556…NICE, 제32권 제4호, 2014 Korean Journal of Chemical Engineering, Vol.31, No.7, 1095-1104, 2014
Organic solar cells based on conjugated polymers: History and recent advances
Kim H, Nam S, Jeong J, Lee S, Seo J, Han H, Kim YAbstract - Organic solar cells have attracted huge attention because of their potential in the low-cost manufacturing of plastic solar modules featuring flexible, lightweight, ultrathin, rollable and bendable shapes. The power conversion efficiency of organic solar cells is now passing ~10%, which is a critical sign toward commercialization because organic solar cells surpass any other types of solar cells in terms of development speed. The encouraging efficiency enhancement could be realized by introducing a ‘bulk heterojunction’concept that overcomes the weakness of organic semiconductors by minimizing their charge transport paths through making effective p-n junctions inside bulk organic films. However, there are several hurdles for commercialization, including stability and lifetime issues, owing to the bulk heterojunction concept. This review summarizes the important aspects of organic solar cells, particularly focusing on conjugated polymers as an active layer component.
Korean Journal of Chemical Engineering, Vol.31, No.7, 1110-1114, 2014
Does lower energy usage mean lower carbon dioxide emissions?- A new perspective on the distillation process
Andika R, Husnil YA, Lee M
Abstract - Although fossil fuels play an important role as the primary energy source that currently cannot be replaced easily with other energy sources, their depletion and environmental impact are becoming major concerns. Improvements in energy efficiency are believed to solve both problems simultaneously. We examined the relationships between the improvement in energy efficiency, energy usage and CO2emissions in industry, especially in the distillation process. The energy efficiency improvement of dimethyl ether (DME) purification performed with dividing-wall column distillation (DWC) and acetic acid recovery performed with mechanical vapor recompression (MVR) were evaluated by recalculating the amount of fuel burnt and its CO2emission. The results showed that the paradigm of lower energy being directly proportional to lower CO2emissions is not entirely correct. To avoid this confusion, a tool for examining the uncommon behavior of various systems was developed.
Korean Journal of Chemical Engineering, Vol.31, No.7, 1168-1173, 2014
Effect of La
2O
3promoter on NiO/Al
2O
3catalyst in CO methanation
Qin H, Guo C, Wu Y, Zhang JAbstract - A series of NiO/Al2O3catalysts promoted by different La2O3contents were prepared by impregnation method.
The physicochemical properties of NiO-La2O3/Al2O3were characterized by N2adsorption-desorption, X-ray diffraction (XRD), H2temperature programmed reduction (H2-TPR) and H2chemisorption. The effect of La2O3on the activity of NiO/Al2O3for CO methanation was investigated in a fixed bed reactor. A lifetime test, as well as thermogravimetric (TG)analysis, was performed to investigate the stability performance and anti-carbon deposition of catalysts. The results showed that the addition of La2O3can restrain the growth of NiO particles, increase the H2uptake and Ni dispersion, and therefore enhance the activity of catalysts. When the La2O3content was 3 wt%, a CO conversion of 98% and a selectivity to CH4 of 96% were obtained at 400 ℃. Furthermore, the catalyst NiO-La2O3/Al2O3with 3 wt% La2O3content displayed highly stable performance in long-term tests, especially exhibiting good anti-carbon deposition property.
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NEWS & INFORMATION FOR CHEMICAL ENGINEERS, Vol. 32, No. 4, 2014…557 Korean Journal of Chemical Engineering,
Vol.31, No.8, 1289-1305, 2014
Functionalization of magnetic nanoparticles for biomedical applications
Nguyen DT, Kim KSAbstract - Interest in utilizing magnetic nanoparticles for biomedical treatments originates from their external controllability of transportation and movement inside biological objects and magnetic heat generation. Advances in nanoparticle and nanotechnology enable us to produce magnetic nanoparticles of specific morphology and to engineer particle surfaces to manipulate their characteristics for specific applications. Intensive investigations and developments have been carried out in improving the quality of magnetic particles, regarding their size, shape, size distribution, their magnetism and their surface. The magnetic nanoparticles with appropriate surface chemistry can conjugate various biomaterials such as drugs, proteins, enzymes, antibodies, or nucleotides to be used for numerous in vivo applications including MRI contrast enhancement, immunoassay, hyperthermia, drug delivery, and cell separation. Here we review both the key technical principles of magnetic nanoparticle synthesis and the ongoing advancement of biomedical treatments using magnetic nanoparticles, specifically, the advancement in controlled drug delivery and hyperthermia.
