본 연구에서는 산 폐수에서 효율적인 산-금속이온 분리를 위한 전기투석 공정에 적용할 수 있는 1가 이온에 대한 높은 선택성을 가진 양이온 교환막의 제조에 관한 연구를 수행하였다. 설폰산기를 가진 sodium 4-vinylbenzenesulfonate (NaSS), 포스폰산기를 가진 vinylphosphonic acid (VPA) 단량체 및 가교제를 비대칭 구조의 다공성 지지체에 충진하고 in-situ 광중합을 통해 세공충진 양이온 교환막을 제조하였다. 제조된 세공충진 양이온 교환막은 상용막 대비 이온교환용량이 다소 낮았으나 실제 응용에 적합한 수준의 전기적 저항 및 기계적 물성을 나타내었다. 다양한 NaSS:VPA 몰 비율로 제조된 세공충진 양이온 교환막과 상용막(CSE, Astom, Japan)의 H+/Fe2+ 혼합용액에서의 선택투과도를 측정한 결과 NaSS:VPA = 25:75 조건에서 가장 우수한 선택투과도를 확인하였으며 이는 상용막 대비 10 이상 높은 값이었다. 또한 최적 조건의 제조막 을 이용한 H+/Fe2+ 혼합용액의 전기투석 결과 상용막 대비 우수한 산-금속 이온 분리 성능을 확인할 수 있었다. 이온전도성이 우수한 설폰산기와 금속이온에 대한 결합력이 강한 포스폰산을 함께 도입한 양이온 교환막은 Fe2+ 이외에도 산 폐액으로부터 다양한 유가 금속이온을 분리하는 데 효과적일 것으로 기대된다.

As the demand for electric vehicles increases, the stability of batteries has become one of the most significant issues. The battery housing, which protects the battery from external stimuli such as vibration, shock, and heat, is the crucial element in resolving safety problems. Conventional metal battery housings are being converted into polymer composites due to their lightweight and improved corrosion resistance to moisture. The transition to polymer composites requires high mechanical strength, electrical insulation, and thermal stability. In this paper, we proposes a high-strength nanocomposite made by infiltrating epoxy into a 3D aligned h-BN structure. The developed 3D aligned h-BN/epoxy composite not only exhibits a high compressive strength (108 MPa) but also demonstrates excellent electrical insulation and thermal stability, with a stable electrical resistivity at 200 °C and a low thermal expansion coefficient (11.46×ppm/°C), respectively.

높은 내화학성과 소수성 특성을 갖는 polymethylpentene (PMP) 소재는 polypropylene 소재 대비 결정성이 낮아 dense skin층을 갖는 비대칭 분리막을 제조하기 수월하지만 녹는점이 높아 가공이 용이하지 않다. 본 연구에서는 비용매 유도 상분리법(NIPS)과 열유도 상분리법(TIPS)을 혼합한 N-TIPS 법을 활용하여 polymethylpentene (PMP) 고분자 분리막을 제조 하고 성능과 특성을 평가하였다. Cyclohexane을 용매로 사용하여 PMP 도프용액을 제조하였으며, 상전이조로 물, EtOH, IPA 를 사용하였다. Cyclohexane과 섞이지 않는 물을 비용매로 상전이한 분리막은 TIPS 영향으로 인해 큰 기공과 높은 기체 투과 도를 보였으나, 표면이 거칠고 구조가 불안정한 특성을 보였다. 반면, cyclohexane과 혼합될 수 있는 알코올류(ethanol, isopropanol) 를 상전이조로 사용한 경우 NIPS 효과로 인해 dense skin층이 형성됨을 확인하며, 높은 기계적 강도를 보였다. 추가 적인 기공형성을 위해 polyethylene glycol (PEG)를 첨가한 경우 기체투과도가 높아지는 결과를 얻을 수 있었다.

