Steady state and time resolved spectroscopic study of C-dots―MEH―PPV polymer nanoparticles composites

• Published in: Physical chemistry chemical physics : PCCP 2013-10, Vol.15 (39), p.16834-16840
• Main Authors: MONOJ KUMAR BARMAN, BHATTACHARYYA, Santanu, PATRA, Amitava
• Format: Article
• Language: English
• Subjects: Carbon; Chemistry; Colloidal state and disperse state; Decay; Energy transfer; Exact sciences and technology; General and physical chemistry; Nanoparticles; Nanostructure; Photoluminescence; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Polymer matrix composites; Pyrolysis
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c3cp51547h

Fluorescent carbon dots (C-dots) have been found to be a new class of nanomaterial for potential applications. Herein, polyethylenimine branched (BPEI) functionalized carbon dots (C-dots) are synthesized by changing the synthesis time using a microwave pyrolysis method. The photoluminescence intensity and average decay time of C-dots are found to be increased with increasing the crystallinity of the C-dots. C-dots-MEH-PPV polymer nanoparticles composites are formed by electrostatic interaction between these particles. The intensity of C-dots quenches dramatically with increasing the concentration of MEH-PPV nanoparticles (PNPs) and the intensity of PNPs increases gradually under excitation at 370 nm. This phenomenon may be due to energy transfer from C-dots to PNPs because there is a good spectral overlap between the emission spectra of C-dots and the absorption spectra of PNPs. The drastic photoluminescence quenching and the shortening of the decay time of C-dots in the composites confirms the efficient resonance energy transfer from C-dots to polymer nanoparticles. The energy transfer efficiency (66% to 89%) and rate of energy transfer are found to depend strongly on the time of pyrolysis. These C-dots-polymer composites will open up a way for developing new challenging materials for potential applications.