We developed a positively charged membrane with acid resistance via the introduction of a branched-poly(ethyleneimine) (b-PEI) hydrogel layer onto the surface of a polyethersulfone (PES) membrane, which was achieved by immobilization of b-PEI at the PES membrane surface using cross-linking agent. The combined results of ATR FT-IR, XPS and FE-SEM measurements confirmed that the b-PEI hydrogel layer was successfully coated on the PES NF membrane surface. In particular, the b-PEI hydrogel coated membrane surface had positive charge at whole pH range. The positively charged surface could enhance multivalent ion rejection. As a result, the membrane effectively recovered acid substance under strong acidic condition. Moreover, the selective separation was well preserved after exposure to highly concentrated sulfuric acid solution.

본 발표에서는, 팔라듐계 수소분리막의 구성과 원리, 응용분야, 국내외 연구기관별 연구현황 및 한국에너지기술연구원에서 진행한 연구결과를 소개한다. 다공성지지체의 표면에 치밀질 팔라듐계 합금을 코팅하여, 수소를 선택적으로 분리할 수 있는 분리막의 특성, 모듈구성, 이를 이용한 CCS 공정에 적용예를 통하여 설명한다. 구체적인 내용으로, 1. 분리막 제조부분에서는, 평판형 다공성 니켈지지체 표면에 컬럼형태의 세라믹을 일차적으로 코팅하고, 이의 표면에 팔라듐을 코팅해서 치밀화는 공정을 설명한다. 2. 모듈 부분에서는, 모듈형태에 따른 수소플럭스와 회수율에 미치는 영향을 설명한다. 3. 개발한 분리막/모듈을 이용한 응용공정 소개를 통하여 이의 활용성 및 향후 연구방향을 제시한다.

We reported a novel polymer/metal nanoparticles/electron acceptor composite for facilitated olefin transport and ionic liquid/Cu nanocomposite membrane for facilitated CO2 transport. The electronic structure of the metal nanoparticles such as AgNP and Cu NP surface was tuned by the electron acceptor p-benzoquinone(p-BQ) and ionic liquid to induce positive charges on the surface. The chemically activated metal surface is expected to form complexes with olefin or CO2 molecules, resulting in gas carrier for facilitated transport. Such facilitated transport membranes were applied for separation of olefin/paraffin or CO2/N2 mixtures. In particular, the interaction between gases and the carriers in a permeable polymer matrix or ionic liquid was expected to show excellent separation performance with long-term stability. In this study, the preparation method and characteristics of facilitated transport membranes will be introduced in detail.

Gas separation is one of the major chemical processes to manufacture petrochemicals and to recover the valuable chemicals from mixtures. However, the conventional gas separation processes requires enormous energy consumption and high costs. Membrane-based gas separation has been a major separation technology for various applications including natural gas sweetening, nitrogen generation, olefin/paraffin separation, CO2 capture, and biogas upgrading, etc. Most commercial gas separation membranes have been prepared using polymeric materials (e.g. cellulose acetate, polyimide, polyamideimide, polysulfone, and poly(dimethyl siloxane)(PDMS), etc.) as the form of hollow fiber membrane or thin film composite (TFC). In this presentation, polymeric gas separation membranes will be briefly introduced in terms of materials and fabrication methods.

Amphiphilic copolymeric membranes are ideally suited for separation of greenhouse gases and control its emission to the environment. Amphiphilic copolymers are a class of polymer that self-assemble in a nanophase domain. Amphiphilic copolymers are also useful in the pressure retarded osmosis process in which clean energy is generated from sea water which is highly essential at the current demand of clean and renewable energy demand. Mixed matrix membrane is another kind of separation process in which the pristine polymer are mixed with inorganic counterpart to prepare higher selectivity as well as permeability. Amphiphilic copolymer comes into handy again due to its synergistic effect mainly with the hydrophilic counterpart and the inorganic filler introduced into the copolymer.

