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Transparent dispensible high‐refractive index ZrO 2 /epoxy nanocomposites for LED encapsulation
Author(s) -
Tao Peng,
Li Ying,
Siegel Richard W.,
Schadler Linda S.
Publication year - 2013
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.39652
Subject(s) - epoxy , materials science , nanocomposite , high refractive index polymer , dispersity , composite material , refractive index , nanoparticle , solvent , chemical engineering , polymer chemistry , nanotechnology , chemistry , layer (electronics) , organic chemistry , optoelectronics , engineering
In this study, we report a facile ex situ approach to preparing transparent dispensible high‐refractive index ZrO 2 /epoxy nanocomposites for LED encapsulation. Highly crystalline, near monodisperse ZrO 2 nanoparticles (NPs) were synthesized by a nonaqueous approach using benzyl alcohol as the coordinating solvent. The synthesized particles were then modified by (3‐glycidyloxypropyl)trimethoxysilane (GMS) ligand. It was found that, with tiny amount of surface‐treating ligand, the modified ZrO 2 NPs were able to be easily dispersed in a commercial epoxy matrix because of the epoxy compatible surface chemistry design as well as the small matrix molecular weight favoring mixing. Transparent thick (1 mm) ZrO 2 /epoxy nanocomposites with a particle core content as high as 50 wt % and an optical transparency of 90% in the visible light range were successfully prepared. The refractive index of the prepared composites increased from 1.51 for neat epoxy to 1.65 for 50 wt % (20 vol %) ZrO 2 loading and maintained the same high‐Abbe number as the neat epoxy matrix. Compared with the neat epoxy encapsulant, an increase of 13.2% in light output power of red LEDs was achieved with the 50 wt % ZrO 2 /epoxy nanocomposite as the novel encapsulant material. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3785–3793, 2013