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Forensics of polymer networks

Abstract

Our lives cannot be imagined without polymer networks, which range widely, from synthetic rubber to biological tissues. Their properties—elasticity, strain-stiffening and stretchability—are controlled by a convolution of chemical composition, strand conformation and network topology. Yet, since the discovery of rubber vulcanization by Charles Goodyear in 1839, the internal organization of networks has remained a sealed ‘black box’. While many studies show how network properties respond to topology variation, no method currently exists that would allow the decoding of the network structure from its properties. We address this problem by analysing networks’ nonlinear responses to deformation to quantify their crosslink density, strand flexibility and fraction of stress-supporting strands. The decoded structural information enables the quality control of network synthesis, comparison of targeted to actual architecture and network classification according to the effectiveness of stress distribution. The developed forensic approach is a vital step in future implementation of artificial intelligence principles for soft matter design.

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Fig. 1: Forensics methodology.
Fig. 2: Forensics of phantom networks.
Fig. 3: Elasticity and percolation transition.
Fig. 4: Forensics of brush network elasticity.
Fig. 5: Network topology classification.

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Data availability

All data supporting the findings are provided as figures and accompanying tables in the article and Supplementary Information. Data files for all figures are available from the corresponding authors on request.

References

  1. Treloar, L. R. G. The Physics of Rubber Elasticity (Clarendon Press, 1975).

  2. Flory, P. J. Principles of Polymer Chemistry (Cornell Univ. Press, 1971).

  3. Sheiko, S. S. & Dobrynin, A. V. Architectural code for rubber elasticity: from supersoft to superfirm materials. Macromolecules 52, 7531–7546 (2019).

    Article  CAS  Google Scholar 

  4. McKenna, G. B. Soft matter: rubber and networks. Rep. Prog. Phys. 81, 0666602 (2018).

    Article  Google Scholar 

  5. Danielsen, S. P. O. et al. Molecular characterization of polymer networks. Chem. Rev. 121, 5042–5092 (2021).

    Article  CAS  Google Scholar 

  6. Dossin, L. M. & Graessley, W. W. Rubber elasticity and well-characterized polybutadiene networks. Macromolecules 12, 123–130 (1979).

    Article  CAS  Google Scholar 

  7. Patel, S. K., Malone, S., Cohen, C., Gillmor, J. R. & Colby, R. H. Elastic-modulus and equilibrium swelling of poly(dimethylsiloxane) networks. Macromolecules 25, 5241–5251 (1992).

    Article  CAS  Google Scholar 

  8. Zhong, M., Wang, R., Kawamoto, K., Olsen, B. D. & Johnson, J. A. Quantifying the impact of molecular defects on polymer network elasticity. Science 353, 1264–1268 (2016).

    Article  CAS  Google Scholar 

  9. Chase, W., Lang, M., Sommer, J.-U. & Saalwächter, K. Cross-link density estimation of PDMS networks with precise consideration of networks defects. Macromolecules 45, 899–912 (2012).

    Article  Google Scholar 

  10. Chasse, W., Lang, M., Sommer, J.-U. & Saalwächter, K. Correction to cross-link density estimation of PDMS networks with precise consideration of networks defects. Macromolecules 48, 1267–1268 (2015).

    Article  CAS  Google Scholar 

  11. Smith, S. B., Cui, Y. J. & Bustamante, C. Overstretching B-DNA: the elastic response of individual double-stranded and single-stranded DNA molecules. Science 271, 795–799 (1996).

    Article  CAS  Google Scholar 

  12. Neuman, K. C., Lionnet, T. & Allemand, J. F. Single-molecule micromanipulation techniques. Ann. Rev. Mater. Res. 37, 33–67 (2007).

    Article  CAS  Google Scholar 

  13. Flory, P. J. Network topology and the theory of rubber elasticity. Br. Polym. J. 17, 96–102 (1985).

    Article  CAS  Google Scholar 

  14. Langley, N. R. Elasticity effective strand density in polymer networks. Macromolecules 1, 348–352 (1968).

    Article  CAS  Google Scholar 

  15. Miller, D. R. & Macosko, C. W. New derivation of post gel properties of network polymers. Macromolecules 9, 206–211 (1976).

    Article  CAS  Google Scholar 

  16. Sandakov, G. I., Smirnov, L. P., Sosikov, A. I., Summanen, K. T. & Volkova, N. N. NMR analysis of distribution of chain lengths between crosslinks of polymer networks. J. Polym. Sci. Polym. Phys. 32, 1585–1592 (1994).

    Article  CAS  Google Scholar 

  17. Bastide, J. & Candau, S. J. in Physical Properties of Polymeric Gels (ed. Cohen, J. P.) 143−308 (Wiley, 1996).

  18. Edwards, S. F. & Vilgis, T. A. The tube model theory of rubber elasticity. Rep. Prog. Phys. 51, 243–297 (1988).

    Article  Google Scholar 

  19. Mullins, L. Determination of degree of crosslinking in natural rubber vulcanizates. Part IV. Stress-strain behavior at large extensions. J. Appl. Polym. Sci. 2, 257–263 (1959).

    Article  CAS  Google Scholar 

  20. Vatankhah-Varnosfaderani, M. et al. Mimicking biological stress–strain behaviour with synthetic elastomers. Nature 549, 497–501 (2017).

