Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to analyze poly(ether ether ketone) (PEEK) based membranes. PEEK membranes have been shown to be effective in the separation of CO2 from flue gases (post-combustion technique). The PEEK membranes were synthesized using novel aromatic ether-ketone linkages inspired by PEEK with polymeric backbone bistriflimide [Tf2N] counterions. One of the keys to advancing this technology is developing membranes that are selective and permeable toward CO2, in which PEEK based membranes have been shown to be. Furthermore, the compatibility between various water lean solvents also needs to be investigated. Surface analytical techniques such as x-ray photoelectron spectroscopy and ToF-SIMS are useful for investigating chemical changes between membranes. Herein, we present ToF-SIMS data obtained in the negative ion mode for four different PEEK membranes designed for use in CO2 capture systems. Positive ion mode spectra are reported in Paper I.

  • Accession #: 01896, 01897, 01898, and 01899

  • Technique: SIMS

  • Specimen: PEEK-ionenes

  • Instrument: ION-TOF TOF-SIMS 5

  • Major Species in Spectra: C, N, O, F, and S

  • Minor Species in Spectra: None

  • Published Spectra: 4

  • Spectral Category: Reference

Over the past several decades, there has been increasing CO2 emissions, which are known to create an increase in the overall global temperature. One way to reduce the amount of carbon emissions is to capture the CO2 from emitting sources and convert it to usable carbon containing fuels. However, capturing CO2 from concentrated streams requires highly selective and permeable membrane (Refs. 1 and 2). Amount materials used for CO2 separation membranes, polymers have been the most promising. Additionally, including various functional groups on the polymer can induce changes into the system such as increasing CO2 solubility and selectivity (Ref. 3). Additionally, the combination of ionic liquids (ILs) with polymeric membranes have been widely studied due to their high CO2 solubility and selectivity over other gases (Ref. 4). More specifically, an ionene-based poly(ether ether) ketone is a promising membrane material that has also been tested with water-lean solvent compatibility for CO2 capture via ToF-SIMS and XPS, which was used to understand interfacial chemistry between the membrane and solvent (Ref. 5). There are four different PEEK-ionene samples characterized via ToF-SIMS in this work. The monomer unit of the membranes differs with the ether-ether-ketone (EEK) linkage backbone in regard to containing the xylene linkage, alkyl imidazolium cations, and number of the cations on the backbone (as seen in the structures in Fig. 1). These variations have a significant effect of the affinity for certain gases such as CO2 and the overall organization of the polymer matrix.

FIG. 1.

Chemical structures and formulas of four PEEK-ionenes analyzed by static ToF-SIMS in this work, including (a) p([K(EEK)2(2mIm)6(C6)5][Tf2N]6), (b) p([K(EEK)2(2mIm)4(C6XylC6)][Tf2N]4), (c) p([K(EEK)2(2mIm)4(XylC6Xyl)][Tf2N]4), (d) p([K(EEK)2(2mIm)4(C6C6C6)][Tf2N]4, and (e) Tf2N anion.

FIG. 1.

Chemical structures and formulas of four PEEK-ionenes analyzed by static ToF-SIMS in this work, including (a) p([K(EEK)2(2mIm)6(C6)5][Tf2N]6), (b) p([K(EEK)2(2mIm)4(C6XylC6)][Tf2N]4), (c) p([K(EEK)2(2mIm)4(XylC6Xyl)][Tf2N]4), (d) p([K(EEK)2(2mIm)4(C6C6C6)][Tf2N]4, and (e) Tf2N anion.

Close modal

ToF-SIMS provides invaluable insight to the solvent/membrane compatibility due to its superior selectivity and surface sensitivity. Due to the increasing use of ToF-SIMS for numerous applications, there is a need to provide reliable reference spectra. Herein, we report in-house synthesized membrane spectra for p([K(EEK)2(2mIm)6(C6)5][Tf2N]6), p([K(EEK)2(2mIm)4(C6XylC6)][Tf2N]4), p([K(EEK)2(2mIm)4(XylC6Xyl)][Tf2N]4), and p([K(EEK)2(2mIm)4(C6C6C6)][Tf2N]4 (as shown in Fig. 1, respectively), which are promising ionene-based polymeric membranes for CO2 capture and separation. We have reported the mass spectra from m/z 0–800 in the negative ion mode, complemented by the corresponding positive ion mode spectra presented in “In-house Synthesized Poly(ether ether ketone) Ionenes: ToF-SIMS spectra in the positive ion mode (Paper I).” Together, these two parts of our research provide a holistic overview of both negative and positive spectra across the same set of samples.

Specimen: Synthesized PEEK-ionene sample No. 1

CAS Registry #: N/A

Specimen Characteristics: Homogeneous; solid; unknown crystallinity; unknown conductivity; and polymer

Chemical Name: PEEK-ionene

Source: Synthesized at University of Alabama

Specimen Composition: N/A

Form: Thin film

Lot Number: N/A

Structure: p([K(EEK)2(2mIm)6(C6)5][Tf2N]6)

History and Significance: PEEK-ionene is developed and optimized for gas separation with improved selectivity and permeability. Polymetric membranes for gas separation are rapidly developing with growing interest.

As Received Condition: As-received film

Analyzed Region: 200 × 200 μm2

Ex Situ Preparation/Mounting: ∼8 × 8 mm2 membrane piece was cut from the membrane film and stabilized on a back-mount holder.

