Dispersion of ZnO Nanoparticles in Aqueous Solutions Using Polyvinylamine as the Dispersant

以聚乙烯胺為分散劑在水溶液中分散氧化鋅奈米粒子

韓妮可(Nanik Hendrawati) ； 侯聖澍(Sheng-Shu Hou)

《界面科學會誌》 30卷1~4期 (2008/07) Pp. 62-71

https://doi.org/10.30020/JCCIS.200807.0007

摘要

如何製備穩定的無機奈米粒子分散水溶液一直是奈米技術的重要研究課題之一。在此研究中，我們利用聚乙烯胺做為分散劑，成功地製備穩定的奈米氧化鋅分散水溶液。我們利用靜置沉澱測試與光吸收法來評估聚乙烯胺的分散效能，並利用zeta potential來研究聚乙烯胺對於奈米氧化鋅粒子表面電位的影響。在未添加聚乙烯胺時，水溶液中的奈米氧化鋅粒子的表面電位偏低，造成奈米氧化鋅粒子會在數小時內明顯地聚集成大小約為2到3微米顆粒，並且快速地沉澱於底部而造成分相。然而，在添加聚乙烯胺做為分散劑時，奈米氧化鋅粒子的表面電位會大於+30 mV，甚至可以高達+70 mV；因此，奈米氧化鋅可以穩定地被分散在水溶液中。我們發現奈米氧化鋅水溶液的分散穩定性與水溶液的pH值有關，當水溶液的pH值介於3到7時，可以得到最穩定的奈米氧化鋅分散水溶液。

關鍵字

乙烯胺 ； 氧化鋅 ； 奈米粒子 ； 分散

並列摘要

Dispersion of inorganic solids, such as ZnO nanoparticles, at nanoscale in aqueous suspension is one of the important issues in nanotechnological processes. In this study, we have prepared the nano- ZnO aqueous suspensions using polyvinylamine (PVAm) as the dispersant. The dispersion efficiency was evaluated by the sedimentation test and the optical absorption intensity of the dispersion solution. The zeta potential measurement was used to study the effect of PVAm on the surface chargaes of ZnO nanoparticles. In the absence of PVAm, ZnO nanoparticles in water precipitate very quickly in several hours, resulting in large ZnO macro-aggregates in the size of 2 ~ 3 μm. This is because that ZnO nanoparticles do not carry enough surface charges. By introduction of PVAm into suspension as the dispersant, the stability of nano-ZnO aqueous suspensions increases significantly, and it could be evidenced by the small amount of precipitation for several days. In the presence of polymer, the zeta potentials of ZnO nanoparticles exceeds + 30 mV and can be up to + 70 mV. Additionally, the stability of nano-ZnO aqueous suspensions closely relates to the pH of suspension, and the most stable suspension occurs at pH = 7 to 11.

並列關鍵字

Polyvinylamine ； zinc oxide ； nanoparticles ； dispersion