Solid films of deoxyribonucleic acid (DNA) containing a hydrated ionic liquid, choline dihydrogen phosphate (CDP), were prepared by a solvent-casting method. Thermal properties, aggregation structure, thermal molecular motion, and tensile properties of CDP-containing DNA films were examined by thermogravimetry (TG), wide-angle X-ray diffraction (WAXD) measurement, dynamic mechanical analysis (DMA), and tensile tests, respectively. The water retentivity of the films at room temperature was much improved with CDP. The packing density of DNA helical chains clearly depended on the amount of CDP in the film. A small amount of CDP contributed to the suppression of the BI → BII conformational transition and the cooperative motion of the DNA duplex in the film. The tensile properties of the film drastically changed in the presence of CDP. When the amount of hydrated CDP in the film increased, the mechanical response of the film changed from glassy-like to rubbery-like via a semicrystalline-like state. The above results make it clear that CDP plays two major roles as a water absorber and plasticizer in the DNA film. Thus, it can be concluded that the use of an ionic liquid as an additive significantly increases the possibility of using a DNA solid film as a structural material.

中文翻译：

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基于水合离子液体的脱氧核糖核酸固体膜的机械稳定性

通过溶剂浇铸法制备包含水合离子液体磷酸胆碱二氢（CDP）的脱氧核糖核酸（DNA）固体膜。通过热重分析（TG），广角X射线衍射（WAXD）测量，动态力学分析（DMA）和拉伸试验来检查含CDP的DNA膜的热性能，聚集结构，热分子运动和拉伸性能，分别。CDP大大提高了室温下薄膜的保水性。DNA螺旋链的堆积密度显然取决于薄膜中CDP的量。少量的CDP有助于抑制BI→BII构象转变和胶片中DNA双链体的协同运动。在存在CDP的情况下，薄膜的拉伸性能急剧变化。当膜中水合CDP的量增加时，膜的机械响应通过半结晶状从玻璃状变为橡胶状。以上结果清楚表明，CDP在DNA膜中起着吸水剂和增塑剂的两个主要作用。因此，可以得出结论，使用离子液体作为添加剂显着增加了将DNA固体膜用作结构材料的可能性。