@article{oai:kanazawa-u.repo.nii.ac.jp:00047479,
 author = {炭竈, 享司 and Ajito, Katsuhiro and Ueno, Yuko and Kim, Jae-Young and Sumikama, Takashi},
 issue = {42},
 journal = {Journal of the American Chemical Society},
 month = {Oct},
 note = {Sodium chloride (NaCl) aqueous solution becomes NaCl hydrate, NaCl·2H2O, at low temperature, which is different from potassium chloride and is a typical complex model for studying the freeze-drying process in foods and pharmaceuticals. Here, we detected unit-cell-sized NaCl particles in ice as precursor substances of NaCl·2H2O during freezing of NaCl solution by using terahertz (THz) spectroscopy. In the freezing process, Na+ and Cl– ions form two types of metastable unit-cell-sized NaCl particles on the pathway to the well-known NaCl·2H2O crystal production, which are not listed in the phase diagram of freezing of NaCl solution but have absorption peaks in THz spectra. This finding of single unit-cell-sized particles signifies the importance of studying the freeze-drying process in-depth and offers a new possibility for the development of freeze-drying technology for the manufacture of nanometer-sized particles such as ultrafine pharmaceutical powders, which more readily dissolve in water., Embargo Period 12 months, 金沢大学新学術創成研究機構ナノ生命科学研究所},
 pages = {13793--13797},
 title = {Capturing the freeze-drying dynamics of NaCl nanoparticles using THz spectroscopy},
 volume = {140},
 year = {2018}
}