CCD-RSM을 이용한 시벅턴 오일의 탈색공정 최적화 및 자외선 흡수능력 평가

홍세흠 ( Seheum Hong ),정윈페이 ( Yunfei Zheng ),이승범 ( Seung Bum Lee ) 한국공업화학회 2021 공업화학 Vol.32 No.1

본 연구에서는 천연 오일인 시벅턴 오일의 천연 자외선 흡수제로의 사용 가능성을 알아보기 위하여 시벅턴 원유에 대한 흡착 탈색공정을 수행하고, 이를 CCD-RSM (central composite design model-response surface methodology)을 이용하여 최적화하였다. CCD-RSM의 반응치로는 탈색과정의 탈색효과, 탈색 후 정제유의 산가 및 290 nm에서의 자외선흡광도로 설정하였으며, 독립변수로는 탈색제의 첨가량, 탈색온도, 탈색시간으로 설정하였다. CCD-RSM에 의한 통계학적 최적화 결과와 수학적 최적화 결과를 비교한 결과 3가지 반응치를 동시에 만족하는 최적조건으로 탈색제의 첨가량(4.32 wt.%), 탈색온도(134.9 ℃) 및 탈색시간(19.8 min)으로 나타났다. 이 최적 조건하에서 예측된 반응치 중 탈색과정의 탈색효과는 94.78%, 탈색 후 정제유의 산가는 2.08 mg/g KOH, 그리고 290 nm에서의 자외선 흡광도는 2.91로 나타났으며, 오차율은 2% 이하로 낮게 나타났다. 따라서 CCD-RSM을 시벅턴 원유의 흡착 탈색공정에 적용할 경우 매우 높은 수준의 만족하는 결과를 얻을 수 있음을 확인하였으며 천연 식물성 오일인 시벅턴 오일을 천연 자외선 흡수제로서 사용 가능함을 확인하였다. In this study, the adsorption decolorization process of sea buckthorn oil was carried out to verify the possibility of the sea buckthorn oil as a natural UV absorber. The optimization was carried out by using the central composite design model-response surface methodology (CCD-RSM). The response values of CCD-RSM were selected as the decolorization effect through the process, acid value after decolorization, and UV absorbance of the decolored oil at 290nm. The amount of adsorbent, temperature and time were selected as the process variables for the experiments. According to the results of CCD-RSM, the results of optimization were all consistent. The optimal conditions, which satisfy CCD-RSM statically and mathematically, were 4.32 wt.%, 134.90 ℃, and 19.8 min for the amount of adsorbent, temperature and time, respectively. The estimated response values expected under these optimal conditions values were 94.78%, 2.08 mg/g KOH, and 2.91 for the decolorization effect, acid value and UV absorbance at 290 nm, respectively. Also the average error from actual experiment for verifying the conclusions was smaller than 2%. Therefore, it was confirmed that the application of CCD-RSM to the adsorption decolorization process of sea buckthorn oil showed a very high level of acceptable results and that the sea buckthorn oil has high possibility to be used as a natural UV absorber.

밀배아유 원료 O/W 유화액의 제조 및 안정성평가: CCD-RSM을 이용한 최적화

홍세흠 ( Seheum Hong ),장현식 ( Hyun Sik Jang ),이승범 ( Seung Bum Lee ) 한국공업화학회 2021 공업화학 Vol.32 No.5

