Polymerothermal synthesis-A facile and versatile method towards functional nanocomposites

This work discusses a facile and one-step method used for the preparation of functional nanoparticles (NPs)/polymer nanocomposite, based on regularly dispersed and zinc oxide (ZnO) quantum dot sized NPs in different polymer matrices without agglomeration. The synthesis was carried out in the absence of any organic additive or ligand. Readily available metal acetate precursor was employed and its conversion to NPs was achieved via low temperature heat treatment. Different self-assembled morphologies, obtainable and tailorable depending on selected polymers as the synthesis media, were elucidated in terms of specific coordination of the functionalities of the polymers towards metallic species, matching of polymer glass transition temperature (T_g) with precursor decomposition temperature, as well as the solid-state polymeric chain movement. This method is not only versatile for NP dispersion and morphological control, but also beneficial for functional device applications. Therefore, we also demonstrate the usage of ZnO NPs/poly(methyl methacrylate) (PMMA) nanocomposite thin film in a light emitting diode (LED) device, which emits bluish white light at relatively low turn-on voltage. Our new synthetic method is described as a 'polymerothermal' synthesis because the conversion to NPs took place in only polymer medium that is literally solvent-free.