In this thesis the interaction of amphiphilic and polyphilic molecules with model membranes is examined. For the investigation advanced solid-state NMR methods were employed, particularly via measuring residual dipolar couplings of the several sample systems. The considered guest molecules include a liquid-crystal-like amphiphilc molecule as well as an amphiphilic and a polyphilic blockcopolymer, resp., showing phase separation within a model membrane. The results show a clear indication for the insertion of the guest molecules into the lipid bilayer without restricting the motional amplitude of the lipid molecules in the liquid-crystalline phase. Further the properties of the guest molecules were elucidated in the bulk substance as well as in the mixture with the lipid bilayer. Thus, different anisotropic motions of the guest molecules within the membrane were characterized.