In Situ Preparation: N/A

Charge Control Conditions and Procedures: Low energy electrons

Temp. During Analysis: 298 K

Pressure During Analysis: 2.1 × 10−5 Pa

Preanalysis Beam Exposure: N/A

Specimen: Synthesized PEEK-ionene sample No. 2

CAS Registry #: N/A

Specimen Characteristics: Homogeneous; solid; unknown crystallinity; unknown conductivity; and polymer

Chemical Name: PEEK-ionene

Source: Synthesized at University of Alabama

Specimen Composition: N/A

Form: Dark brown powder

Lot Number: N/A

Structure: p([K(EEK)2(2mIm)4(C6XylC6)][Tf2N]4)

History and Significance: PEEK-ionene is developed and optimized for gas separation with improved selectivity and permeability. Polymetric membranes for gas separation are rapidly developing with growing interest.

As Received Condition: As-received powder

Analyzed Region: 200 × 200 μm2

Ex Situ Preparation/Mounting: ∼100 mg of powder was pressed into Indium foil (5 × 5 mm2) and the latter was stabilized on a top-mount holder.

In Situ Preparation: N/A

Charge Control Conditions and Procedures: Low energy electrons

Temp. During Analysis: 298 K

Pressure During Analysis: 4.3 × 10−6 Pa

Preanalysis Beam Exposure: N/A

Specimen Material: Synthesized PEEK-ionene sample No. 3

CAS Registry #: N/A

Specimen Characteristics: Homogeneous; solid; unknown crystallinity; unknown conductivity; and polymer

Chemical Name: PEEK-ionene

Source: Synthesized at University of Alabama

Specimen Composition: N/A

Form: Light brown powder

Lot Number: N/A

Structure: p([K(EEK)2(2mIm)4(XylC6Xyl)][Tf2N]4)

History and Significance: PEEK-ionene is developed and optimized for gas separation with improved selectivity and permeability. Polymetric membranes for gas separation are rapidly developing with growing interest.

As Received Condition: As-received powder

Analyzed Region: 200 × 200 μm2

Ex Situ Preparation/Mounting: ∼100 mg of powder was pressed into Indium foil (5 × 5 mm2) and the latter was stabilized on a top-mount holder.

In Situ Preparation: N/A

Charge Control Conditions and Procedures: Low energy electrons

Temp. During Analysis: 298 K

Pressure During Analysis: 6.3 × 10−6 Pa

Preanalysis Beam Exposure: N/A

Specimen Material: Synthesized PEEK-ionene sample No. 4

CAS Registry #: N/A

Specimen Characteristics: Homogeneous; solid; unknown crystallinity; unknown conductivity; and polymer

Chemical Name: PEEK-ionene

Source: Synthesized at University of Alabama

Specimen Composition: N/A

Form: Thin film

Lot Number: N/A

Structure: p([K(EEK)2(2mIm)4(C6C6C6)][Tf2N]4

History and Significance: PEEK-ionene is developed and optimized for gas separation with improved selectivity and permeability. Polymetric membranes for gas separation are rapidly developing with growing interest.

As Received Condition: As-received film

Analyzed Region: 200 × 200 μm2

Ex Situ Preparation/Mounting: ∼8 × 8 mm2 membrane piece was cut from the membrane film and stabilized on a back-mount holder.

In Situ Preparation: N/A

Charge Control Conditions and Procedures: Low energy electrons

Temp. During Analysis: 298 K

Pressure During Analysis: 1.1 × 10−5 Pa

Preanalysis Beam Exposure: N/A

Manufacturer and Model: IONTOF TOF-SIMS 5

Analyzer Type: Time-of-flight

Experiment Type: Mass spectrum

Sample Rotation: No

Rotation Rate: N/A

Oxygen Flood Source: N/A

Oxygen Flood Pressure: N/A

Other Flood Source: N/A

Other Flood Pressure: N/A

Unique Instrument Features Used: N/A

Energy Acceptance Window: 20 eV

Postacceleration Voltage: 10 000 eV

Sample Bias: 0 eV

Specimen Normal-to-analyzer (Θe): 90°

Ion source 1 of Bi3++

Purpose of this Ion Source: Analysis beam

Ion Source Manufacturer: IONTOF (Münster, Germany)

Ion Source Model: Bin+ cluster ion source

Beam Mass Filter: Yes

Beam Species and Charge State: Bi3++

Beam Gating Used: No

Additional Beam Comments: N/A

Beam Voltage: 50 000 eV

Net Beam Voltage (impact voltage): 50 000 eV

Ion Pulse Width: 0.8–1.0 ns

Ion Pulse Rate: 10.0 kHz

DC Beam Current: 14 nA

Pulsed Beam Current: 0.0002 nA

Current Measurement Method: Faraday cup

Beam Diameter: 5 μm

Beam Raster Size: 200 × 200 μm2

Beam Incident Angle: 45°

Source-to-Analyzer Angle: 45°

Ion Source 2 of Ar cluster

Purpose of this Ion Source: Sputtering beam

Ion Source Manufacturer: IONTOF (Münster, Germany)

Ion Source Model: Ar cluster ion source

Beam Mass Filter: Yes

Beam Species and Charge State: Ar+

Beam Gating Used: No

Additional Beam Comments: The Ar cluster was applied to remove potential surface contamination and was performed prior to the analysis with the Bi beam.

