In this paper, four natural deep eutectic solvents (NADES) systems were prepared at specific molar ratios, La:Bet (2:1) (lactic acid/betaine), La:Hist (9:1) (lactic acid/histidine), Ma:Bet:H₂O (1:2:3) (malic acid/betaine/water) and Ma:Bet:Pro:H₂O (1:1:1:2) (malic acid/betaine/proline/water). Their physical and thermodynamic properties were studied, namely viscosity, electrical conductivity, and heat capacity. The viscosity and electrical conductivity were determined as a function of temperature and the correlation for the temperature dependence was obtained and discussed based on Arrhenius theory. The heat capacity for all eutectic systems was measured by differential scanning calorimetry (DSC) over a temperature range of 293.15–363.15 K. The ability of these NADES to reduce cellulose crystallinity was evaluated. Cellulose crystallinity after suspension in these NADES was studied by X-ray diffraction. Cellulose suspended in Ma/Bet/H₂O (1:2:3) suffer the highest crystallinity reduction among the systems studied and was about of 20%.

中文翻译：

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乳酸和苹果酸基天然深共晶溶剂的合成及其物理和热力学性质

本文以特定的摩尔比制备了四种天然深共熔溶剂（NADES）系统：La：Bet（2：1）（乳酸/甜菜碱），La：Hist（9：1）（乳酸/组氨酸）， Ma：Bet：H ₂ O（1：2：3）（苹果酸/甜菜碱/水）和Ma：Bet：Pro：H ₂O（1：1：1：2）（苹果酸/甜菜碱/脯氨酸/水）。研究了它们的物理和热力学性质，即粘度，电导率和热容量。确定粘度和电导率随温度的函数，并基于Arrhenius理论获得与温度相关的相关性并进行讨论。通过差示扫描量热法（DSC）在293.15–363.15 K的温度范围内测量了所有共晶体系的热容量。评估了这些NADES降低纤维素结晶度的能力。通过X射线衍射研究了悬浮在这些NADES中的纤维素结晶度。在研究的系统中，悬浮在Ma / Bet / H ₂ O（1：2：3）中的纤维素的结晶度降低最高，约为20％。