Polyvinylpyrrolidone macromolecules function as a diffusion barrier during dealloying
Polyvinylpyrrolidone macromolecules function as a diffusion barrier during dealloying
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DOI：
10.1016/j.matchemphys.2014.03.022
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发表时间：
2014-08-14
影响因子：
4.6
通讯作者：
Hara, Nobuyoshi
中科院分区：
文献类型：
--
作者：
Dan, Zhenhua;Qin, Fengxiang;Hara, Nobuyoshi
研究了脱合金化过程中聚乙烯吡咯烷酮(PVP)对Ti60Cu40非晶态合金在氢氟酸(HF)中形成纳米孔铜的抑制作用。Ti60Cu40脱合金化后在Ti60Cu40表面形成了双连续的纳米多孔铜结构。在0.03M氢氟酸溶液中加入0.01M和0.03M的PVP，在相同的脱合金化时间43.2k后，纳米孔铜的孔径分别减小到12 nm和11 nm。表面扩散系数由0.03M氟化氢溶液中的2.5×10~(-18)m~(-2)S(-1)降至1.84×10~(-21)m~(-2)S(~(-1))，加入0.03M PVP时降至1.42×10~(-21)m~(-2)m~(-1)。在0.03M的HF溶液中加入0.03M的PVP，比在0.01M的溶液中吸附了更多的PVP大分子，从而形成了较小的纳米孔。由于PVP大分子抑制了铜原子的扩散，形成了比在0.03M HF溶液中形成的更细小的铜韧带。这种长链有机分子在脱合金过程中对金属吸附原子的扩散起到了扩散屏障的作用，并形成了纳米孔结构。(C)2014爱思唯尔B.V.保留所有权利。
The inhibition effect of polyvinylprrolidone (PVP) during dealloying on the formation of nanoporous Cu from a Ti60Cu40 amorphous alloy in hydrofluoric acids (HF) was investigated. A bicontinuous nanoporous Cu structure formed on Ti60Cu40 after dealloying. The pore size of nanoporous Cu formed in HF solution was 71 nm, but this decreased to 12 nm and 11 nm after dealloying for the same period of dealloying time of 43.2 ks when 0.01 M and 0.03 M PVP, respectively, was added into the 0.03 M HF base solution. The surface diffusivity was estimated to decrease from 2.5 x 10(-18) m(2) s(-1) in 0.03 M HF solution to 1.84 x 10(-21) m(2) s(-1) when 0.01 M PVP was added, and to 1.42 x 10(-21) m(2) s(-1) when 0.03 M PVP was added. More PVP macromolecules were adsorbed onto the nanoporous Cu surface in the 0.03 M HF solution with the addition of 0.03 M PVP than when 0.01 M PVP was added to the solution, which resulted in the formation of smaller nanopores. The suppressed diffusion of Cu adatoms due to the PVP macromolecule resulted in the formation of finer Cu ligaments than that formed in 0.03 M HF solution. This long chain organic molecule was shown to act as a diffusion barrier for the diffusion of metal adatoms during dealloying and to elaborate the nanoporous structure. (C) 2014 Elsevier B.V. All rights reserved.