Exploring the Dynamics of Bound Water in Nylon Polymers with Terahertz Spectroscopy.
Exploring the Dynamics of Bound Water in Nylon Polymers with Terahertz Spectroscopy.
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利用太赫兹光谱探索尼龙聚合物中结合水的动力学。
DOI：
10.26434/chemrxiv.10007027
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
M. Ruggiero
中科院分区：
文献类型：
--
作者：
H. Hoshina;T. Kanemura;M. Ruggiero
太赫兹（THz）光谱被用来观察吸附的水的结构和动态聚合物膜，最终提供了一个强有力的理由所观察到的水解吸率。尼龙-6薄膜的太赫兹吸收光谱在水合和干燥过程中发生了剧烈的变化。此外，α-尼龙6在6.5THz处的特征谱带还观察到了水合作用引起的γ晶向α晶的结构变化。重要的是，通过对α-尼龙在脱水过程中的连续测量，观察到尼龙膜中吸附水以及氘代水的THz光谱。差分光谱清楚地显示了水分子的三个吸收带，称为峰I、II和III，其在H2O和D2 O材料之间表现不同。使用从头算分子动力学模拟和固态密度泛函理论计算相结合的光谱进行分配，并与以前的散装水的光谱分配进行比较。结果表明，列入H2O和D2 O到聚合物薄膜的结果在一组不同的光谱特征，而类似的频率散装水的动力学，代表显着不同的运动，由于材料内独特的化学环境。这些结果突出了使用太赫兹光谱研究这类重要材料中束缚水的水合动力学和光谱特征的重要实用性。
Terahertz (THz) spectroscopy was used to observe adsorbed water structure and dynamics within polymer films, ultimately providing a strong rationale for the observed rates of water desorption. The THz absorption spectra of nylon-6 films undergo drastic changes during the hydration and drying process. Additionally, the structural change from γ to α crystals, induced by the hydration, was observed by the characteristic band of α-nylon-6 at 6.5 THz. Importantly, the THz spectra of adsorbed water, as well as deuterated water, within in the nylon films were observed by the continuous measurement of α-nylon during dehydration. The differential spectra clearly show three absorption bands of water molecules named Peak I, II and III, which behaved differently between the H2O and D2O materials. The spectra were assigned using a combination of ab initio molecular dynamics simulations and solid-state density functional theory calculations, and were compared to previous spectral assignments of bulk water. The results show that the inclusion of H2O and D2O into polymer films results in a distinct set of spectral features that, while similar in frequencies to the dynamics of bulk water, represent significantly different motions owing to the unique chemical environment within the material. These results highlight the significant utility of using THz spectroscopy to study the hydration dynamics and spectral signature of bound water in this important class of materials.
在模拟中子散射光谱中观察到的水合对低频蛋白质动力学的影响。
DOI：
--
发表时间：
2008
期刊：
Biophysical Journal 94(印刷中)
影响因子：
--
作者：
George Chikenji;Yoshimi Fujitsuka;Shoji Takada;Yasumasa Joti
通讯作者：
Yasumasa Joti
基于超宽带介电谱重新思考液态水的弛豫线形
DOI：
--
发表时间：
2018
期刊：
影响因子：
--
作者：
Ishii Naoki;Walinda Erik;Iwakawa Naoto;Morimoto Daichi;Iwai Kazuhiro;Sugase Kenji;Shirakawa Masahiro;Keiichiro Shiraga
通讯作者：
Keiichiro Shiraga