In order to maximize the function and increase the compatibility of silicone hydrogel lens, this study compared and analyzed the properties of Amino modified silicone oil using mini and microemulsion technique, respectively. Optical and physical properties were evaluated by spectral transmittance, refractive index, water content, oxygen transmittance and contact angle measurements to evaluate the performance of the manufactured hydrogel lens. The spectral transmittance results revealed the copolymerization method lens showed 31 % of the visible light area, which did not satisfy the basic optical properties. However, the lens using the mini and microemulsion materials showed more than 90 % of the visible light area, satisfying the optical characteristics. In addition, all physical properties were superior to a basic hydrogel lens. The mini and microemulsion techniques effectively improved the stability and function of the ophthalmic hydrogel lens and are considered a promising ways of manufacturing an ophthalmic hydrogel contact lens with increased compatibility and stability.

In this study, we report significant improvements in lithium-ion battery anodes cost and performance, by fabricating nano porous silicon (Si) particles from Si wafer sludge using the metal-assisted chemical etching (MACE) process. To solve the problem of volume expansion of Si during alloying/de-alloying with lithium ions, a layer was formed through nitric acid treatment, and Ag particles were removed at the same time. This layer acts as a core-shell structure that suppresses Si volume expansion. Additionally, the specific surface area of Si increased by controlling the etching time, which corresponds to the volume expansion of Si, showing a synergistic effect with the core-shell. This development not only contributes to the development of high-capacity anode materials, but also highlights the possibility of reducing manufacturing costs by utilizing waste Si wafer sludge. In addition, this method enhances the capacity retention rate of lithium-ion batteries by up to 38 %, marking a significant step forward in performance improvements.

With the wide application of portable wearable devices, a variety of electronic energy storage devices, including microsupercapacitors (MSCs), have attracted wide attention. Laser-induced graphene (LIG) is widely used as electrode material for MSCs because of its large porosity and specific surface area. To further improve the performance of MSCs, it is an effective way to increase the specific surface area and the number of internal active sites of laser-induced graphene electrode materials. In this paper, N-doped polyimide/polyvinyl alcohol (PVA) as precursor was used to achieve in situ doping of nitrogen atoms in laser-induced graphene by laser irradiation. Through the addition of N atoms, nitrogen-doped laser-induced threedimensional porous graphene (N-LIG) exhibits large specific surface area, many active sites, and good wettability all of which are favorable conditions for enhancing the capacitive properties of laser-induced graphene. After assembly with PVA/H2SO4 as gel electrolyte, the high surface capacitance of the MSC device with N-LIG as electrode material is 16.57 mF cm− 2 at the scanning rate of 5 mV s− 1, which is much higher than the 2.89 mF cm− 2 of the MSC device with LIG as electrode material. In addition, MSC devices with N-LIG as electrode materials have shown excellent cyclic stability and flexibility in practical tests, so they have a high application prospect in the field of flexible wearable microelectronics.