Beam Voltage: 10 000 eV

Net Beam Voltage (impact voltage): 10 000 eV

Ion Pulse Width: 30 000 ns

Ion Pulse Rate: 10 kHz

DC Beam Current: 12 nA

Pulsed Beam Current: 5.1 nA

Current Measurement Method: Faraday cup

Beam Diameter: 20 μm

Beam Raster Size: 1000 × 1000 μm2

Raster Pixel Dimensions: 128 × 128

Beam Incident Angle: 45°

Source-to-Analyzer Angle: 45°

SPECTRAL FEATURES TABLE

Spectrum ID #Mass (Δm) DaSpeciesPeak Assignment
01896-01 61.971 (−1.9) NSO Tf2N fragment 
01896-01 68.995 (−18.1) CF3 Tf2N fragment 
01896-01 73.006 (−33.1) C6H PEEK fragment (Ref. 6
01896-01 77.969 (40.6) NSO2 Tf2N fragment 
01896-01 82.961 (1.9) SO2F Tf2N fragment 
01896-01 132.953 (−28.5) CF3SO2 Tf2N fragment 
01896-01 146.960 (−2.2) CF3SO2N Tf2N fragment 
01896-01 194.928 (0.6) CF3SO2NSO Tf2N fragment 
01896-01 210.918 (−22.6) CF3SO2NSO2 Tf2N fragments 
01896-01 229.922 (5.2) CF3SO2NSO2F Tf2N fragment 
01896-01 263.927 (18.2) CF3SONSO2CF3 Tf2N fragment 
01896-01 279.926 (29.6) CF3SO2NSO2CF3 Tf2N anion 
01896-01 329.916 (4.3) {[CF3SO2NSO2][NC2H3][NSO2]} Cluster ion of Tf2N and imidazolium fragments 
Spectrum ID #Mass (Δm) DaSpeciesPeak Assignment
01896-01 61.971 (−1.9) NSO Tf2N fragment 
01896-01 68.995 (−18.1) CF3 Tf2N fragment 
01896-01 73.006 (−33.1) C6H PEEK fragment (Ref. 6
01896-01 77.969 (40.6) NSO2 Tf2N fragment 
01896-01 82.961 (1.9) SO2F Tf2N fragment 
01896-01 132.953 (−28.5) CF3SO2 Tf2N fragment 
01896-01 146.960 (−2.2) CF3SO2N Tf2N fragment 
01896-01 194.928 (0.6) CF3SO2NSO Tf2N fragment 
01896-01 210.918 (−22.6) CF3SO2NSO2 Tf2N fragments 
01896-01 229.922 (5.2) CF3SO2NSO2F Tf2N fragment 
01896-01 263.927 (18.2) CF3SONSO2CF3 Tf2N fragment 
01896-01 279.926 (29.6) CF3SO2NSO2CF3 Tf2N anion 
01896-01 329.916 (4.3) {[CF3SO2NSO2][NC2H3][NSO2]} Cluster ion of Tf2N and imidazolium fragments 

Accession #:01896-01
■ Specimen: Synthesized PEEK-ionene sample No. 1 
■ Technique: SIMS 
Instrument: IONTOF TOF-SIMS 5 
Analyzer Type: Time-of-flight 
Analyzer Mass Resolution: 6075 m/Δm 
Mass Resolution Determined at: 25.010 (C2H) Da 
Species Used for Mass Calibration: C, OH, C2H, CF, NSO, CF3SO2N 
Specimen Normal-to-Analyzer: 0° 
Source-to-Analyzer Angle: 45° 
Primary Beam Ion Gun: Bi liquid metal ion gun 
Primary Ion Species: Bi3++ 
Primary Ion Dose: 1.0 × 1011 ion/cm2 
Primary Ion Pulse Width: 0.8–1.0 ns 
Primary Ion Pulse Rate: 10.0 kHz 
Net Beam Voltage: 50 000 eV 
Pulsed Beam Current: 0.0002 nA 
DC Beam Current: 14 nA 
Beam Diameter: 5 μ
Beam Raster Size: 200 × 200 μm2 
Beam Incident Angle: 45° 
Secondary Source Polarity: Negative 
Mass Range Minimum: 0 Da 
Mass Range Maximum: 800 Da 
Spectrum Dead Time Corrected: Yes 
Total Spectral Acquisition Time: 200 s 
Comment: Data not binned prior to plotting 
Accession #:01896-01
■ Specimen: Synthesized PEEK-ionene sample No. 1 
■ Technique: SIMS 
Instrument: IONTOF TOF-SIMS 5 
Analyzer Type: Time-of-flight 
Analyzer Mass Resolution: 6075 m/Δm 
Mass Resolution Determined at: 25.010 (C2H) Da 
Species Used for Mass Calibration: C, OH, C2H, CF, NSO, CF3SO2N 
Specimen Normal-to-Analyzer: 0° 
Source-to-Analyzer Angle: 45° 
Primary Beam Ion Gun: Bi liquid metal ion gun 
Primary Ion Species: Bi3++ 
Primary Ion Dose: 1.0 × 1011 ion/cm2 
Primary Ion Pulse Width: 0.8–1.0 ns 
Primary Ion Pulse Rate: 10.0 kHz 
Net Beam Voltage: 50 000 eV 
Pulsed Beam Current: 0.0002 nA 
DC Beam Current: 14 nA 
Beam Diameter: 5 μ
Beam Raster Size: 200 × 200 μm2 
Beam Incident Angle: 45° 
Secondary Source Polarity: Negative 
Mass Range Minimum: 0 Da 
Mass Range Maximum: 800 Da 
Spectrum Dead Time Corrected: Yes 
Total Spectral Acquisition Time: 200 s 
Comment: Data not binned prior to plotting 

