apparent surface charge from microscopic simulations and mean-field models are significantly different. Moreover, our simulations found that the chemical features of the surface ligand (e.g., primary vs. quaternary amines, heterogeneous ligand lengths) modulate the interfacial ion and water distributions and therefore the interfacial potential. The importance of interfacial water is further highlighted by the observation that introducing a fraction of hydrophobic ligands enhances the strength of electrostatic binding of the charged peptide. Finally, the simulations highlight that the electric double layer is perturbed upon binding interactions. As a result, it is the bare charge density rather than the apparent charge density or ζ potential that better correlates with binding affinity of the nanoparticle to a charged peptide. Overall, our study highlights the importance of molecular features of the nanoparticle/water interface and underscores a set of design rules for the modulation of electrostatic driven interactions at nano/bio interfaces.
Collapse
Affiliation(s)
- Dongyue Liang
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | | | | | | | | | | | | | | |
Collapse
|
55
|
Lin C, Darling GR, Forster M, McBride F, Massey A, Hodgson A. Hydration of a 2D Supramolecular Assembly: Bitartrate on Cu(110). J Am Chem Soc 2020; 142:13814-13822. [PMID: 32692550 PMCID: PMC7458425 DOI: 10.1021/jacs.0c04747] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
![]()
Hydration
layers play a key role in many technical and biological
systems, but our understanding of these structures remains very limited.
Here, we investigate the molecular processes driving hydration of
a chiral metal–organic surface, bitartrate on Cu(110), which
consists of hydrogen-bonded bitartrate rows separated by exposed Cu.
Initially water decorates the metal channels, hydrogen bonding to
the exposed O ligands that bind bitartrate to Cu, but does not wet
the bitartrate rows. At higher temperature, water inserts into the
structure, breaks the existing intermolecular hydrogen bonds, and
changes the adsorption site and footprint. Calculations show this
process is driven by the creation of stable adsorption sites between
the carboxylate ligands, to allow hydration of O–Cu ligands
within the interior of the structure. This work suggests that hydration
of polar metal–adsorbate ligands will be a dominant factor
in many systems during surface hydration or self-assembly from solution.
Collapse
Affiliation(s)
- Chenfang Lin
- Surface Science Research Centre and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - George R Darling
- Surface Science Research Centre and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - Matthew Forster
- Surface Science Research Centre and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - Fiona McBride
- Surface Science Research Centre and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - Alan Massey
- Surface Science Research Centre and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - Andrew Hodgson
- Surface Science Research Centre and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, United Kingdom
| |
Collapse
|
56
|
Lesnicki D, Zhang Z, Bonn M, Sulpizi M, Backus EHG. Oberflächenladungen an der CaF
2
‐Wasser‐Grenzfläche erlauben eine sehr schnelle intermolekulare Übertragung von Schwingungsenergie. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202004686] [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)
- Dominika Lesnicki
- Institut für Physik Johannes Gutenberg Universität Mainz Staudingerweg 7 55099 Mainz Deutschland
| | - Zhen Zhang
- Abteilung für molekulare Spektroskopie Max-Planck-Institut für Polymerforschung Ackermannweg 10 55128 Mainz Deutschland
| | - Mischa Bonn
- Abteilung für molekulare Spektroskopie Max-Planck-Institut für Polymerforschung Ackermannweg 10 55128 Mainz Deutschland
| | - Marialore Sulpizi
- Institut für Physik Johannes Gutenberg Universität Mainz Staudingerweg 7 55099 Mainz Deutschland
| | - Ellen H. G. Backus
- Abteilung für molekulare Spektroskopie Max-Planck-Institut für Polymerforschung Ackermannweg 10 55128 Mainz Deutschland
- Fachbereich für Physikalische Chemie Universität Wien Währinger Strasse 42 1090 Vienna Österreich
| |
Collapse
|
57
|
Xie Y, Fu L, Niehaus T, Joly L. Liquid-Solid Slip on Charged Walls: The Dramatic Impact of Charge Distribution. PHYSICAL REVIEW LETTERS 2020; 125:014501. [PMID: 32678629 DOI: 10.1103/physrevlett.125.014501] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 04/24/2020] [Accepted: 06/12/2020] [Indexed: 05/25/2023]
Abstract
Nanofluidic systems show great promise for applications in energy conversion, where their performance can be enhanced by nanoscale liquid-solid slip. However, efficiency is also controlled by surface charge, which is known to reduce slip. Combining molecular dynamics simulations and analytical developments, we show the dramatic impact of surface charge distribution on the slip-charge coupling. Homogeneously charged graphene exhibits a very favorable slip-charge relation (rationalized with a new theoretical model correcting some weaknesses of the existing ones), leading to giant electrokinetic energy conversion. In contrast, slip is strongly affected on heterogeneously charged surfaces, due to the viscous drag induced by counterions trapped on the surface. In that case slip should depend on the detailed physical chemistry of the interface controlling the fraction of bound ions. Our numerical results and theoretical models provide new fundamental insight into the molecular mechanisms of liquid-solid slip, and practical guidelines for searching new functional interfaces with optimal energy conversion properties, e.g., for blue energy or waste heat harvesting.
