The nanocomposites formation by in situ polymerization used a metallocene catalyst (butyl‐2‐cyclopentadienyl zirconium 2‐chlorines) and a hectorite synthetic clay type which is discussed. This research was carried out in two phases. The first phase consisted of mixing the components of the metallocenic polymerization reaction (metallocene‐methylaluminoxane‐ethylene) with clay in a reactor. In the second phase, the metallocenic catalytic system was supported by clay particles and then a polymerization reaction was made. In this second phase, the clay particles were modified using a sol‐gel reaction with different pH values: pH = 3, pH = 8, and pH = 12. The results were compared in terms of the catalytic activity in the different systems (phase 1 and phase 2) and the nanoparticle morphology of nanocomposites generated in this study.