Carbon fibers of polyacrylonitrile (PAN) type were coated with nickel nanoparticles using a chemical reduction method in alkaline hydrazine bath. The carbon fibers were firstly heated at 400 °C and then chemically treated in hydrochloric acid followed by nitric acid to clean, remove any foreign particles and functionalized its graphitic surfaces by introducing some functional groups. The functionalized carbon fibers were coated with nickel to produce 10 wt% Cf/Ni nanocomposites. The uncoated heat treated and the nickel coated carbon fibers were investigated by SEM, EDS, FTIR and XRD to characterize the particle size, morphology, chemical composition and the crystal structure of the investigated materials. The nickel nanoparticles were successfully deposited as homogeneous layer on the surface of the functionalized carbon fibers. Also, the deposited nickel nanoparticles have quazi-spherical shape and 128–225 nm median particle size. The untreated and the heat treated as well as the 10 wt% Cf/Ni nanocomposite particles were further reinforced in ethylene vinyl acetate (EVA) polymer separately by melt blending technique to prepare 0.5 wt% Cf-EVA polymer matrix stretchable conductive composites. The microstructures of the prepared polymer composites were investigated using optical microscope. The carbon fibers as well as the nickel coated one were homogenously distributed in the polymer matrix. The obtained samples were analyzed by TGA. The addition of the nickel coated carbon fibers to the EVA was improved the thermal stability by increasing the thermal decomposition temperature Tmax1 and Tmax2. The electrical and the mechanical properties of the obtained 10 wt% Cf/Ni nanocomposites as well as the 0.5 wt% Cf-EVA stretchable conductive composites were evaluated by measuring its thermal stability by thermogravimetric analysis (TGA), electrical resistivity by four probe method and tensile properties. The electrical resistivity of the fibers was decreased by coating with nickel and the 10 wt% Cf/Ni nanocomposites has lower resistivity than the carbon fibers itself. Also, the electrical resistivity of the neat EVA is decreased from 3.2 × 1010 to 1.4 × 104 Ω cm in case of the reinforced 0.5 wt% Cf/Ni-EVA polymer composite. However, the ultimate elongation and the Young’s modulus of the neat EVA polymer was increased by reinforcing with carbon fibers and its nickel composite.

Vitrification, one of the most promising solidification processes for various materials, has been applied to radioactive waste to improve its disposal stability and reduce its volume. Because the thermal decomposition of dry active waste (DAW) significantly reduces its volume, the volume reduction factor of DAW vitrification is high. The KHNP developed the optimal glass composition for the vitrification of DAW. Since vitrification offers a high-volume reduction ratio, it is expected that disposal costs could be greatly reduced by the use of such technology. The DG-2 glass composition was developed to vitrify DAW. During the maintenance of nuclear power plants, metals containing paper, clothes, and wood are generated. ZrO2 and HfO2 are generally considered to be network-formers in borosilicate-based glasses. In this study, a feasibility study of vitrification for DAW that contains metal particulates is conducted to understand the applicability of this process under various conditions. The physicochemical properties are characterized to assess the applicability of candidate glass compositions.

As environmental concerns escalate, the increase in recycling of aluminum scrap is notable within the aluminum alloy production sector. Precise control of essential components such as Al, Cu, and Si is crucial in aluminum alloy production. However, recycled metal products comprise various metal components, leading to inherent uncertainty in component concentrations. Thus, meticulous determination of input quantities of recycled metal products is necessary to adjust the composition ratio of components. This study proposes a stable input determination heuristic algorithm considering the uncertainty arising from utilizing recycled metal products. The objective is to minimize total costs while satisfying the desired component ratio in aluminum manufacturing processes. The proposed algorithm is designed to handle increased complexity due to introduced uncertainty. Validation of the proposed heuristic algorithm's effectiveness is conducted by comparing its performance with an algorithm mimicking the input determination method used in the field. The proposed heuristic algorithm demonstrates superior results compared to the field-mimicking algorithm and is anticipated to serve as a useful tool for decision-making in realistic scenarios.

해당 연구는 산업 폐수에서 염료를 효율적으로 제거하기 위한 고급 박막 나노복합체(TFN) 기반 나노여과막을 개 발하여 효과적인 폐수 처리 방법을 제시합니다. 최근 연구의 동향을 보면, 나노카본, 실리카 나노스피어, 금속-유기 프레임워 크(MOF) 및 MoS2와 같은 혁신적인 재료를 포함하는 TFN 막의 제조에 중점을 둡니다. 주요 목표는 염료 제거 효율을 향상 시키고 오염 방지 특성을 개선하며 염료/염 분리에 대한 높은 선택성을 유지하는 것입니다. 이 논문은 넓은 표면적, 기계적 견고성 및 특정 오염 물질 상호 작용 능력을 포함하여 이러한 나노 재료의 뚜렷한 이점을 활용하여 현재 나노여과 기술의 제 한을 극복하고 물 처리 문제에 대한 지속 가능한 솔루션을 제공하는 것을 목표로 합니다.