1 / 18

The use of ion-mobility spectrometry-mass spectrometry to elucidate polymer architecture

TULANE UNIVERSITY. Tulane University Department of Chemistry. The use of ion-mobility spectrometry-mass spectrometry to elucidate polymer architecture. Scott M. Grayson, 1 * Casey D. Foley 2 , Boyu Zhang 1 , Alina M. Alb 3 , Sarah Trimpin 2

mruddy
Download Presentation

The use of ion-mobility spectrometry-mass spectrometry to elucidate polymer architecture

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. TULANE UNIVERSITY Tulane University Department of Chemistry The use of ion-mobility spectrometry-mass spectrometry to elucidate polymer architecture Scott M. Grayson,1* Casey D. Foley2, Boyu Zhang1, Alina M. Alb3, Sarah Trimpin2 1 Department of Chemistry, Tulane University, New Orleans, LA 2 Department of Chemistry, Wayne State University, Detroit, MI 3 Department of Physics, Tulane University, New Orleans, LA

  2. IMS-MS instrumental set-up WATERS SYNAPT G2 Vacuum Mass-Separation Regime Gas-Phase Size-Separation Regime Ion Mobility Spectrometry (IMS) – ESI Mass Spectrometry (MS) enables tandem measurement of size and molecular weight

  3. Separation by mass/charge Gas (N2) ● IMS separates components by size and charge (drift time) ● ToF-MS separates components by molecular weight and charge (m/z) Can IMS-MS distinguish different polymer architectures?

  4. Synthesis of Poly(e-caprolactone) architectures: Linear and Cyclic Dr. Jessica N. Hoskins “c-PCL” “l-PCL-OH” Identical Mn, Mw, differing only in architecture Incomplete end group functionalization or click cyclization may yield linear impurities “l-PCL-alk” Laurent, B. A.; Grayson, S. M. J. Am. Chem. Soc,. 2006,128, 4328-4329. Hoskins, J. N.; Grayson, S. M. Macromolecules, 2009, 42, 6406-6413.

  5. IMS-MS analysis of linear PCL Non-linearity of each charge state suggests change in confirmation with respect to change in m/z Higher m/z More Compact Dm/z114 / 2 = 57 [M+2Li]+2 [M+3Li]+3 [M+4Li]+4 [M+5Li]+5 and higher charge states Dm/z114 / 3 = 38 Lower m/z More Extended Dm/z114 / 4 = 28.5 Smaller size Larger size Hoskins, J. N.; Trimpin, S.; Grayson, S. M. Macromolecules, 2011, 44, 6915-6918.

  6. IMS-MS comparison of linear & cyclic PCL Comparison of linear and cyclic architectures in the [M+2Li]2+ charge state Conditions: analyte 20 pmolμL-1 in 50:50 acetonitrile : isopropanol with 0.1% LiCl Dr. Jessica N. Hoskins 24-mer More compact 21-mer 22-mer shift to more compact configuration m/z More extended 10-mer 11-mer 10-mer Drift Time (Bins) Hoskins, J. N.; Trimpin, S.; Grayson, S. M. Macromolecules, 2011, 44, 6915-6918.

  7. IMS-MS architectural analysis ● Can discern regioisomers:n-Bu vs. t-Bu in poly(butylmethacrylate): Trimpin, S.; Clemmer, D. E. Anal. Chem. 2008, 80, 9073−9083. ● Can discern topologies: linear vs. cyclic polymers: Hoskins, J. N.; Trimpin, S.; Grayson, S. M. Macromolecules, 2011, 44, 6915-6918. Li, X.; Guo, L.; Casiano-Maldonado, M.; Zhang, D.; Wesdemiotis, C. Macromolecules 2011, 44, 4555−4564. Josse, T.; De Winter, J.; Dubois, P.; Coulembier, O.; Gerbaux,P.; Memboeuf, A. Polym. Chem. 2015, 6, 64−69. ● Can discern stars with differing numbers of arms: Morsa, D.; Defize, T.; Dehareng, D.; Jerome, C.; de Pauw, E. Anal. Chem. 2014, 86, 9693−9700. ● Can discern stereoisomers: D- vs. L- polylactide: Kim, K.; Lee, J. W.; Chang, T.; Kim, H. I. J. Am. Soc. Mass Spectrom. 2014, 25, 1771−1779. But can IMS-MS distinguish architectural dispersity? Can it resolve pure architectures vs. mixed architectures?

  8. Importance of Branching ● Branching remains one of the key properties of polymers for determining their usage, but remains challenging to quantify LDPE LLDPE HDPE ● 0.915-0.925 g/cm3 ● 0.940-0.960 g/cm3 ● 0.910-0.940 g/cm3 ● <0.1 % of repeating units are branch points, as quantified by 13C NMR. ● ~1.6 % of repeating units are branch points, as quantified by 13C NMR. ● ~1.3-1.8 % of repeating units are branch points, as quantified by 13C NMR. ● Very few side chains due to use of transition metal catalysts ● Exclusively well-defined branching from olefin monomers ● Both short and long branches off of main chain ● $33,000,000,000 global market in 2013 ● $40,000,000,000 global market in 2013 ● 30,000,000 tons global market in 2007 ● Most analytical techniques measure the average branching of an entire sample, but are their techniques for measuring the dispersity of branching within a sample?

