• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.165-169
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• 2015

N-propyl-N,N-dimethylethanolamine was directly ultrasonicated in acidic water for 6 minute to give clear stock solutions. The catalytic hydrolysis of N-propyl-N,N-dimethylethanolamine was studied at $30{\sim}55^{\circ}C$ in the presence of uni-lamellar vesicle and mixture of uni- and multi-lamellar aggregates. The difference of rate between uni- and mixture was observed, where uni-lamellar reaction was more catalytic effect. The phase transition temperature of vesicle was $37{\sim}44^{\circ}C$. The particle size of multi-lamellar than that of uni-lamellar of biological membrane was measured more largely.

• Journal of the Korean Applied Science and Technology
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• v.32 no.2
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• pp.330-338
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• 2015

The influences of fluorescence, scattering, and flocculation in turbid material by light scattering of N-propyl-N,N-dimethylethanolamine, fluorescence agent and absorption agent were interpreted for the scattered fluorescence intensity and wavelength. They have been studied the molecular properties by the spectroscopy of laser induced fluorescence (LIF) and flocculation. The effects of optical properties in scattering media have been found by the optical parameters(${\mu}_s$, ${\mu}_a$, ${\mu}_t$). Flocculation is an important step in many solid-liquid separation processes and is widely used. When two particles approach each other, interactions of several colloid particles can come into play which may have major effect on the flocculation and LIF process. The values of scattering coefficient ${\mu}_s$ are large by means of the increasing scattering of scatterer, The values have been found that the slope decays exponentially as a function of concentration from laser source to detector by our experimental result. It may also aid in designing the best model for oil chemistry, bio-pharmaceutical, laser medicine and application of medical engineering on LIF and coagulation in particle transport mode.

• Journal of the Korean Applied Science and Technology
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• v.31 no.1
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• pp.66-73
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• 2014

In this work, the current-voltage curves for stainless steel in the ethanolamine solution containing alkyl group were measured using the conventional three electrodes of cyclic voltammetry. Stainless steel as working electrode, Ag/AgCl electrode as reference electrode and Pt wire as counter electrode were used respectively. As a result, the C-V characteristics of stainless steel were to be for an irreversible process due to the oxidation current from cyclic voltammogram, using N-ethylethanolamine and N,N-dimethylethanolamine solutions. Effective diffusivity of corrosion inhibitors was decreased with increasing concentration. It was found from SEM images of the metal that the electrolyte (specific name ?)(0.5 N) as corrosion inhibitor was added into a N, N-diethylethanolamine solution ($1.0{\times}10^{-3}M$) containing copper and nickel, the corrosion inhibiting effect was enhanced.

• BMB Reports
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• v.31 no.2
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• pp.170-176
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• 1998

Phosphatidylethanolamine N-methyltransferase (PEMT) is known to be a membrane-associated protein. However, cytosolic PEMT was detected when sufficient amounts of exogenous phospholipids were added in the incubation media. The methylation of phospholipids was measured by the incorporation of the $[^3H]-methyl$ group from S-adenosylmethionine and the methylated phospholipids were analyzed by thinlayer chromatography. The essence of the assay condition for the cytosolic enzyme was the inclusion of 200 ${\mu}g$ of each substrate, phosphatidylethanolamine (PE), phosphatidyl N-monomethylethanolamine (PME) and phosphatidyl N,N-dimethylethanolamine (PDE), in the reaction mixture of 100 ${\mu}l$. The subcellular fractionation of brain PEMT activities revealed that approximately 38.1 % for PME, 39.5% for PDE, and 22.4% for PC formation was present in the cytosolic fraction. The general properties of cytosolic PEMT were characterized and compared with those of neuronal nuclei PEMT.

• Applied Chemistry for Engineering
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• v.26 no.3
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• pp.331-335
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• 2015

We prepared films by a bar-coating of various graphene oxide (GO) pastes by varying pH with amine compounds. The thermal treatment of films at $150^{\circ}C$ and measurement of surface resistances exhibited that the pH variation does not significantly affect the surface resistance. We, however, found that the addition of amines reduced the surface resistance by approximately 10 times and N,N-dimethylethanolamine (DMEA) showed the most significant effect among all amines investigated. XPS studies demonstrated that the addition of DMEA accelerated the reduction reaction of GO, and finally enhanced the electrical properties of GO films.

• Macromolecular Research
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• v.12 no.3
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• pp.263-268
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• 2004

We have synthesized a water-soluble polyimide precursor, poly(amic acid) amine salt (PAD), from pyromellitic dianhydride (PMDA), 4,4'-oxydianiline, and N,N -dimethylethanolamine (DMEA) and have investigated in detail its properties with respect to the degree of salt formation (D$\_$sf/). The maximum value of D$\_$sf/ we obtained upon precipitation of the precursor solution into acetone was 79%. We synthesized a PAD having a D$\_$sf/ of 100% (PAD100) by the solid state drying of an organic solution. The precursors showed different solubility depending on the D$\_$sf/ to make up to 4 wt% solutions in water containing a small amount of DMEA. PAD100 is completely soluble in pure water. We investigated the imidization behavior of PAD in aqueous solution using various spectroscopic methods, which revealed that PAD 100 has faster imidization kinetics relative to that of the poly(amic acid)-type precursors. The resulting polyimide films prepared from an aqueous precursor solution possess almost similar physical and thermal properties as those prepared from N-methyl-2-pyrrolidone(NMP) solution. Therefore, we have demonstrated that PAD can be used as a water-based precursor of polyimide; this procedure avoids the use of toxic organic solvents, such as NMP.