Antigravity confined interfacial self-assembly approach for the synthesis and characterization of nanofilms.

Gravitationally induced stratification during self-assembly often leads to density-driven vertical segregation, resulting in an inherent density gradient that severely limits the synthesis of metastable nanofilms requiring inverted architectures. Here we show an antigravity confined interfacial self-assembly approach based on a liquid-liquid interface formed between hydrophilic and hydrophobic porous membranes, where capillary forces suppress gravitational effects to enable precise molecular organization. Experimental data, supported by quantum chemistry, density functional theory, and Fick's first law, demonstrate that capillary forces enhance local concentration and interaction probability, yielding highly ordered, stable nanofilms. Our approach achieves a 17-fold increase in film area than gravity-limited methods and a 109-fold improvement over unconfined techniques. These nanofilms exhibit the stability and mechanical property, showing promise for green enhanced oil recovery and multifunctional material development. Furthermore, our strategy offers a paradigm for nanofilm mechanical characterization, paving the way for future advances in the design and application of nanomaterials.