Soo-Jung Kang

Negative-type photolithography of functionalized gold nanoparticles

ConclusionsThiol-stabilized gold nanoparticles ranging in size from 2 to 13 nm were synthesized using a two-phase reduction method. The thiol-stabilized gold nanoparticles formed micropatterns on a glass substrate through UV irradiation and chemical oxidation. Overall, the micro-pattern obtained through this simple procedure has great potential in the electronics industry.

Lithium ion battery fabricated by curable copolyester/Al2O3 composite-coated nonwoven poly(ethylene terephthalate) separator

The advantages of a curable copolyester (Ester)/Al2O3 composite and nonwoven poly(ethylene terephthalate) (NWPET) separator were combined in attempt to develop a separator system for lithium ion batteries that is predicted to be quite stable at high temperatures, up to 200 00B0;C. Various properties of separators, including the battery performance of unit cells fabricated from them, were investigated. The curable copolyester/Al2O3 compositecoated nonwoven PET (Ester-NWPET) separator remained quite stable up to 200 °C when exposed in polycarbonate. In battery performance tests, the Ester-NWPET separator showed better cycle life than bare polyethylene (PE) separator because of enhanced wettability of the developed separator.

Synthesis and Properties of Copolyesters Derived from 1,4-Cyclohexanedimethanol, Terephthalic Acid, and 2,6-Naphthalenedicarboxylic Acid with Enhanced Thermal and Barrier Properties

In this work, a series of poly(1,4-cyclohexylenedimethylene terephthalate-co-1,4-cyclohexylene dimethylene 2,6-naphthalenedicarboxylate) (PCTN) copolymers with different compositions of two diacids: terephthalic acid (TPA) and 2,6-naphthalenedicarboxylic acid (NDA), and stoichiometry matched 1,4-cyclohexanedimethanol (CHDM) were synthesized directly by a melt polymerization technique. Thermal properties of synthesized copolymers were measured by a differential scanning calorimetry (DSC). The incorporation of either NDA or CHDM improved the glass transition temperature (Tg) of PCTN compared to poly(ethylene terephthalate) (PET). Thermal degradation behaviors were analyzed using a thermogravimetric analysis (TGA). Chemical structures of the obtained copolyesters were investigated by a nuclear magnetic resonance spectroscopy (H NMR). Our results showed that the thermal and optical properties (determined by UV-Vis spectrophotometer) of the PCTN copolyesters were directly dependent on the ratio of TPA and NDA. It was also found that PCTN films have superior optical, thermal, and barrier (reduced water absorption) properties than PET and poly(ethylene naphthalate) (PEN) films.

The oral dose toxicity test and skin irritation test of eco-friendly plasticizer using crude glycerol derived

ABSTRACT Objectives: The major objective of this study is the oral dose toxicity test and skin irritation test of eco-friendly plasticizer using crude glycerol derived from the biodiesel process. Methods: Glyceroldiacetate laurate(GDL) was synthesized from glycerol monolaurat(GML) and acetic acid. The synthesis of the GDL plasticizer was measured with nuclear magnetic resonance spectroscop(NMR) and FT-IR(Fourier Transform Infrared Spectrometer). To provide information on the safety of GDL, we carried out an oral dose toxicity test for GDL in Sprague-Dawley rats. Also, we carried out a skin irritation test for GDL in New Zealand White rabbits. Results: The oral dose toxicity test in Sprague-Dawley rats showed that GDL is a non-toxic material. The result of the skin irritation test on New Zealand White rabbits showed that GDL is non-irritating. Conclusions: From the results of oral dose toxicity test and skin irritation test, we concluded that the developed plasticizer showed excellent eco-friendly property. Based on our results, we confirmed the development of an eco-friendly non-phthalate plasticizer. Applicability for PVC toys and food and drug packaging materials was found.