Collapse
Affiliation(s)
- Yanbo Xie
- MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xian, 710072, China
| | - Li Fu
- Univ Lyon, Ecole Centrale de Lyon, Laboratoire de Tribologie et Dynamique des Systèmes, UMR 5513, 36 avenue Guy de Collongue, 69134 Ecully Cedex, France
| | - Thomas Niehaus
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Villeurbanne, France
| | - Laurent Joly
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Villeurbanne, France
- Institut Universitaire de France (IUF), 1 rue Descartes, 75005 Paris, France
| |
Collapse
|
58
|
Bates JS, Bukowski BC, Greeley J, Gounder R. Structure and solvation of confined water and water-ethanol clusters within microporous Brønsted acids and their effects on ethanol dehydration catalysis. Chem Sci 2020; 11:7102-7122. [PMID: 33250979 PMCID: PMC7690318 DOI: 10.1039/d0sc02589e] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 06/18/2020] [Indexed: 11/21/2022] Open
Abstract
Water networks confined within zeolites solvate clustered reactive intermediates and must rearrange to accommodate transition states that differ in size and polarity, with thermodynamic penalties that depend on the shape of the confining environment.
Aqueous-phase reactions within microporous Brønsted acids occur at active centers comprised of water-reactant-clustered hydronium ions, solvated within extended hydrogen-bonded water networks that tend to stabilize reactive intermediates and transition states differently. The effects of these diverse clustered and networked structures were disentangled here by measuring turnover rates of gas-phase ethanol dehydration to diethyl ether (DEE) on H-form zeolites as water pressure was increased to the point of intrapore condensation, causing protons to become solvated in larger clusters that subsequently become solvated by extended hydrogen-bonded water networks, according to in situ IR spectra. Measured first-order rate constants in ethanol quantify the stability of SN2 transition states that eliminate DEE relative to (C2H5OH)(H+)(H2O)n clusters of increasing molecularity, whose structures were respectively determined using metadynamics and ab initio molecular dynamics simulations. At low water pressures (2–10 kPa H2O), rate inhibition by water (–1 reaction order) reflects the need to displace one water by ethanol in the cluster en route to the DEE-formation transition state, which resides at the periphery of water–ethanol clusters. At higher water pressures (10–75 kPa H2O), water–ethanol clusters reach their maximum stable size ((C2H5OH)(H+)(H2O)4–5), and water begins to form extended hydrogen-bonded networks; concomitantly, rate inhibition by water (up to –3 reaction order) becomes stronger than expected from the molecularity of the reaction, reflecting the more extensive disruption of hydrogen bonds at DEE-formation transition states that contain an additional solvated non-polar ethyl group compared to the relevant reactant cluster, as described by non-ideal thermodynamic formalisms of reaction rates. Microporous voids of different hydrophilic binding site density (Beta; varying H+ and Si–OH density) and different size and shape (Beta, MFI, TON, CHA, AEI, FAU), influence the relative extents to which intermediates and transition states disrupt their confined water networks, which manifest as different kinetic orders of inhibition at high water pressures. The confinement of water within sub-nanometer spaces influences the structures and dynamics of the complexes and extended networks formed, and in turn their ability to accommodate the evolution in polarity and hydrogen-bonding capacity as reactive intermediates become transition states in Brønsted acid-catalyzed reactions.
Collapse
Affiliation(s)
- Jason S Bates
- Charles D. Davidson School of Chemical Engineering , Purdue University , 480 Stadium Mall Drive , West Lafayette , IN 47907 , USA . ;
| | - Brandon C Bukowski
- Charles D. Davidson School of Chemical Engineering , Purdue University , 480 Stadium Mall Drive , West Lafayette , IN 47907 , USA . ;
| | - Jeffrey Greeley
- Charles D. Davidson School of Chemical Engineering , Purdue University , 480 Stadium Mall Drive , West Lafayette , IN 47907 , USA . ;
| | - Rajamani Gounder
- Charles D. Davidson School of Chemical Engineering , Purdue University , 480 Stadium Mall Drive , West Lafayette , IN 47907 , USA . ;
| |
Collapse
|
59
|
Lesnicki D, Zhang Z, Bonn M, Sulpizi M, Backus EHG. Surface Charges at the CaF 2 /Water Interface Allow Very Fast Intermolecular Vibrational-Energy Transfer. Angew Chem Int Ed Engl 2020; 59:13116-13121. [PMID: 32239715 PMCID: PMC7496624 DOI: 10.1002/anie.202004686] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Indexed: 01/15/2023]
Abstract
We investigate the dynamics of water in contact with solid calcium fluoride, where at low pH, localized charges can develop upon fluorite dissolution. We use 2D surface‐specific vibrational spectroscopy to quantify the heterogeneity of the interfacial water (D2O) molecules and provide information about the sub‐picosecond vibrational‐energy‐relaxation dynamics at the buried solid/liquid interface. We find that strongly H‐bonded OD groups, with a vibrational frequency below 2500 cm−1, display very rapid spectral diffusion and vibrational relaxation; for weakly H‐bonded OD groups, above 2500 cm−1, the dynamics slows down substantially. Atomistic simulations based on electronic‐structure theory reveal the molecular origin of energy transport through the local H‐bond network. We conclude that strongly oriented H‐bonded water molecules in the adsorbed layer, whose orientation is pinned by the localized charge defects, can exchange vibrational energy very rapidly due to the strong collective dipole, compensating for a partially missing solvation shell.
