Korea Institute of Science and Technology

Other

Jae Min Hong

Hyun Nam Cho

Young Chan Ko

Il Seok Choi

Yong Soo Kang

Il Doo Kim

Kyu Hong Ahn

Hyun Chae Park

Young Jin Heo

Hee Dok Choi

Hyoung-Wook Lee

Seong Ryong Ha

Provided is an oxygen sensor using surface plasmon resonance, including: a laser diode emitting light; a polarizer converting the emitted light into polarized light; a prism receiving the polarized light from the polarizer and having a sensor substrate on one surface thereof so that the polarized light is reflected, the sensor substrate coated with oxygen-sensitive organic material; an oxygen concentration measurement chamber provided to enclose the sensor substrate so that oxygen whose concentration is to be measured is contained therein; a photodiode measuring an amount of light reflected from the prism; and a microcontroller unit controlling operation of the oxygen sensor and calculating the oxygen concentration. Further, the oxygen concentration is determined using the microcontroller unit having absolute concentrations corresponding to the amount of light measured using the photodiode, and the oxygen concentration is measured where an incidence angle of the polarized light incident on the sensor substrate is fixed.

Oxygen sensor using principle of surface plasmon resonance and oxygen transmission rate measurement system including the same

The present invention provides a process for preparing polyethylene naphthalate polymers comprising: esterifying a slurry comprising NDCA or a dicarboxylic acid containing NDCA or derivatives thereof, and ethylene glycol or a glycol containing ethylene glycol or derivatives thereof to produce esterification compounds comprising bis (beta-hydroxyethyl) naphthalate or low molecular weight polymers thereof, wherein one or more primary alcohol is added to the slurry; and polycondensing the above resultant esterification compounds to produce polyethylene naphthalate polymers. The process of the present invention allows for the preparation of a slurry more easily and to maximize the manufacturing efficiency. Ultimately, it is possible to increase the productivity of the PEN polymers and to obtain high quality PEN since the method of the present invention has an effect of minimizing side products of the polymerization by reducing the amount of ethylene glycol considerably and of shortening the reaction time of the esterification reaction.

Process for preparing polyethylene naphthalate based polymers by using NDCA or its derivates

A process for preparing polyethylene naphthalate polymer by using a composite catalyst. The process comprises the steps of esterifying a dicarboxylic acid containing 2,6-NDCA, a dicarboxylic ester containing 2,6-NDC or derivatives thereof, with ethylene glycol or a glycol containing ethylene glycol to produce esterification polymers containing bis(beta-hydroxyethyl)naphthalate; continuously polycondensing the obtained esterification polymers to prepare a polymers of polyethylene naphthalate; and wherein the process includes using a composite polymerization catalyst, said composite polymerization catalyst comprising a titanium compound, a phosphorous compound and optionally an antimony compound. The process can considerably reduce both the esterification time and the polycondensation time and provides a good color and excellent physical characteristics.

Process for preparing polyethylene naphthalate based polymers

The present invention describes a method for preparing an asymmetric porous membrane by a dry-wet phase inversion method, which comprises contacting a cast or spun polymer solution with water or organic vapor prior to immersing into the non-solvent precipitation medium, whereby said water or organic vapor is adsorbed onto the cast or spun polymer solution. Higher permeability and excellent rejection ability can be obtained, due to the high porosity and uniform pore size of said membranes according to the present invention.

Method for preparing porous membranes utilizing water or organic vapor

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Seoul, South Korea

Jae Min Hong