Polyolefin/clay nanocomposites with an exfoliated structure are prepared by a process which employs a specific chain end functionalized polyolefin that serves as the clay/polyolefin interfacial compatibilizer (or polymeric surfactant). The polyolefin contains a hydrophilic terminal functional group and an unperturbed hydrophobic high molecular weight polymer chain. The reaction may be carried out in a melt or solution process. Also disclosed are materials made by the process. Also disclosed are materials made by the process.