

FOLLOWUS
School of Nuclear Science and Technology, National Synchrotron Radiation Laboratory, State Key Laboratory of Advanced Glass Materials, Anhui Provincial Engineering Research Center for Advanced Functional Polymer Films, University of Science and Technology of China, Hefei 230029, China
wc003@mail.ustc.edu.cn
Received:28 February 2026,
Accepted:31 March 2026,
Online First:10 June 2026,
Published:05 September 2026
Scan QR Code
You, L. P.; Xie, J. Y.; Li, Y.; Guang, X.; Chen, W. From molecular defect to macroscopic performance: manipulating dichroism and mechanics in iodine-doped poly(vinyl alcohol) via ethylene incorporation. Chinese J. Polym. Sci. 2026, 44, 3092–3103
Liang-Peng You, Jia-Yu Xie, Yao Li, et al. From Molecular Defect to Macroscopic Performance: Manipulating Dichroism and Mechanics in Iodine-doped Poly(vinyl alcohol)
You, L. P.; Xie, J. Y.; Li, Y.; Guang, X.; Chen, W. From molecular defect to macroscopic performance: manipulating dichroism and mechanics in iodine-doped poly(vinyl alcohol) via ethylene incorporation. Chinese J. Polym. Sci. 2026, 44, 3092–3103 DOI: 10.1007/s10118-026-3693-7.
Liang-Peng You, Jia-Yu Xie, Yao Li, et al. From Molecular Defect to Macroscopic Performance: Manipulating Dichroism and Mechanics in Iodine-doped Poly(vinyl alcohol)
Based on ethylene defect engineering and Leveraging employing
in situ
synchrotron radiation X-ray scattering techniques to characterize the condensed structure
this work successfully achieved the regulation of the mechanical and optical properties of polarizing films through poly(vinyl alcohol) (PVA) structure control.
Molecular chain defect engineering is a pivotal strategy for tailoring the macroscopic properties of polymeric materials. However
establishing a definitive relationship between molecular-level defects and bulk material performance remains challenging
due to the difficulty in precisely controlling not only the molecular architecture but also the subsequent chain packing
which critically governs material performance. In this work
we demonstrate that introducing ethylene units as chain defects into poly(vinyl alcohol) (PVA) enables precise modulation of the dichroism in iodine-doped PVA polarizers. This approach allows for concurrent control over the iodine-PVA complexation
the crystalline network and the mechanical properties. The dichroic behavior originates from the formation of oriented I
3
−
and I
5
−
species
with I
3
−
absorbing between 400–520 nm and I
5
−
between 520–780 nm. Therefore
optimizing optical performance—namely transmitta
nce and polarization efficiency—requires careful tuning of the I
3
−
/I
5
−
ratio and their overall concentration. The incorporation of ethylene defects addresses this need through three synergistic effects: (1) It increases the I
3
−
/I
5
−
ratio by shortening the vinyl-alcohol sequence length in the amorphous regions
given that ethylene unit does not complex with iodine; (2) It reduces the overall crystallinity
as ethylene units are excluded from the crystalline domains; (3) It weakens intermolecular interactions (reflected by an increased Flory-Huggins parameter)
which lowers the modulus but enhances drawability. This study illustrates how molecular-level defect engineering can be effectively translated into precise control over both chemical complexation and physical networks
thereby enabling the simultaneous manipulation of optical and mechanical properties in polymer materials.
Franklin, D.; Frank, R.; Wu, S.-T.; Chanda, D. Actively addressed single pixel full-colour plasmonic display. Nat. Commun. 2017 , 8 , 15209..
Kim, K. H.; Song, J. K. Technical evolution of liquid crystal displays. NPG Asia Mater. 2009 , 1 , 29−36..
Chen, H. W.; Lee, J. H.; Lin, B.Y.; Chen, S.; Wu, S. T. Liquid crystal display and organic light-emitting diode display: present status and future perspectives. Light: Sci. Appl. 2018 , 7 , 17168..
