聚合物分散剂对纳米TiO_2水悬浮液分散稳定性的影响

纳米TiO2复合乳胶漆的制备一般要求预先分散纳米TiO2并制成水悬浮液。为了制备稳定分散的纳米TiO2水悬浮液,研究了乳胶漆中常用的分散剂SN5040和PEG对纳米TiO2在水溶液中分散稳定性的影响,并分析了分散剂的作用机理。实验结果表明:SN5040能有效分散纳米TiO2,按照先SN5040后PEG的方式添加一定比例的混合分散剂,PEG能在SN5040吸附层上嵌入式吸附,显著提高了纳米TiO2的Zeta电位值,更有利于纳米TiO2水悬浮液的分散稳定性。红外光谱分析(FT-IR)表明:SN5040主要是通过与表面裸露的Ti4+形成配位键而吸附到纳米TiO2粒子表面上的。

Influence of Polymer Dispersants on Dispersion Stability of Nano-sized TiO2 Aqueous Suspension

Pre-dispersed nano-sized TiO2 aqueous suspension is requiredduring the preparation of nano-composite latex paints. The effects ofSN5040 and PEG that are commonly used in latex paints for dispers-ants on dispersion stability were studied and the dispersion mechanismswere also discussed for new highly-stable nano-sized TiO2 aqueoussuspension. The results showed that SN5040 was an effective dispers-ant for TiO2 in suspension. The suspension in the combined presenceof SN5040 and PEG was more stable in the case of adding SN5040 firstand then PEG. PEG can implant the intervals of pre-adsorbed SN5040layer on the TiO2 surface. This increases the Zeta potential of TiO2particles remarkably. FT-IR experiments confirmed that SN5040 wasadsorbed onto the TiO2 surface by complexation with the naked Ti4+ .