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Detailed Program
Paper Number : LD-O04
Time Frame : 14:45~14:57
Presentation Date : Thurse day, 27, November
Session Name : LED and Display Materials
Session Chair 1# : Inhwan Lee
Session Chair 2# : Yasushi Nanishi
Deposition of nanoparticles on substrate for layer-by-layer assembly
Myeong-Ji DONG
Chonbuk National University
In nanotechnology there exists a serious problem of controllably depositing nanoparticles on the chosen surface. The methods for the assembly of thin films with various degrees of molecular order and stability include: spin coating and solution casting, polyion layer-by-layer self-assembly, chemical self-assembly and Langmuir-Blodgett technique. Layer-by-layer (LbL) assembly has been proven to be a convenient and versatile method to fabricate functional films. This technique makes use of the alternate adsorption of oppositely charged macromolecules to build up multilayered structures. These films have a lower molecular order than Langmuir-Blodgett (LB) films or self-assembled monolayer (SAM) films but they have the advantage of high strength, easy preparation and possibility to be deposited on supports of any shape and dimension. However, using traditional dipping LbL assembly to fabricate micrometer-thick films is time consuming, while the spin-coating electrostatic self-assembly technique has been shown to facilitate the rapid fabrication of polyelectrolyte multilayer assemblies. Films prepared by LbL assembly have been used in a wide range of applications, such as antireflection coatings, super hydrophobic surfaces, electrochromic devices, biosensors, cell adhesion, drug delivery systems, proton exchange membranes, solar-energy conversion, and separation membranes.
In this study, LbL assembly was fabricated using a spin coating technique. Poly (allylamine hydrochloride) (PAH) / poly(sodium 4-styrenesulfonate) (PSS) films were formed by spin-assisted LbL assembly by alternately spinning aqueous solutions of PAH and PSS onto a charged substrate. Subsequently, the particles are coated by the dip coating method on a charged polymer film. In this way, we can coat nanoparticles on various structural templates. Also, it allows to coat the nanoparticles by adjusting their density and then to evaluate the optical properties of the films. In addition, the approach was used to coat a monolayer of quantum dots on charged polymer film. The coated quantum dot films thus prepared were studied to evaluate the optical, electronic and structural properties.


Figure 1. Simplified molecular picture of two adsorption steps.

References:

[1] G. Decher, Science 277 (1997) 1232.
[2] Y. Li, X. Wang and J. Sun, Chem. Soc. Rev 41 (2012) 5998-6009.
Acknowledgements : This research was supported by National Research Foundation of Korea(NRF) funded by Ministry of Science, ICT & Future Planning (2013R1A2A2A07067688, 2010-0019626)