Analysis of valence XPS and AES of (PP, P4VP, PVME, PPS, PTFE) polymers by DFT calculations using the model molecules

Endo, Kazunaka; Shimada, Shizuo; Kato, Nobuhiko; Ida, Tetsuo

doi:10.1016/j.molstruc.2016.04.087

Cited by 9 publications

(6 citation statements)

References 25 publications

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“…Summarizing, most of the mentioned methods have been applied only to simple diatomics, first row hydrides, halogen hydrides, and small molecules consisting of not more than two heavy atoms. Studies of larger molecular systems, such as tetrahedral molecules, small aldehydes, and amides [53,54], solvated metal ions [11] and polymers [55] are very scarce. In fact, the Fano-ADC [32,33] and the XMOLECULE [40,41] approaches are the only publicly available tools that allow to simulate AIS for a variety of systems without restricting the molecular geometry.…”

Section: Introductionmentioning

confidence: 99%

Multireference quantum chemistry protocol for simulating autoionization spectra: Test of ionization continuum models for the neon atom

2019

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In this contribution we present a protocol to evaluate partial and total Auger decay rates combining the restricted active space self-consistent field electronic structure method for the bound part and numerically obtained continuum orbitals in the single-channel scattering theory framework. On top of that, the two-step picture is employed to evaluate the partial rates. The performance of the method is exemplified for the prototypical Auger decay of the neon 1s −1 3p resonance. Different approximations to obtain the continuum orbitals, the partial rate matrix elements, and the electronic structure of the bound part are tested against theoretical and experimental reference data. It is demonstrated that the partial and total rates are most sensitive to the accuracy of the continuum orbital. For instance, it is necessary to account for the true direct Coulomb potential of the ion for the determination of the continuum wave functions. The Auger energies, however, can be reproduced quite well already with a rather small active space. Finally, perspectives of the application of the proposed protocol to molecular systems are discussed. arXiv:1905.05785v1 [physics.chem-ph]

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Section: Introductionmentioning

confidence: 99%

Multireference quantum chemistry protocol for simulating autoionization spectra: Test of ionization continuum models for the neon atom

2019

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“…A typical PTFE long‐chain structure was chosen as the model for PTFE. [ 25 ] Figure 3c shows the different molecular interactions on CuO and PTFE surfaces. NO 3 − , H 2 O, NH 3 , and H 2 were adsorbed on the CuO (111) surface and PTFE structure in different orientations until the lowest energy configuration was found, and the free energy was then computed for each.…”

Section: Resultsmentioning

confidence: 99%

Decoupling Electron‐ and Phase‐Transfer Processes to Enhance Electrochemical Nitrate‐to‐Ammonia Conversion by Blending Hydrophobic PTFE Nanoparticles within the Electrocatalyst Layer

Gao

Young

et al. 2023

Advanced Energy Materials

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that could potentially reduce the reliance on the traditional fossil-fuel-based Haber-Bosch NH 3 production. [1] From a thermodynamic point of view, the electrochemical nitrogen reduction reaction (NRR) may benefit from a higher energy efficiency by about 20% than the Haber-Bosch process. [2] Nevertheless, achieving high-efficiency NRR is challenging due to the high dissociation energy of the NN bond (941 kJ mol −1 ) in N 2 and the low standard reduction potential (E°) of NRR (0.09 V vs RHE). As a result, the hydrogen evolution reaction (0 V vs RHE) becomes one of the competing reactions. [3] Thus, NRR usually suffers the low Faradaic efficiency for NH 3 generation (mostly <10%) and the low NH 3 production rate as indicate by the low NH 3 partial current density (mostly <1 mA cm −2 ). [4]

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“…18 Later, it was found that this accuracy was achieved as a result of consistent error cancellation, but it is occasionally still used in the estimation of BEs. 19,20 Other approaches, for example, those employing correlation-consistent basis sets or configuration interaction calculations, display a mean error of around 0.15 eV. 21,22 However, the high computational cost limits their applicability for larger structures and use on 'average' PCs.…”

Section: Introductionmentioning

confidence: 99%

“…The unrestricted generalised transition‐state (uGTS) method was one of the earlier methods to provide accurate absolute BEs for small gas molecules, displaying a mean error of 0.2 eV compared with experimental BEs 18 . Later, it was found that this accuracy was achieved as a result of consistent error cancellation, but it is occasionally still used in the estimation of BEs 19,20 . Other approaches, for example, those employing correlation‐consistent basis sets or configuration interaction calculations, display a mean error of around 0.15 eV 21,22 .…”

Section: Introductionmentioning

confidence: 99%

Processing and interpretation of core‐electron XPS spectra of complex plasma‐treated polyethylene‐based surfaces using a theoretical peak model

Bruggeman

Zelzer

Dong

et al. 2022

Surface & Interface Analysis

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Interpretation of X‐ray photoelectron spectroscopy (XPS) spectra of complex material surfaces, such as those obtained after surface plasma treatment of polymers, is confined by the available references. The limited understanding of the chemical surface composition may impact the ability to determine suitable coupling chemistries used for surface decoration or assess surface‐related properties like biocompatibility. In this work, XPS is used to investigate the chemical composition of various ultra‐high‐molecular‐weight polyethylene (UHMWPE) surfaces. UHMWPE doped with α‐tocopherol or functionalised by active screen plasma nitriding (ASPN) was investigated as a model system. Subsequently, a more complex combined system obtained by ASPN treatment of α‐tocopherol doped UHMWPE was investigated. Through ab initio orbital calculations and by employing Koopmans' theorem, the core‐electron binding energies (CEBEs) were evaluated for a substantial number of possible chemical functionalities positioned on PE‐based model structures. The calculated ΔCEBEs showed to be in reasonable agreement with experimental reference data. The calculated ΔCEBEs were used to develop a material‐specific peak model suitable for the interpretation of merged high‐resolution C 1 s, N 1 s and O 1 s XPS spectra of PE‐based materials. In contrast to conventional peak fitting, the presented approach allowed the distinction of functionality positioning (i.e. centred or end‐chain) and evaluation of the long‐range effects of the chemical functionalities on the PE carbon backbone. Altogether, a more detailed interpretation of the modified UHMWPE surfaces was achieved whilst reducing the need for manual input and personal bias introduced by the spectral analyst.

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Analysis of valence XPS and AES of (PP, P4VP, PVME, PPS, PTFE) polymers by DFT calculations using the model molecules

Cited by 9 publications

References 25 publications

Multireference quantum chemistry protocol for simulating autoionization spectra: Test of ionization continuum models for the neon atom

Multireference quantum chemistry protocol for simulating autoionization spectra: Test of ionization continuum models for the neon atom

Decoupling Electron‐ and Phase‐Transfer Processes to Enhance Electrochemical Nitrate‐to‐Ammonia Conversion by Blending Hydrophobic PTFE Nanoparticles within the Electrocatalyst Layer

Processing and interpretation of core‐electron XPS spectra of complex plasma‐treated polyethylene‐based surfaces using a theoretical peak model

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