Gold Nanoprobes Exploring the Ice Structure in the Aqueous Dispersion of Poly(Ethylene Glycol)−Gold Hybrid Nanoparticles
Gold Nanoprobes Exploring the Ice Structure in the Aqueous Dispersion of Poly(Ethylene Glycol)−Gold Hybrid Nanoparticles
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金纳米探针探索聚乙二醇水分散体中的冰结构-金混合纳米粒子
DOI：
10.1021/acs.langmuir.1c02783
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发表时间：
2022
期刊：
影响因子：
3.9
通讯作者：
Tobias Kraus
中科院分区：
文献类型：
--
作者：
Peng Zhang;Ruike Zou;Shuwang Wu;Lars-Arne Meyer;Jianjun Wang;Tobias Kraus
冰的结构及其形成过程对低温生物学、地球科学和物理化学至关重要。在这项工作中，我们通过将水溶性聚乙二醇（PEG）接枝到球形金纳米粒子上合成了金纳米探针，并分析了所得到的PEG- au杂化纳米粒子（AuPEGNPs）附近的冰形成结构。温度依赖性原位小角度x射线散射（SAXS）表明，AuPEGNPs和PEG一样，导致了大块球晶冰的形成。与聚乙二醇不同，我们观察到层状冰的形成周期为4.6 nm，其热力学稳定性不如块状冰。在- 19℃的冷却过程中，AuPEGNP团聚形成片层冰，在随后的- 20 ~ - 11℃的加热过程中，片层冰保持不变，并在- 10℃左右融化，远低于大块冰的融化温度。我们解释了AuPEGNP和自由PEG对冰形成的不同影响。聚块金核上高度集中的聚乙二醇链导致聚乙二醇水合物的形成，聚乙二醇水合物以4.6 nm的周期聚集成片层冰。
Ice structures and their formation process are fundamentally important to cryobiology, geoscience, and physical chemistry. In this work, we synthesized gold nanoprobes by grafting water-soluble polyethylene glycol (PEG) onto spherical gold nanoparticles and analyzed the structure of ice formation in the vicinity of the resulting hybrid PEG-Au nanoparticles (AuPEGNPs). Temperature-dependentin situsmall-angle X-ray scattering (SAXS) indicated that AuPEGNPs, like PEG, caused the formation of bulk spherulite ice. Unlike for PEG, we observed the formation of lamellar ice with a periodicty of 4.6 nm, which is thermodynamically less stable than the bulk form. The lamellar ice formed after AuPEGNP agglomeration during cooling at −19 °C, and it remained during subsequent heating from −20 to −11 °C and melted at around −10 °C, far below the melting temperature of bulk ice. We explain different effects of AuPEGNP and free PEG on ice formation by the topological differences. The highly concentrated PEG chains on the agglomerated Au cores lead to the formation of PEG-hydrates that assemble into lamellar ice with a periodicity of 4.6 nm.