Accession #:01896-01
■ Specimen: Synthesized PEEK-ionene sample No. 1 
■ Technique: SIMS 
Instrument: IONTOF TOF-SIMS 5 
Analyzer Type: Time-of-flight 
Analyzer Mass Resolution: 6075 m/Δm 
Mass Resolution Determined at: 25.010 (C2H) Da 
Species Used for Mass Calibration: C, OH, C2H, CF, NSO, CF3SO2N 
Specimen Normal-to-Analyzer: 0° 
Source-to-Analyzer Angle: 45° 
Primary Beam Ion Gun: Bi liquid metal ion gun 
Primary Ion Species: Bi3++ 
Primary Ion Dose: 1.0 × 1011 ion/cm2 
Primary Ion Pulse Width: 0.8–1.0 ns 
Primary Ion Pulse Rate: 10.0 kHz 
Net Beam Voltage: 50 000 eV 
Pulsed Beam Current: 0.0002 nA 
DC Beam Current: 14 nA 
Beam Diameter: 5 μ
Beam Raster Size: 200 × 200 μm2 
Beam Incident Angle: 45° 
Secondary Source Polarity: Negative 
Mass Range Minimum: 0 Da 
Mass Range Maximum: 800 Da 
Spectrum Dead Time Corrected: Yes 
Total Spectral Acquisition Time: 200 s 
Comment: Data not binned prior to plotting 
Accession #:01896-01
■ Specimen: Synthesized PEEK-ionene sample No. 1 
■ Technique: SIMS 
Instrument: IONTOF TOF-SIMS 5 
Analyzer Type: Time-of-flight 
Analyzer Mass Resolution: 6075 m/Δm 
Mass Resolution Determined at: 25.010 (C2H) Da 
Species Used for Mass Calibration: C, OH, C2H, CF, NSO, CF3SO2N 
Specimen Normal-to-Analyzer: 0° 
Source-to-Analyzer Angle: 45° 
Primary Beam Ion Gun: Bi liquid metal ion gun 
Primary Ion Species: Bi3++ 
Primary Ion Dose: 1.0 × 1011 ion/cm2 
Primary Ion Pulse Width: 0.8–1.0 ns 
Primary Ion Pulse Rate: 10.0 kHz 
Net Beam Voltage: 50 000 eV 
Pulsed Beam Current: 0.0002 nA 
DC Beam Current: 14 nA 
Beam Diameter: 5 μ
Beam Raster Size: 200 × 200 μm2 
Beam Incident Angle: 45° 
Secondary Source Polarity: Negative 
Mass Range Minimum: 0 Da 
Mass Range Maximum: 800 Da 
Spectrum Dead Time Corrected: Yes 
Total Spectral Acquisition Time: 200 s 
Comment: Data not binned prior to plotting 

Close modal

SPECTRAL FEATURES TABLE

Spectrum ID #Mass (Δm) DaSpeciesPeak Assignment
01897-01 61.972 (25.5) NSO Tf2N fragment 
01897-01 68.995 (−9.4) CF3 Tf2N fragment 
01897-01 73.007 (−23.1) C6H PEEK fragment 
01897-01 77.970 (58.6) NSO2 Tf2N fragment 
01897-01 82.962 (11.5) SO2F Tf2N fragment 
01897-01 108.015 (−58.5) C6H4O2 PEEK fragment 6 
01897-01 132.953 (−33.2) CF3SO2 Tf2N fragment 
01897-01 146.966 (39.6) CF3SO2N Tf2N fragment 
01897-01 194.926 (−10.7) CF3SO2NSO Tf2N fragment 
01897-01 229.923 (10.5) CF3SO2NSO2F Tf2N fragment 
01897-01 261.929 (11.4) {[NC2H4][SNO2][SO2NSO2]} Cluster ion of Tf2N and imidazolium fragments 
01897-01 263.924 (5.3) CF3SONSO2CF3 Tf2N fragment 
01897-01 279.933 (53.8) CF3SO2NSO2CF3 Tf2N anion 
01897-01 329.899 (−44.4) {[CF3SO2NSO2][NC2H3][NSO2]}- Cluster ion of Tf2N and imidazolium fragments 
Spectrum ID #Mass (Δm) DaSpeciesPeak Assignment
01897-01 61.972 (25.5) NSO Tf2N fragment 
01897-01 68.995 (−9.4) CF3 Tf2N fragment 
01897-01 73.007 (−23.1) C6H PEEK fragment 
01897-01 77.970 (58.6) NSO2 Tf2N fragment 
01897-01 82.962 (11.5) SO2F Tf2N fragment 
01897-01 108.015 (−58.5) C6H4O2 PEEK fragment 6 
01897-01 132.953 (−33.2) CF3SO2 Tf2N fragment 
01897-01 146.966 (39.6) CF3SO2N Tf2N fragment 
01897-01 194.926 (−10.7) CF3SO2NSO Tf2N fragment 
01897-01 229.923 (10.5) CF3SO2NSO2F Tf2N fragment 
01897-01 261.929 (11.4) {[NC2H4][SNO2][SO2NSO2]} Cluster ion of Tf2N and imidazolium fragments 
01897-01 263.924 (5.3) CF3SONSO2CF3 Tf2N fragment 
01897-01 279.933 (53.8) CF3SO2NSO2CF3 Tf2N anion 
01897-01 329.899 (−44.4) {[CF3SO2NSO2][NC2H3][NSO2]}- Cluster ion of Tf2N and imidazolium fragments 

