Highly Fluorescent and Stable Quantum Dot-Polymer-Layered Double Hydroxide Composites

• Published in: Chemistry of materials Vol. 25; no. 7; pp. 1071 - 1077
• Main Authors: Cho, Seungho, Kwag, Jungheon, Jeong, Sanghwa, Baek, Yeonggyeong, Kim, Sungjee
• Format: Journal Article
• Language: English
• Published: American Chemical Society 09.04.2013
• Subjects: quantum dot; layered double hydroxide; photoluminescence quantum yield; photostability; amphiphilic polymer encapsulation
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/cm3040505

We report a designed strategy for a synthesis of highly luminescent and photostable composites by incorporating quantum dots (QDs) into layered double hydroxide (LDH) matrices without deterioration of a photoluminescence (PL) efficiency of the fluorophores during the entire processes of composite formations. The QDs synthesized in an organic solvent are encapsulated by polymers, poly(maleic acid-alt-octadecene) to transfer them into water without altering the initial surface ligands. The polymer-encapsulated QDs with negative zeta potentials (−29.5 ± 2.2 mV) were electrostatically assembled with positively charged (24.9 ± 0.6 mV) LDH nanosheets to form QD-polymer-LDH composites (PL quantum yield: 74.1%). QD-polymer-LDH composite films are fabricated by a drop-casting of the solution on substrates. The PL properties of the films preserve those of the organic QD solutions. We also demonstrate that the formation of the QD-polymer-LDH composites affords enhanced photostabilities through multiple protections of QD surface by polymers and LDH nanosheets from the environment.