Collapse
Affiliation(s)
- Dominika Lesnicki
- Institute of Physics, JohannesGutenberg University MainzStaudingerweg 755099MainzGermany
| | - Zhen Zhang
- Department for Molecular SpectroscopyMax Planck Institute for Polymer ResearchAckermannweg 1055128MainzGermany
| | - Mischa Bonn
- Department for Molecular SpectroscopyMax Planck Institute for Polymer ResearchAckermannweg 1055128MainzGermany
| | - Marialore Sulpizi
- Institute of Physics, JohannesGutenberg University MainzStaudingerweg 755099MainzGermany
| | - Ellen H. G. Backus
- Department for Molecular SpectroscopyMax Planck Institute for Polymer ResearchAckermannweg 1055128MainzGermany
- Department of Physical ChemistryUniversity of ViennaWähringer Strasse 421090ViennaAustria
| |
Collapse
|
60
|
Seki T, Yu CC, Yu X, Ohto T, Sun S, Meister K, Backus EHG, Bonn M, Nagata Y. Decoding the molecular water structure at complex interfaces through surface-specific spectroscopy of the water bending mode. Phys Chem Chem Phys 2020; 22:10934-10940. [PMID: 32373844 DOI: 10.1039/d0cp01269f] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The structure of interfacial water determines atmospheric chemistry, wetting properties of materials, and protein folding. The challenge of investigating the properties of specific interfacial water molecules has frequently been confronted using surface-specific sum-frequency generation (SFG) vibrational spectroscopy using the O-H stretch mode. While perfectly suited for the water-air interface, for complex interfaces, a potential complication arises from the contribution of hydroxyl or amine groups of non-water species present at the surface, such as surface hydroxyls on minerals, or O-H and N-H groups contained in proteins. Here, we present a protocol to extract the hydrogen bond strength selectively of interfacial water, through the water bending mode. The bending mode vibrational frequency distribution provides a new avenue for unveiling the hydrogen bonding structure of interfacial water at complex aqueous interfaces. We demonstrate this method for the water-CaF2 and water-protein interfaces. For the former, we show that this method can indeed single out water O-H groups from surface hydroxyls, and that with increasing pH, the hydrogen-bonded network of interfacial water strengthens. Furthermore, we unveil enhanced hydrogen bonding of water, compared to bulk water, at the interface with human serum albumin proteins, a prototypical bio-interface.
Collapse
Affiliation(s)
- Takakazu Seki
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
61
|
Tuladhar A, Dewan S, Pezzotti S, Brigiano FS, Creazzo F, Gaigeot MP, Borguet E. Ions Tune Interfacial Water Structure and Modulate Hydrophobic Interactions at Silica Surfaces. J Am Chem Soc 2020; 142:6991-7000. [DOI: 10.1021/jacs.9b13273] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Aashish Tuladhar
- Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
- Physical Sciences Division, Physical & Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Shalaka Dewan
- Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - Simone Pezzotti
- LAMBE UMR8587, Université d’Evry val d’Essonne, CNRS, CEA, Université Paris-Saclay, 91025 Evry, France
| | - Flavio Siro Brigiano
- LAMBE UMR8587, Université d’Evry val d’Essonne, CNRS, CEA, Université Paris-Saclay, 91025 Evry, France
| | - Fabrizio Creazzo
- LAMBE UMR8587, Université d’Evry val d’Essonne, CNRS, CEA, Université Paris-Saclay, 91025 Evry, France
| | - Marie-Pierre Gaigeot
- LAMBE UMR8587, Université d’Evry val d’Essonne, CNRS, CEA, Université Paris-Saclay, 91025 Evry, France
| | - Eric Borguet
- Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
| |
Collapse
|
62
|
Monroe J, Barry M, DeStefano A, Aydogan Gokturk P, Jiao S, Robinson-Brown D, Webber T, Crumlin EJ, Han S, Shell MS. Water Structure and Properties at Hydrophilic and Hydrophobic Surfaces. Annu Rev Chem Biomol Eng 2020; 11:523-557. [PMID: 32169001 DOI: 10.1146/annurev-chembioeng-120919-114657] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The properties of water on both molecular and macroscopic surfaces critically influence a wide range of physical behaviors, with applications spanning from membrane science to catalysis to protein engineering. Yet, our current understanding of water interfacing molecular and material surfaces is incomplete, in part because measurement of water structure and molecular-scale properties challenges even the most advanced experimental characterization techniques and computational approaches. This review highlights progress in the ongoing development of tools working to answer fundamental questions on the principles that govern the interactions between water and surfaces. One outstanding and critical question is what universal molecular signatures capture the hydrophobicity of different surfaces in an operationally meaningful way, since traditional macroscopic hydrophobicity measures like contact angles fail to capture even basic properties of molecular or extended surfaces with any heterogeneity at the nanometer length scale. Resolving this grand challenge will require close interactions between state-of-the-art experiments, simulations, and theory, spanning research groups and using agreed-upon model systems, to synthesize an integrated knowledge of solvation water structure, dynamics, and thermodynamics.
