3 research outputs found
Sol–Gel Derived Transparent Zirconium-Phenyl Siloxane Hybrid for Robust High Refractive Index LED Encapsulant
We report a zirconium-phenyl siloxane
hybrid material (ZPH) that can be used as a robust LED encapsulant.
The ZPH encapsulant was fabricated via hydrosilylation-curing of sol–gel derived multifunctional (vinyl-
and hydride-functions) siloxane resins containing phenyl-groups and
Zr–O–Si heterometallic phase for achieving a high refractive
index (<i>n</i> ≈ 1.58). In thermal aging, the ZPH
LED encapsulant exhibited superior performances with a high optical
transparency (∼88% at 450 nm) and exhibited high thermal stability
(no yellowing at 180 °C for 1008 h), compared to a commercial
LED encapsulant (OE-6630, Dow Corning Corporation). This suggests
potential for ZPH to be a robust LED encapsulant
Ultraviolet Light Stable and Transparent Sol–Gel Methyl Siloxane Hybrid Material for UV Light-Emitting Diode (UV LED) Encapsulant
An
ultraviolet (UV) transparent and stable methyl-siloxane hybrid
material was prepared by a facile sol–gel method. The transparency
and stability of a UV-LED encapsulant is an important issue because
it affects UV light extraction efficiency and long-term reliability.
We introduced a novel concept for UV-LED encapsulation using a thermally
curable oligosiloxane resin. The encapsulant was fabricated by a hydrosilylation
of hydrogen-methyl oligosiloxane resin and vinyl-methyl siloxane resin,
and showed a comparable transmittance to polydimethylsiloxane (PDMS)
in the UVB (∼300 nm) region. Most remarkably, the methyl-siloxane
hybrid materials exhibited long-term UV stability under light soaking
in UVB (∼300 nm) for 1000 h
Conducting Nanopaper: A Carbon-Free Cathode Platform for Li–O<sub>2</sub> Batteries
For a lithium–oxygen
(Li–O<sub>2</sub>) battery air
electrode, we have developed a new all-in-one platform for designing
a porous, carbon-free conducting nanopaper (CNp), which has dual functions
as catalyst and current-collector, composed of one-dimensional conductive
nanowires bound by a chitin binder. The CNp platform is fabricated
by a liquid diffusion-induced crystallization and vacuum filtration
methods. Employing less than 1 wt % chitin to connect the conductive
skeleton, pores and active sites for reactions have become maximized
in self-standing CNp. The carbon-free CNp enables the Li–O<sub>2</sub> air electrode to be more stably operated compared to carbon
nanofibers and other CNps bound by PVDF and PMMA; side reactions are
largely suppressed on the CNp. The versatile chitin is highlighted
for diverse conducting nanopapers that can be used in various applications