We present an interfacial assembly strategy for constructing asymmetric multilayered colloidal fi lms through lateral compression

of laterally segregated particle microdomains at the air–water interface. These microdomains—composed of polystyrene

(PS) and silica (SiO 2 ) particles—serve as lateral templates that direct vertical rearrangement during monolayer collapse.

Utilizing hydrophilic PS and SiO 2 particles with distinct interfacial adsorption affi nities, we demonstrate that depletion interactions

and compression-induced instabilities induce domain-selective subduction, a process in which one type of particle

domain is driven beneath another. Specifi cally, more hydrophilic silica domains preferentially collapse and subduct beneath

less hydrophilic PS domains, resulting in pronounced vertical asymmetry concentrated at the domain boundaries. Langmuir

isotherm analysis and SEM imaging reveal that both the lateral extent of domain segregation and the vertical thickness of

the resulting multilayers can be tuned by varying the compression distance and depletant concentration. Lower depletant

concentrations reduce depletion pressure, facilitating enhanced particle desorption and enabling the formation of broader

and more asymmetric multilayer structures. Importantly, this assembly framework remains eff ective even when the relative

wettability of the particle types is reversed. By introducing sulfonic acid functional groups onto PS, we transform it into a

highly hydrophilic species. Adjusting subphase pH to suppress SO 3 H dissociation allows both particle types to adsorb at

the interface. Under acidic conditions, the PS–SO 3 H particles collapse fi rst and subduct beneath silica domains, producing

inverted stratifi cation. This inversion confi rms that the subduction-driven assembly is not limited to specifi c wettability

pairings, but instead governed by dynamic interfacial energetics and domain interactions.