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Hore DK. Phase of the second-order susceptibility in vibrational sum frequency generation spectroscopy: Origins, utility, and measurement techniques. J Chem Phys 2024; 161:060902. [PMID: 39132786 DOI: 10.1063/5.0220817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Accepted: 07/17/2024] [Indexed: 08/13/2024] Open
Abstract
Vibrational sum frequency generation can provide valuable structural information at surfaces and buried interfaces. Relating the measured spectra to the complex-valued second-order susceptibility χ(2) is at the heart of the technique and a requisite step in nearly all subsequent analyses. The magnitude and phase of χ(2) as a function of frequency reveal important information about molecules and materials in regions where centrosymmetry is broken. In this tutorial-style perspective, the origins of the χ(2) phase are first described, followed by the utility of phase determination. Finally, some practical methods of phase extraction are discussed.
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Affiliation(s)
- Dennis K Hore
- Department of Chemistry, University of Victoria, Victoria, British Columbia V8W 3V6, Canada and Department of Computer Science, University of Victoria, Victoria, British Columbia V8W 3V6, Canada
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2
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Xu Z, Zhang Y, Wu Y, Lu X. Spectroscopically Detecting Molecular-Level Bonding Formation between an Epoxy Formula and Steel. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:13261-13271. [PMID: 36254887 DOI: 10.1021/acs.langmuir.2c02325] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The formation of the interfacial adhesion between an epoxy adhesive and a substrate was normally accompanied by the epoxy curing process on the substrate. Although the debate on the formation mechanism of the interfacial adhesion is still ongoing, this issue can causally be resolved by studying the interfacial structural formation between the epoxy adhesive and the substrate. Herein, to reveal the interfacial structural formation of a representative formula composed of epoxy (digylcidyl ether of biphenyl A, DGEBA) and amine hardener (2,2'-(ethylenedioxy) diethylamine, EDDA) with the steel substrate upon curing and postcuring treatments, sum-frequency generation (SFG) vibrational spectroscopy with a sandwiched transparent window/epoxy adhesive/steel setup was applied to detect and track the buried molecular-level structures at the epoxy adhesive/steel interface. An X-ray photoelectron spectroscopic (XPS) experiment was performed to probe the intentionally exposed interface to disclose the occurring interfacial chemical reaction. The reaction between the epoxy groups and the steel-surface OH groups and the molecular reconstruction of interfacial epoxy methyl groups upon curing and postcuring steps were confirmed. The latter also indirectly indicated the formation of the additional hydrogen bonding and the former bonding reaction at the interface. The above two spectroscopic experimental results matched up with the further examination of the adhesion strength. Therefore, this work elucidates the formation of the interfacial bonding between the epoxy formula and the steel substrate upon curing and postcuring treatments at the molecular level, thus providing an in-depth insight into the origin of the interfacial adhesion.
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Affiliation(s)
- Zhaohui Xu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing210096, China
| | - Yinyu Zhang
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang621900, China
| | - Yeping Wu
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang621900, China
| | - Xiaolin Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing210096, China
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Ma XY, Zhang WY, Ye K, Jiang K, Cai WB. Electrolyte-Layer-Tunable ATR-SEIRAS for Simultaneous Detection of Adsorbed and Dissolved Species in Electrochemistry. Anal Chem 2022; 94:11337-11344. [PMID: 35930311 DOI: 10.1021/acs.analchem.2c02092] [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
A balanced detection of both adsorbates and dissolved species is very important for the clarification of the electrochemical reaction mechanism yet remains a major challenge for different modes of electrochemical infrared (IR) spectroscopy. Among others, conventional attenuated total reflection-surface-enhanced IR absorption spectroscopy (ATR-SEIRAS) is far less sensitive to low-concentration solution species than to surface species. We report herein an electrochemical wide-frequency ATR-SEIRAS with a novel thin-layer flow cell design, fulfilling the simultaneous detection of the variations of surface and solution species. This setup consists of a silicon wafer (with one side micromachined and the other side metallized), a thin-layer electrolyte structure with tunable thickness and flow rate, and a tilt-correction system based on laser collimation, enabling a well-controlled mass transport within the electrolyte layer and the spectral differentiation of solution species from adsorbates. Using acidic methanol oxidation on a Pt film electrode as a model system, besides SEIRA bands for adsorbed CO and formate intermediates, IR spectral signals for dissolved products CO2, formic acid, and methyl formate can be readily identified for a quiescent electrolyte layer of ∼20 μm, which are otherwise undetected with conventional ATR-SEIRAS, as indicated by the trend of spectral features with increasing thickness or flow rate.