Collapse
Affiliation(s)
- Jacob Monroe
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA;
| | - Mikayla Barry
- Department of Materials, University of California, Santa Barbara, California 93106, USA
| | - Audra DeStefano
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA;
| | - Pinar Aydogan Gokturk
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Sally Jiao
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA;
| | - Dennis Robinson-Brown
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA;
| | - Thomas Webber
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA;
| | - Ethan J Crumlin
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Songi Han
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; .,Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, USA
| | - M Scott Shell
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA;
| |
Collapse
|
63
|
Bakels S, Gaigeot MP, Rijs AM. Gas-Phase Infrared Spectroscopy of Neutral Peptides: Insights from the Far-IR and THz Domain. Chem Rev 2020; 120:3233-3260. [PMID: 32073261 PMCID: PMC7146864 DOI: 10.1021/acs.chemrev.9b00547] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
![]()
Gas-phase, double
resonance IR spectroscopy has proven to be an
excellent approach to obtain structural information on peptides ranging
from single amino acids to large peptides and peptide clusters. In
this review, we discuss the state-of-the-art of infrared action spectroscopy
of peptides in the far-IR and THz regime. An introduction to the field
of far-IR spectroscopy is given, thereby highlighting the opportunities
that are provided for gas-phase research on neutral peptides. Current
experimental methods, including spectroscopic schemes, have been reviewed.
Structural information from the experimental far-IR spectra can be
obtained with the help of suitable theoretical approaches such as
dynamical DFT techniques and the recently developed Graph Theory.
The aim of this review is to underline how the synergy between far-IR
spectroscopy and theory can provide an unprecedented picture of the
structure of neutral biomolecules in the gas phase. The far-IR signatures
of the discussed studies are summarized in a far-IR map, in order
to gain insight into the origin of the far-IR localized and delocalized
motions present in peptides and where they can be found in the electromagnetic
spectrum.
Collapse
Affiliation(s)
- Sjors Bakels
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7-c, 6525 ED Nijmegen, The Netherlands
| | - Marie-Pierre Gaigeot
- LAMBE CNRS UMR8587, Université d'Evry val d'Essonne, Blvd F. Mitterrand, Bât Maupertuis, 91025 Evry, France
| | - Anouk M Rijs
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7-c, 6525 ED Nijmegen, The Netherlands
| |
Collapse
|
64
|
Smirnov KS. Structure and sum-frequency generation spectra of water on uncharged Q 4 silica surfaces: a molecular dynamics study. Phys Chem Chem Phys 2020; 22:2033-2045. [PMID: 31904065 DOI: 10.1039/c9cp05765j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The structural characteristics and sum-frequency generation (SFG) spectra of water near neutral Q4 silica surfaces were investigated by molecular dynamics simulations. The interactions of water molecules with atoms of the solid were described by different potential models, in particular by the CLAYFF [Cygan et al., J. Phys. Chem. B, 2004, 108, 1255] and INTERFACE [Heinz et al. Langmuir, 2013, 29, 1754] force fields. The calculations of the contact angle of water have shown that the silica surface modeled with CLAYFF behaves as macroscopically hydrophilic, in contrast to the surface described with the INTERFACE model. The hydrophilicity of CLAYFF stems from too attractive electrostatic surface-water interactions. Regardless of the surface's affinity for water, the aqueous phase has a layered structure in the direction perpendicular to the surface with density fluctuations decaying within a distance of 10 Å from the surface. The orientational ordering of H2O molecules was found to be more short-range than the density fluctuations, especially for the hydrophobic surfaces. Modeling the SFG spectra has shown that the spectra of all studied hydrophobic silica-water interfaces are similar and have features in common with the spectrum of the water-vapor interface. The spectra fairly agree with experimental results obtained for the silica-water interface at low pH conditions [Myalitsin et al., J. Phys. Chem. C, 2016, 120, 9357]. The spectral response for the hydrophobic interface was computed to primarily arise from the topmost molecules of the first layer of interfacial water. In contrast, the SFG signal from the hydrophilic silica-water interface is accumulated over a greater distance extending for several water layers due to more long-range perturbation of the structure by the surface.