We have studied ternary polymer blend system (A-B/C), which A and C polymers have attractive interactions. The blend was prepared as thin layer coating on the top of the supporting membrane, such as alumina, by layer-by-layer deposition of each polymer from the diluted solution. By controlling the fraction of polymer, the morphology of the blend showed various states including inter-connected porous structure at a certain condition. In addition, we tried to have the better control in pore size and function by introducing small molecule-containing layers atop of the blended coating. The selectivity of filtering and flux of the coated membrane was studied by filtration experiments with aqueous mixtures of various sized solutes including inorganic and organic compounds. Beneficially, the active layer coating exhibited anti-fouling effect.

Zeolite membranes can be used as vapor separation membranes due to the adsorption properties of zeolite crystals. Recently, vapor separation membranes are paid attention in the petrochemical complexes by combining with distillation separation methods. Heat duty for separation can be reduced by the combination of distillation and membrane. Zeolite membranes are usually crystalized on porous ceramic substrates such as a porous alumina substrates. Here, we had paid attention to novel porous silica substrates. In this study, effects of porous silica substrates on preparation of MFI zeolite membranes were investigated to obtain high permselective membranes. Acetic acid vapor permeation tests were conducted for the typical application in the petrochemical complexes. Porous silica (pore size: 500 nm) or porous α-alumina (pore size: 700 nm) were used as ceramic substrates. The seed crystals were coated by changing the seed slurry (0.5g L-1) of pH from 2 to 12. MFI membranes were crystalized at 180 °C for 16 h. The parent gel compositions for the membranes synthesis were SiO2: TPABr: Na2O: H2O=1: 0.2: 0.04: 600 (mol/mol). Vapor permeation tests of acetic acid/water were carried out at 110 °C. N2 permeance through the membrane prepared on the silica substrate was 3.6 × 10-6 mol m-2 s-1 Pa-1, while that through the membrane prepared on the alumina substrate was only 1.4 × 10-6 mol m-2 s-1 Pa-1. The initial resistance through the alumina substrate was lower than that through the silica substrate. This shows that the effective MFI layer was thinner on the silica substrate. N2 permeances through all the membranes were similar at around 4 × 10-6 mol m-2 s-1 Pa-1. The maximum N2/SF6 permeance ratio was 79.3 through the membrane coated at pH 2. Thus, seed coating was important to obtain high gas permselective membranes. The separation factor of acetic acid through the MFI membrane was over 20. Thus, we have concluded the MFI membrane was acetic acid permselective membrane.

Although disinfection in drinking water treatment plants provides a safer water supply by inactivating pathogenic microorganisms, harmful disinfection by-products may be formed. In this study, the disinfectant, chlorine, was produced on-site from the electrolysis of salt (NaCl), and the by-products of the disinfection process, bromate and chlorate, were analyzed. The provisional guideline levels for bromate and chlorate in drinking water are 10 μg/L and 700 μg/L, in Korea, respectively. Bromide salt was detected at concentrations ranging from 6.0 ~ 622 mg/kg. Bromate and chlorate were detected at concentrations ranging from non-detect (ND) ~ 45.3mg/L and 40.5 ~ 1,202 mg/L, respectively. When comparing the bromide concentration in the salt to the bromate concentration in the chlorine produced by salt electrolysis, the correlation of bromide to bromate concentration was 0.870 (active chlorine concentration from on-site production: 0.6–0.8%, n=40). The correlation of bromate concentration in the chlorine produced to that in the treated water was 0.866.

This paper deals with the production plan for the foaming process, the core part of the refrigerator manufacturing process. In accordance with this change, the refrigerator manufacturing process has also been converted into the mixed-model production system and it is necessary to optimize the production release pattern for the foaming process. The pattern optimization is to create a mixed-model combination which can minimize the number of setup operations and maintain mixed-model production. The existing method is a simple heuristic that depends on the demand priority. Its disadvantages are low mixed-model configuration rate and high setup frequency. Therefore, demand partitioning occurs frequently. In this study, we introduce the tolerance concept and propose a new pattern optimization algorithm based the large neighborhood search (LNS). The proposed algorithm was applied to a refrigerator plant and it was found that mixed-model configuration rate can be improved without demand partitioning.