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Affiliation(s)
- Xian-Yin Ma
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Fudan University, Shanghai 200438, China
| | - Wei-Yi Zhang
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Fudan University, Shanghai 200438, China
| | - Ke Ye
- Interdisciplinary Research Center, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Kun Jiang
- Interdisciplinary Research Center, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Wen-Bin Cai
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Fudan University, Shanghai 200438, China
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Xu Z, Zhang Y, Wu Y, Lu X. Molecular-Level Correlation between Spectral Evidence and Interfacial Bonding Formation for Epoxy Adhesives on Solid Substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:5847-5856. [PMID: 35441517 DOI: 10.1021/acs.langmuir.2c00470] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Interfacial bonding strength of an epoxy-based adhesive depends on the interfacial interaction between the adhesive and the substrate. Normally, the curing process at the interface accompanied by the interfacial bonding formation is different from that in the bulk, and it is still a big challenge to probe the interfacial bonding formation at a molecular level. In this study, to trace the interfacial structural evolution of a representative formula of epoxy (digylcidyl ether of biphenyl A, DGEBA) and amine hardener [1,2-bis(2-aminoethoxy)ethane, EDDA] with the sapphire and silica substrates upon curing and post-curing steps, sum frequency generation (SFG) vibrational spectroscopy is employed to detect the molecular-level interfacial structural information. For the sapphire substrate, upon curing, backbone methylene (CH2) stretching signals decrease, indicating the formation of a rigid chain network structure and thus losing the local methylene order, while vibrational signals of the sapphire surface hydroxyl (OH) groups (including hydrogen-bonded and unbonded) increase significantly, indicating the formation of a strong hydrogen-bonding and polar interaction between the epoxy adhesive and the sapphire surface. Upon post-curing, increased backbone CH2 signals and decreased sapphire OH signals suggest interfacial chemical bonding formation due to the reaction between the epoxy rings and the sapphire surface OH groups. Orientation analysis confirms the enhanced ordering of the sapphire surface OH groups upon curing and post-curing, in comparison to the uncured epoxy formula. As for the fused silica, weak vibrational signals of the methylene (CH2) and methyl (CH3) groups are observed before curing, while both of them increase slightly for the cured and post-cured epoxy formulae, suggesting relatively less hydrophilic nature of the silica surface compared to that of the sapphire surface, also evidenced by the very weak OH signals upon curing and post-curing. Further measurement on the adhesion strength matches up with the above spectroscopic experimental results, substantiating the correlation between the macroscopic bonding strength of the epoxy adhesive and the microscopic molecular-level structure.