Collapse
Affiliation(s)
- Konstantin S Smirnov
- Univ. Lille, CNRS, UMR 8516 - LASIR - Laboratoire de Spectrochimie Infrarouge et Raman, F-59000 Lille, France.
| |
Collapse
|
65
|
Chen M, Zhou H, Zhu R, Lu X, He H. Closest-Packing Water Monolayer Stably Intercalated in Phyllosilicate Minerals under High Pressure. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:618-627. [PMID: 31886678 DOI: 10.1021/acs.langmuir.9b03394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The directional hydrogen-bond (HB) network and nondirectional van der Waals (vdW) interactions make up the specificity of water. Directional HBs could construct an ice-like monolayer in hydrophobic confinement even in the ambient regime. Here, we report a water monolayer dominated by vdW interactions confined in a phyllosilicate interlayer under high pressure. Surprisingly, it was in a thermodynamically stable state coupled with bulk water at the same pressure (P) and temperature (T), as revealed by the thermodynamic integration approach on the basis of molecular dynamics (MD) simulations. Both classical and ab initio MD simulations showed water O atoms were stably trapped and exhibited an ordered hexagonal closest-packing arrangement, but OH bonds of water reoriented frequently and exhibited a specific two-stage reorientation relaxation. Strikingly, hydration in the interlayer under high pressure had no relevance with surface hydrophilicity rationalized by the HB forming ability, which, however, determines wetting in the ambient regime. Intercalated water molecules were trapped by vdW interactions, which shaped the closest-packing arrangement and made hydration energetically available. The high pressure-volume term largely drives hydration, as it compensates the entropy penalty which is restricted by a relatively lower temperature. This vdW water monolayer should be ubiquitous in the high pressure but low-temperature regime.
Collapse
Affiliation(s)
- Meng Chen
- CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Institutions of Earth Science , Chinese Academy of Sciences (CAS) , Guangzhou 510640 , China
| | - Huijun Zhou
- CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Institutions of Earth Science , Chinese Academy of Sciences (CAS) , Guangzhou 510640 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Runliang Zhu
- CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Institutions of Earth Science , Chinese Academy of Sciences (CAS) , Guangzhou 510640 , China
| | - Xiancai Lu
- State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering , Nanjing University , Nanjing 210093 , China
| | - Hongping He
- CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Institutions of Earth Science , Chinese Academy of Sciences (CAS) , Guangzhou 510640 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| |
Collapse
|
66
|
Del Grosso CA, Leng C, Zhang K, Hung HC, Jiang S, Chen Z, Wilker JJ. Surface hydration for antifouling and bio-adhesion. Chem Sci 2020; 11:10367-10377. [PMID: 34094298 PMCID: PMC8162394 DOI: 10.1039/d0sc03690k] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Antifouling properties of materials play crucial roles in many important applications such as biomedical implants, marine antifouling coatings, biosensing, and membranes for separation. Poly(ethylene glycol) (or PEG) containing polymers and zwitterionic polymers have been shown to be excellent antifouling materials. It is believed that their outstanding antifouling activity comes from their strong surface hydration. On the other hand, it is difficult to develop underwater glues, although adhesives with strong adhesion in a dry environment are widely available. This is related to dehydration, which is important for adhesion for many cases while water is the enemy of adhesion. In this research, we applied sum frequency generation (SFG) vibrational spectroscopy to investigate buried interfaces between mussel adhesive plaques and a variety of materials including antifouling polymers and control samples, supplemented by studies on marine animal (mussel) behavior and adhesion measurements. It was found that PEG containing polymers and zwitterionic polymers have very strong surface hydration in an aqueous environment, which is the key for their excellent antifouling performance. Because of the strong surface hydration, mussels do not settle on these surfaces even after binding to the surfaces with rubber bands. For control samples, SFG results indicate that their surface hydration is much weaker, and therefore mussels can generate adhesives to displace water to cause dehydration at the interface. Because of the dehydration, mussels can foul on the surfaces of these control materials. Our experiments also showed that if mussels were forced to deposit adhesives onto the PEG containing polymers and zwitterionic polymers, interfacial dehydration did not occur. However, even with the strong interfacial hydration, strong adhesion between mussel adhesives and antifouling polymer surfaces was detected, showing that under certain circumstances, interfacial water could enhance the interfacial bio-adhesion. Antifouling properties of materials play crucial roles in many important applications such as biomedical implants, marine antifouling coatings, biosensing, and membranes for separation.![]()
