• Title/Summary/Keyword: Photoluminescent multilayers

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Highly Stable Photoluminescent Qunatum Dot Multilayers by Layer-by-Layer Assembly via Nucleophilic Substitution Reaction in Organic Media

  • Yun, Mi-Seon;Kim, Yeong-Hun;Jeong, Sang-Hyeok;Baek, Hyeon-Hui;Jo, Jin-Han
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2011.05a
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    • pp.244.2-244.2
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    • 2011
  • We introduce a novel and robust method for the preparation of nanocomposite multilayers, which allows the excellent photoluminescent (PL) properties as well as the accurate control over the composition and dimensions of multilayers. By exchanging the oleic acid stabilizers of CdSe@ZnS quantum dots (QDs) synthesized in organic solvent with 2-bromo-2-methylpropionic acid (BMPA) in the same solvent, these nanoparticles were be alternately deposited by nucleophilic substitution reaction with highly branched poly(amidoamine) dendrimer (PAMA) through layer-by-layer (LbL) assembly process. Our approach does not need to be transformed into the water-dispersible nanoparticles with electrostatic or hydrogen-bonding groups, which can deteriorate their inherent properties, for the built-up of multilayers. The nanocomposite multilayers including QDs exhibited the strong PL properties achieving densely packed surface coverage as well as long-term PL stability under atmospheric conditions in comparison with those of conventional LbL multilayers based on electrostatic interaction. Furthermore, we demonstrate that the flexible multilayer films with optical properties can be easily prepared using nucleophilic substitution reaction between bromo and amino groups in organic media. This robust and tailored method opens a new route for the design of functional film devices based on nanocomposite multilayers.

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Highly Stable Photoluminescent and Magnetic Multilayers Using Nucleophilic Substitution Reaction in Organic Media

  • Jo, Jin-Han
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.262-262
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    • 2010
  • We introduce a novel and efficient strategy for producing free-standing functional films via photo-crosslinking and electrostatic layer-by-layer (LbL) assembly, which can allow the buildup of hydrophilic multilayers onto hydrophobic surfaces. Hydrophobic multilayers were deposited on ionic substrates by a photo-crosslinking LbL process using photo-crosslinkable polymers. The photo-crosslinked surface was converted to an anionic surface by excess UV light irradiation. This treatment allowed also the stable adhesion between metal electrode or cationic polyelectrolyte and hydrophobic multilayers. After dissolving the ionic substrates in water, the formed free-standing films exhibited unique functionalities of inserted components within hydrophobic and/or hydrophilic multilayers.

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