Poly(di-n-hexyl)silanes (PDNHS), which are sigma-conjugated conductive polymers were synthesized by the conventional Wurtz-type coupling reaction. PDNHS were incorporated into polymer networks obtained by cross-linking vinyl terminated poly(dimethyl)siloxanes and methylhydrosiloxane-dimethylsiloxane copolymers. From the UV spectra of polysilane/polysiloxane composites, it can be derived that direct correlations exist between the structure of the polysiloxane matrix and the conformation of small amounts of added polysilanes. The degree of cross-linking plays an important role to understand the structure of the polysiloxane matrix. In addition, rheological measurements indicate that the mechanical properties and the degree of cross-linking in the PDNHS/polysiloxane composites are directly correlated. This implies that the optical properties of small amounts of added PDNHS can be correlated to the mechanical properties of the surrounding polymer matrix. Furthermore, this correlation confirms that PDNHS are suitable to probe the properties of complex polymeric structures.