Accession #:01897-01
■ Specimen: Synthesized PEEK-ionene sample No. 2 
■ Technique: SIMS 
Instrument: IONTOF TOF-SIMS 5 
Analyzer Type: Time-of-flight 
Analyzer Mass Resolution: 3602 m/Δm 
Mass Resolution Determined at: 25.008 (C2H) Da 
Species Used for Mass Calibration: C, OH, C2H, CF, NSO, CF3SO2N 
Specimen Normal-to-Analyzer: 0° 
Source-to-Analyzer Angle: 45° 
Primary Beam Ion Gun: Bi liquid metal ion gun 
Primary Ion Species: Bi3++ 
Primary Ion Dose: 1.0 × 1011 ion/cm2 
Primary Ion Pulse Width: 0.8–1.0 ns 
Primary Ion Pulse Rate: 10.0 kHz 
Net Beam Voltage: 50 000 eV 
Pulsed Beam Current: 0.0002 nA 
DC Beam Current: 14 nA 
Beam Diameter: 5 μ
Beam Raster Size: 200 × 200 μm2 
Beam Incident Angle: 45° 
Secondary Source Polarity: Negative 
Mass Range Minimum: 0 Da 
Mass Range Maximum: 800 Da 
Spectrum Dead Time Corrected: Yes 
Total Spectral Acquisition Time: 200 s 
Comment: Data not binned prior to plotting 
Accession #:01897-01
■ Specimen: Synthesized PEEK-ionene sample No. 2 
■ Technique: SIMS 
Instrument: IONTOF TOF-SIMS 5 
Analyzer Type: Time-of-flight 
Analyzer Mass Resolution: 3602 m/Δm 
Mass Resolution Determined at: 25.008 (C2H) Da 
Species Used for Mass Calibration: C, OH, C2H, CF, NSO, CF3SO2N 
Specimen Normal-to-Analyzer: 0° 
Source-to-Analyzer Angle: 45° 
Primary Beam Ion Gun: Bi liquid metal ion gun 
Primary Ion Species: Bi3++ 
Primary Ion Dose: 1.0 × 1011 ion/cm2 
Primary Ion Pulse Width: 0.8–1.0 ns 
Primary Ion Pulse Rate: 10.0 kHz 
Net Beam Voltage: 50 000 eV 
Pulsed Beam Current: 0.0002 nA 
DC Beam Current: 14 nA 
Beam Diameter: 5 μ
Beam Raster Size: 200 × 200 μm2 
Beam Incident Angle: 45° 
Secondary Source Polarity: Negative 
Mass Range Minimum: 0 Da 
Mass Range Maximum: 800 Da 
Spectrum Dead Time Corrected: Yes 
Total Spectral Acquisition Time: 200 s 
Comment: Data not binned prior to plotting 

Accession #:01897-01
■ Specimen: Synthesized PEEK-ionene sample No. 2 
■ Technique: SIMS 
Instrument: IONTOF TOF-SIMS 5 
Analyzer Type: Time-of-flight 
Analyzer Mass Resolution: 3602 m/Δm 
Mass Resolution Determined at: 25.008 (C2H) Da 
Species Used for Mass Calibration: C, OH, C2H, CF, NSO, CF3SO2N 
Specimen Normal-to-Analyzer: 0° 
Source-to-Analyzer Angle: 45° 
Primary Beam Ion Gun: Bi liquid metal ion gun 
Primary Ion Species: Bi3++ 
Primary Ion Dose: 1.0 × 1011 ion/cm2 
Primary Ion Pulse Width: 0.8–1.0 ns 
Primary Ion Pulse Rate: 10.0 kHz 
Net Beam Voltage: 50 000 eV 
Pulsed Beam Current: 0.0002 nA 
DC Beam Current: 14 nA 
Beam Diameter: 5 μ
Beam Raster Size: 200 × 200 μm2 
Beam Incident Angle: 45° 
Secondary Source Polarity: Negative 
Mass Range Minimum: 0 Da 
Mass Range Maximum: 800 Da 
Spectrum Dead Time Corrected: Yes 
Total Spectral Acquisition Time: 200 s 
Comment: Data not binned prior to plotting 
Accession #:01897-01
■ Specimen: Synthesized PEEK-ionene sample No. 2 
■ Technique: SIMS 
Instrument: IONTOF TOF-SIMS 5 
Analyzer Type: Time-of-flight 
Analyzer Mass Resolution: 3602 m/Δm 
Mass Resolution Determined at: 25.008 (C2H) Da 
Species Used for Mass Calibration: C, OH, C2H, CF, NSO, CF3SO2N 
Specimen Normal-to-Analyzer: 0° 
Source-to-Analyzer Angle: 45° 
Primary Beam Ion Gun: Bi liquid metal ion gun 
Primary Ion Species: Bi3++ 
Primary Ion Dose: 1.0 × 1011 ion/cm2 
Primary Ion Pulse Width: 0.8–1.0 ns 
Primary Ion Pulse Rate: 10.0 kHz 
Net Beam Voltage: 50 000 eV 
Pulsed Beam Current: 0.0002 nA 
DC Beam Current: 14 nA 
Beam Diameter: 5 μ
Beam Raster Size: 200 × 200 μm2 
Beam Incident Angle: 45° 
Secondary Source Polarity: Negative 
Mass Range Minimum: 0 Da 
Mass Range Maximum: 800 Da 
Spectrum Dead Time Corrected: Yes 
Total Spectral Acquisition Time: 200 s 
Comment: Data not binned prior to plotting 

