Effect of Patch Size and Attraction Energy on Polymer Chain Adsorption in Slits Created by Opposing Patch‐Patterned Surfaces

ABSTRACT The adsorption behavior of a polymer chain within a slit composed of two patch‐patterned surfaces is investigated using Langevin dynamics simulations. Each surface exhibits periodic attractive square patches (period d , size L , attraction energy ε ps ), with a 0.5 d misalignment between the two surfaces. The adsorption degree increases with L , while the mean number of occupied patches < n pa > and the surface‐parallel component of the mean square radius of gyration < R 2 g,xy > exhibit a complex dependence on L . We identify distinct adsorption regimes: a single‐surface and single‐patch adsorbed state for L > L s , an upper‐lower and multi‐patch adsorbed state for L > L m , and a complete adsorbed state for L > L c . At weak ε ps , the polymer chain adopts single‐surface and single‐patch adsorption for middle L and upper‐lower and multi‐patch adsorption for large L . Conversely, a strong ε ps promotes upper‐lower and multi‐patch adsorption for small L , and single‐surface and single‐patch adsorption as L increases. The adsorption degree increases monotonically to saturate with ε ps , while < n p > initially increases and subsequently decays toward stability. Notably, < R 2 g,xy > first decreases, then increases, and finally decreases to stabilize as ε ps increases. These results highlight the role of patch geometry and interaction strength in governing polymer adsorption behavior.