NMR spectroscopy study of local correlations in water

Francesco Mallamace; Carmelo Corsaro; Domenico Mallamace; Sebastiano Vasi; H Eugene Stanley

doi:10.1063/1.4968589

NMR spectroscopy study of local correlations in water

J Chem Phys. 2016 Dec 7;145(21):214503. doi: 10.1063/1.4968589.

Authors

Francesco Mallamace¹, Carmelo Corsaro², Domenico Mallamace³, Sebastiano Vasi¹, H Eugene Stanley⁴

Affiliations

¹ Dipartimento MIFT, Sezione di Fisica, Università di Messina, I-98166 Messina, Italy.
² Consiglio Nazionale delle Ricerche-IPCF Messina, I-98158 Messina, Italy.
³ Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase - CSGI, Sesto Fiorentino, Firenze 50019, Italy.
⁴ Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215, USA.

PMID: 28799351
DOI: 10.1063/1.4968589

Abstract

Using nuclear magnetic resonance we study the dynamics of the hydrogen bond (HB) sub-domains in bulk and emulsified water across a wide temperature range that includes the supercooled regime. We measure the proton spin-lattice T₁ and spin-spin T₂ relaxation times to understand the hydrophilic interactions that determine the properties of water. We use (i) the Bloembergen, Purcell, and Pound approach that focuses on a single characteristic correlation time τ_c, and (ii) the Powles and Hubbard approach that measures the proton rotational time τ_θ. We find that when the temperature is low both relaxation times are strongly correlated when the HB lifetime is long, and that when the temperature is high a decrease in the HB lifetime destroys the water clusters and decouples the dynamic modes of the system.