Polymer surfaces and interfaces are mobile and rearrange or reorient at interfaces to minimize the interfacial free energy with the surrounding phase. As a model system for the polymer surface dynamics, we used immobilized n-alkyldimethyl monochlorosilanes on rigid borosilicate substrates. Dynamic contact angles by the Wilhelmy plate method were measured as functions of varying alkyl chain lengths and surface concentrations in various solvent environments. And their surface energies were calculated from advancing contact angle values using nonlinear programming methods. In the medium alkyl chain range of n = 4 to 8, alkyl chains exhibit the minimum contact angles and higher surface energies. This suggests that these chains may be relatively more disordered or "liquid-like" than the self-assembling or "crystalline-like" of n = 18 case. This is probably a result of an excluded-volume effect due to the low degree of van der Waals interactions between the attached intermediate-length chains. These results are consistent with those of other related works.