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Affiliation(s)
- Zhaohui Xu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Yinyu Zhang
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
| | - Yeping Wu
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
| | - Xiaolin Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
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Ge A, Inoue KI, Ye S. Probing the electrode-solution interfaces in rechargeable batteries by sum-frequency generation spectroscopy. J Chem Phys 2020; 153:170902. [PMID: 33167651 DOI: 10.1063/5.0026283] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
An in-depth understanding of the electrode-electrolyte interaction and electrochemical reactions at the electrode-solution interfaces in rechargeable batteries is essential to develop novel electrolytes and electrode materials with high performance. In this perspective, we highlight the advantages of the interface-specific sum-frequency generation (SFG) spectroscopy on the studies of the electrode-solution interface for the Li-ion and Li-O2 batteries. The SFG studies in probing solvent adsorption structures and solid-electrolyte interphase formation for the Li-ion battery are briefly reviewed. Recent progress on the SFG study of the oxygen reaction mechanisms and stability of the electrolyte in the Li-O2 battery is also discussed. Finally, we present the current perspective and future directions in the SFG studies on the electrode-electrolyte interfaces toward providing deeper insight into the mechanisms of discharging/charging and parasitic reactions in novel rechargeable battery systems.
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Affiliation(s)
- Aimin Ge
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Ken-Ichi Inoue
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Shen Ye
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
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Li B, Andre JS, Chen X, Walther B, Paradkar R, Feng C, Tucker C, Mohler C, Chen Z. Observing a Chemical Reaction at a Buried Solid/Solid Interface in Situ. Anal Chem 2020; 92:14145-14152. [DOI: 10.1021/acs.analchem.0c03228] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Bolin Li
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - John S. Andre
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Xiaoyun Chen
- Core R&D,The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Brian Walther
- Packaging and Specialty Plastics,The Dow Chemical Company, Lake Jackson, Texas 77566, United States
| | - Rajesh Paradkar
- Packaging and Specialty Plastics,The Dow Chemical Company, Lake Jackson, Texas 77566, United States
| | - Chuang Feng
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Christopher Tucker
- Core R&D,The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Carol Mohler
- Core R&D,The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Zhan Chen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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Bhattacharyya D, Dhar P, Liu Y, Djurovich PI, Thompson ME, Benderskii AV. Vibrational Sum Frequency Generation Study of the Interference Effect on a Thin Film of 4,4'-Bis( N-carbazolyl)-1,1'-biphenyl (CBP) and Its Interfacial Orientation. ACS APPLIED MATERIALS & INTERFACES 2020; 12:26515-26524. [PMID: 32406227 DOI: 10.1021/acsami.0c01394] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Molecular organization of vapor-deposited organic molecules in the active layer of organic light-emitting diodes (OLEDs) has been a matter of great interest as it directly influences various optoelectronic properties and the overall performance of the devices. Contrary to the general assumption of isotropic molecular orientation in vacuum-deposited thin-film OLEDs, it is possible to achieve an anisotropic molecular distribution at or near the surface under controlled experimental conditions. In this study, we have used interface-specific vibrational sum frequency generation (VSFG) spectroscopy to determine the orientation of a low-molecular weight OLED material, 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP), at free (air) and buried (CaF2) interfaces. VSFG spectra were measured at four different polarization combinations for five different thicknesses of the CBP film. The spectral shift and VSFG intensity changes with the film thickness can be accurately modeled by considering the optical interference effect of the signals coming from the CBP/air and CBP/CaF2 interfaces. A global fitting of the experimental spectra for all thicknesses along with theoretical simulations reveal that the long molecular axis of CBP is oriented at an angle of ∼58° (47-70°) from the surface normal at the air/CBP interface, whereas at the CBP/CaF2 interface, the angle is ∼48° (43-52°). Such a change in the angle (∼10°) suggests that the CBP molecule tends to orient more vertically (edge-on) at the buried CaF2 interface, which may be attributed to the intermolecular π-π stacking interaction between adjacent CBP molecules.
