摘要
纳米流控系统的能量吸收密度远高于传统吸能材料,构建具有梯级蓄能特性的纳米流控系统,可同时实现不同品级能量的吸收,使其应用更广泛.本文采用碳纳米管构建双管不同径及单管变径2种梯级孔道模型,研究了水分子侵入2种不同梯级孔道模型的过程,获得了使纳米流控系统形成梯级蓄能特性的临界孔径差.结果表明,当水分子侵入小孔径的渗透压小于其填满大孔径的渗透压时,纳米流控系统不展现梯级蓄能特性.多级孔道结构的变径方式影响系统各级临界渗透压,继而影响其梯级蓄能特性.单管变径纳米流控系统中,由于水分子在侵入底管的过程中氢键数目减少,顶管临界渗透压低于相应孔径的单级系统临界渗透压.本文研究结果可为构建碳纳米管多级纳米流控系统提供指导,为渗入研究多级纳米流控系统奠定基础.
Nanofluidic energy absorption system(NEAS)is kind of energy absorption/conversion system construct of nano porous material and functional liquid.Because of the huge surface area of nano porous material,the energy absorption density of NEAS is much higher than that of traditional energy absorbing materials.The multistage nanofluidic energy absorption system(MNEAS)with cascade energy absorption characteristics can absorb energy of different grade,which has wider application.In this paper,carbon nanotubes were used to construct models of MNEAS.To consider the influence of channel structure on the cascade energy absorption characteristic,two kinds of NEAS models are constructed.One system is of two carbon tubes with one end of both immersed in the pool,namely DNEAS.The other is of two carbon tubes laid on top of each other with only one end of the big one submerged in the pool,namely SNEAS.The processes of water molecules infiltrating into two kinds of MNEAS models were studied.The pressure-volume characteristic curves of DNEAS and SNEAS indicated that,NEASs with combinations of tubes with different diameter sometimes show cascade characteristics,while sometimes does not.Further study found that,when the critical infiltration pressure of water molecules infiltrating small tube is lower than that of water molecules filling the big tube,NEAS does not exhibit cascade characteristic.In DNEAS,the processes of water molecules infiltrating the big tube and the small tube are independent.The critical infiltration pressure of each level corresponds to the critical infiltration pressure of the corresponding single stage NEAS.The pressure-volume characteristic curve is a linear superposition of the pressure-volume characteristic curves of the corresponding single stage NEAS.In SNEAS,water molecules first fill the bottom tube and then infiltrate the top tube.During the process of invading the bottom tube,water molecules may lose some hydrogen bonds,thus the critical infiltration pressure of top tube is affected by the diameter of the bottom tube,and smaller than that of the single stage NEAS.The critical aperture differenceΔd_(cr)is defined as the minimum difference of tube diameters which enables the system to exhibit cascade characteristic.By distinguishing between all conditions with or without cascade characteristic,the correlation formula of the critical aperture difference under two models are obtained.In the case of DNEAS,Δd~D_(cr)is 0.136 nm when d_(big)≤1.898 nm and 0.272 nm when 1.898 nmd_(big)≤2.17 nm.For SNEAS,Δd~S_(cr)=0.136 nm when d_(bottom)≤1.898 nm,andΔd~S_(cr)=(0.75d_(bottom)-1.483)nm when 1.898 nmd_(bottom)≤2.17 nm.The results of this study can provide guidance for the construction of multistage nanofluidic energy absorption system and lay a foundation for infiltration research for it.
作者
章娅菲
肖洪玖
刘慎磊
桑鹏飞
窦益华
ZHANG Ya-feil;XIAO Hong-ju;LIU Shen-lei;SANG Peng-fei;DOU Yi-hua(Mechnical Engineering College,Xi'an ShiyouUniversity,Xi'an 710065,China;Xian Key Laboratory of Wellbore Integrity Evaluation,Xi'an 710065,China;Petrochina Southwest Oil and Gas Field Company Engineering Technology Research Institute,Chengdu 610000,China)
出处
《分子科学学报》
CAS
北大核心
2023年第4期327-335,共9页
Journal of Molecular Science
基金
国家自然科学基金资助项目(51974246,51806173)
陕西省教育厅青年创新团队建设科研计划项目(21JP096)
陕西省人才推进计划-青年科技新星项目(2021KJXX-40)。
关键词
多级纳米流控系统
梯级蓄能
碳纳米管
临界孔径差
临界渗透压
multistage nanofluidic energy absorption system
cascade energy absorption
carbon nanotubes
critical aperture difference
critical infiltration pressure