Korean Journal of Chemical Engineering, Vol.31, No.8, 1306-1315, 2014
Surface forces apparatus and its applications for nanomechanics of underwater adhesives
Oh DX, Shin S, Yoo HY, Lim C, Hwang DSAbstract - Successful adhesion on wet surfaces is one of the most important challenges in biomedical engineering. Marine fouling organisms exhibit effective adhesion for wet substrates, and the measurement of adhesion forces in wet conditions is the first step toward mimicking the smart strategies of the marine organisms. Surface forces apparatus (SFA) is one of the most powerful nanomechanical tools used to directly measure time- and distance-dependent interactions between biological macromolecules or biological surfaces in an aqueous medium at the molecular level. Recently, SFA has been adapted to probe the biomechanical nature of the underwater adhesive in marine organisms. This review describes some strategies of the marine fouling organisms for successful underwater adhesion determined using SFA.
Korean Journal of Chemical Engineering, Vol.31, No.8, 1480-1489, 2014
Influence of thermally induced, dehydroxylated nanoclay on polymer nanocomposites
Pandey P, Mohanty S, Nayak SKAbstract - This work reports a novel approach towards a chemical-free treatment of nanoclay through extensive thermal exposure. Dehydroxylation at high temperature was utilized to enhance the influence of nanoclay on the properties of polymer. The effect of this treatment of nanoclay, on the polymer properties, with reference to Polypropylene (PP) has been investigated. The FTIR spectra revealed the successful removal of water from the intergallery spacing of the nanoclay. The maintained structural configuration of the clay was confirmed using WAXD pattern. The uniform dispersion and exfoliation of thermally treated clay layers inside the polymer matrix was confirmed through enhanced mechanical properties. Improved crystallization properties, thermal stability and flame retardant characteristic were also noticed in the nanocomposites reinforced with thermally dehydroxylated clay. This study revealed that the dehydroxylation approach of modification of nanoclay may provide much enhanced properties of polymer, without involvement of any chemical for modification.
558…NICE, 제32권 제4호, 2014 Korean Chemical Engineering Research, Vol.52, No.3, 279-288, 2014
파이로프로세싱을 위한 전해환원 공정기술 개발
Electrochemical Reduction Process for Pyroprocessing
최최은은영영, 홍홍순순석석, 박박우우신신, 임임현현숙숙, 오오승승철철, 원원찬찬연연, 차차주주선선, 허허진진목목
Abstract - 원자력발전은 국가의 안정적인 에너지 공급원 및 저탄소 발생 에너지원으로써 기능을 해왔으나, 원
자력발전에 필수적으로 발생하는 사용 후 핵연료 축적이라는 큰 숙제를 안고 있다. 이를 해결하기 위한 방법 중 의 하나가 파이로프로세싱과 소듐냉각고속로를 연계한 사용 후 핵연료의 재활용이다. 용융염 전해공정을 이용 하는 파이로프로세싱은 사용 후 핵 연료에 존재하는 장 반감기 고독성 원소와 고방열 핵종을 분리하여 고준위 폐기물을 줄이면서도 고속로의 원료물질을 공급하고, 소듐냉각고속로에서는 이를 이용하여 전력을 생산한 후 다시 그 사용 후 핵연료를 파이로프로세싱에서 원료물질로 가공하는 개념이다. 파이로프로세싱의 전단부에 해 당하는 전해환원 공정은 산화물 형태의 사용 후 핵연료를 금속으로 전환시켜 후속 공정인 전해정련공정에 금 속을 공급하는 역할을 한다. 파이로프로세싱을 위한 전해환원 공정의 상용화를 위해서는 고용량, 고효율의 시 스템 개발이 요구되므로 양극과 음극에서 공정 속도의 영향을 미치는 인자를 연구하였다.