천연 밀배아유와 복합 sugar ester를 이용하여 밀배아유 원료 O/W (oil in water) 유화액을 제조하였다. HLB 값, 유화제의 첨가량 및 유화시간이 O/W wheat germ oil 유화액의 평균 입자크기, 유화점도 및 ESI에 미치는 영향을 조사하였으며, 반응표면분석방법인 중심합성계획모델에 의해 제조된 유화과정의 파라미터를 모의하고 최적화하였다. O/W wheat germ oil 유화액의 제조를 위한 최적의 공정조건은 HLB 값(hydrophile-lipophile balance value)은 8.4, 유화제의 첨가량은 6.4 wt%, 유화시간은 25.4 min이며, 최적조건에서 중심합성계획(central composite design, CCD-RSM) 모델을 통한 예측 반응치는 7일 후의 유화액을 기준으로 MDS (mean droplet size)= 206 nm, 점도 = 8125 cP, ESI 98.2%이었다. 또한 실제 실험을 통해 얻어진 유화액의 MDS, 점도 및 ESI는 각각 209 nm, 7974 cP 및 98.7%로 나타났다. 따라서 중심합성계획 모델을 통해 밀배아유 원료 유화액의 안정성을 평가하는 최적화 과정을 설계할 수 있었다. An O/W (oil in water) emulsion, wheat germ oil raw material, was produced by using natural wheat germ oil and composite sugar-ester. The effects of variables such as the hydrophile-lipophile balance (HLB) value, added emulsifier amount, and emulsification time on the average particle size, emulsification viscosity and ESI of O/W wheat germ oil emulsion were investigated. The parameters of the emulsification process produced by the central composite design model of the response surface methodology (CCD-RSM), which is a reaction surface analysis method, were simulated and optimized. The optimum process conditions obtained from this paper for the production of O/W wheat germ oil emulsion were 8.4, 6.4 wt%, 25.4 min for the HLB value, amount of emulsifier, and emulsion time, respectively. The predicted reaction values by CCD-RSM model under the optimum conditions were 206 nm, 8125 cP, and 98.2% for mean droplet size (MDS), viscosity, and ESI, respectively, based on the emulsion after 7 days. The MDS, viscosity and ESI of the emulsion obtained from actual experiments were 209 nm, 7974 cP and 98.7%, respectively. Therefore, it was possible to design an optimization process for evaluating the stability of the emulsion of wheat germ oil raw material by CCD-RSM.

천연 혼합유화제를 이용한 O/W 유화액의 제조 : 중심합성계획모델을 이용한 유화안정성 최적화

홍세흠 ( Seheum Hong ),천추이웨이 ( Cuiwei Chen ),이승범 ( Seung Bum Lee ) 한국공업화학회 2023 공업화학 Vol.34 No.3

In this study, the O/W emulsification processes with the natural surfactants that were extracted from Medicago sativa L. and Sapindus saponaria L. as emulsifiers were optimized using the central composite design-response surface methodology (CCD-RSM). Herein, independent parameters were the amounts of mixed emulsifiers, the mixing ratio of natural emulsifiers (soapberry saponin/alfalfa saponin), and the emulsification time, whereas the reaction parameters were the emulsion stability index (ESI), mean droplet size (MDS), and antioxidant activity (DPPH radical scanvenging activity). Through basic experiments, the ranges of operation variables for the amount of mixed emulsifiers, the mixing ratio of natural emulsifiers, and the emulsification time were 12~14 wt%, 30~70%, and 20~30 min, respectively. The optimum operation variables deduced from CCD-RSM for the amount of mixed emulsifiers, the mixing ratio of natural emulsifiers, and the emulsification time were 13.2 wt%, 44.2%, and 25.8 min, respectively. Under these optimal conditions, the expected values of the ESI, MDS, and antioxidant activity were 88.7%, 815.5 nm, and 38.7%, respectively. And, the measured values of the ESI, MDS, and antioxidant activity were 90.6%, 830.2 nm, and 39.6%, respectively, and the average experimental error for validating the accuracy was about 2.1%. Therefore, it was possible to design an optimization process for evaluating the O/W emulsion process using CCD-RSM.