Back, J. H.; Kwon, Y.; Cho, H.; Lee, H.; Ahn, D.; Kim, H.-J.; Yu, Y.; Kim, Y.; Lee, W.; Kwon, M. S. Visible-light-curable acrylic resins toward UV-light-blocking adhesives for foldable displays. Adv. Mater. 2023 , 35 , 2204776..
Kim, D.; Kim, H.; Jeon, W.; Kim, H. J.; Choi, J.; Kim, Y.; Kwon, M. S. Ultraviolet light debondable optically clear adhesives for flexible displays through efficient visible-light curing. Adv. Mater. 2024 , 36 , 2309776..
Lv, J.; Han, J. H.; Han, G.; An, S.; Kim, S. J.; Kim, R. M.; Ryu, J.; Oh, R.; Choi, H.; Ha, I. H.; Lee, Y. H.; Kim, M.; Park, G. S.; Jang, H. W.; Doh, J.; Choi, J.; Nam, K. T. Spatiotemporally modulated full-polarized light emission for multiplexed optical encryption. Nat. Commun. 2024 , 15 , 8257..
Montali, A.; Bastiaansen, C.; Smith, P.; Weder, C. Polarizing energy transfer in photoluminescent materials for display applications. Nature 1998 , 392 , 261−264..
[Miyasaka, K. PVA-Iodine complexes: Formation, structure, and properties. in Structure in Polymers with Special Properties, Springer Berlin Heidelberg, 1993 , 91–129.
Shin, E. J.; Lyoo, W. S.; Lee, Y. H. Polarizer effect and structure of iodinated before and after casting poly(vinyl alcohol) film. J. Appl. Polym. Sci. 2011 , 120 , 397−405..
Zwick, M. M. Poly(vinyl alcohol)–iodine complexes. J. Appl. Polym. Sci. 1965 , 9 , 2393−2424..
Tashiro, K.; Kitai, H.; Saharin, S. M.; Shimazu, A.; Itou, T. Quantitative Crystal Structure Analysis of Poly(vinyl alcohol)–iodine complexes on the basis of 2D X-ray diffraction, Raman spectra, and computer simulation techniques. Macromolecules 2015 , 48 , 2138−2148..
Tashiro, K.; Takahama, T.; Wang, M. F. X-ray study of Poly(vinyl Alcohol)-Iodine complex prepared from the dilute iodine solution as a hint to know the inner structure of polarizer. Polymer 2021 , 233 , 124180..
Li, Y.; Yang, J.; Cheng, H.; Cai, L.; Ye, K.; Xia, Z.; Zhang, Q.; Wang, D.; Chen, W. Network structure of swollen iodine-doped poly(vinyl alcohol) amorphous domain as characterized by low field NMR. Soft Matter 2021 , 17 , 8973−8981..
Choi, Y.-S.; Oishi, Y.; Miyasaka, K. Change of poly(vinyl alcohol) crystal lattice by iodine sorption. Polym. J. 1990 , 22 , 699−708..
Kojima, Y.; Furuhata, K.; Miyasaka, K. Sorption and permeation of iodine in water-swollen poly(vinyl alcohol) membranes and iodine complex formation. J. Appl. Polym. Sci. 1985 , 30 , 1617−1628..
Müllen, K. Molecular defects in organic materials. Nat. Rev. Mater. 2016 , 1 , 15013..
Shuang, F.; Liu, K.; Ji, Y.; Gao, W.; Laurenti, L.; Dey, P. Modeling extensive defects in metals through classical potential-guided sampling and automated configuration reconstruction. npj Comput. Mater. 2025 , 11 , 118..
Ding, K.; Lang, E.; Hattar, K.; Zhu, T.; Kacher, J.; Pierron, O. Direct observation of grain-boundary-migration-assisted radiation damage healing in ultrafine grained gold under mechanical stress. Nano Lett. 2023 , 23 , 3282−3290..