Close modal

SPECTRAL FEATURES TABLE

Spectrum ID #Mass (Δm) DaSpeciesPeak Assignment
01898-01 61.972 (24.9) NSO Tf2N fragment 
01898-01 68.996 (−3.0) CF3 Tf2N fragment 
01898-01 73.008 (−10.8) C6H PEEK fragment 
01898-01 82.961 (0.9) SO2F Tf2N fragment 
01898-01 108.015 (−61.1) C6H4O2 PEEK fragment 
01898-01 132.953 (−31.4) CF3SO2 Tf2N fragment 
01898-01 146.960 (−2.8) CF3SO2N Tf2N fragment 
01898-01 194.925 (−15.4) CF3SO2NSO Tf2N fragment 
01898-01 229.923 (10.1) CF3SO2NSO2F Tf2N fragment 
01898-01 261.930 (11.9) {[NC2H4][SNO2][SO2NSO2]} Cluster ion of Tf2N and imidazolium fragments 
01898-01 263.924 (6.5) CF3SONSO2CF3 Tf2N fragment 
01898-01 279.934 (58.6) CF3SO2NSO2CF3 Tf2N anion 
01898-01 329.921 (21.7) {[CF3SO2NSO2][NC2H3][NSO2]} Cluster ion of Tf2N and imidazolium fragments 
Spectrum ID #Mass (Δm) DaSpeciesPeak Assignment
01898-01 61.972 (24.9) NSO Tf2N fragment 
01898-01 68.996 (−3.0) CF3 Tf2N fragment 
01898-01 73.008 (−10.8) C6H PEEK fragment 
01898-01 82.961 (0.9) SO2F Tf2N fragment 
01898-01 108.015 (−61.1) C6H4O2 PEEK fragment 
01898-01 132.953 (−31.4) CF3SO2 Tf2N fragment 
01898-01 146.960 (−2.8) CF3SO2N Tf2N fragment 
01898-01 194.925 (−15.4) CF3SO2NSO Tf2N fragment 
01898-01 229.923 (10.1) CF3SO2NSO2F Tf2N fragment 
01898-01 261.930 (11.9) {[NC2H4][SNO2][SO2NSO2]} Cluster ion of Tf2N and imidazolium fragments 
01898-01 263.924 (6.5) CF3SONSO2CF3 Tf2N fragment 
01898-01 279.934 (58.6) CF3SO2NSO2CF3 Tf2N anion 
01898-01 329.921 (21.7) {[CF3SO2NSO2][NC2H3][NSO2]} Cluster ion of Tf2N and imidazolium fragments 

Accession #:01898-01
■ Specimen: Synthesized PEEK-ionene sample No. 3 
■ Technique: SIMS 
Instrument: IONTOF TOF-SIMS 5 
Analyzer Type: Time-of-flight 
Analyzer Mass Resolution: 3972 m/Δm 
Mass Resolution Determined at: 25.008 (C2H) Da 
Species Used for Mass Calibration: C, OH, C2H, CF, NSO, CF3SO2N 
Specimen Normal-to-Analyzer: 0° 
Source-to-Analyzer Angle: 45° 
Primary Beam Ion Gun: Bi liquid metal ion gun 
Primary Ion Species: Bi3++ 
Primary Ion Dose: 1.0 × 1011 ion/cm2 
Primary Ion Pulse Width: 0.8–1.0 ns 
Primary Ion Pulse Rate: 10.0 kHz 
Net Beam Voltage: 50 000 eV 
Pulsed Beam Current: 0.0002 nA 
DC Beam Current: 14 nA 
Beam Diameter: 5 μ
Beam Raster Size: 200 × 200 μm2 
Beam Incident Angle: 45° 
Secondary Source Polarity: Negative 
Mass Range Minimum: 0 Da 
Mass Range Maximum: 800 Da 
Spectrum Dead Time Corrected: Yes 
Total Spectral Acquisition Time: 200 s 
Comment: Data not binned prior to plotting 
Accession #:01898-01
■ Specimen: Synthesized PEEK-ionene sample No. 3 
■ Technique: SIMS 
Instrument: IONTOF TOF-SIMS 5 
Analyzer Type: Time-of-flight 
Analyzer Mass Resolution: 3972 m/Δm 
Mass Resolution Determined at: 25.008 (C2H) Da 
Species Used for Mass Calibration: C, OH, C2H, CF, NSO, CF3SO2N 
Specimen Normal-to-Analyzer: 0° 
Source-to-Analyzer Angle: 45° 
Primary Beam Ion Gun: Bi liquid metal ion gun 
Primary Ion Species: Bi3++ 
Primary Ion Dose: 1.0 × 1011 ion/cm2 
Primary Ion Pulse Width: 0.8–1.0 ns 
Primary Ion Pulse Rate: 10.0 kHz 
Net Beam Voltage: 50 000 eV 
Pulsed Beam Current: 0.0002 nA 
DC Beam Current: 14 nA 
Beam Diameter: 5 μ
Beam Raster Size: 200 × 200 μm2 
Beam Incident Angle: 45° 
Secondary Source Polarity: Negative 
Mass Range Minimum: 0 Da 
Mass Range Maximum: 800 Da 
Spectrum Dead Time Corrected: Yes 
Total Spectral Acquisition Time: 200 s 
Comment: Data not binned prior to plotting 