중심합성계획모델을 이용한 폐식용유 원료 바이오디젤 제조공정의 최적화

홍세흠 ( Seheum Hong ),이원재 ( Won Jae Lee ),이승범 ( Seung Bum Lee ) 한국공업화학회 2017 공업화학 Vol.28 No.5

본 연구에서는 폐식용유를 이용한 바이오디젤 제조공정에 반응표면분석법 중 중심합성계획모델을 이용하여 최적화 과정을 수행하였다. 공정변수로는 폐식용유의 산가, 반응시간, 반응온도, 메탄올/유지 몰비, 촉매량 등을 선택하였고, 반응치로는 FAME 함량(96.5% 이상) 및 동점도(1.9~5.5 cSt)를 설정하였다. 기초실험을 통해 계량인자범위를 반응시간(45~60 min), 반응온도(50~60 ℃), 메탄올/유지 몰비(8~12)로 정하고, 중심합성계획모델을 이용한 최적화 결과 바이오디젤의 제조공정의 최적조건은 반응시간 55.2 min, 반응온도 57.5 ℃, 메탄올/유지 몰비 10으로 나타났다. 이 조건에서 바이오디젤의 예측 FAME 함량은 97.5%, 동점도는 2.40 cSt이었으며, 실제 실험을 통해 확인한 결과 FAME 함량(97.7%), 동점도(2.41 cSt)로 측정되어 오차율은 각각 0.23, 0.29%로 나타났다. 따라서 폐식용유 원료 바이오디젤 제조공정 최적화 과정에 반응표면분석법 중 중심합성계획모델을 적용할 경우 매우 낮은 오차율을 얻을 수 있었다. In this study, the optimization process was carried out by using the central composite model of the response surface methodology in waste cooking oil based biodiesel production process. The acid value, reaction time, reaction temperature, methanol/ oil molar ratio, and catalyst amount were selected process variables. The response was evaluated by measuring the FAME content (more than 96.5%) and kinematic viscosity (1.9~5.5 cSt). Through basic experiments, the range of optimum operation variables for the central composite model, such as reaction time, reaction temperature and methanol/oil molar ratio, were set as between 45 and 60 min, between 50 and 60 ℃, and between 8 and 12, respectively. The optimum operation variables, such as biodiesel production reaction time, temperature, and methanol/oil molar ratio deduced from the central composite model were 55.2 min, 57.5 ℃, and 10, respectively. With those conditions the results deduced from modeling were as followings: the predicted FAME content of the biodiesel and the kinematic viscosity of 97.5% and 2.40 cSt, respectively. We obtained experimental results with deduced operating variables mentioned above as followings: the FAME content and kinematic viscosity of 97.7% and 2.41 cSt, respectively. Error rates for the FAME content and kinematic viscosity were 0.23 and 0.29%, respectively. Therefore, the low error rate could be obtained when the central composite model among surface reaction methods was applied to the optimized production process of waste cooking oil raw material biodiesel.

Effect of electrodes configuration on single-walled carbon nanotube chemocapacitive sensors

Seheum YEON,Dawoon JUNG,Hong-Seok KIM,Jae-Hee HAN 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

시멘트 6가 크롬 (Cr(VI))정량분석법에 관한 고찰

문세흠(Moon, Seheum),정재홍(eong, Jae Hong),이승훈(Lee, Seunghoon),이승헌(Lee, Seungheun) 한국콘크리트학회 2008 한국콘크리트학회 학술대회 논문집 Vol.2008 No.5

CCD-RSM을 이용한 알팔파 추출물인 천연계면활성제가 포함된 O/W 유화액의 최적화

홍세흠,호우지아천,이승범,Seheum Hong,Jiachen Hou,Seung Bum Lee 한국공업화학회 2023 공업화학 Vol.34 No.2

In this study, natural surfactants were extracted from Medicago sativa L. The O/W emulsification processes with the extracted natural surfactants were optimized using central composite design model-response surface methodology (CCD-RSM) and a 95% confidence interval was used to confirm the reasonableness of the optimization. Herein, independent parameters were the ratio of saponins to total surfactant (P), amount of surfactant (W), and emulsification speed (R), whereas the reaction parameters were the emulsion stability index (ESI), mean droplet size (MDS), and viscosity (V). Using the multiple reaction, the optimal conditions for the ratio of saponins to total surfactant, amount of surfactant, and emulsification speed for O/W emulsification were 49.5%, 9.1 wt%, and 6559.5 rpm, respectively. Under these optimal conditions, the expected values of ESI, MDS, and V as the reaction parameters were 89.9%, 1058.4 nm, and 1522.5 cP, respectively. The values of ESI, MDS, and V from these expected values were 88.7%, 1026.4 nm, and 1486.5 cP, respectively, and the average experimental error for validating the accuracy was about 2.3 (± 0.4)%. Therefore, it was possible to design an optimization process for evaluating the O/W emulsion process with Medicago sativa L. using CCD-RSM.

