| 修饰离子聚合度对膜-颗粒体系静电自组装的影响 |
| Influence of Polymerization of Decorated Poly-ions on Electro-statically Self-assembled Nano-particles Coated Membrane |
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| 摘要: 采用不同聚合度的季铵阳离子聚合物作为修饰离子,对纳米Pt颗粒的合成及其在全氟磺酸膜(Ｎａｆｉｏｎ)上的静电自组装行为进行了研究,结合Ｎａｆｉｏｎ膜电导率的变化对膜-颗粒自组装机理进行了分析。结果表明:自组装过程中Ｎａｆｉｏｎ膜电导率的下降总是比Pt组装量的上升先达到平衡,表明膜-颗粒体系(MPS)的静电自组装是一个先由大量的小阳离子占据空位,然后由离子修饰的大颗粒(纳米Pt)取代的过程；改变修饰离子的聚合度同时会引起组装液中游离修饰离子的数目的变化,从而对电导率的衰减速度和组装第二阶段的脱附-组装平衡造成影响,因此随着修饰离子聚合度的增加,导电率达到平衡的时间增加,组装量达到平衡的时间减少。 |
| 关键词: 静电自组装 Ｎａｆｉｏｎ膜 修饰离子 聚合度 |
| 基金项目: |
| Abstract: Pt nano-particles decorated with NR4+ were synthesized with chemical reduction. With the presence of Proton-conduct Nafion membranes,the charged Pt particles were self-assembled on Nafion surface due to electrostatic force,and the comparison of exchanged ions to the assembled Pt content were used for exploring the electrostatic self-assembly mechanism.At the same time,PDDA with different polymerization were employed in the particles fabrication and self-assembly.It is found that the assembly procedure can be divided into two ｓｅｇｍｅｎｔｓ: ｔｈｅ ｓｍａｌｌ ｃａｔｉｏｎｓ ｗｉｌｌ ｐｏｓｓｅｓｓ ｔｈｅ -SO3－ ａｎｉｏｎ ｇｒｏｕｐｓ ｄｕｅ ｔｏ ｔｈｅ ｒａｐｉｄ ｔｈｅｒｍａｌ ｖｅｌｏｃｉｔｙ ｏｎ ｔｈｅ ｆｉｒｓｔ ｓｔｅｐ, ｔｈｅｎ ｔｈｅ ｓｍａｌｌ ｃａｔｉｏｎｓ ｗｉｌｌ ｂｅ ｒｅｐｌａｃｅｄ ｂｙ ｃｈａｒｇｅｄ Pt ｐａｒｔｉｃｌｅｓ ｄｕｒｉｎｇ ｔｈｅ ｐｒｏｌｏｎｇｅｄ ａｓｓｅｍｂｌｙ-ｄｅｓｏｒｐｔｉｏｎ ｄｙｎａｍｉｃ ｂａｌａｎｃｅ． Tｈｅ ｄｉｓｐｅｒｓｅ ｃａｐａｃｉｔｙ ｏｆ PDDA ｗｉｔｈ ｄｉｆｆｅｒｅｎｔ ｐｏｌｙｍｅｒｉｚａｔｉｏｎ ａｒｅ ｃｈａｎｇｅｄ ａｓ ａ ｒｅｓｕｌｔ ｏｆ ｔｈｅ ｄｉｆｆｅｒｅｎｔ ｓｔｅｒｉｃ ｅｆｆｅｃｔ ａｎｄ ｅｌｅｃｔｒｏｓｔａｔｉｃ ｅｆｆｅｃｔ, ａｎｄ ｔｈｅ ｌｅｓｓｅｒ ｐｏｌｙｍｅｒｉｚａｔｉｏｎ ｗｅｒｅ ｕｓｅｆｕｌ ｆｏｒ ｓｙｎｔｈｅｓｉｓ Pt ｐａｒｔｉｃｌｅｓ ｗｉｔｈ ｍｏｒｅ ｅｘｐｏｓｅｄ ｓｕｒｆａｃｅ ａｔｏｍｓ． Tｈｅｎ PDDA ｗｉｔｈ ｌｅｓｓｅｒ ｐｏｌｙｍｅｒｉｚａｔｉｏｎ ｗａｓ ｕｓｅｄ, ｔｈｅ ａｓｓｅｍｂｌｉｎｇ ｔｉｍｅ ｗｉｌｌ ｂｅ ｐｒｏｌｏｎｇｅｄ, ｈｏｗｅｖｅｒ, ｔｈｅ ｃｏｎｄｕｃｔｉｖｉｔｙ ｗｉｌｌ ｒｅａｃｈ ｔｈｅ ｂａｌａｎｃｅ ｍｏｒｅ ｒａｐｉｄｌｙ． Ａｓ ｔｈｅ ｒｅｓｕｌｔ, ｔｈｅ ｏｂｔａｉｎｅｄ Ｎａｆｉｏｎ ｍｅｍｂｒａｎｅｓ ｃｏａｔｅｄ ｗｉｔｈ ｈｏｍｏ-ｄｉｓｐｅｒｓｅｄ ｎａｎｏ-ｐａｒｔｉｃｌｅｓ ｈａｖｅ ａ ｐｒｏｍｉｓｅｄ ａｐｐｌｉｃａｔｉｏｎ ａｓ ｍｅｍｂｒａｎｅ ｅｌｅｃｔｒｏ-ｃａｔａｌｙｓｔ ａｓｓｅｍｂｌｅ (ＭＥＡ) ｉｎ ｐｒｏｔｏｎ ｅｘｃｈａｎｇｅ ｍｅｍｂｒａｎｅ (PEM) ｆｕｅｌ ｃｅｌｌ． |
| Keywords: electrostatic self-assembly Nafion membrane decorating ion polymerizadtion |
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| 唐浩林,潘 牧,木士春,袁润章.修饰离子聚合度对膜-颗粒体系静电自组装的影响[J].无机化学学报,2004,20(2):128-132. |
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