|Table of Contents|

[1] Li Jiapeng, Bi Kedong, Chen Yunfei, Chen Min, et al. Molecular dynamics study of viscosity of aqueous NaCl solutionconfined in nanoscale channels [J]. Journal of Southeast University (English Edition), 2011, 27 (3): 257-260. [doi:10.3969/j.issn.1003-7985.2011.03.006]
Copy

Molecular dynamics study of viscosity of aqueous NaCl solutionconfined in nanoscale channels()
纳尺度通道中氯化钠溶液黏度的分子动力学研究
Share：

Journal of Southeast University (English Edition)[ISSN:1003-7985/CN:32-1325/N]

Volumn:
27
Issue:
2011 3
Page:
257-260
Research Field:
Mathematics, Physics, Mechanics
Publishing date:
2011-09-30

Info

Title:
Molecular dynamics study of viscosity of aqueous NaCl solutionconfined in nanoscale channels
纳尺度通道中氯化钠溶液黏度的分子动力学研究
Author(s):
Li Jiapeng1;  Bi Kedong1;  Chen Yunfei1;  2;  Chen Min1;  Wang Zhu1(1 Jiangsu Key Laboratory for Design and Fabrication of Micro-Nano Biomedical Instruments;  Southeast University;  Nanjing 211189;  China)
2 Key Laboratory of MEMS of Educational Ministry, Southeast University, Nanjing 210096, China
李家鹏1;  毕可东1;  陈云飞1;  2;  陈敏1;  王柱1
1东南大学江苏省微纳生物医疗器械设计与制造重点实验室, 南京211189; 2东南大学MEMS教育部重点实验室, 南京210096
Keywords:
nanochannel;  molecular dynamics simulation;  vibrating silicon atom;  shear rate;  viscosity
纳米通道;  分子动力学模拟;  热运动的硅原子;  剪切率;  黏度
PACS:
O351.2
DOI:
10.3969/j.issn.1003-7985.2011.03.006
Abstract:
A physical model of bulk-nanochannel-bulk with buffer baths is built up using nonequilibrium molecular dynamics(MD)simulation to study the effects of vibrating silicon atoms on the viscosity of aqueous NaCl solutions confined in the nanochannel. The simulation is performed under different moving speeds of the upper wall, different heights and different surface charge densities in the nanochannel. The simulation results indicate that with the increase in the surface charge density and the decrease in the nanochannel height and the shear rate, the vibration effect of silicon atoms on the shear viscosity of the confined fluid in the nanochannel cannot be ignored. Compared with still silicon atoms, the vibrating silicon atoms result in the decrease in the viscosity when the height of the nanochannel is less than 0.8 nm and the shear rate is less than 1.0×1011 s-1, and the effect of the vibrating silicon atoms on the shear viscosity is significant when the shear rate is small. This is due to the fact that the vibrating silicon atoms weaken the interactions between the counter-ions(Na+)and the charged surface.
建立一个2侧带有缓冲池的bulk-nanochannel-bulk模型, 采用非平衡态的分子动力学模拟方法研究热运动的硅原子对受限于纳通道中氯化钠溶液黏度的影响.该模拟在不同的通道上板移动速度、通道高度和通道壁面电荷密度的情况下进行.模拟结果表明:随着通道壁面电荷密度的增加、通道高度和剪切率的减小, 热运动的硅原子对受限于纳米通道中流体的剪切黏度有着不可忽视的影响, 当通道高度小于0.8 nm, 剪切率小于1.0×1011s-1时, 热运动的硅原子导致了通道中氯化钠溶液的黏度减小, 并且剪切率越小, 这一现象越明显.这是由于热运动的硅原子减弱了反离子(Na+)和带电的通道壁面之间的相互作用引起的.

References:

