HNS溶解度与介稳区的光流控测定方法研究

Measuring Method of Solubility and Metastable Zone of HNS Based on Optofluidics

为了获得炸药晶体的溶解度、介稳区宽度等结晶热力学参数,提出了一种基于光流控的炸药结晶热力学参数的测定方法,并以六硝基茋(HNS)炸药为样本验证了该种方法的适用性。以5 K为步长,测定了HNS自318.15 K至353.15 K,在体积比为10∶0,7∶3,5∶5,3∶7,0∶10的DMSO/DMF溶剂体系下的溶解度及HNS在以上DMSO/DMF溶剂体系,318.15 K至333.15 K下的介稳区宽度。采用Apelblat模型、λh模型对收集到的溶解度数据进行拟合,研究了溶剂体系对介稳区宽度的影响,并对结晶参数进行了筛选。根据经典成核理论计算了HNS的表观成核级数m,并对HNS的降温结晶成核机理进行了分析。结果表明,基于光流控的结晶热力学参数测定方法对HNS晶体有着很好的适用性。随着温度的升高与体系内DMSO体积比例的增加,HNS的溶解度增大。随着体系内DMSO体积比例的增加,介稳区宽度变窄。得到最佳结晶条件:以纯DMSO作为溶剂,溶液温度设置为333.15 K,溶质浓度为0.029 g·mL-1。m的值约为4,受起始温度的影响不大,可以推测HNS的成核机制属于连续成核。

A measurement method of explosive crystallization thermodynamic parameters based on optofluidics was proposed to obtain the crystallization thermodynamic parameters such as solubility and metastable zone width of explosive crystal,and the applicability of this method was verified by taking HNS explosive as a sample.The solubility of HNS in DMSO/DMF solvent system with volume ratio of 10∶0,7∶3,5∶5,3∶7 and 0∶10 from 318.15 to 353.15 K and the metastable zone width of HNS in the above DMSO/DMF solvent system from 318.15 to 333.15 K were measured with a step of 5 K.Apelblat model andλh model were employed to fit the collected solubility data.The effect of solvent system on the metastable zone width was studied,and the crystallization parameters were screened.According to the classical nucleation theory,the apparent nucleation order m of HNS was calculated,and the nucleation mechanism of HNS by cooling crystallization was analyzed.The results indicate that the measurement method of crystallization thermodynamic parameters based on optofluidics exhibit exceptional applicability to HNS crystals.With the increase of temperature and the volume ratio of DMSO in the system,the solubility of HNS increases.With the increase of DMSO volume ratio in the system,the width of metastable zone becomes narrower.The optimum crystallization conditions are as follows:pure DMSO is utilized as solvent,the solution temperature is set at 333.15 K,and the solute concentration is 0.029 g·mL-1.The value of m is approximately 4,which is not affected by the initial temperature.It can be inferred that the nucleation mechanism of HNS belongs to continuous nucleation.