Accession #:01898-01
■ Specimen: Synthesized PEEK-ionene sample No. 3 
■ Technique: SIMS 
Instrument: IONTOF TOF-SIMS 5 
Analyzer Type: Time-of-flight 
Analyzer Mass Resolution: 3972 m/Δm 
Mass Resolution Determined at: 25.008 (C2H) Da 
Species Used for Mass Calibration: C, OH, C2H, CF, NSO, CF3SO2N 
Specimen Normal-to-Analyzer: 0° 
Source-to-Analyzer Angle: 45° 
Primary Beam Ion Gun: Bi liquid metal ion gun 
Primary Ion Species: Bi3++ 
Primary Ion Dose: 1.0 × 1011 ion/cm2 
Primary Ion Pulse Width: 0.8–1.0 ns 
Primary Ion Pulse Rate: 10.0 kHz 
Net Beam Voltage: 50 000 eV 
Pulsed Beam Current: 0.0002 nA 
DC Beam Current: 14 nA 
Beam Diameter: 5 μ
Beam Raster Size: 200 × 200 μm2 
Beam Incident Angle: 45° 
Secondary Source Polarity: Negative 
Mass Range Minimum: 0 Da 
Mass Range Maximum: 800 Da 
Spectrum Dead Time Corrected: Yes 
Total Spectral Acquisition Time: 200 s 
Comment: Data not binned prior to plotting 
Accession #:01898-01
■ Specimen: Synthesized PEEK-ionene sample No. 3 
■ Technique: SIMS 
Instrument: IONTOF TOF-SIMS 5 
Analyzer Type: Time-of-flight 
Analyzer Mass Resolution: 3972 m/Δm 
Mass Resolution Determined at: 25.008 (C2H) Da 
Species Used for Mass Calibration: C, OH, C2H, CF, NSO, CF3SO2N 
Specimen Normal-to-Analyzer: 0° 
Source-to-Analyzer Angle: 45° 
Primary Beam Ion Gun: Bi liquid metal ion gun 
Primary Ion Species: Bi3++ 
Primary Ion Dose: 1.0 × 1011 ion/cm2 
Primary Ion Pulse Width: 0.8–1.0 ns 
Primary Ion Pulse Rate: 10.0 kHz 
Net Beam Voltage: 50 000 eV 
Pulsed Beam Current: 0.0002 nA 
DC Beam Current: 14 nA 
Beam Diameter: 5 μ
Beam Raster Size: 200 × 200 μm2 
Beam Incident Angle: 45° 
Secondary Source Polarity: Negative 
Mass Range Minimum: 0 Da 
Mass Range Maximum: 800 Da 
Spectrum Dead Time Corrected: Yes 
Total Spectral Acquisition Time: 200 s 
Comment: Data not binned prior to plotting 

Close modal

SPECTRAL FEATURES TABLE

Spectrum ID #Mass (Δm) DaSpeciesPeak Assignment
01899-01 61.972 (17.7) NSO Tf2N fragment 
01899-01 68.996 (0.2) CF3 Tf2N fragment 
01899-01 73.007 (−16.2) C6H PEEK fragment 
01899-01 77.969 (48.4) NSO2 Tf2N fragment 
01899-01 82.962 (12.1) SO2F Tf2N fragment 
01899-01 132.954 (−25.4) CF3SO2 Tf2N fragment 
01899-01 146.968 (51.5) CF3SO2N Tf2N fragment 
01899-01 194.926 (−8.6) CF3SO2NSO Tf2N fragment 
01899-01 229.919 (−7.3) CF3SO2NSO2F Tf2N fragment 
01899-01 263.924 (4.3) CF3SONSO2CF3 Tf2N fragment 
01899-01 279.935 (62.8) CF3SO2NSO2CF3 Tf2N anion 
01899-01 329.914 (0.7) {[CF3SO2NSO2][NC2H3][NSO2]} Cluster ion of Tf2N and imidazolium fragments 
Spectrum ID #Mass (Δm) DaSpeciesPeak Assignment
01899-01 61.972 (17.7) NSO Tf2N fragment 
01899-01 68.996 (0.2) CF3 Tf2N fragment 
01899-01 73.007 (−16.2) C6H PEEK fragment 
01899-01 77.969 (48.4) NSO2 Tf2N fragment 
01899-01 82.962 (12.1) SO2F Tf2N fragment 
01899-01 132.954 (−25.4) CF3SO2 Tf2N fragment 
01899-01 146.968 (51.5) CF3SO2N Tf2N fragment 
01899-01 194.926 (−8.6) CF3SO2NSO Tf2N fragment 
01899-01 229.919 (−7.3) CF3SO2NSO2F Tf2N fragment 
01899-01 263.924 (4.3) CF3SONSO2CF3 Tf2N fragment 
01899-01 279.935 (62.8) CF3SO2NSO2CF3 Tf2N anion 
01899-01 329.914 (0.7) {[CF3SO2NSO2][NC2H3][NSO2]} Cluster ion of Tf2N and imidazolium fragments 

