Editor’s Choice

Editor’s Choice

636

Korean Journal of Chemical Engineering, Vol.35, No.9, 1765-1778, 2018

Recent advances in protein-based nanoparticles Lee EJ

Abstract - Certain naturally occurring proteins consist of a number of subunit building blocks that are capable of selfassembling to form nanoscale particles with highly organized, symmetrical, and homogeneous structures. These protein- based nanoparticles have high surface/volume ratios and other favorable properties, including mono-dispersibility, high stability, low toxicity, biocompatibility, biodegradability, and capacity for easy genetic and chemical modification. Thus, these particles have attracted considerable research attention and have been manipulated for various applications in different fields. This review describes the engineering of existing protein nanoparticles, with a particular focus on scientific advances in diverse applications, including bioassays, molecular imaging diagnostics, drug delivery, biocatalysis, and materials science. In addition, barriers for the widespread industrial use of such nanoparticles and outlook for the design and creation of novel self-assembled protein-based nanoparticles are considered.

Korean Journal of Chemical Engineering, Vol.35, No.9, 1844-1853, 2018

Synthesis and characterization of CMC/MMT nanocomposite for Cu

sequestration in wastewater treatment Heiba HF, Taha AA, Mostafa AR, Mohamed LA, Fahmy MA

Abstract - Organic-inorganic hybrid nanocomposites are promising materials for remediation of pollutants from wastewater, as they exhibit the unique characteristics of both inorganic and organic materials. In this study, carboxymethyl cellulose/montmorillonite Nanocomposite (CMC/MMT-NC) was prepared and applied for Cu

sequestration. CMC/MMT- NC was characterized by FTIR and SEM before and after the sequestration process, indicating fundamental changes in surface morphology after treatment experiments. The parameters affecting the process such as pH, contact time, CMC/

MMT-NC mass, Cu

concentration and temperature were experimentally adjusted. Statistical regression variables (R

, RMSE, RSS, F-Value and P-Value) were calculated to predict the best-applied isotherm, kinetic and thermodynamic modeling. Freundlich isotherm model successfully described the equilibrium data, which implies a multilayer adsorption process. Kinetic results were well fitted to pseudo-second-order kinetic model. Intraparticle diffusion (IPD) model showed the control of the boundary layer moreover, IPD model cannot be accepted as the only rate-determining step. The apparent activation energy (Ea) was 35.65 kJ/mol, which revealed a physisorption process. The thermodynamic study in means of ΔG

, ΔH

, and ΔS

demonstrated the feasibility, spontaneity and exothermicity of Cu

sequestration. Application study confirmed the efficiency of CMC/MMT nanocomposite to remediate Cu

from synthetic and natural polluted seawater.

Korean Journal of Chemical Engineering, Vol.35, No.9, 1854-1859, 2018

Improved reutilization of industrial crude lysine to 1,5-diaminopentane by enzymatic decarboxylation using various detergents and organic solvents

Kim HY, Yoo HY, Kim YH, Kim IK, Byun EH, Yang YH, Park SJ, Na JG, Sohn HS, Lee T, Kim JR, Park CH

Abstract - World-wide production of L-lysine has rapidly increased in recent years. In the industrial scale production, it is

cost effective to minimize waste as many waste materials are generated during downstream processing. Therefore, the

conversion of crude lysine to a more valuable product reduces waste emission. In this study, 1,5-diaminopentane (DAP,

trivial name: cadaverine) was produced by L-lysine decarboxylation using Hafnia alvei. The conditions of enzymatic

reaction were determined. In particular, the addition of specific detergent (Brij 56) was significantly affected in the

bioconversion system. Addition of hydrophobic organic solvent improved the mixing of the reactants. Finally, an industrial

crude form of lysine served as a substrate. The DAP conversion by analytical, feed and industrial crude Llysine was 93.9%,

90.3%, and 63.8%, respectively.

