글리세린과 프로필렌 글리콜을 이용한 대기 중 수분의 흡습 효율 평가

김대현,호시모비 딜숏,송동하,박찬열,손윤석 한국냄새환경학회 2023 실내환경 및 냄새 학회지 Vol.22 No.3

This study was carried out to develop a system to reduce ultrafine dust using hygroscopic materials such as glycerin and propylene glycol. Prior to the development of an ultrafine dust reduction system, the moisture condensation efficiency of glycerin and propylene glycol was investigated based on relative humidity (RH). The results showed that when no substances (glycerin and propylene glycol) were added to a tedlar bag, the relative humidity and temperature remained constant. The moisture condensation efficiency of glycerin was 60%, and the time it took to reach 50% of the initial relative humidity was about 40minutes. In the case of propylene glycol, the moisture condensation efficiency was 75%, and the time it took to reach 50% of the initial relative humidity was about 10 minutes. When glycerin and propylene glycol mixture was added, the moisture condensation efficiency was 68% and it took 20 minutes to reach 50% of the initial relative humidity. These results suggest that hygroscopic materials such as glycerin and propylene glycol can actually condense moisture in the atmosphere. In addition, considering actual atmospheric conditions, the relative humidity was set to 60% and 40% or less, and the moisture condensation efficiency was measured. The results showed that the mixture of glycerin and propylene glycol yielded the highest condensation efficiencies, at 69% and 62%, respectively. Therefore, it is preferable to use a mixture of glycerin and propylene glycol to condense moisture in the range of relative humidity in the actual atmosphere.

Stabilization method of an alkaline protease from inactivation by heat, SDS and hydrogen peroxide

Joo, Han-Seung,Koo, Yoon-Mo,Choi, Jang-Won,Chang, Chung-Soon Elsevier 2005 Enzyme and microbial technology Vol.36 No.5

<P><B>Abstract</B></P><P>An investigation was carried out to evaluate the protective effect of polyhydric alcohols, such as propylene glycol and glycerol on the inactivation of an alkaline protease by sodium dodecyl sulfate (SDS) and H<SUB>2</SUB>O<SUB>2</SUB>. Addition of polyols increased the stability of a <I>Bacillus clausii</I> I-52 alkaline protease towards not only the thermal-induced, but also the SDS and H<SUB>2</SUB>O<SUB>2</SUB>-induced inactivation. Among the polyols examined, the best results were obtained with propylene glycol. The half-life of the enzyme was increased by 43- and >105-fold by the addition of 10% (v/v) propylene glycol to the enzyme preparations containing 5% (w/v) SDS and 5% (v/v) H<SUB>2</SUB>O<SUB>2</SUB> at 50°C, respectively. Besides the protection effect of propylene glycol from enzyme inactivation by SDS and H<SUB>2</SUB>O<SUB>2</SUB>, it also improved the hydrolytic efficiency towards substrate like BSA during the protease reaction containing SDS or H<SUB>2</SUB>O<SUB>2</SUB>. This result suggests that propylene glycol has a significant potential as a good stabilizer of an alkaline protease preparation, which finds use as an additive in industrial applications, especially, the detergent industry.</P>

혐기성 혼합배양 조건에서 프로필렌 글라이콜의 초기 분해기전

석종혁 ( Jong Hyuk Seok ) 한국수처리학회(구 한국수처리기술연구회) 2021 한국수처리학회지 Vol.29 No.1

This study was conducted to identify intermediate products and a possible pathway of propylene glycol degradation under anaerobic conditions. In a 60-day continuous run of two chemostat in series, suspended growth was inoculated with a detached biofilm from the anaerobic fluidized bed bioreactor(AFBR) carriers. The influent was made up of 9.0g COD/L of propylene glycol with an essential nutrient supplement for anaerobes. The fermentative bacteria were dominant in the reactor. Propionaldehyde, propionate, propanol and acetate were detected and identified in the anaerobic propylene glycol degradation. Propionate and propanol were produced at equal concentrations in the intermediate products. No significant growth of microorganisms was observed in the reactor under the imposed experimental conditions. A considerable amount hydrogen was observed at about 1.08~1.10×10^-3atm, indicating that hydrogen plays a key role in the anaerobic propylene glycol degradation. This suggests a possible pathway, where propionaldehyde is an intermediate via a dehydration reaction in the initial diol cleavage. This result leads to a hypothesis of a possible pathway that has propionaldehyde as a transient intermediate product in the very initial degradation stages of propylene glycol. Propionaldehyde would then be disproportionated into an equal molar amount of propionate and n-propanol, which would be further converted to acetate and hydrogen. Propionate would be subsequently degraded to acetate, carbon dioxide and hydrogen. Lastly, methane would be produced both from acetate by acetoclastic methanogens and from hydrogen and carbon dioxide by hydrogenotrophic methanogens.