Li, H.; Zong, H.; Li, S.; Jin, S.; Chen, Y.; Cabral, M. J.; Chen, B.; Huang, Q.; Chen, Y.; Ren, Y.; Yu, K.; Han, S.; Ding, X.; Sha, G.; Lian, J.; Liao, X.; Ma, E.; Sun, J. Uniting tensile ductility with ultrahigh strength via composition undulation. Nature 2022 , 604 , 273−279..
Dreyer, C. E.; Janotti, A.; Lyons, J. L.; Wickramaratne, D. Defects in semiconductors. J. Appl. Phys. 2024 , 136 , 190401..
Lin, W.; Li, G.; Qian, J.; Ge, G.; Wang, S.; Lin, J.; Lin, J.; Shen, B.; Zhai, J. Achieving ultrahigh electrocaloric response in (Bi0.5Na0.5)TiO3-based ceramics through B-site defect engineering. ACS Nano 2024 , 18 , 13322−13332..
Huangfu, G.; Zeng, K.; Wang, B.; Wang, J.; Fu, Z.; Xu, F.; Zhang, S.; Luo, H.; Viehland, D.; Guo, Y. Giant electric field-induced strain in lead-free piezoceramics. Science 2022 , 378 , 1125−1130..
Oses, C.; Toher, C.; Curtarolo, S. High-entropy ceramics. Nat. Rev. Mater. 2020 , 5 , 295−309..
Han, X.-W.; Zhang, X.; Zhou, Y.; Maimaitiming, A.; Sun, X.-L.; Gao, Y.; Li, P.; Zhu, B.; Chen, E. Y.-X.; Kuang, X.; Tang, Y. Circular olefin copolymers made de novo from ethylene and α -olefins. Nat. Commun. 2024 , 15 , 1462..
Takahashi, M.; Tashiro, K.; Amiya, S. Crystal structure of ethylene−vinyl alcohol copolymers. Macromolecules 1999 , 32 , 5860−5871..
Flory, P. Theory of crystallization in copolymxrs. Trans. Faraday Soc. 1955 , 51 , 848−857..
Becker, P.; Buback, M.; Sandmann, J. Initiator efficiency of peroxides in high-pressure ethene polymerization. Macromol. Chem. Phys. 2002 , 203 , 2113−2123..
Sattler, W.; Carter, M. C. D.; Irick, N. J.; DeFelippis, J.; Even, R. C. End-Group control in the radical polymerization of methyl methacrylate with tert -butyl peroxypivalate initiator in the presence of thiol chain transfer agents. ACS Appl. Polym. Mater. 2020 , 2 , 3936−3947..
[Ketels, H. H. T. M., Synthesis, characterization and applications of ethylene vinylalcohol copolymers. Thesis, Technische Universiteit Eindhoven, 1989 .
Wu, Z.; Xiong, Y.; L i, C.; Cheng, H.; Li, Y.; Chen, W. Exploring the Interphase Structure of Poly(vinyl alcohol) during Sol–Gel transition using selective probes with varied molecular sizes. Macromolecules 2023 , 56 , 7113−7124..
Gao, W.; Ma, R.; Dela Peña, T. A.; Yan, C.; Li, H.; Li, M.; Wu, J.; Cheng, P.; Zhong, C.; Wei, Z.; Jen, A. K.-Y.; Li, G. Efficient all-small-molecule organic solar cells processed with non-halogen solvent. Nat. Commun. 2024 , 15 , 1946..
Robertson, A. R. The CIE 1976 Color-difference formulae. Color Res. Appl. 1977 , 2 , 7−11..
Tsarev, S.; Proniakova, D.; Liu, X.; Wu, E.; Matt, G. J.; Sakhatskyi, K.; Ferraresi, L. L. A.; Kothandaraman, R.; Fu, F.; Shorubalko, I.; Yakunin, S.; Kovalenko, M. V. Vertically stacked monolithic perovskite colour photodetectors. Nature 2025 , 642 , 592−598..
[Junghare, V.; Bhattacharya, S.; Ansari, K.; Hazra, S. Markov state models of molecular simulations to study protein folding and dynamics. in Protein folding dynamics and stability , Springer Nature Singapore, 2023 , p. 147–164..
