泡沫是热力学不稳定体系，纳米粒子的加入可显著提高泡沫稳定性。然而，均质纳米粒子表面活性低，加入后使强泡沫的生成需要更高的剪切率或更低的多孔介质渗透率。鉴于泡沫在多孔介质中的传输是液膜不断破灭、再生的过程，如何改善强泡沫的生成能力是值得研究的课题。双面神纳米粒子活性高，在降低表面张力的同时可增大表面扩张模量；磁性纳米粒子在磁场作用下可实现转向。上述两类纳米粒子在改善泡沫生成能力方面有巨大的潜力。课题拟将改善纳米粒子的表面活性和外加磁场作用下使粗泡沫转向两思路相结合，合成磁性双面神纳米粒子。设计单连通孔喉模型、分叉模型研究磁性双面神纳米粒子对卡断和液膜分离的影响，并建立表面扩张流变性质对泡沫流动阻力的贡献关系。在此基础上，研究磁场作用下磁性双面神纳米粒子使粗泡沫转向和利用渗透率低的垂向孔隙作为生泡介质的效果，从而揭示磁性双面神纳米粒子改善多孔介质中强泡沫生成能力的机制。

Foam is a thermodynamically metastable system. It is reported that the foam stability can be substantially enhanced by adding nanoparticles. However, uniform nanoparticles have low surface activity. When adding nanoparticles to foaming agents, generation of strong foam needs higher shear rates or lower permeability. Since lamella can be destructed and regenerated continuously during foam flow and transport in porous media, how to improve foam generation ability in porous media needs to be investigated. Janus nanoparticles have high surface activity. They can not only decrease surface tension but also increase surface dilatational modulus. Magnetic nanoparticles can turn to another direction under the action of magnetic field. These two nanoparticles have great potential in improving foam generation ability. The magnetic-Janus nanoparticles are expected to be developed by the combination of improving nanoparticles’ surface activity and turning coarse foam under magnetic field. The mechanism of snap off and lamella division will be investigated on the in-house designed singly connected pore throat model and branched model and expression of surface dilatational properties to foam flow resistance will be established. On this basis, effect of magnetic-Janus nanoparticles on turning coarse foam and foam generated by vertical pore will be studied under magnetic field, and consequently, the effects of magnetic-Janus nanoparticles on foam generation in porous media will be elucidated.