This study was performed to develop patties with quality characteristics using mealworm powder, followed by assessments of general compositions and the branched-chain amino acid (BCAA) levels of the patties. An analysis of the chromaticity of the patties shows that the lightness and yellowness were decreased, whereas the redness was increased, as the amount of mealworm powder was increased. According to the sensory evaluation, the mealworm patty that contain 20% of mealworm powder (M20) showed an overall high preference level. In terms of the mechanical properties, the hardness, gumminess, and chewiness were significantly increased, whereas the springiness and cohesivensee were decreased, as the amount of mealworm powder was increased. The general composition of the M20 consists of 41.84% (moisture), 8.78% (carbohydrates), 34.42% (crude protein), 13.15% (crude fats), and 1.81% (crude ash). The BCAA contents (leucine, isoleucine, and valine) significantly increased in correspondence with the increases of the as mealworm-powder amount regarding the M20, the BCAA composition consists of the following: leucine (2,906.25 mg/100 g), isoleucine (1,459.09 mg/100 g), and valine (1,813.18 mg/100g). The conclusion of this study suggests that mealworm is a potential food material that could possibly replace meat.

다공성 PE (polyethylene) 정밀여과막 지지체 위에 이온교환고분자 물질을 염석법 및 가압법(phase separated and pressurization, PSP)으로 코팅하여 저압용 나노여과막을 제조하였다. 제조한 나노여과막의 코팅유무는 SEM 사진을 통하여 확인하였으며 코팅물질, 코팅시간, 이온세기에 따라 NaCl 100 ppm에서 투과도와 배제율을 측정하였다. PEI와 PSSA_MA의 농도를 동일하게 10,000 ppm으로 하고, 3 atm의 코팅압력을 주어 코팅한 결과, PEI의 투과도는 91.2 LMH, 제거율은 64.6% 이었으며 PSSA_MA의 투과도는 122.7 LMH, 제거율은 38.1%의 결과를 얻을 수 있었다. 본 연구로부터 염석법과 가압법을 통해 복합막 제조가 가능하다는 결론을 얻을 수 있었다.

이 연구는 양이온 불균질막을 제조하기 위해 PVdF와 상용 양이온교환수지를 배합하여 제조하고 최적의 조건제시 및 기존 상용화막과 비교 평가하였다. 연구결과 불균질막이 기존의 상용화막보다 이온교환용량, 전기저항, 함수율 부분에서 높은 물성을 나타내기 위해서는 이온교환수지의 무게 비율을 40% 이상 첨가해야 한다는 것을 확인하였다. 인장강도가 상용화 막보다 높기 위해서는 이온교환수지의 무게 비율을 50% 이하로 첨가해야 한다는 것을 확인하였다. 따라서 화학적 특성과 기 계적 특성을 고려했을 때, PVdF와 이온교환분말의 최적 비율은 60 : 40이며, 이때의 전기저항 1.82 Ω⋅cm-1, 함수율 79%, 이 온교환용량 1.60 meq/g으로 측정되었고 기계적 강도는 0.97 MPa로 측정되었다. 이때, TDS 제거율은 약 40%로 측정되었다.

다공성 지지체인 Polyvinylidene fluoride (PVDF) 중공사막에 염석법을 기반으로 하여 Polyethyleneimine (PEI)와 Polyvinylsulfonic acid (PVSA)를 가압법(phase separated and pressurization, PSP)으로 코팅시켜 다층막을 제조하였다. 이에 열처리 온도, 코팅농도, 유입수 농도, 가교시간 및 가교제 농도에 대하여 NaCl 100 ppm을 공급액으로 하여 4 atm에서 투과 도와 제거율을 알아보고자 하였다. 가장 좋은 결과로는 PEI 20,000 ppm과 PVSA 1,000 ppm, PEI 15%에 말산 2% 수용액으 로 가압코팅 후 열처리하였을 때 투과도 24.3 LMH, 제거율 82.1%의 결과를 얻을 수 있었다.