Collapse
Affiliation(s)
| | - Chuan Leng
- Department of Chemistry
- University of Michigan
- Ann Arbor
- USA
| | - Kexin Zhang
- Department of Chemistry
- University of Michigan
- Ann Arbor
- USA
| | - Hsiang-Chieh Hung
- Department of Chemical Engineering
- University of Washington
- Seattle
- USA
| | - Shaoyi Jiang
- Department of Chemical Engineering
- University of Washington
- Seattle
- USA
| | - Zhan Chen
- Department of Chemistry
- University of Michigan
- Ann Arbor
- USA
| | - Jonathan J. Wilker
- Department of Chemistry
- Purdue University
- West Lafayette
- USA
- School of Materials Engineering
| |
Collapse
|
67
|
de Aguiar HB, McGraw JD, Donaldson SH. Interface-Sensitive Raman Microspectroscopy of Water via Confinement with a Multimodal Miniature Surface Forces Apparatus. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:15543-15551. [PMID: 31310142 DOI: 10.1021/acs.langmuir.9b01889] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Modern interfacial science is increasingly multidisciplinary. Unique insight into interfacial interactions requires new multimodal techniques for interrogating surfaces with simultaneous complementary physical and chemical measurements. Here, we describe the design and testing of a microscope that incorporates a miniature surface forces apparatus (μSFA) in sphere vs flat geometry for force-distance measurements, while simultaneously acquiring Raman spectra of the confined zone. The simple optical setup isolates independent optical paths for (i) the illumination and imaging of Newton's rings and (ii) Raman scattering excitation and efficient signal collection. We benchmark the methodology by examining Teflon thin films in asymmetric (Teflon-water-glass) and symmetric (Teflon-water-Teflon) configurations. Water is observed near the Teflon-glass interface with nanometer-scale sensitivity in both the distance and Raman signals. We perform chemically resolved, label-free imaging of confined contact regions between Teflon and glass surfaces immersed in water. Remarkably, we estimate that the combined approach enables vibrational spectroscopy with single water monolayer sensitivity within minutes. Altogether, the Raman-μSFA allows exploration of molecular confinement between surfaces with chemical selectivity and correlation with interaction forces.
Collapse
Affiliation(s)
- Hilton B de Aguiar
- Département de Physique , Ecole Normale Supérieure/PSL Research University, CNRS , 24 rue Lhomond , 75005 Paris , France
| | - Joshua D McGraw
- Département de Physique , Ecole Normale Supérieure/PSL Research University, CNRS , 24 rue Lhomond , 75005 Paris , France
- Gulliver CNRS UMR 7083 , PSL Research University, ESPCI Paris , 10 rue Vauquelin , 75005 Paris , France
| | - Stephen H Donaldson
- Département de Physique , Ecole Normale Supérieure/PSL Research University, CNRS , 24 rue Lhomond , 75005 Paris , France
| |
Collapse
|
68
|
Pezzotti S, Galimberti DR, Gaigeot MP. Deconvolution of BIL-SFG and DL-SFG spectroscopic signals reveals order/disorder of water at the elusive aqueous silica interface. Phys Chem Chem Phys 2019; 21:22188-22202. [PMID: 31441490 DOI: 10.1039/c9cp02766a] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Through the prism of the rather controversial and elusive silica/water interface, ab initio DFT-based molecular dynamics simulations of the structure and non-linear SFG spectroscopy of the interface are analysed. Following our recent work [Phys. Chem. Chem. Phys., 2018, 20, 5190-5199], we show that once the interfacial water is decomposed into BIL (Binding Interfacial Layer) and DL (Diffuse Layer) interfacial regions, the SFG signals can be deconvolved and unambiguously interpreted, and a global microscopic understanding on silica/water interfaces can be obtained. By comparing crystalline quartz/water and amorphous (fused) silica/water interfaces, the dependence of interfacial structural and spectroscopic properties on the degree of surface crystallinity is established, while by adding KCl electrolytes at the quartz/water interface, the chaotropic effect of ions on the interfacial molecular arrangement is unveiled. The evolution of structure and SFG spectra of silica/water interfaces with respect to increasing surface deprotonation, i.e., with respect to pH conditions, is also evaluated. Spectroscopic BIL-SFG markers that experimentally allow one detect the water order/disorder in the BIL as a function of surface hydroxylation and ion concentration are revealed, while the pH-induced modulations in the experimentally recorded SFG spectra are rationalized in terms of changes in both BIL and DL SFG signatures.
