近日，瑞典于默奥大学Jean-François Boily团队报道了单次冷冻循环可改变铁矿物的转变方向。相关论文于2026年7月9日发表在《科学》杂志上。

多晶冰的形成会将矿物纳米颗粒浓缩到生长冰晶之间的液态边界中。

研究组表明，仅数分钟的冻结过程就能决定铁矿物在随后数月水相老化中的归宿。单个冻融循环通过物理与化学机制的协同作用，使水铁矿发生不可逆的聚集。冻结浓缩使静电势垒坍塌，同时冰吸作用剥离水合层并将纳米颗粒压缩成微米级的平面状聚集体。化学证据指向界面（羟基）氧桥键合以及氢键作用，这些作用抵抗了解聚。

这些机制将纳米颗粒锁定为类似介晶的组装体，这种组装体保留了纳米尺度的身份特征，但抑制了向针铁矿的溶解-再沉淀过程，反而有利于向赤铁矿的固态转变。因此，冰的形成充当了一个地球化学反应器，驱动聚集和界面键合，从而改变了铁的形态，这对冰冻圈内的营养循环和碳保存具有广泛影响。

附：英文原文

Title: A single freeze cycle redirects iron mineral transformation

Author: Tao Luo, Tao Chen, Tra My Bui Thi, James Behan, Crispin Hetherington, Khalil Hanna, Jean-Franois Boily

Issue&Volume: 2026-07-09

Abstract: Polycrystalline ice formation concentrates mineral nanoparticles into liquid boundaries between growing ice crystals. Here we show that minutes of freezing dictate iron mineral fate over subsequent months of aqueous aging. A single freeze–thaw cycle irreversibly aggregates ferrihydrite through converging physical and chemical mechanisms. Freeze concentration collapses electrostatic barriers while cryosuction strips hydration layers and compresses nanoparticles into micrometer-scale planar aggregates. Chemical evidence points to interfacial (hydr)oxo bridging, alongside hydrogen bonding, that resists disaggregation. These mechanisms lock nanoparticles into mesocrystal-like assemblages that retain their nanoscale identity but inhibit dissolution–reprecipitation to goethite, instead favoring solid-state transformation to hematite. Ice formation thus acts as a geochemical reactor, driving aggregation and interfacial bonding that redirect iron speciation, with broad implications for nutrient cycling and carbon preservation across the cryosphere.

DOI: aee9519

Source: https://www.science.org/doi/10.1126/science.aee9519