文摘
A three-dimensional (3D) model is proposed to study the self-assembly of triangular molecules at the solid–liquid interface and the effects of the surface–molecule interaction on molecular ordering. In our model the molecules are subject to the H-bond (eH) and surface-molecule (es) interaction at the lowest plane (interface), while higher planes serve as an additional reservoir of molecules. To determine the ordering and adsorption properties, we study the temperature dependences of the specific heat CV(T) at various values of es/eH ratio. For low and intermediate values of es/eH, in addition to the peak related to the ordering into the honeycomb phase at Tc, the low temperature CV(T) peak (Schottky anomaly), caused by adsorption of molecules in the pores of the honeycomb structure, is found. For larger values of es/eH the molecules are adsorbed on the entire first plane, and the adsorption-related peak of CV(T) is found at higher temperature than the peak at Tc. For both es/eH regimes the frustrated phase is obtained instead of the honeycomb phase at high molecular densities. At es/eH < 2.3 the ordering temperature Tc strongly depends on the number of planes LZ decreasing for es = 0 and LZ → ∞ by 40% as compared to the 2D (LZ = 1) model. For es/eH ≳ 2.3 the ordering properties of the 3D model are equivalent to those of the 2D model.