• Membrane Journal
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• v.24 no.4
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• pp.268-275
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• 2014

The water-insoluble poly(phenoxy-methylamino)phosphazene has been synthesized and investigated as the new type of diagnostic membrane for the measurements of blood glucose level. Final absorbances at 680 nm through activated polyphosphazene membranes were measured at various concentration of glucose in blood. The end-point results of varing absorbance values according to time (K/S) were used to obtain glucose concentration. The effects of substitution rates with hydrophilic methylamino groups and hydrophobic phenoxy groups on the measurements of glucose concentration were studied. Dose-response slope (DRS) values between glucose concentration and K/S values increased as the hydrophilic substitution rates increased. However, in less than 5% of the hydrophilic substitution rates, DRS values are too low, and in more than 25% of the hydrophilic substitution rates, because DRS increased rapidly, it was difficult to measure exact concentration level of glucose.

• Membrane Journal
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• v.27 no.2
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• pp.138-146
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• 2017

The new types of phenoxy-carboxylatophenoxy cosubstituted polyphosphazene were synthesized with various substitution rates. Diabetic diagnostic membranes were prepapared with these types of polyphosphazenes and final absorbances at 680 nm through these membranes were measured at various concentrations of glucose in blood. Basically, the end-point results of varying absorbance values according to time (K/S) had a linear relationship to the glucose concentration. The effects of substitution rates with hydrophilic carboxylatophenoxy groups and hydrophobic phenoxy groups on the glucose concentration measurements were examined. It was very difficult to measure glucose concentration in less than 10% of the hydrophilic substitution rates, because the glucose penetration rate was too slow. But dose-response slope (DRS) values between glucose concentration and K/S values increased as the hydrophilic substitution rates increased in more than 10% of the hydrophilic substitution rates. However, in more than 30% of the hydrophilic substitution rates, DRS value was too rapidly increased, because glucose penetration rate was too fast.

• The Journal of Natural Sciences
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• v.9 no.1
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• pp.89-93
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• 1997

Polyorganophosphazenes bearing various hydrophilic and hydrophobic side groups were synthesized. These polymers were crosslinked by three methods. The side groups were (2-methoxyethoxy)ethoxy, 2,2,2-trifluoroethoxy, phenyloxy, ethyl ester of alanin. Polymers synthesized in this study were crosslinked by gamma ray irradiation, UV irradiation, and UV irradiation in the presence of crosslinker and photosensitizer. Polymers crosslinked by UV irradiation in the presence of crosslinker and photosenitizer yielded hydrogels of highest elasticity. All hydrogels had lower critical separation temperature behavior.

• Membrane Journal
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• v.23 no.4
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• pp.297-303
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• 2013

Diagnostic membranes which were made of polyphosphazenes were prepared for the measurements of blood glucose concentration. The effects of possible interferents in human blood on the glucose concentration measurements were examined. Above those interferents, ascorbic acid (AA) showed 3~9% higher K/S values compared to the standard plasma solution, tolbutamide (TA) showed 11~13% lower K/S values than those of plasma, triglycerides and bovine serum albumin (BSA) showed 20~25% lower K/S values than those of plasma. However, most of the interferents except above materials did not show any serious effects on the blood glucose measurements.

• Applied Chemistry for Engineering
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• v.9 no.3
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• pp.435-439
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• 1998

A new series of ion separation membrane materials based on pheonoxy and trifluoroethoxy co-substituted polyphosphazene has been designed and synthesized. The polymers were characterized by $^{31}P$ NMR, FT-IR spectroscopy, elemental analysis, and get permeation chromatography. The basic phosphazene membranes were sulfonated to obtain better hydrophilicity and ion-selectivity. The membrane from $[NP(OC_6H_4SO_3H)_{1.58}(OCH_2CF_3)_{0.42}]_n$ gave excellent values of ion transport number, area resistivity, and also ion exchange capacity, compared with the commercial membranes.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.445-449
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• 1999

Hydrophilic polyphosphazenes were synthesized from hydrophobic polyphosphazenes by adding methoxyethylenoxy side chains and cast by dip-coating method into membranes supported on porous polypropylene mesh filter sheet for metal separation testing. A solution of $Cr^{3+},\;Co^{2+},\;Mn^{2+}$ nitrates was used in diffusion experiments which were conducted from $25^{\circ}C$ to $60^{\circ}C$. lt was found that the ion transport properties were increased as the repeating number of ethylenoxy side chain increased. Membrane from trifluoroethoxy methoxyethoxyethoxyethoxy co-substituted polyphosphazenes was found to separate $Cr^{3+}$ ion from $Mn^{2-}$ and $Co^{2+}$ ions with separation factor of 4.5 at $60^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• v.24 no.7
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• pp.901-905
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• 2003

The lower critical solution temperature (LCST) of thermosensitive poly(organophosphazenes) with methoxypoly(ethylene glycol) (MPEG) and amino acid esters as side groups was studied as a function of saccharide concentration in aqueous solutions of mono-, di-, and polysaccharides. Most of the saccharides decreased the LCST of the polymers, and the LCST decrease was more prominently observed by saccharides containing a galactose ring, such as D-galactose, D-galactosamine and D-lactose, and also the polysacccharide, 1-6-linked D-dextran effectively decreased the LCST of the polymers. Such an effect was discussed in terms of intramolecular hydrogen bonding of saccharides in polymer aqueous solution. The saccharide effect was found to be almost independent on the kinds of the amino acid esters and MPEG length of the polymers. Such a result implies that the polymer-saccharide interaction in aqueous solution is clearly influenced by the structure of sacchardes rather than by that of the polymers. The acid saccharides such as D-glucuronic and D-lactobionic acid increased the LCST, which seems to be due to their pH effect.

• Proceedings of the Membrane Society of Korea Conference
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• 2003.11a
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• pp.61-63
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• 2003

A major research objective related to proton exchange membrane(PEM) for DMFC is to achieve high proton conductivity over 10$^{-2}$ S/cm, high hydrolytic stability and low methanol permeability with low cost base materials. for the purpose, a lot of thermoplastic polymers such as polysulfones, polyethersulfone, polyetherketones, polyimides, polyoxadiazole, polyphosphazene and polybenzimidazol have been investigated. Amongst those polymers, polyimides have been suggested as a potential PEM due to their excellent thermal, chemical stability and good mechanical properties. Generally, polyimides are synthesized by polycondensation with numerious diamines and dianhydriedes. In our study, polyimide was prepared using non-sulfonated diamine, sulfonated diamine directly synthesized by fuming sulfuric acid, and naphthalenic dianhydride to improve the hydrolysis stability under acidic condition. Through monomer sulfonation-subsequent polymerization method, the high proton conducting capability and the desired sulfonation level were effectively controlled at the same time. To reduce severe methanol transport through the membrane, the chemical crosslinking among polymer chains was introduced using various crosslinking agents with different chain lengths. The crosslinked sulfonated polyimide membranes showed high proton conductivity up to 8.09$\times$10$^{-2}$ S/cm and from crosslinking effect methanol transport through the membranes was considerably reduced as compared with unmodified membranes. For increase of chain length of crosslinker, methanol permeability was adversely reduced to 10$^{-8}$ $\textrm{cm}^2$/s due to decrease of IEC and increase of crosslinking desity.