摘要
采用色散校正的密度泛函方法、分子动力学和Monte Carlo模拟技术,对乙酸乙酯(EA)与六硝基六氮杂异戊兹烷(ε-CL-20)晶面的微观作用机制进行研究,分析了晶面特性和EA与各晶面的相互作用。结果表明,附着能模型预测真空中ε-CL-20有6个晶面,其表面积(101)>(11-1)>(110)>(10-1)>(011)>(002),粗糙度(10-1)>(11-1)>(011)>(101)>(110)>(002)。带隙最大的两个晶面为(002)(3.522eV)和(101)(3.512eV),而(110)(3.179eV)和(11-1)(3.193eV)的带隙最小。EA分子通过C—H…O弱氢键、范德华力等相互作用与ε-CL-20晶面上的活性位点结合。正的吸附热和负的吸附能表明EA分子在所有晶面上的吸附均为放热过程。EA分子通过(11-1)面上的袋状空隙进入晶格,形成最厚的界面溶剂层(约10A)和最大的结合能(291.93kJ/mol)。该晶面吸附EA分子的个数和吸附能的绝对值(86.36kJ/mol)均最大,等量吸附热最小(70.99kJ/mol)。而EA分子只能吸附在(002)平坦的表面上,形成最薄的界面溶剂层(约4A)和最小的结合能(133.11kJ/mol)。该晶面吸附EA分子的个数和吸附能的绝对值(72.21kJ/mol)均最低,而等量吸附热最大(80.29kJ/mol),其他4个晶面介于这两个晶面之间。
By using density functional theory with dispersion correction,molecular dynamics and Monte Carlo simulation methods,the microscopic interaction mechanism of ethyl acetate(EA)and crystal faces of hexanitrohexaazaisowurtzitane(ε-CL-20)were studied.The order of the surface area of predicted sixε-CL-20 crystal faces based on attachment energy model is(002)>(011)>(10-1)>(110)>(11-1)>(101),and the order of the roughness of above crystal faces is(10-1)>(11-1)>(011)>(101)>(110)>(002).The(002)(3.522 eV)and(101)(3.512 eV)faces have the largest band gap,while the(110)(3.179 eV)and(11-1)(3.193 eV)faces have the smallest band gap.EA molecules integrate with the active sites ofε-CL-20 crystal faces by C—H…O weak hydrogen bonds and van der Waals forces,etc.The positive adsorption heat and negative adsorption energy suggest that the adsorption on all habit facets ofε-CL-20 is exothermic process.On the(11-1)face,the periodic arrangement of bag-shaped voids forms adsorption channel,by which EA molecules enter lattice to obtain the thickest interfacial solvent layer(around 10A)and the greatest binding energy(291.93 kJ/mol).Meanwhile,the saturation adsorption capacity and absolute value of adsorption energy(86.36 kJ/mol)are maximum along with minimum isosteric adsorption heat(70.99 kJ/mol)for(11-1)face.On the other hand,EA molecules can only adsorb on smooth surface of(002)face and give the thinnest interfacial solvent layer(above 4A)and the lowest binding energy(133.11 kJ/mol).Both the saturation adsorption capacity and solute value of adsorption energy(72.21 kJ/mol)are minimum,while the isosteric adsorption heat(80.29 kJ/mol)is the greatest.The interactions of EA with other four habit facets fall between these two habit facets.
作者
游婷
谢五喜
廖奕玫
陈伶媛
段晓惠
YOU Ting;XIE Wu-xi;LIAO Yi-mei;CHEN Ling-yuan;DUAN Xiao-hui(State Key Laboratory of Environment-friendly Energy Materials,Southwest University of Science and Technology,Mianyang Sichuan 621010,China;Xi'an Modern Chemistry Research Institute,Xi'an 710065,China)
出处
《火炸药学报》
EI
CAS
CSCD
北大核心
2022年第5期688-696,共9页
Chinese Journal of Explosives & Propellants
基金
国家自然科学基金(No.22075230)。