The Effect of Oleic Acid and Propylene Glycol on the Electrical Properties of Skin

오승열,Oh, Seaung-Youl,Guy, Richard H. 한국약제학회 1994 Journal of Pharmaceutical Investigation Vol.24 No.4

The effects of oleic acid, propylene glycol and 5% (w/w) oleic acid in propylene glycol on the electrical properties of hairless mouse skin were studied and the results were compared. The complex electrical impedance was measured as a function of frequency, and resistance and capacitance were determined from the Nyquist plot. Immediately after the treatment with oleic acid, resistance was 145% of the pretreatment value. However it decreased with time and, after 20 hours, it was about 25% of its pretreatment value. Capacitance increased; immediately after the treatment, it was about 125% of pretreatment value and it seemed to increase slowly with time. When the skin was treated with propylene glycol, resistance decreased about 5O% and capacitance increased about 65%. Similar results were observed when the skin was treated with 5% (w/w) oleic acid in propylene glycol, except that the magnitude of resistance drop was much larger. Oleic acid acted synergistically with propylene glycol. Together with the flux data in the literature, the results obtained in this work indicate that electrical resistance is closely related to the permeability of drug molecules through the skin. The results are discussed in terms of the mechanism of action of these penetration enhancers. Overall, this work provided further mechanistic insight into the role of SC lipids in skin resistance and capacitance.

혼합 금속산화물 촉매에서 글리세롤의 수소화 분해반응을 통한 프로필렌 글리콜의 합성

김동원(Dong Won Kim),문명준(Myung Joon Moon),류영복(Young Bok Ryu),이만식(Man Sig Lee),홍성수(Seong-Soo Hong) 한국청정기술학회 2014 청정기술 Vol.20 No.1

이원계 및 삼원계 금속산화물 촉매에서 프로필렌 글리콜의 글리세롤의 전환반응을 행하였다. Cu/Zn 및 Cu/Cr 혼합산화물 촉매에서는 단일 금속 산화물에 비해 글리세롤의 전환율과 프로필렌 글리콜의 선택도가 증가하였다. 또한, Cu/Zn 촉매에 Al이 첨가된 혼합산화물 촉매에서는 글리세롤의 전환율과 프로필렌 글리콜의 선택도가 매우 크게 증가하였다. 반응온도가 증가함에 따라 글리세롤의 전환율은 점차 증가하지만 프로필렌 글리콜의 선택도는 200 ℃에서 최대값을 보이다가 250 ℃에서는 오히려 감소하였다. 글리세롤의 농도가 커질수록 글리세롤의 전환율과 프로필렌 글리콜의 선택도가 감소하였다. Hydrogenolysis of glycerol to propylene glycol was performed over binary and ternary metal oxide catalysts. The conversion of glycerol and selectivity to propylene glycol were increased on Cu/Zn and Cu/Cr mixed oxides compared to pure CuO and ZnO oxides. The addition of alumina into Cu/Zn mixed oxide very highly increased the conversion of glycerol and selectivity to propylene glycol. The conversion of glycerol was increased with increasing the reaction temperature but the selectivity to propylene glycol was shown to have maximum value at 200 ℃ and then decreased at 250 ℃. The conversion of glycerol and selectivity to propylene glycol were decreased with increasing the glycerol concentration.

