本篇以分子動力模擬的方法研究離子液體1-alkyl-3-methy-limidazolium tetrafluoroborate之烷基鏈長及濃度的改變對於離子液體/PC混合系統之導電性之影響。此外也探討當濃度固定時，1-ethyl-3-methy-limidazolium tetrafluoroborate (EMIBF4)分別與溶劑AN、GBL、PC混合後導電性之差異。
　　模擬結果顯示，當濃度固定，但imidazolium環之烷基鏈長增加時，離子擴散係數與比導電度隨之下降，這是因為溶液之介電常數遞減且陽離子之體積遞增所致。烷基鏈長的增加也使得imidazolium環周圍之BF4-離子配位數下降，且游離態之陽離子比率升高。隨著融鹽含量的增加，擴散係數、比導電度與自由離子機率也隨之下降，這是由於能進入陽離子周圍第一配位殼層之PC分子數較少所致。
　　2.8 M EMIBF4/溶劑系統中，EMI+離子周圍第一殼層內BF4-之配位數，以溶劑為AN時最大(4.55)，PC時最小(3.31)。在AN中，EMI+與較多的BF4-配位，使得離子結合較嚴重，故自由離子之比率三種溶劑中最低(約0.30)。

　　Molecular dynamics simulation method has been used to study the influence of the chain length of the alkyl group in 1-alkyl-3-methylimidazolium
tetrafluoroborate and its concentration on the ionic conductivities of ionic liquid/PC mixed system. Moreover, the difference in the conductivity for 1-ethtyl-3-methy-limidazolium tetrafluoroborate EMIBF4/solvent (AN、GBL and PC) at 2.8 M was also investigated.
　　The result shows that at the same concentration, the ionic diffusion coefficients and the specific conductivity decrease with the increase of the chain length of the alkyl group. This is due to the decrease of the dielectric constant of solution and the increment of the molecular volume of cations. It also decreases the number of coordinating BF4- ions around imidazolium ring and increase the fraction of the free cations. As the content of ion liquid increases, the ionic diffusion coefficients、specific conductivity and the free ion probability decrease, which is ascribable to the less PC molecules into the first coordination sphere of cation.
　　At 2.8 M EMIBF4/solvent system, the number of BF4- ions around the first coordination sphere of EMI+ is the largest for AN(4.55), but the smallest for PC (3.31). In AN, more BF4- anions coordinate with EMI+, therefore the ionic association is much more severe, giving the lowest fraction of free ions(about 0.30) among three solvent systems.

1.Walden, P. Bull. Acad. Imper. Sci. (St. Petersburg), 1914, 1800-1808.
2.Wilkes, J. S.; Levisky, J. A.; Wilson, R. A.; Hussey, C. L. Inorg. Chem., 1982, 21, 1263-1264.
3.Wilkes, J. S.; Zaworotko, M. J.; J. Chem. Soc., Chem. Commun., 1912,965,
4.Hesse, H.; Meier, M.; Zeeh. B.; Spektroskopische Methoden in der organischen Chemie, 2nd ed., 1984.
5.Bonhôte, P.; Dias, A.-P.; Papageogiou, N.; Kalyanasundaram, K.; and Grätzel, M.; Inorg. Chem., 1996, 35, 1168.
6.Huang, J. F.; Chen, P. Y.; Sun, I. W. and Wang, S. P.; Inorg. Chim. Acta, 2001, 320, 7.
7.McEwen, A. B.; McDevitt, S. F.; andKoch, V. R.; J. Electrochem. Soc., 1997, 144, L84.
8.Nishida, T.; Tashiro Y.; and Yamamoto, M.; J. Fluorine. Chem. 2003,120,135
9.“Discover User Guide”, version 4.0. San Diego: Biosym Technologies, 1996.
10.Theodoroa, D. N.; Suter, U. W. Macromolecules, 1985, 18, 1206-1214.
11.Bsskir, J. N.; Suter, U. W. Macromolecules, 1988, 21, 1877-1878.
12.Iglesias, T. P.; Fernández, J. P. J. Chem. Thermodynamics, 2001, 33, 1375-1381.
13.Fricke, H. J. Phys. Chem., 1953, 57, 934-937.
14.Zimm, B. H.; Lundberg, J. L. J. Phys. Chem., 1956, 60, 425-428.
15.Lundberg, J. L. J. Macromol. Sci., 1969, B3, 693.
16.Sergio, M. U. and M. C. C. Ribeiro J. Chem. Phys. 2005, 122, 24511
17.王鴻益，國立成功大學化學研究所碩士論文，2003
18.劉詩潔，國立成功大學化學研究所碩士論文，2004