Cassone Giuseppe, Martelli Fausto
Institute for Chemical-Physical Processes, National Research Council, Viale F. Stagno d'Alcontres 37, Messina, 98158, Italy.
IBM Research Europe, Keckwik Lane, Daresbury, WA4 4AD, UK.
Nat Commun. 2024 Feb 29;15(1):1856. doi: 10.1038/s41467-024-46131-z.
Water is routinely exposed to external electric fields. Whether, for example, at physiological conditions, in contact with biological systems, or at the interface of polar surfaces in countless technological settings, water responds to fields on the order of a few V Å in a manner that is under intense investigation. Dating back to the 19th century, the possibility of solidifying water upon applying electric fields - a process known as electrofreezing - is an alluring promise that has canalized major efforts since, with uncertain outcomes. Here, we perform long (up to 500 ps per field strength) ab initio molecular dynamics simulations of water at ambient conditions under external electric fields. We show that fields of 0.10 - 0.15 V Å induce electrofreezing to a ferroelectric amorphous phase which we term f-GW (ferroelectric glassy water). The transition occurs after ~ 150 ps for a field of 0.15 V Å and after ~ 200 ps for a field of 0.10 V Å and is signaled by a structural and dynamic arrest and the suppression of the fluctuations of the hydrogen bond network. Our work reports evidence of electrofreezing of bulk liquid water at ambient conditions and therefore impacts several fields, from fundamental chemical physics to biology and catalysis.
水经常会受到外部电场的作用。例如,无论是在生理条件下、与生物系统接触时,还是在无数技术环境中的极性表面界面处,水都会以一种受到深入研究的方式对几伏每埃量级的电场做出反应。自19世纪以来,在施加电场时使水凝固的可能性——这一过程被称为电冷冻——是一个诱人的前景,此后人们为此付出了巨大努力,但结果并不确定。在这里,我们在外部电场作用下对环境条件下的水进行了长时间(每个场强高达500皮秒)的从头算分子动力学模拟。我们表明,0.10 - 0.15伏每埃的电场会诱导水冷冻成一种铁电非晶相,我们将其称为f - GW(铁电玻璃态水)。对于0.15伏每埃的电场,转变在约150皮秒后发生;对于0.10伏每埃的电场,转变在约200皮秒后发生,其标志是结构和动力学的停滞以及氢键网络波动的抑制。我们的工作报道了在环境条件下大块液态水电冷冻的证据,因此对从基础化学物理到生物学和催化等多个领域都有影响。