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On the Nature of Macroradicals Formed upon Radiolysis of Aqueous Poly(N-?vinylpyrrolidone)Solutions
Published
Author(s)
Richard D. Holbrook, Clelia Dispenza, Maria Antonietta Sabatino, Natascia Grimaldi, Bjorn Dahlgren, Mohamad Al-Sheikhly, James F. Wishart, Zois Tsinas, Mats Jonsson
Abstract
In this work we have explored the nature of macroradicals formed upon radiolysis of aqueous poly(N-‐vinylpyrrolidone) (PVP) solutions using pulse radiolysis, density functional theory (DFT) and literature data. On the basis of literature data on site-‐specific kinetics of hydrogen abstraction from simple amides and spectra corresponding to specific radical sites on the same amides we have assessed the distribution of H-‐atom abstraction by OH radicals from different positions on the pyrrolidone ring and the polymer backbone. Pulse radiolysis experiments performed at different doses per pulse and different PVP concentrations demonstrate that the H-‐abstracting radiolysis products are not quantitatively scavenged by the polymer when the dose/pulse exceeds 40 Gy. The implications of this are discussed in the context of radical-‐ initiated crosslinking reactions. At a 0.1 wt% PVP and doses per pulse ranging from 7 to 117 Gy, the overall radical decay observed at 390 nm follows second order kinetics with rate constants on the order of 109 dm3 mol-‐1 s-‐1.
Holbrook, R.
, Dispenza, C.
, Sabatino, M.
, Grimaldi, N.
, Dahlgren, B.
, Al-Sheikhly, M.
, Wishart, J.
, Tsinas, Z.
and Jonsson, M.
(2020),
On the Nature of Macroradicals Formed upon Radiolysis of Aqueous Poly(N-­?vinylpyrrolidone)Solutions, Journal of Radiation Research, [online], https://doi.org/10.1016/j.radphyschem.2020.108900, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=928451
(Accessed October 13, 2025)