• Proceedings of the Membrane Society of Korea Conference
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• 2003.05a
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• pp.41-44
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• 2003

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.272-272
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• 2006

In recent years, water-free polymer electrolyte membranes are attracting serious attention due to the possibility of the fuel cell operation at intermediate temperatures ($100{\sim}200^{\circ}C$). It was reported that phosphonic acids have proton conductivity under anhydrous conditions and in particular, relatively high proton conductivity could be obtained from the composite materials with heterocycles such as imidazole, pyrazole, etc. In this work, styrene based polymers, poly((4-vinylbenzyloxy)alkylphosphonic acid), which have phophonic acid group at the end of alkyl chain was synthesized. These polymers were analyzed in terms of thermal stability and proton conductivity. Additionally, cyclic oligosiloxanes tethered with triazole were prepared and analyzed.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3621-3628
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• 2013

Novel 5'-deoxythreosyl purine phosphonic acid analogues containing a 2'-electropositive moiety such as fluorine atom, were designed and synthesized from commercially available 1,3-dihydroxy acetone. Condensation successfully proceeded from a glycosyl donor 6 under Vorbr$\ddot{u}$ggen conditions and cross-metathesis gave the desired phosphonate analogues 7a, 7b, 17a and 17b. The synthesized nucleoside phosphonic acid analogues 13, 16, 23, 26, 28 were subjected to antiviral screening against HIV-1. The bis(SATE) adenine analogue 28 exhibited significant in vitro activities against HIV-1.

• Journal of Adhesion and Interface
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• v.23 no.2
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• pp.53-58
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• 2022

Here, the surface characteristics of the dielectric were controlled by introducing the self-assembled monolayers (SAMs) as the intermediate layers on the surface of the AlOx dielectric, and the electrical performances of the organic charge modulated transistor (OCMFET) were significantly improved. The organic intermediate layer was applied to control the surface energy of the AlOx gate dielectric acting as a capacitor plate between the control gate (CG) and the floating gate (FG). By applying the intermediate layers on the gate dielectric surface, and the field-effect mobility (μ_OCMFET) of the OCMFET devices could be efficiently controlled. We used the four kinds of SAM materials, octadecylphosphonic acid (ODPA), butylphosphonic acid (BPA), (3-bromopropyl)phosphonic acid (BPPA), and (3-aminopropyl)phosphonic acid (APPA), and each μ_OCMFET was measured at 0.73, 0.41, 0.34, and 0.15 cm2V-1s-1, respectively. The results could be suggested that the characteristics of each organic SAM intermediate layer, such as the length of the alkyl chain and the type of functionalized end-group, can control the electrical performances of OCMFET devices and be supported to find the optimized fabrication conditions, as an efficient sensing platform device.

• Journal of the Korean Applied Science and Technology
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• v.22 no.1
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• pp.50-55
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• 2005

A comparison of alkali metal cation and alkaline earth cation solvent extraction was made for three additional monoionizable crown ethers and one diionizable crown ether. sym-(n-Octyldibenzo)-16-crown-5-oxyacetic acid $\underline{1}$ exhibited high efficiency and selecvity in solvent extraction of alkali metal cations with respect to that observed with alkaline earth cations. Sizes of $Na^+$ and $Ca^{2+}$ appropriately match with the cavity size of monoethyl sym-bis[4(5)-tert-butylbenzo]-16-crown-5-oxymethylphosphonic acid $\underline{3}$. As the result, $Na^+$ and $Ca^{2+}$ are the best extracted. sym-(n-Octyldibenzo)-16-crown-5-oxymethyldiphosphonic acid $\underline{4}$was found to be somewhat selective for $Na^+$ over $Li^+$ and other alkaline earth metal cations. In the complexation of alklaine earth cations by crown ether diphosphonic acid $\underline{4}$, $Ca^{2+}$ and $Sr^{2+}$ are the appropriate sizes, but lager $Ba^{2+}$ may be due to favorable formation of a sandwich type complex between the crown ether cavity and the dianion of the deprotonated crown ether phoaphonic acid moiety.

• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.112-117
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• 2017

This study demonstrated the emission of combustion gases of medium density fibreboard (MDF)s coated with piperazinomethyl-bis-phosphonic acid (PIPEABP), methylpiperazinomethyl-bis-phosphonic acid (MPIPEABP), N,N-dimethylethylenediaminomethyl-bis-phosphonic acid (MDEDAP), or bis-(dimethylaminomethyl) phosphinic acid (DMDAP). Each MDFs were coated in three times with a brush with 15 wt% aqueous solution of the phosphorus-nitrogen acid additives. After the specimens were dried at room temperature, the emission of combustion gases was tested using a cone calorimeter (ISO 5660-1, 2). The peak smoke production rate ($SPR_{peak}$) of the specimens coated with phosphorus-nitrogen acids was 18.5 to 41.5%, which is lower than that of using the virgin plate. However, the production of peak carbon monoxide ($CO_{peak}$) was 6.7 to 24.2% higher than that of using the virgin plate. Also, the peak carbon dioxide ($CO_{2peak}$) was 4.2 to 24.4% lower than that of using virgin plate. While the peak oxygen depletion rate was much higher than the level of 15%, which can be fatal to humans and the resulting risk could thus be eliminated. Overall, the combustibility of coated specimens was partially suppressed, but showed a negative effect on the reduction of carbon monoxide.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.101-101
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• 1989

Multilayer films of inorganic analogues of Langmuir-Blodgett films have been prepared on silicon and gold substrates and characterized by ellipsometry, XPS, FT-IRRS, and electrochemical measurements. The deposition technique requires first covalent attachment or adsorption of a phosphonic acid anchoring agent; $HO(CH_3)(CH_2)_2Si(CH_2)_3PO_3H_2$ and $[-S(CH_2)_4PO_3H_2]_2$ were used with Si and Au, respectively. The functionalized substrates are exposed alternately to aqueous $ZrOCl_2$ and l,l0-decanediylbis(phosphonic acid) solutions to yield multilayer films. Surface-sensitive probes show that the films are compact and grow in an oriented fashion suggestive of good structural order.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.745-749
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• 2005

A simple synthetic route for the synthesis of novel methyl branched cyclopropyl phosphonic acid nucleosides is described. The characteristic cyclopropyl moiety 8 was constructed by employing Simmons-Smith reaction as a key step. The condensation of mesylate 11 with natural nucleosidic bases (A,C,T,U) under standard nucleophilic substitution conditions ($K_2CO_3$, 18-Crown-6, DMF) and after subsequent hydrolysis resulted in the formation of target nucleosides, 16, 17, 18, and 19. In addition, the antiviral evaluations of the synthesized nucleotides against various viruses were also performed.

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.05a
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• pp.140-140
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• 1999

• Bulletin of the Korean Chemical Society
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• v.19 no.1
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• pp.27-29
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• 1998