Accession #:01899-01
■ Specimen: Synthesized PEEK-ionene sample No. 4 
■ Technique: SIMS 
Instrument: IONTOF TOF-SIMS 5 
Analyzer Type: Time-of-flight 
Analyzer Mass Resolution: 3850 m/Δm 
Mass Resolution Determined at: 25.008 (C2H) Da 
Species Used for Mass Calibration: C, OH, C2H, CF, NSO, CF3SO2N 
Specimen Normal-to-Analyzer: 0° 
Source-to-Analyzer Angle: 45° 
Primary Beam Ion Gun: Bi liquid metal ion gun 
Primary Ion Species: Bi3++ 
Primary Ion Dose: 1.0 × 1011 ion/cm2 
Primary Ion Pulse Width: 0.8–1.0 ns 
Primary Ion Pulse Rate: 10.0 kHz 
Net Beam Voltage: 50 000 eV 
Pulsed Beam Current: 0.0002 nA 
DC Beam Current: 14 nA 
Beam Diameter: 5 μ
Beam Raster Size: 200 × 200 μm2 
Beam Incident Angle: 45° 
Secondary Source Polarity: Negative 
Mass Range Minimum: 0 Da 
Mass Range Maximum: 800 Da 
Spectrum Dead Time Corrected: Yes 
Total Spectral Acquisition Time: 200 s 
Comment: Data not binned prior to plotting 
Accession #:01899-01
■ Specimen: Synthesized PEEK-ionene sample No. 4 
■ Technique: SIMS 
Instrument: IONTOF TOF-SIMS 5 
Analyzer Type: Time-of-flight 
Analyzer Mass Resolution: 3850 m/Δm 
Mass Resolution Determined at: 25.008 (C2H) Da 
Species Used for Mass Calibration: C, OH, C2H, CF, NSO, CF3SO2N 
Specimen Normal-to-Analyzer: 0° 
Source-to-Analyzer Angle: 45° 
Primary Beam Ion Gun: Bi liquid metal ion gun 
Primary Ion Species: Bi3++ 
Primary Ion Dose: 1.0 × 1011 ion/cm2 
Primary Ion Pulse Width: 0.8–1.0 ns 
Primary Ion Pulse Rate: 10.0 kHz 
Net Beam Voltage: 50 000 eV 
Pulsed Beam Current: 0.0002 nA 
DC Beam Current: 14 nA 
Beam Diameter: 5 μ
Beam Raster Size: 200 × 200 μm2 
Beam Incident Angle: 45° 
Secondary Source Polarity: Negative 
Mass Range Minimum: 0 Da 
Mass Range Maximum: 800 Da 
Spectrum Dead Time Corrected: Yes 
Total Spectral Acquisition Time: 200 s 
Comment: Data not binned prior to plotting 

Accession #:01899-01
■ Specimen: Synthesized PEEK-ionene sample No. 4 
■ Technique: SIMS 
Instrument: IONTOF TOF-SIMS 5 
Analyzer Type: Time-of-flight 
Analyzer Mass Resolution: 3850 m/Δm 
Mass Resolution Determined at: 25.008 (C2H) Da 
Species Used for Mass Calibration: C, OH, C2H, CF, NSO, CF3SO2N 
Specimen Normal-to-Analyzer: 0° 
Source-to-Analyzer Angle: 45° 
Primary Beam Ion Gun: Bi liquid metal ion gun 
Primary Ion Species: Bi3++ 
Primary Ion Dose: 1.0 × 1011 ion/cm2 
Primary Ion Pulse Width: 0.8–1.0 ns 
Primary Ion Pulse Rate: 10.0 kHz 
Net Beam Voltage: 50 000 eV 
Pulsed Beam Current: 0.0002 nA 
DC Beam Current: 14 nA 
Beam Diameter: 5 μ
Beam Raster Size: 200 × 200 μm2 
Beam Incident Angle: 45° 
Secondary Source Polarity: Negative 
Mass Range Minimum: 0 Da 
Mass Range Maximum: 800 Da 
Spectrum Dead Time Corrected: Yes 
Total Spectral Acquisition Time: 200 s 
Comment: Data not binned prior to plotting 
Accession #:01899-01
■ Specimen: Synthesized PEEK-ionene sample No. 4 
■ Technique: SIMS 
Instrument: IONTOF TOF-SIMS 5 
Analyzer Type: Time-of-flight 
Analyzer Mass Resolution: 3850 m/Δm 
Mass Resolution Determined at: 25.008 (C2H) Da 
Species Used for Mass Calibration: C, OH, C2H, CF, NSO, CF3SO2N 
Specimen Normal-to-Analyzer: 0° 
Source-to-Analyzer Angle: 45° 
Primary Beam Ion Gun: Bi liquid metal ion gun 
Primary Ion Species: Bi3++ 
Primary Ion Dose: 1.0 × 1011 ion/cm2 
Primary Ion Pulse Width: 0.8–1.0 ns 
Primary Ion Pulse Rate: 10.0 kHz 
Net Beam Voltage: 50 000 eV 
Pulsed Beam Current: 0.0002 nA 
DC Beam Current: 14 nA 
Beam Diameter: 5 μ
Beam Raster Size: 200 × 200 μm2 
Beam Incident Angle: 45° 
Secondary Source Polarity: Negative 
Mass Range Minimum: 0 Da 
Mass Range Maximum: 800 Da 
Spectrum Dead Time Corrected: Yes 
Total Spectral Acquisition Time: 200 s 
Comment: Data not binned prior to plotting 

Close modal

This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division, Materials Science and Separation Science Programs (No. FWP 76830).

The authors have no conflicts to disclose.

Lyndi Strange: Writing – original draft (equal). Sudhir Ravula: Methodology (equal); Resources (equal); Writing – review & editing (equal). Zihua Zhu: Writing – review & editing (equal). Jason E. Bara: Methodology (equal); Resources (equal); Writing – review & editing (equal). Ping Chen: Writing – review & editing (equal). David J. Heldebrant: Funding acquisition (equal); Project administration (equal); Writing – review & editing (equal). Jennifer Yao: Supervision (equal); Validation (equal); Writing – review & editing (equal).

The data that support the findings of this study are available within the article and its supplementary material.

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Supplementary Material