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Affiliation(s)
- Dhritiman Bhattacharyya
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
| | - Purnim Dhar
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
| | - Yifei Liu
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
| | - Peter I Djurovich
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
| | - Mark E Thompson
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
| | - Alexander V Benderskii
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
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Li X, Lu X. Interfacial Irreversibly and Loosely Adsorbed Layers Abide by Different Evolution Dynamics. ACS Macro Lett 2019; 8:1426-1431. [PMID: 35651186 DOI: 10.1021/acsmacrolett.9b00472] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Within the interfacial region of the substrate, polymer chains can form the inner irreversibly adsorbed and outer loosely adsorbed layers upon annealing. Owing to their different constrained environments, the evolution dynamics of the two layers are supposedly different. To trace such evolution dynamics, we thus resorted to sum frequency generation (SFG) vibrational spectroscopy, using polystyrene (PS) with a series of molar masses on sapphire substrates. By plotting the integrated SFG intensity as a function of the annealing time, we found that the inner irreversibly adsorbed layer had two segmental evolution processes (replacement and local structural relaxation), and the outer loosely adsorbed layer had the monotonical evolution dynamics (structural relaxation), with both evolving toward the dissipation of the interfacial molecular order of the backbones. A critical evolution time was defined for the inner irreversibly adsorbed layer, and a characteristic relaxation time was defined for the outer loosely adsorbed layer. With respect to the molar mass, phenomenologically, both the critical evolution time and the characteristic relaxation time show an asymptotic increase. In summary, this SFG investigation provides the first-hand experimental data on understanding the structural evolution dynamics of the interfacial adsorbed polymer chains, which would gradually split up into the irreversibly adsorbed layer and loosely adsorbed layer upon annealing.
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Affiliation(s)
- Xu Li
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, Jiangsu Province, P. R. China
| | - Xiaolin Lu
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, Jiangsu Province, P. R. China
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Thämer M, Garling T, Campen RK, Wolf M. Quantitative determination of the nonlinear bulk and surface response from alpha-quartz using phase sensitive SFG spectroscopy. J Chem Phys 2019. [DOI: 10.1063/1.5109868] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- Martin Thämer
- Fritz Haber Institute of the Max Planck Society, 4-6 Faradayweg, 14195 Berlin, Germany
| | - Tobias Garling
- Fritz Haber Institute of the Max Planck Society, 4-6 Faradayweg, 14195 Berlin, Germany
| | - R. Kramer Campen
- Fritz Haber Institute of the Max Planck Society, 4-6 Faradayweg, 14195 Berlin, Germany
| | - Martin Wolf
- Fritz Haber Institute of the Max Planck Society, 4-6 Faradayweg, 14195 Berlin, Germany
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Li X, Lu X. Evolution of Irreversibly Adsorbed Layer Promotes Dewetting of Polystyrene Film on Sapphire. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b01141] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Xu Li
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, Jiangsu Province, P. R. China
| | - Xiaolin Lu
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, Jiangsu Province, P. R. China
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11
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Thämer M, Campen RK, Wolf M. Detecting weak signals from interfaces by high accuracy phase-resolved SFG spectroscopy. Phys Chem Chem Phys 2018; 20:25875-25882. [DOI: 10.1039/c8cp04239j] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Phase-resolved, collinear, time domain SFG spectrometer for the detection of weak vibrational signals from interfaces.