[1] Freund J B. Electro-osmosis in a nanometer-scale channel studied by atomistic simulation[J]. J Chem Phys, 2002, 116(5):2194-2200.
[2] Qiao R, Aluru N R. Ion concentrations and velocity profiles in nanochannel electro-osmotic flows[J]. J Chem Phys, 2003, 118(10):4692-4701.
[3] Qiao R, Aluru N R. Charge inversion and flow reversal in a nanochannel electro-osmotic flow[J]. Phys Rev Lett, 2004, 92(19):198301.
[4] Besteman K, Zevenbergen M A G, Lemay S G. Charge inversion by multivalent ions: dependence on dielectric constant and surface-charge density[J]. Phys Rev E, 2005, 72(6): 061501.
[5] Zhu W, Singer S J, Zheng Z, et al. Electro-osmotic flow of a model electrolyte[J]. Phys Rev E, 2005, 71(4):041501.
[6] Greberg H, Kjellander R. Charge inversion in electric double layers and effects of different sizes for counterions and coions[J]. J Chem Phys, 1998, 108(7): 2940-2953.
[7] Urbakh M, Klafter J, Gourdon D, et al. The nonlinear nature of friction[J]. Nature, 2004, 430(6999): 525-528.
[8] Zhu Y X, Granick S. Viscosity of interfacial water[J]. Phys Rev Lett, 2001, 87(9): 096104.
[9] Raviv U, Klein J. Fluidity of bound hydration layers[J]. Science, 2002, 297(5586):1540-1543.
[10] Israelachvili J N. Measurement of the viscosity of liquids in very thin-films[J]. J Colloid Interf Sci, 1986, 110(3):263-271.
[11] Israelachvili J N. Intermolecular and surface forces [M]. 3rd ed. New York: Oxford, 2011:341-380.
[12] Hu H W, Carson G A, Granick S. Relaxation-time of confined liquids under shear[J]. Phys Rev Lett, 1991, 66(21): 2758-2761.
[13] Raviv U, Laurat P, Klein J. Fluidity of water confined to subnanometre films[J]. Nature, 2001, 413(6851):51-54.
[14] Raviv U, Perkin S, Laurat P, et al. Fluidity of water confined down to subnanometer films[J]. Langmuir, 2004, 20(13):5322-5332.
[15] Sakuma H, Otsuki K, Kurihara K. Viscosity and lubricity of aqueous NaCl solution confined between mica surfaces studied by shear resonance measurement[J]. Phys Rev Lett, 2006, 96(4):046104.
[16] Major R C, Houston J E, McGrath M J, et al. Viscous water meniscus under nanoconfinement[J]. Phys Rev Lett, 2006, 96(17):177803.
[17] Li T D, Gao J P, Szoszkiewicz R, et al. Structured and viscous water in subnanometer gaps[J]. Phys Rev B, 2007, 75(11):115415.
[18] Lee S H, Rossky P J. A comparison of the structure and dynamics of liquid water at hydrophobic and hydrophilic surfaces—a molecular-dynamics simulation study[J]. J Chem Phys, 1994, 100(4): 3334-3345.
[19] Sakuma H, Tsuchiya T, Kawamura K, et al. Local behavior of water molecules on brucite, talc, and halite surfaces: a molecular dynamics study[J]. Molecular Simulation, 2004, 30(15):861-871.
[20] Leng Y, Cummings P T. Fluidity of hydration layers nanoconfined between mica surfaces[J]. Phys Rev Lett, 2005, 94(2):026101.
[21] Leng Y S, Cummings P T. Hydration structure of water confined between mica surfaces[J]. J Chem Phys, 2006, 124(7):074711.
[22] Leng Y S, Cummings P T. Shear dynamics of hydration layers[J]. J Chem Phys, 2006, 125(10):104701.
[23] Martini A, Liu Y, Snurr R Q, et al. Molecular dynamics characterization of thin film viscosity for EHL simulation[J]. Tribol Lett, 2006, 21(3): 217-225.
[24] Jorgensen W L, Chandrasekhar J, Madura J D, et al. Comparison of simple potential functions for simulating liquid water[J]. J Chem Phys, 1983, 79(2):926-935.
[25] Miyamoto S, Kollman P A. SETTLE: an analytical version of the SHAKE and RATTLE algorithm for rigid water models[J]. J Comput Chem, 1992, 13(8): 952-962.
[26] Koneshan S, Rasaiah J C, Lynden-Bell R M, et al. Solvent structure, dynamics, and ion mobility in aqueous solutions at 25℃[J]. J Phys Chem B, 1998, 102(21): 4193-4204.
[27] Allen M P, Tildesley D J. Computer simulation of Liquids[M]. New York: Oxford, 1987:152-154.
[28] Yeh I C, Berkowitz M L. Ewald summation for systems with slab geometry[J]. J Chem Phys, 1999, 111(7): 3155-3162.
[29] Berendsen H J C, Postma J P M, Vangunsteren W F, et al.Molecular-dynamics with coupling to an external bath[J]. J Chem Phys, 1984, 81(8): 3684-3690.
[30] Stillinger F H, Weber T A. Computer-simulation of local order in condensed phases of silicon[J]. Phys Rev B, 1985, 31(8): 5262-5271.
[31] Xu D Y, Leng Y S, Chen Y F, et al. Water structures near charged(100)and(111)silicon surfaces[J]. Appl Phys Lett, 2009, 94(20):201901.
[32] Poppe H, Cifuentes A, Kok W T. Theoretical description of the influence of external radial fields on the electroosmotic flow in capillary electrophoresis[J]. Anal Chem, 1996, 68(5): 888-893.

Memo

Memo:
Biographies: Li Jiapeng(1981—), male, graduate; Chen Yunfei(corresponding author), male, doctor, professor, yunfeichen@seu.edu.cn.
Foundation items: The National Basic Research Program of China(973 Program)(No.2006CB300404), the National Natural Science Foundation of China(No.50875047, 50676019), the Natural Science Foundation of Jiangsu Province(No.BK2006510, BK2008201).
Citation: Li Jiapeng, Bi Kedong, Chen Yunfei, et al. Molecular dynamics study of viscosity of aqueous NaCl solution confined in nanoscale channels. [J].Journal of Southeast University(English Edition), 2011, 27(3):257-260.[doi:10.3969/j.issn.1003-7985.2011.03.006]
Last Update: 2011-09-20