Propylene Glycol과 glycerine의 열본해 특성

이재곤,이창국,백신,장희진,곽재진,이동욱,Lee Jae-Gon,Lee Chang-Gook,Baek Shin,Jang Hee-Jin,Kwag Jae-Jin,Lee Dong-Wook 한국연초학회 2005 한국연초학회지 Vol.27 No.1

This study was conducted to evaluate the characterization of the pyrolysis products of propylene glycol(PG) and glycerine alone and together with tobacco. The weight change of the samples during the pyrolysis was measured by a thermal analyzer(STD-2960). The pyrolysis products were determined by GC/MS after pyrolysis using a curie-point pyrolyzer(CPP, $220^{\circ}C,\;420^{\circ}C,\;650^{\circ}C,\;and\;920^{\circ}C$) and a double-shot pyrolyzer(DSP, $220^{\circ}C,\;420^{\circ}C,\;650^{\circ}C,\;and\;800^{\circ}C$), respectively. The pyrolysis products from tobacco with and without the addition of PG($2\%$) and glycerine($2\%$ were assayed for its pyrolytic behavior. The results showed that a dramatic change in weight of PG and glycerine was observed at $175^{\circ}C\;and\;249^{\circ}C$, respectively. PG and glycerine showed different patterns for their pyrolysis products according to the method of pyrolysis. Namely, the change rate in pyrolysis with DSP was much higher than that of CPP at above $650^{\circ}C$. The major pyrolysis products of PG were propene, acetaldehyde, propanal, and acetol; the major pyrolysis products of glycerine were 2-propenal, 2-propenol, acetol, and acetic acid. In the pyrolysis experiments of tobacco added PG and glycerine, the pyrolysis products of PG and glycerine weren't detected additionally, except for diethyleneglycol diacetate. From these results, it can be concluded that the PG and glycerine added to tobacco would not be expected to pyrolyse extensively during smoking.

제빙액의 혐기성 분해 기전 및 특성

석종혁(Jong-Hyuk Seok) 한국환경관리학회 2007 環境管理學會誌 Vol.13 No.4

제빙액의 혐기성 분해기전과 특성을 연구하였다. 연속식 반응기의 조작을 위한 초기단계의 연구로서 2개의 serum bottle을 사용하였다. BMP 실험결과 12일간의 실험기간 동안 프로필렌 글리콜의 94.4%와 96.0%가 메탄으로 전환되 었으며 1㎎의 COD 당 0.38~0.39mL의 메탄이 발생하였다. 중간생성물로서 프로판올과 프로피온산 및 아세트산이 관찰되었는데, 초기 반응으로 먼저 프로필렌 글리콜은 프로판올과 프로피온산으로 분해된 다음 프로판올은 프로피온산으로 전환된다. 프로피온산은 아세트산을 거쳐 메탄과 이산화탄소로 최종 분해된다. 프로필렌 글리콜의 메탄화 공정의 반응속도 상수는 0.116~0.121 ㎎ COD/㎎ SS-day으로 나타났다. Mechanism and characteristics of anaerobic de-icing wastewater degradation are studied. For this study, serum bottle testing was conducted in parallel to obtain general information that would be utilized in operating continuous type of reactor. Biochemical methane potential(BMP) test results indicated that 94.4% and 96.0% of propylene glycol was transformed to methane during the test period(12days) and 0.38~0.39mL methane was produced with the degradation of 1㎎ COD. Intermediates study suggested that propylene glycol is degraded to propanol and propionic acid as a primary breakage. The propanol is instantly transformed into propionic acid and the propionic acid is further degraded to acetic acid. Finally, the acetic acid is transformed into methane and carbon dioxide as end products in anaerobic degradation of propylene glycol. The reaction constant of propylene glycol methanization was 0.116~0.121 ㎎ COD/㎎ SS-day.

Degradation of poly(ethylene glycol-propylene glycol) copolymer and its influences on copper electrodeposition

Choe, S.,Kim, M.J.,Kim, H.C.,Lim, T.,Park, K.J.,Kim, K.H.,Ahn, S.H.,Lee, A.,Kim, S.K.,Kim, J.J. Elsevier Sequoia 2014 Journal of Electroanalytical Chemistry Vol.714 No.-

In this work, the degradation of poly(ethylene glycol-propylene glycol) copolymer (PEG-PPG) and its effect on the electrodeposition of Cu were investigated. PEG-PPG became fragmented during the electrodeposition with changing its terminal groups from hydroxyl to aldehyde, formic ester, and ketone. The aged solution showed a higher saturation current density than the fresh solution in chronoamperometry (CA) measurements, resulting from an easier desorption of the cleaved PEG-PPG from the copper surface through the competition with bis-(3-sulfopropyl)-disulfide (SPS). Furthermore, the electrical resistivity of Cu films deposited from the aged solution increased due to a decrease in the grain sizes.