  9. Library of Branched Stars Synthetic Scheme: Dr. Boyu Zhang (commercially available) linear, 1 3-arm mikto-star, 2 3-arm homo-star, 4 4-arm homo-star, 3 Zhang, B.; Zhang, H.; Elupula, R.; Alb, A.; Grayson, S. Macromol. Rapid Commun. 2014, 35, 146.

  10. Mass Range Analyzed Mass Range 8500-9700 LINEAR, 1 ● In order to enable the side-by-side comparison of different polymer architectures by IMS-MS, they need to be compared in the same m/z range and the same charge state. 3-ARM MIKTO STAR, 2 MALDI-TOF mass spectra 3-ARM HOMO STAR, 4 ● The versatile click-conjugation approach provide a library of PEG stars where the number of arms as well as the length of the arms could be tailored. 4-ARM HOMO STAR, 3 7000 8000 9000 10000 m/z

  11. Determination of Branching via Viscometry ● Traditional polymer characterization using viscometry coupled with MALDI-ToF MS or light scattering can measure increased extent of branching, but yield only one data point per polymer sample (cannot measure branching dispersity). [h] = (0.067)M(0.55) ● Samples with increasing branching (e.g. 3-arm mikto-star and 4-arm homo-star) exhibit decreasing viscosity, as predicted. ● However, binary mixtures of linear and highly branched cannot be distinguished from a pure, lightly branched.

  12. Analysis of Star Library by IMS-MS 3-ARM HOMO STAR, 4 LINEAR, 1 +7 +7 Due to the volume of data, we need to carefully select the region for further analysis 4-ARM HOMO STAR, 3 3-ARM MIKTO STAR, 2 +7 +7

  13. +7 LINEAR, 1 Comparison of [M+7Cs]7+ Charge State of Star Library 100 % +8 1397 m/z Conditions: 25 μM PEG analyte in 50:50 water : acetonitrile with 1:10 ratio of cesium acetate to polymer 1348 ● In order to optimize differentiation, polymers should be compared in the same charge state, and with a high enough number of charges to distinguish conformational flexibility. 10.92 Drift time (ms) 15.33 3-ARM MIKTO-STAR, 2 +7 100 % +6 +7 +7 ● Direct comparison of the linear, 3-arm mikto-star and 4-arm homo-star confirm that the more compact architectures exhibit reduced drift times. 100 1397 % +8 m/z 1397 ● One of the most unique and promising aspects of IMS-MS is the ability to resolve different architectures within a single sample. 1348 m/z 15.33 10.92 Drift time (ms) 1348 4-ARM HOMO-STAR, 3 10.92 15.33 +7 Drift time (ms) % 100 1397 m/z Foley, C. D.; Zhang, B.; Alb, A. M.; Trimpin, S.; Grayson, S. M. ACS Macro Letters, 2015, 4, online ASAP. 1348 10.92 Drift time (ms) 15.33

  14. Conclusion [h] = (0.067)M(0.55) ● The richness of the IMS-MS data sets are further demonstrated by the clear ability to generate a resolved drift time and m/z for every single n-mer within the polymer distribution. IMS-MS 1: linear 2: 3-arm mikto-star 4: 3-arm homo-star Average drift time (ms) ● This is in stark contrast to NMR, viscometry, light scattering, etc. which generate a single branching value as an average of an entire sample, and therefore is incapable of analyzing branching dispersity. 3: 4-arm homo-star Mass/charge (m/z) Viscometry Foley, C. D.; Zhang, B.; Alb, A. M.; Trimpin, S.; Grayson, S. M. ACS Macro Letters, 2015, 4, online ASAP.

  15. Thank you for your attention! Graduate Fellowships Funding NSF-MRI CHE #0619770 NSF CAREER (ARRA) DMR #0844662 NSF-EPSCoR #1003897 NSF-EPSCoR IIA #1430280 NSF-CHE #1412439 NSF-DMR #1460637 Department of Chemistry Wayne State University Casey Foley Sarah Trimpin GoMRI 2012-II-798 Department of Physics Tulane University Alina Alb ACS-PRF 53980-ND7

  16. IMS-MS instrumental set-up

  17. Importance of Branching ● Branching remains one of the key properties of polymers for determining their usage, but remains challenging to quantify LDPE LLDPE HDPE ● 0.910-0.940 g/cm3 ● 0.915-0.925 g/cm3 ● 0.940-0.960 g/cm3 ● ~1.3-1.8 % of repeating units are branch points, as quantified by 13C NMR. ● ~1.6 % of repeating units are branch points, as quantified by 13C NMR. ● <0.1 % of repeating units are branch points, as quantified by 13C NMR. ● Both short and long branches off of main chain ● Exclusively well-defined branching from olefin monomers ● Very few side chains due to use of transition metal catalysts ● $33,000,000,000 global market in 2013 ● $40,000,000,000 global market in 2013 ● 30,000,000 tons global market in 2007 ● Most analytical techniques measure the average branching of an entire sample, but are their techniques for measuring the dispersity of branching within a sample?

More Related