폐기물 매립지 최종복토시스템 차단층 재료인 다짐점토층의 다짐조건에 따른 가스전도도 변화에 관한 연구

김민지(Kim Min-Ji),문세흠(Moon Seheum),김재영(Kim Jae Young),민수홍(Min Soo-Hong) 대한토목학회 2006 대한토목학회 학술대회 Vol.2006 No.10

천연유래 멘톨을 함유한 투명 아크릴 감압성 점착제 제조 및 점착특성

백승석(Seung-Suk Beak),홍세흠(Seheum Hong),황석호(Seok-Ho Hwang) 한국고분자학회 2016 폴리머 Vol.40 No.5

본 연구는 2-ethylhexyl acrylate와 2-hydroxyethyl acrylate 기본 조성물에 천연물질인 menthol로부터 합성한 menthyl acrylate(MnA)와 석유화학 기반 isobornyl acrylate(IBOA)의 조성비를 변화시키면서 광중합된 공중합체를 이용하여 자외선 경화형 투명 감압성 점착제를 제조하였다. 시럽의 기본 물성인 고형분 및 분자량 분석뿐만 아니라 제조된 감압성 점착제의 점착특성과 광학특성을 고찰하였다. 모든 아크릴 감압성 점착제는 약 3.5 kgf/25 mm의 180° 박리력과 약 0.25 kgf의 초기점착력을 IBOA와 MnA 조성비에 상관없이 거의 유지하였다. 또한 모든 아크릴 감압성 점착제에서 93% 이상의 광투과도와 1.0% 이하의 haze 값, 그리고 1.0 이하의 색차값을 보여주었다. Transparent acrylic pressure sensitive adhesives (PSAs) were successfully prepared by photopolymerization with 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate as a default constituent and with isobornyl acrylate and biomass-derived menthyl acrylate as a variable constituent. The concentration effect of menthyl acrylate in the acrylic PSAs was investigated on adhesion and the optical properties as well as the characteristics (solid content, and molecular weight) of the syrups were also investigated. Regardless of increasing menthyl acrylate concentration in the acrylic PSAs, the acrylic PSAs exhibited almost the same adhesion performance such as 180° peel strength (~3.5 kgf/25 mm) and probe tack (~0.25 kgf). All acrylic PSA samples also showed high transmittance (more than 93%), low haze (less than 1.0%) and low color-difference (less than 1.0).

Chemical Structure Effect of Diisocyanate on the Coating Performance of Polyurethane-based Gel-coats

( Jin Hwan Park ),( Seung-suk Baek ),( Oh Young Kim ),( Seheum Hong ),( Dong Hyup Park ),( Seok-ho Hwang ) 한국고무학회 2019 엘라스토머 및 콤포지트 Vol.54 No.1

Four different diisocyanates (IPDI; isophorone diisocyanate, HDI; hexamethylene diisocyanate, HMDI; dicyclohexylmethane-4,4'-diisocyanate, and XDI; m-xylylene diisocyanate) were used to prepare polyurethane gel-coats, and the weatherabilities, physical properties, and surface characteristics of the gel-coats were investigated with respect to the chemical structure of the diisocyanates. The weathering test results indicated that all of the diisocyanates used in this study were suitable for use in the preparation of the polyurethane gel-coat. However, the set-to-touch times and physical properties of the polyurethane gel-coat indicated that the cycloaliphatic diisocyanate (IPDI and HMDI) were ideal for the preparation of polyurethane gel-coats.