Carbon nanofibers supported Ru catalyst for sorbitol hydrogenolysis to glycols: Effect of calcination

Jinghong Zhou,Long Zhao,Hong Chen,Mingguang Zhang,Zhijun Sui,Xinggui Zhou 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.5

Carbon nanofiber (CNFs) supported Ru catalysts for sorbitol hydrogenolysis to ethylene glycol and propylene glycol were prepared by incipient wetness impregnation, calcination and reduction. The effect of calcination on catalyst properties was investigated using thermal gravimetry analysis, temperature-programmed reduction, X-ray diffraction,X-ray photoelectron spectroscopy, transmission electron microscopy and N2 physisorption. The results indicated that calcination introduced a great amount of surface oxygen-containing groups (SOCGs) onto CNF surface and induced the phase transformation of Ru species, but slightly changed the texture of Ru/CNFs. The catalytic performance in sorbitol hydrogenolysis showed that Ru/CNFs catalyst calcined at 240 oC presented the highest glycol selectivities and reasonable glycol yields. It was believed that the inhibition and confinement effect of SOCGs around Ru particles as well as the high dispersion of Ru particles was the key factor for the catalytic activity.

프로필렌글리콜에 분산된 나피온 이오노머로 제조된 공기극 촉매층의 연료전지 성능 특성 연구

우승희,양태현,박석희,임성대 한국화학공학회 2019 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.57 No.4

고분자연료전지용 막전극접합체(Membrane Electrode Assembly, MEA)의 저가화 및 고성능화를 위하여 촉매층을 구성하는 촉매와 이오노머의 계면 특성에 대한 이해가 중요한 연구주제가 되고 있다. 본 연구에서는 이오노머의 구조 제어를 위하여 상용 이오노머의 용매로 사용되는 물 대신에 프로필렌글리콜(Propylene Glycol, PG)을 용매로 사용하여단측쇄(Short Side Chain, SSC) 나피온 이오노머가 분산된 현탁액을 제조하고 이를 이용하여 공기극 촉매층을 제조하여 연료전지 성능 특성을 평가하였다. PG 기반 이오노머의 함량을 20~35 wt%로 증가시키면서 제조된 촉매층의 연료전지 성능은 상용 물 기반 이오노머와는 달리 이오노머 함량이 35 wt%까지 증가함에 따라 성능도 지속적으로 증가하였다. PG 기반 이오노머의 작은 입도와 느린 건조 속도는 균일 구조의 촉매층 형성을 유도하여 수소이온전달에는 효과적이었지만 PG 기반 이오노머 필름의 낮은 산소투과도는 MEA 성능을 저하시키는 주요 문제로서 개선이 필요하였다. To develop a membrane electrode assembly (MEA) with lower Pt loading and higher performance in proton exchange membrane fuel cells (PEMFCs), it is an important research issue to understand interfacial structure of Pt/C catalyst and ionomer and design the catalyst layer structure. In this study, we prepared short-side-chain Nafion-based ionomer dispersion using propylene glycol (PG) as a solvent instead of water which is commonly used as a solvent for commercially available ionomers. Cathode catalyst layers with different ionomer content from 20 to 35 wt% were prepared using the ionomer dispersion for the fabrication of four different MEAs, and their fuel cell performance was evaluated. As the ionomer content increased to 35 wt%, the performance of the prepared MEAs increased proportionally, unlike the commercially available water-based ionomer, which exhibited an optimum at about 25 wt%. Small size micelles and slow evaporation of PG in the ionomer dispersion were effective in proton transfer by inducing the formation of a uniformly structured catalyst layer, but the low oxygen permeability problem of the PG-based ionomer film should be resolved to improve the MEA performance.