Editor’s Choice

NEWS & INFORMATION FOR CHEMICAL ENGINEERS, Vol. 36, No. 5, 2018 …

637 Korean Journal of Chemical Engineering,

Vol.35, No.10, 1955-1968, 2018

A review and recent developments on strategies to improve the photocatalytic elimination of organic dye pollutants by BiOX (X=Cl, Br, I, F) nanostructures

Singh S, Sharma R, Khanuja M

Abstract - The main environmental problems associated with water body pollution are typically those caused by the discharge of untreated effluents released by various industries. Wastewater from the textile dye industry is itself a large contributor and contains a huge number of complex components, a wide spectrum of organic pollutants with high concentration of biochemical oxygen demand (BOD)/chemical oxygen demand (COD) and other toxic elements. One of several potential techniques to degrade such reactive dyes before being discharged to water bodies is photocatalysis, and bismuth-based photocatalysts are rapidly gaining popularity in this direction. Bismuth oxyhalides, BiOX (X=Cl, Br, I, F), as a group of ternary compound semiconductors (V-VI-VII), have been explored extensively for their photocatalytic activity due to their unique crystal attice with special layered structure in pure as well as modified form. With suitable band gap and band edge positions, which are a required condition for efficient water breakup and high photon absorption, BiOCl scores over other oxyhalides. Photocatalytic activity depends on many factors such as synthesis method, morphology, size, illumination type, dye choice among others. This paper gives a critical review on bismuth oxyhalides as a family on various aspects of modifications such as doping (with unique and interesting metals as well), morphology and synthesis parameters, polymer and carbon assisted composites in order to further enhance the photocatalytic efficiency in UV/visible region of solar spectrum.

Korean Journal of Chemical Engineering, Vol.35, No.10, 2036-2042, 2018

Nanoliter scale microloop reactor with rapid mixing ability for biochemical reaction Jeong SG, Jeong JH, Kang KK, Jin SH, Lee BJ, Choi CH, Lee CS

Abstract - The mixing rate is a crucial factor in determining the reaction rate and product distribution in reactors for academic and industrial application. Especially, in pharmaceutical or dangerous chemistry, it is essential to create rapidly homogeneous mixture under the control of a small volume of precious sample. In this study, we propose a microloop reactor that is capable of rapid mixing for homogeneous reaction by utilizing programmable actuated microvalves (PAVs), which can generate the rotary flow rapid mixing in the reactor. The microloop reactor is composed of a stacked layered structure, which is prepared by a soft lithography method. The top layer (fluidic layer) has microchannels for supplying each reagent that is assembled with the bottom layer (control layer). The bottom layer has ultrathin polymer membrane, which can be an on-off valve to precisely control the nanoliter-scale volume of reagents in the reactor. To evaluate mixing performance, we use peroxidase reaction that produces fluorescent by-product (resorufin), thereby observing how fast they are mixed together. We quantify the uniformity of fluorescent intensity throughout the reaction loop, indicating that our proposed microloop reactor exhibits a homogeneous reaction. We envision the microreactor has potential to provide optimized microenvironments in which to perform dangerous chemistry, pharmaceuticals.

Korean Journal of Chemical Engineering, Vol.35, No.10, 2127-2132, 2018

Photo-synthesized copper phenylacetylide nanobelts with preferential photocatalytic active facet exposure Xie X, Qiu Y, Zhao S, Jiang HY, Lu J

Abstract - We recently reported that PhC

Cu nanobelt exhibits excellent photocatalytic degradation of organic pollutants

and activation of molecular O

. However, there has been no further research about the relationship between its crystal

structure and photocatalytic activity. Herein, a new safe and energy-save method, photo-synthesis, to prepare PhC

Cu

nanobelts with preferential active exposure facet was developed. It was used to study the relationship between its crystal

Editor’s Choice

638

structure and photocatalytic activity, compared to the PhC

Cu nanobelts prepared by thermal-synthesis method. The prepared samples were characterized by X-ray powder diffractometer (XRD), field-emission scanning electron microscopy (FE-SEM), ultraviolet-visible (UV-vis) absorbance spectra and diffuse reflectance spectra (UV-vis Abs and DRS), N

adsorption-desorption isotherms, FT-IR and Raman spectra. The degradation of MB experiments under visible light irradiation shows that the photocatalytic activity of PhC

Cu prepared by photo-synthesis method is much higher than that by traditional thermal-synthesis method. Moreover, the photocatalytic mechanism of PhC

Cu nanobelts was further studied by the photocatalytic generation of O

· and .OH.