Collapse
Affiliation(s)
- Simone Pezzotti
- LAMBE CNRS UMR8587, Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement, Université d'Evry val d'Essonne, Blvd F. Mitterrand, Bat Maupertuis, 91025 Evry, France.
| | | | | |
Collapse
|
69
|
Ojha D, Kaliannan NK, Kühne TD. Time-dependent vibrational sum-frequency generation spectroscopy of the air-water interface. Commun Chem 2019. [DOI: 10.1038/s42004-019-0220-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Abstract
Vibrational sum-frequency generation spectroscopy is a powerful method to study the microscopic structure and dynamics of interfacial systems. Here we demonstrate a simple computational approach to calculate the time-dependent, frequency-resolved vibrational sum-frequency generation spectrum (TD-vSFG) of the air-water interface. Using this approach, we show that at the air-water interface, the transition of water molecules with bonded OH modes to free OH modes occurs at a time scale of $$\sim$$
~
3 ps, whereas water molecules with free OH modes rapidly make a transition to a hydrogen-bonded state within $$\sim$$
~
2 ps. Furthermore, we also elucidate the origin of the observed differential dynamics based on the time-dependent evolution of water molecules in the different local solvent environments.
Collapse
|
70
|
Wang H, Xu Q, Liu Z, Tang Y, Wei G, Shen YR, Liu WT. Gate-Controlled Sum-Frequency Vibrational Spectroscopy for Probing Charged Oxide/Water Interfaces. J Phys Chem Lett 2019; 10:5943-5948. [PMID: 31448602 DOI: 10.1021/acs.jpclett.9b01908] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The rich chemistry of oxide/aqueous interfaces originates from the interfacial layer formed by surface charges and adjoining water molecules. Yet not much is clear about such layers, because they are difficult to access, and measurements unavoidably collect signals from the diffuse layer nearby, which is perturbed by the surface potential extending into the bulk water. Here we show that gating of a semiconductor/oxide/water junction can effectively vary the surface charge density at the oxide/water interface but keep the surface potential low and barely varying, allowing effective removal of the diffuse layer contribution. With sum-frequency vibrational spectroscopy on a silicon/silica/deionized-water model junction, the variation of the bonded layer water structure in response to surface charging can be readily detected. This new scheme is generally applicable to all oxide/water interfaces, providing opportunities for future investigations at a deeper molecular level.
Collapse
Affiliation(s)
- Hongqing Wang
- Physics Department, State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures [Ministry of Education] , Fudan University , Shanghai 200433 , China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , China
| | - Qian Xu
- Physics Department, State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures [Ministry of Education] , Fudan University , Shanghai 200433 , China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , China
| | - Zhihua Liu
- Physics Department, State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures [Ministry of Education] , Fudan University , Shanghai 200433 , China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , China
| | - Yiming Tang
- Physics Department, State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures [Ministry of Education] , Fudan University , Shanghai 200433 , China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , China
| | - Guanghong Wei
- Physics Department, State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures [Ministry of Education] , Fudan University , Shanghai 200433 , China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , China
| | - Y Ron Shen
- Physics Department, State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures [Ministry of Education] , Fudan University , Shanghai 200433 , China
- Department of Physics , University of California , Berkeley 94720 , California , United States
| | - Wei-Tao Liu
- Physics Department, State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures [Ministry of Education] , Fudan University , Shanghai 200433 , China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , China
| |
Collapse
|
71
|
Abstract
The conformation of water around proteins is of paramount importance, as it determines protein interactions. Although the average water properties around the surface of proteins have been provided experimentally and computationally, protein surfaces are highly heterogeneous. Therefore, it is crucial to determine the correlations of water to the local distributions of polar and nonpolar protein surface domains to understand functions such as aggregation, mutations, and delivery. By using atomistic simulations, we investigate the orientation and dynamics of water molecules next to 4 types of protein surface domains: negatively charged, positively charged, and charge-neutral polar and nonpolar amino acids. The negatively charged amino acids orient around 98% of the neighboring water dipoles toward the protein surface, and such correlation persists up to around 16 Å from the protein surface. The positively charged amino acids orient around 94% of the nearest water dipoles against the protein surface, and the correlation persists up to around 12 Å. The charge-neutral polar and nonpolar amino acids are also orienting the water neighbors in a quantitatively weaker manner. A similar trend was observed in the residence time of the nearest water neighbors. These findings hold true for 3 technically important enzymes (PETase, cytochrome P450, and organophosphorus hydrolase). Our results demonstrate that the water-amino acid degree of correlation follows the same trend as the amino acid contribution in proteins solubility, namely, the negatively charged amino acids are the most beneficial for protein solubility, then the positively charged amino acids, and finally the charge-neutral amino acids.
