Pore size effect on proton transfer in sol-gel porous silica glasses
Pore size effect on proton transfer in sol-gel porous silica glasses
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DOI：
10.1016/j.micromeso.2004.02.005
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发表时间：
2004-04
影响因子：
5.2
通讯作者：
Y. Daiko;T. Kasuga;M. Nogami
中科院分区：
文献类型：
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作者：
Y. Daiko;T. Kasuga;M. Nogami
利用溶胶-凝胶衍生的多孔硅玻璃研究了质子在纳米孔中的转移。采用溶胶-凝胶法制备了孔径为2 ~ 25nm的玻璃，并通过测量其电导率、电模量和扩散系数，讨论了吸附在孔隙中的水分子对质子的传导。在孔径大于~ 15 nm的多孔玻璃中，孔隙没有被水分子填充，导致质子传导降低。随着孔隙尺寸的减小，孔隙中充满了物理结合的水分子，形成了质子传导的通道。另一方面，在小于~ 2 nm的孔隙中，大部分吸附的水被化学束缚，限制了质子的跳跃。结果表明，孔径为~ 4nm的玻璃更适合作为快质子导电玻璃。
The proton transfer in nanopores was investigated using the sol–gel-derived porous silica glasses. The glasses with the pore size of 2–25 nm in diameter were prepared using the sol–gel method and the proton conduction through water molecules adsorbed in pores was discussed by the measurement of the conductivity, electrical modulus, and diffusion coefficient. In the porous glasses with pores larger than ∼15 nm, the pores are not filled with the water molecules, resulting into the decreased proton conduction. As the pore size decreases, the pores are filled with the physically bonded water molecules, which act to form the pass way of proton conduction. On the other hand, in the pores smaller than ∼2 nm, much of the adsorbed water is chemically bound and restricts the proton hopping. It was found that the glass having pores ∼4 nm diameter is more appropriate for the fast-proton-conducting glasses.