Immobilization of poly(fluorene) within clay nanocomposite: An easy way to control keto defect

► Polymer-nanocomposites composed of cationic poly(fluorene) and native MMT prepared by solution blending method. ► Change of overall morphology of composites films. ► Enhanced thermal stability and photostability of composites than pristine poly(fluorene). ► Effective way to tune the keto defects.