疏水改性核壳结构颗粒对Pickering乳液的稳定作用

为了探究固体颗粒对乳液的稳定作用,采用双亲染料分子罗丹明B对核壳结构的Fe_3O_4@SiO_2纳米颗粒进行疏水改性,并将改性后的纳米颗粒作为稳定剂制备Pickering乳液。通过Zeta电位、FTIR、XRD、SEM、接触角测量、光学显微镜、电导率仪对Fe_3O_4@SiO_2纳米颗粒以及Pickering乳液的结构、形貌和性能进行表征与分析,结果表明:制备的纳米颗粒粒径小,约为150 nm,为单分散球形核壳结构;罗丹明B成功修饰到Fe_3O_4@SiO_2纳米颗粒表面,改性后颗粒接触角由30°增加至120°;随乳化剂颗粒质量浓度的增加,制备的乳液液滴的粒径减小。另外,所得Pickering乳液具有良好的磁场响应性,可通过外加磁场实现对乳液稳定性的可逆调控,且此过程可重复3次以上。

Hydrophobic Modification of Core-shell Nanoparticles and Its Stabilizing Effect on Pickering Emulsions

The dye molecule Rhodamine-B was used to hydrophobically modify the core-shell Fe3O4@SiO2 nanoparticles, and the modified nanoparticles were used as stabilizer to prepare Pickering emulsions. The modified Fe3O4@SiO2 nanoparticles and Pickering emulsions were characterized and investigated by Zeta potential, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), contact angle measurement, optical microscope and conductivity measurement. The results showed that the mono-disperse nanoparticles with particle diameter 150 nm were synthesized successfully. Rhodamine-B was successfully modified to the surface of Fe3O4@SiO2 nanoparticles and the contact angle increases from 30? to 120?. And the concentration of emulsifier particles has great effects on the stability of the emulsions. Moreover, the stability of emulsions can be modulated by applying a magnetic field.