Korean Chemical Engineering Research, Vol.52, No.3, 366-370, 2014
전자전달증대기(ERE)를 이용한 태양전지의 전력 향상
Improvement of Solar Cell Power Using Electron Relay Enhancer (ERE)
윤윤소소영영, 홍홍주주희희, 김김학학희희, 김김학학수수
Abstract - 태양전지의 전력향상을 위해 외부에 연결된 시스템적인 접근방법으로써 가변병렬공급기(DC1)와 가 변직렬공급기(DC2)가 부착된 전자 전달 증대기(Electron Relay Enhancer: ERE)를 이용한 연구를 수행하였다.
DC1의 전압이 태양전지 전압보다 높을 경우 DC1은 저항과 같은 역할을 하므로 태양전지의 전압이 상승하게 되고 반면 전류는 낮아지게 된다. 이 때 낮아진 전류는 DC2에서 보충해주어 태양전지의 출력이 증가하게 된다.
DC ERE 직-병렬 시스템은 병렬 전압의 1.5~2.0 V 증가로 태양전지의 전압을 2.0~3.0 V 높일 뿐 아니라 전력 증가 율도 약 10% 정도 향상시켰다.
Korean Chemical Engineering Research, Vol.52, No.3, 382-387, 2014
PC/ABS 블렌드의 고속전단성형에 따른 모폴로지 변화에 관한 연구 Study on the Morphology of the PC/ABS Blend by High Shear Rate Processing
이
이동동욱욱, 용용다다경경, 이이한한기기, 최최석석진진, 유유재재정정, 이이형형일일, 김김선선홍홍, 이이기기윤윤, 이이승승구구
Abstract - 본 연구에서는 PC/ABS 블렌드를 고속전단성형법을 사용하여 제조하였고 스크류 회전속도와 전단부 하시간을 공정변수로 하여 이에 따른 블렌드의 모폴로지 변화를 분석하였다. 블렌드의 모폴로지 및 ABS 분산 상의 크기를 주사전자 현미경으로 관찰하여 안정한 상 구조와 최적의 물성을 가지는 고속전단성형조건을 확립 하였고, 전단응력에 의한 블렌드의 열화 현상을 알아보기 위해 기계적 물성의 변화를 측정하였다. 이 때, 스크 류 회전속도는 500 rpm에서 3,000 rpm까지 변화시켰으며 전단부하시간은 10초에서 40초까지 주었다. 고속전단 성형법을 사용하여 제조한 PC/ABS 블렌드 및 고속전단성형을 가하지 않은PC/ABS 컴파운드의 분산상 크기를 명확하게 관찰하기 위하여 블렌드의 단면에 크롬산 수용액을 이용한 에칭공정을 시행하였고 공정 전후의 모폴 로지를 비교 분석하였다. 에칭으로 생긴 블렌드 내의 ABS 홀을 이미지 측정 프로그램인 Image J를 이용하여 측 정한 결과, 스크류 회전속도에 따라 그 크기가 감소하였으며 특히 1,000 rpm 이상의 스크류 회전속도 하에서 제 조된 PC/ABS 블렌드의 경우, 기계적 물성이 급격하게 감소하여 블렌드의 분해가 일어났음을 알 수 있었다. 결 과적으로 PC/ABS 블렌드에 1,000 rpm의 스크류 회전속도를 가한 경우, 나노미터 단위의 분산상을 가지며 가장 안정한 상구조를 관찰할 수 있었고 인장강도 및 신율도 상대적으로 높아서 PC/ABS 블렌드의 최적 고속전단성 형조건이라 할 수 있다.