Zhang, R.; Zhang, Q.; Ji, Y.; Su, F.; Meng, L.; Qi, Z.; Lin, Y.; Li, X.; Chen, X.; Lv, F.; Li, L. Stretch-induced complexation reaction between poly(vinyl alcohol) and iodine: an in situ synchrotron radiation small- and wide-angle X-ray scattering study. Soft Matter 2018 , 14 , 2535−2546..
Chassé, W.; Lang, M.; Sommer, J.-U.; Saalwächter, K. Cross-link density estimation of PDMS networks with precise consideration of networks defects. Macromolecules 2012 , 45 , 899−912..
Fu, Z.; Guo, S.; Li, C.; Wang, K.; Zhang, Q.; Fu, Q. Hydrogen-bond-dominated mechanical stretchability in PVA films: from phenomenological to numerical insights. Phys. Chem. Chem. Phys. 2022 , 24 , 1885−1895..
Flory, P. J. Thermodynamics of high polymer solutions. J. Chem. Phys. 1942 , 10 , 51−61..
Huggins, M. L. Theory of solutions of high polymers 1 . J. Am. Chem. Soc. 1942 , 64 , 1712−1719..
[Hu, W. in Polymer physics: a molecular approach , Springer Vienna, Vienna, 2013 , pp. 155–160..
Li, H.; Yang, H.; Zhang, L.; Wang, S.; Chen, Y.; Zhang, Q.; Zhang, J.; Tian, H.; Han, Y. Optimizing the crystallization behavior and film morphology of donor–acceptor conjugated semiconducting polymers by side-chain–solvent interaction in nonpolar solvents. Macromolecules 2021 , 54 , 10557−10573..
Mullins, L. Effect of Stretching on the Properties of Rubber. Rubber Chem. Technol. 1948 , 21 , 281−300..
Matsuzawa, S.; Yamaura, K.; Noguchi, H. Effect of syndiotacticity on the reaction of poly(vinyl alcohol)s with iodine. Makromol. Chem. 1974 , 175 , 31−41..
Li, Y.; Xie, J.; Cheng, H.; Wei, X.; Chen, J.; You, L.; Chen, W. Polyvinyl alcohol-based polarizers for new displays: molecules, processing and properties. Soft Matter 2025 , 21 , 3148−3167..
Liu, D.; Li, J.-H.; Wang, S.-C.; Zhang, L.; Liu, X.-Y.; Zhang, Q.; Han, Y.-C. Control aggregation of P3HT in solution for high effic iency doping: ensuring structural order and the distribution of dopants. Chinese J. Polym. Sci. 2023 , 41 , 811−823..
Strawhecker, K. E.; Manias, E. AFM of poly(vinyl alcohol) crystals next to an inorganic surface. Macromolecules 2001 , 34 , 8475−8482..
Zhang, Q.; Zhang, R.; Meng, L.; Ji, Y.; Su, F.; Lin, Y.; Li, X.; Chen, X.; Lv, F.; Li, L. Stretch-induced structural evolution of poly (vinyl alcohol) film in water at different temperatures: An in-situ synchrotron radiation small- and wide-angle X-ray scattering study. Polymer 2018 , 142 , 233−243..
Trabelsi, S.; Albouy, P.-A.; Rault, J. Crystallization and melting processes in vulcanized stretched natural rubber. Macromolecules 2003 , 36 , 7624−7639..
[Pilz, I.; Glatter, O.; Kratky, O. [11 ] Small-angle x-ray scattering. in Methods in Enzymology , Elsevier, 1979 , pp. 148–249..
Wu, Z.-S.; Deng, J.-Y.; Chen, W. Tensile deformation mechanism of glycerol plasticized poly(vinyl alcohol) film as elucidate d by in situ synchrotron radiation X-ray scattering: the critical role of hydrolysis. Chinese J. Polym. Sci. 2025 , 43 , 1671−1680..
0
Views
27
Downloads
0
CSCD
Publicity Resources
Related Articles
Related Author
Related Institution
京公网安备11010802046900号