    Article  Google Scholar 

  21. Vatankhah-Varnosfaderani, M. et al. Chameleon-like elastomers with molecularly encoded strain-adaptive stiffening and coloration. Science 359, 1509–1513 (2018).

    Article  CAS  Google Scholar 

  22. Rubinstein, M. & Colby, R. H. Polymer Physics (Oxford Univ. Press, 2003).

  23. Dobrynin, A. V. & Carrillo, J.-M. Y. Universality in nonlinear elasticity of biological and polymeric networks and gels. Macromolecules 44, 140–146 (2011).

    Article  CAS  Google Scholar 

  24. Panyukov, S. Loops in polymer networks. Macromolecules 52, 4145–4153 (2019).

    Article  CAS  Google Scholar 

  25. Fetters, L. J., Lohse, D. J. & Colby, R. H. in Physical Properties of Polymers Handbook (ed. Mark, J. E.) 445–452 (Springer, 2007).

  26. Staufer, D. Introduction to Percolation Theory (Taylor and Francis, 1985).

  27. Ahmad, N. M., Lovell, P. A. & Underwood, S. M. Viscoelastic properties of branched polyacrylate melts. Polym. Int. 50, 625–634 (2001).

    Article  CAS  Google Scholar 

  28. Daniel, W. F. M. et al. Solvent-free, supersoft and superelastic bottlebrush melts and networks. Nat. Mater. 15, 183–189 (2016).

    Article  CAS  Google Scholar 

  29. Liang, H., Cao, Z., Wang, Z., Sheiko, S. S. & Dobrynin, A. V. Combs and bottlebrushes in a melt. Macromolecules 50, 3430–3437 (2017).

    Article  CAS  Google Scholar 

  30. Liang, H., Wang, Z., Sheiko, S. S. & Dobrynin, A. V. Comb and bottlebrush graft copolymers in a melt. Macromolecules 52, 3942–3950 (2019).

    Article  CAS  Google Scholar 

  31. Maw, M. et al. Brush architecture and network elasticity: path to the design of mechanically diverse elastomers. Macromolecules 55, 2940–2951 (2022).

    Article  CAS  Google Scholar 

  32. Cao, Z., Carrillo, J.-M. Y., Sheiko, S. S. & Dobrynin, A. V. Computer simulations of bottle brushes: from melts to soft networks. Macromolecules 48, 5006–5015 (2015).

    Article  CAS  Google Scholar 

  33. Carrillo, J.-M. Y., MacKintosh, F. C. & Dobrynin, A. V. Nonlinear elasticity: from single chain to networks and gels. Macromolecules 46, 3679–3692 (2013).

    Article  CAS  Google Scholar 

  34. Peak, C. W., Wilker, J. J. & Schmidt, G. A review on tougth and sticky hydrogels. Colloid Polym. Sci. 291, 2031–2047 (2013).

    Article  CAS  Google Scholar 

  35. Zhang, Y. S. & Khademhosseini, A. Advances in engineering hydrogels. Science 356, eaaf3627 (2017).

    Article  Google Scholar 

  36. Peppas, N. A., Hilt, J. Z., Khademhosseini, A. & Langer, R. Hydrogels in biology and medicine: from molecular principles to bionanotechnology. Adv. Mater. 18, 1345–1360 (2006).

    Article  CAS  Google Scholar 

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Acknowledgements

This work was supported by the National Science Foundation under grants DMR 1921835 (S.S.S., M.M.), DMR 1921923 (A.V.D., M.J.), DMR 2049518 (A.V.D., Y.T., M.J.) and DMR 2004048 (S.S.S., F.V.). E.A.N. and D.A.I. acknowledge the Ministry of Science and Higher Education of the Russian Federation for financial support in the frame of state contract no. 075-15-2022-1117 from June 30, 2022. A.V.D. and S.S.S. are grateful to E. Samulski for the critical reading of the manuscript and numerous stimulating discussions. We acknowledge the contribution of B. J. Morgan and A. N. Keith to the synthesis of well-defined PBA elastomers and linear–bottlebrush–linear copolymers, reported previously. E.A.N. and D.A.I. acknowledge the European Synchrotron Radiation Facility for provision of synchrotron beamtime at the ID02 beamline and thank the staff of the European Synchrotron Radiation Facility and E. A. Bersenev for assistance.

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Contributions

A.V.D. developed the concept and theoretical foundation; F.V. and M.M. performed the synthesis, characterization and mechanical testing of brush networks; Y.T. analysed correlations between the network structure and mechanical properties; M.J. and Y.T. performed molecular dynamics simulations of polymer networks and analysed their properties; E.A.N. and D.A.I. performed X-ray scattering measurements; and A.V.D. and S.S.S. were the primary writers of the manuscript and the principal investigators. All authors discussed the results and provided feedback on the manuscript.

Corresponding authors

Correspondence to Andrey V. Dobrynin or Sergei S. Sheiko.

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Supplementary Information

Supplementary Figs. 1–13, Tables 1–5, equations (1)–(21) and network synthesis and experimental protocols.

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Dobrynin, A.V., Tian, Y., Jacobs, M. et al. Forensics of polymer networks. Nat. Mater. 22, 1394–1400 (2023). https://doi.org/10.1038/s41563-023-01663-5

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