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Affiliation(s)
- Martin Thämer
- Fritz Haber Institute of the Max Planck Society
- 14195 Berlin
- Germany
| | - R. Kramer Campen
- Fritz Haber Institute of the Max Planck Society
- 14195 Berlin
- Germany
| | - Martin Wolf
- Fritz Haber Institute of the Max Planck Society
- 14195 Berlin
- Germany
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12
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Adsorption of organic carbonate solvents on a carbon surface probed by sum frequency generation (SFG) vibrational spectroscopy. J Electroanal Chem (Lausanne) 2017. [DOI: 10.1016/j.jelechem.2016.09.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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13
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Rey NG, Dlott DD. Studies of electrochemical interfaces by broadband sum frequency generation. J Electroanal Chem (Lausanne) 2017. [DOI: 10.1016/j.jelechem.2016.12.023] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Ge A, Seo JH, Qiao L, Yui N, Ye S. Structural Reorganization and Fibrinogen Adsorption Behaviors on the Polyrotaxane Surfaces Investigated by Sum Frequency Generation Spectroscopy. ACS APPLIED MATERIALS & INTERFACES 2015; 7:22709-22718. [PMID: 26393413 DOI: 10.1021/acsami.5b07760] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Polyrotaxanes, such as supramolecular assemblies with methylated α-cyclodextrins (α-CDs) as host molecules noncovalently threaded on the linear polymer backbone, are promising materials for biomedical applications because they allow adsorbed proteins possessing a high surface flexibility as well as control of the cellular morphology and adhesion. To provide a general design principle for biomedical materials, we examined the surface reorganization behaviors and adsorption conformations of fibrinogen on the polyrotaxane surfaces with comparison to several random copolymers by sum frequency generation (SFG) vibrational spectroscopy. We showed that the polyrotaxane (OMe-PRX-PMB) with methylated α-CDs as the host molecule exhibited unique surface structures in an aqueous environment. The hydrophobic interaction between the methoxy groups of the methylated α-CD molecules and methyl groups of the n-butyl methacrylate (BMA) side chains may dominate the surface restructuring behavior of the OMe-PRX-PMB. The orientation analysis revealed that the orientation of the fibrinogen adsorbed on the OMe-PRX-PMB surface is close to a single distribution, which is different from the adsorption behaviors of fibrinogen on other polyrotaxane or random copolymer surfaces.
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Affiliation(s)
- Aimin Ge
- Catalysis Research Center, Hokkaido University , Sapporo 001-0021, Japan
| | - Ji-Hun Seo
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University , Tokyo 101-0062, Japan
| | - Lin Qiao
- Catalysis Research Center, Hokkaido University , Sapporo 001-0021, Japan
| | - Nobuhiko Yui
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University , Tokyo 101-0062, Japan
| | - Shen Ye
- Catalysis Research Center, Hokkaido University , Sapporo 001-0021, Japan
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Zhang H, Li F, Xiao Q, Lin H. Conformation of Capping Ligands on Nanoplates: Facet-Edge-Induced Disorder and Self-Assembly-Related Ordering Revealed by Sum Frequency Generation Spectroscopy. J Phys Chem Lett 2015; 6:2170-6. [PMID: 26266587 DOI: 10.1021/acs.jpclett.5b00717] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Surface-curvature-amplified conformational disorder in alkyl capping ligands has been observed previously when the nanoparticle radii approach the ligand length. Herein, sum frequency generation studies on oleic-acid-capped nanoplates show that even on faceted surfaces with dimensions tens of times greater than the ligand length a significant proportion of gauche defects exist in the capping layer. The molecular disorder on the nanosized facets is attributed to a facet-edge effect, which is diminished when increasing the facet size or assembling the nanofacets side to side. This feature is further explored to probe the self-assembly dynamics of nanoplates.