Korean Chemical Engineering Research, Vol.56, No.4, 461-468, 2018

용매증발법을 이용한 Poly-L-Lactic Acid (PLLA) 마이크로스피어 제조

Preparation of Poly-L-Lactic Acid (PLLA) Microspheres by Solvent-Evaporation Method 김태형, 송기창

Abstract - Poly-L-lactic acid (PLLA)를 출발물질로 하여 용매증발법에 의해 마이크로스피어를 제조하고, 제조 변수가 형성된 마이크로스피어의 형상 및 평균 입경에 미치는 영향을 살펴보았다. PVA 수용액의 농도가 1~5 wt%로 증가함에 따라 평균 입경이 370~160 μm으로 감소하다가 7 wt%에서 다시 240 μm으로 증가하였다. 그리고 PVA의 첨가 부피가 10~50 mL 로 증가함에 따라 평균 입경은 370~220 μm으로 감소하였다. 또한 교반속도가 500~1,500 rpm으로 증가함에 따라 평균 입경은 370~110 μm으로 감소하였다. 유기용매로써 dichloromethane과 chloroform을 각각 사용한 경우 평균 입경은 큰 차이를 보이지 않았으며, dichloromethane을 사용한 경우 표면에서 공극이 확인되었으나 chloroform을 사용한 경우 매끈한 형상의 구형입자가 얻어졌다.

Korean Chemical Engineering Research, Vol.56, No.4, 585-591, 2018

미세액적 유동반응기 공정에서 연속제조된 나노구조 SiO

: Zn 원환형 입자의 특성

Characteristics of Nano-structured SiO

: Zn Hollow Powders Prepared in the Micro Drop Fluidized Reactor (MDFR) Process

양시우, 강 용, 강 호

Abstract - 미세액적 유동반응기 공정에서 제조된 나노구조 SiO

:Zn 원환형 입자의 특성을 밴드갭 에너지와 표면 반응성의 관점에서 고찰하였다. SiO

:Zn 원환형 입자를 단일 공정에서 연속적이며 합리적인 생산 효율로 첨가제인 THAM(tris(hydroxymethyl)-aminomethane)과 도핑되는 Zn2+ 이온의 농도 변화에 따라 성공적으로 제조할 수 있었다.

그리고 Zn

이온의 도핑은 Si

이온의 conduction band 보다 에너지 레벨이 낮은 Zn

이온의 acceptor level을 형성함으로써 SiO

:Zn 원환형 입자의 밴드갭 에너지를 줄일 수 있었다. 또한, 입자의 원환형 구조는 SiO

:Zn 입자의 밴드갭 에너지를 감소시키는데 기여하였다. 따라서 Zn

이온이 도핑된 SiO

:Zn 원환형 입자는 표면에 SiO-H의 형성과 산소 결함의 생성으로 표면 반응성을 증대시킬 것으로 사료되었다.

Korean Chemical Engineering Research, Vol.56, No.4, 469-473, 2018

순수 수소 공급조건에서 정치용 PEMFC MEA와 차량용 MEA 성능비교

Performance Comparison Between Stationary PEMFC MEA and Automobile MEA under Pure Hydrogen Supply Condition

오소형, 이미화, 이학주, 김욱원, 박정우, 박권필

Abstract - 개질가스를 일반적으로 사용하는 정치용 PEMFC에 순수 수소를 공급했을 때 그 특성을 차량용 막과 전극 합체(MEA) 와 비교하였다. 수소 공급량을 변화시키며 anode에서 수소공급량이 전체 성능에 미치는 영향을 비교하였다.

수소를 1.0~1.7 과잉(stoi.)범위에서 공급량을 변화시켰을 때 정치용이나 차량용 모두 OCV에 미치는 영향은 거의 없었다.

0.7 V에서 정치용 MEA의 전류밀도는 차량용보다 약 16% 높았다. 그리고 상대습도를 변화시키며 I-V 성능, 임피던스,

LSV 를 측정하였다. 상대습도 증가에 따라 OCV와 전해질 막 저항이 모두 감소하였다. 정치용 MEA의 수소투과도가

차량용보다 더 낮아 정치용 MEA의 전해질 막의 내구성이 차량용보다 더 높을 수 있음을 보였다.