Collapse
|
72
|
Protsak I, Gun’ko VM, Henderson IM, Pakhlov EM, Sternik D, Le Z. Nanostructured Amorphous Silicas Hydrophobized by Various Pathways. ACS OMEGA 2019; 4:13863-13871. [PMID: 31497703 PMCID: PMC6714511 DOI: 10.1021/acsomega.9b01508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 07/31/2019] [Indexed: 06/10/2023]
Abstract
Various nanostructured amorphous silicas [fumed silicas such as crude (A-300), hydro-compacted (cA-300, TS 100), and precipitated silica Syloid 244] were modified by different polydimethylsiloxanes such as PDMS5, PDMS100, PDMS200, PDMS1000, and PDMS12500 (the label numbers show the viscosity (η) values) using dimethyl carbonate (DMC) as a siloxane-bond-breaking reagent. In addition, hexamethyldisilazane was used to modify fumed silica cA-300. The nanocomposites were characterized using microscopy, infrared spectroscopy, thermodesorption, nitrogen adsorption-desorption, solid-state NMR spectroscopy, small-angle X-ray scattering, and zeta-potential methods. It was found that the morphological, textural, and structural characteristics of silicas grafted with PDMS depend strongly not only on the type and content of the polymers used but also on the organization of nonporous nanoparticles (NPNP) in secondary structures (aggregates of NPNP and agglomerated aggregates, ANPNP), as well on the reaction temperature (T r). Specifically, we determined that ANPNP with a macro/mesoporous character are favorable for the effective modification of the silicas studied with short polymers and no DMC addition but at higher temperatures or for a longer silicone polymer with the presence of DMC and at lower temperatures. In particular, the PDMS/DMC-modified silicas are of great interest from a practical point of view because they remain in a dispersed state with no strong compaction of the secondary structures after modification, and this corresponds to a better distribution of the modified nanoparticles in polymeric or other matrices.
Collapse
Affiliation(s)
- Iryna
S. Protsak
- College
of Environment, Zhejiang University of Technology, Hangzhou 310014, China
- College
of Science, Zhejiang University of Technology, Hangzhou 310023, China
| | - Volodymyr M. Gun’ko
- Chuiko
Institute of Surface Chemistry of NAS of Ukraine, Kiev 03164, Ukraine
| | - Ian M. Henderson
- Omphalos
Bioscience, LLC, Albuquerque 87110, New Mexico, United States
| | - Evgeniy M. Pakhlov
- Chuiko
Institute of Surface Chemistry of NAS of Ukraine, Kiev 03164, Ukraine
| | | | - Zichun Le
- College
of Science, Zhejiang University of Technology, Hangzhou 310023, China
| |
Collapse
|
73
|
Sivashanmugan K, Squire K, Kraai JA, Tan A, Zhao Y, Rorrer GL, Wang AX. Biological Photonic Crystal-Enhanced Plasmonic Mesocapsules: Approaching Single-Molecule Optofluidic-SERS Sensing. ADVANCED OPTICAL MATERIALS 2019; 7:1900415. [PMID: 32775144 PMCID: PMC7410161 DOI: 10.1002/adom.201900415] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Indexed: 05/05/2023]
Abstract
Surface-enhanced Raman scattering (SERS) sensing in microfluidic devices, namely optofluidic-SERS, suffers an intrinsic trade-off between mass transport and hot spot density, both of which are required for ultra-sensitive detection. To overcome this compromise, photonic crystal-enhanced plasmonic mesocapsules are synthesized, utilizing diatom biosilica decorated with in-situ growth silver nanoparticles (Ag NPs). In our optofluidic-SERS testing, 100× higher enhancement factors and greater than 1,000× better detection limit were achieved compared with traditional colloidal Ag NPs, the improvement of which is attributed to unique properties of the mesocapsules. First, the porous diatom biosilica frustules serve as carrier capsules for high density Ag NPs that form high density plasmonic hot-spots. Second, the submicron-pores embedded in the frustule walls not only create a large surface-to-volume ratio allowing for effective analyte capture, but also enhance the local optical field through the photonic crystal effect. Last, the mesocapsules provide effective mixing with analytes as they are flowing inside the microfluidic channel. The reported mesocapsules achieved single molecule detection of Rhodamine 6G in microfluidic devices and were further utilized to detect 1 nM of benzene and chlorobenzene compounds in tap water with near real-time response, which successfully overcomes the constraint of traditional optofluidic sensing.
Collapse
Affiliation(s)
- Kundan Sivashanmugan
- School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR 97331, USA
| | - Kenneth Squire
- School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR 97331, USA
| | - Joseph A. Kraai
- School of Chemical, Biological, and Ecological Engineering, Oregon State University, Corvallis, OR 97331, USA
| | - Ailing Tan
- School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR 97331, USA
- School of Information Science and Engineering, The Key Laboratory for Special Fiber and Fiber Sensor of Hebei Province, Yanshan University, Qinhuangdao 066004, China
| | - Yong Zhao
- School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR 97331, USA
- School of Electrical Engineering, The Key Laboratory of Measurement Technology and Instrumentation of Hebei Province, Yanshan University, Qinhuangdao, 066004, China
| | - Gregory L. Rorrer
- School of Chemical, Biological, and Ecological Engineering, Oregon State University, Corvallis, OR 97331, USA
| | - Alan X. Wang
- School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR 97331, USA
| |
Collapse
|