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Affiliation(s)
- Hao Zhang
- †i-LAB, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, Suzhou 215123, P. R. China
- ‡School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, P.R. China
| | - Fujin Li
- †i-LAB, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, Suzhou 215123, P. R. China
| | - Qingbo Xiao
- †i-LAB, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, Suzhou 215123, P. R. China
| | - Hongzhen Lin
- †i-LAB, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, Suzhou 215123, P. R. China
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Ye S, Tong Y, Ge A, Qiao L, Davies PB. Interfacial Structure of Soft Matter Probed by SFG Spectroscopy. CHEM REC 2014; 14:791-805. [DOI: 10.1002/tcr.201402039] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Indexed: 01/05/2023]
Affiliation(s)
- Shen Ye
- Catalysis Research Center; Hokkaido University; Sapporo 001-0021 Japan
| | - Yujin Tong
- Catalysis Research Center; Hokkaido University; Sapporo 001-0021 Japan
| | - Aimin Ge
- Catalysis Research Center; Hokkaido University; Sapporo 001-0021 Japan
| | - Lin Qiao
- Catalysis Research Center; Hokkaido University; Sapporo 001-0021 Japan
| | - Paul B. Davies
- Department of Chemistry; Cambridge University; Cambridge CB2 1EW UK
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17
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Qiao L, Ge A, Osawa M, Ye S. Structure and stability studies of mixed monolayers of saturated and unsaturated phospholipids under low-level ozone. Phys Chem Chem Phys 2014; 15:17775-85. [PMID: 24042267 DOI: 10.1039/c3cp52484a] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In the present study, stability and structure of single and binary mixed monolayers of an unsaturated phospholipid, DOPC, and a saturated phospholipid, DPPC-d75, on the water surface, were explored using the π-A isotherm, atomic force microscopy (AFM) and sum frequency generation (SFG) vibrational spectroscopy in various environments. Our results demonstrated that DOPC in the monolayers becomes unstable after the exposure to a low concentration of ozone (20 ± 10 ppb) or even to ambient laboratory air, which has a similar ozone level, but is stable in nitrogen or oxygen. DOPC can be selectively oxidized by a trace amount of ozone in the ambient environment but can be partially inhibited by the presence of DPPC in the monolayer. The present study provides useful information for understanding the physicochemical properties of the cell membranes.
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Affiliation(s)
- Lin Qiao
- Catalysis Research Center, Hokkaido University, Sapporo 001-0021, Japan.
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Kett PJN, Casford MTL, Davies PB. Sum Frequency Generation Vibrational Spectroscopy of Cholesterol in Hybrid Bilayer Membranes. J Phys Chem B 2013; 117:6455-65. [DOI: 10.1021/jp403584j] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Peter J. N. Kett
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Michael T. L. Casford
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Paul B. Davies
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
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19
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Kett P, Casford M, Davies P. Effect of multiple group orientations on sum frequency generation spectra. Mol Phys 2012. [DOI: 10.1080/00268976.2012.711492] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Casford MTL, Davies PB. Adsorption of 1- and 2-butylimidazoles at the copper/air and steel/air interfaces studied by sum frequency generation vibrational spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:10741-10748. [PMID: 22703375 DOI: 10.1021/la301350g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The structure of thin films of 1- and 2-butylimidazoles adsorbed on copper and steel surfaces under air was examined using sum frequency generation (SFG) vibrational spectroscopy in the ppp and ssp polarizations. Additionally, the SFG spectra of both isomers were recorded at 55 °C at the liquid imidazole/air interface for reference. Complementary bulk infrared, reflection-absorption infrared spectroscopy (RAIRS), and Raman spectra of both imidazoles were recorded for assignment purposes. The SFG spectra in the C-H stretching region at the liquid/air interface are dominated by resonances from the methyl end group of the butyl side chain of the imidazoles, indicating that they are aligned parallel or closely parallel to the surface normal. These are also the most prominent features in the SFG spectra on copper and steel. In addition, both the ppp and ssp spectra on copper show resonances from the C-H stretching modes of the imidazole ring for both isomers. The ring C-H resonances are completely absent from the spectra on steel and at the liquid/air interface. The relative intensities of the SFG spectra can be interpreted as showing that, on copper, under air, both butylimidazoles are adsorbed with their butyl side chains perpendicular to the interface and with the ring significantly inclined away from the surface plane and toward the surface normal. The SFG spectra of both imidazoles on steel indicate an orientation where the imidazole rings are parallel or nearly parallel to the surface. The weak C-H resonances from the ring at the liquid/air interface suggest that the tilt angle of the ring from the surface normal at this interface is significantly greater than it is on copper.
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Affiliation(s)
- Michael T L Casford
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom.
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Davies PB. Interference effects in the sum frequency generation spectra of thin organic films. I. Theoretical modeling and simulation. J Chem Phys 2010; 133:034704. [DOI: 10.1063/1.3428668] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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