Fe-30 wt% TiC composite powders are fabricated by in situ reaction synthesis after planetary ball millingof (Fe, TiH2, Carbon) powder mixture. Two sintering methods of a pressureless sintering and a spark-plasma sinteringare tested to densify the Fe-30 wt% TiC composite powder compacts. Pressureless sintering is performed at 1100, 1200and 1300oC for 1-3 hours in a tube furnace under flowing argon gas atmosphere. Spark-plasma sintering is carried outunder the following condition: sintering temperature of 1050oC, soaking time of 10 min, sintering pressure of 50 MPa,heating rate of 50oC/min, and in a vacuum of 0.1 Pa. The curves of shrinkage and its derivative (shrinkage rate) areobtained from the data stored automatically during sintering process. The densification behaviors are investigated fromthe observation of fracture surface and cross-section of the sintered compacts. The pressureless-sintered powder com-pacts are not densified even after sintering at 1300oC for 3 h, which shows a relative denstiy of 66.9%. Spark-plasmasintering at 1050oC for 10 min exhibits nearly full densification of 99.6% relative density under the sintering pressure of50 MPa.

MgB2 bulk superconductors are synthesized by the solid state reaction of (MgB4+xMg) precursors withexcessive Mg compositions (x=1.0, 1.4, 2.0 and 2.4). The MgB4 precursors are synthesized using (Mg+B) powders. Thesecondary phases (MgB4 and MgO) present in the synthesized MgB4 are removed by HNO3 leaching. It is found thatthe formation reaction of MgB2 is accelerated when Mg excessive compositions are used. The magnetization curves ofMg1+xB2 samples show that the transition from the normal state to the superconducting state of the Mg excessive sam-ples with x=0.5 and x=0.7 are sharper than that of MgB2. The highest Jc-B curve at 5 K and 20 K is achieved forx=0.5. Further addition of Mg decreases the Jc owing to the formation of more pores in the MgB2 matrix and smallervolume fraction of MgB2.

We report on the succesful fabrication of ZnO nanorod (NR)-based robust piezoelectric nanogenerators(PNGs) by using Cu foil substrate. The ZnO NRs are successfully grown on the Cu foil substrate by using all solutionbased method, a two step hydrothermal synthesis. The ZnO NRs are grown along c-axis well with an average diameterof 75~80 nm and length of 1~1.5 µm. The ZnO NRs showed abnormal photoluminescence specrta which is attributedfrom surface plasmon resonance assistant enhancement at specific wavelength. The PNGs on the SUS substrates showtypical piezoelectric output performance which showing a frequency dependent voltage enhancement and polarity depen-dent charging and discharging characteristics. The output voltage range is 0.79~2.28 V with variation of input strain fre-quency of 1.8~3.9 Hz. The PNG on Cu foil shows reliable output performance even at the operation over 200 timeswithout showing degradation of output voltage. The current output from the PNG is 0.7 µA/cm2 which is a typical out-put range from the ZnO NR-based PNGs. These performance enhancement is attributed from the high flexibility, highelectrical conductivity and excellent heat dissipation properties of the Cu foil as a substrate.

GNPs have several excellent mechanical properties including high strength, a good young’s modulus, thermal conductivity, corrosion resistance, electronic shielding, etc. In this study, CF/GNP/Epoxy composites were manufactured using GNP weight ratios of 0.15 wt%, 0.3 wt%, 0.5 wt%, 0.7 wt% and 1 wt%. The composites were manufactured with a mechanical method (3-roll-mill). Tensile, impact and wear tests were performed according to ASTM standards D3039, D256 and D3181, respectively. The results show that the CF/GNP0.3wt%/Epoxy composites have good mechanical properties, e.g., tensile strength and impact and wear resistance. In this study, both carbon fabric and GNPs were used as reinforcements in the composites. The mechanical properties increased and weight loss decreased as the GNP content in the resin films was increased.