CAJ | 학술논문

采用分子动力学方法对不同温度(25-120°C)及碱浓度(1：100-1：5,摩尔比)下NaOH和KOH溶液中的氧气进行了模拟。本文考察了NaOH及KOH溶液中溶剂-溶剂、氧气-溶剂及氧气-溶质的径向分布函数,并采用爱因斯坦方程从均方位移曲线中计算得到了氧气及溶质离子的扩散系数。结果显示随着碱浓度的升高,氧气扩散系数逐渐减少；在相同条件下,氧气在NaOH溶液中扩散系数小于在KOH溶液中的扩散系数；溶质离子扩散系数的变化规律与氧气一致。通过与现有实验结果对比,发现了分子动力学方法的可靠性及用于研究实验受限领域的优越性。
채용분자동역학방법대불동온도(25-120°C)급감농도(1：100-1：5,마이비)하NaOH화KOH용액중적양기진행료모의。본문고찰료NaOH급KOH용액중용제-용제、양기-용제급양기-용질적경향분포함수,병채용애인사탄방정종균방위이곡선중계산득도료양기급용질리자적확산계수。결과현시수착감농도적승고,양기확산계수축점감소；재상동조건하,양기재NaOH용액중확산계수소우재KOH용액중적확산계수；용질리자확산계수적변화규률여양기일치。통과여현유실험결과대비,발현료분자동역학방법적가고성급용우연구실험수한영역적우월성。
Molecular dynamics simulations of oxygen molecules in NaOH and KOH solutions at different temperatures (25-120 ° C) and concentrations (1:100-1:5, molar ratios) were performed in this study. The interactions of oxygen molecules with the surrounding solvent and solute were clarified by considering the solvent-solvent, oxygen-solvent, and oxygen-solute radial distribution functions. The self-diffusion coefficients of the oxygen molecules and the solute were both determined by analyzing the mean-squared displacement (MSD) curves, using Einstein's relationship. It was concluded that at al concentrations, the diffusion coefficient of oxygen in NaOH solution is smal er than that in the corresponding KOH solution. The diffusion coefficients for hydroxide, Na+, and K+decrease with increasing solute concentration, fol owing similar trends to those of oxygen. The oxygen diffusion coefficient obtained in this study is in good agreement with the reported experimental value, suggesting that MSD is an attractive approach to study the oxygen diffusion behavior in strong alkaline solutions at elevated temperatures, which are experimentally extremely chal enging.