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        검색결과 125

        1.
        2024.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this work, the depth of the interphase in graphene polymer systems is determined by the properties of graphene and interfacial parameters. Furthermore, the actual volume fraction and percolation onset of the nanosheets are characterized by the actual inverse aspect ratio, interphase depth, and tunneling distance. In addition, the dimensions of graphene, along with interfacial/interphase properties and tunneling characteristics, are utilized to develop the power-law equation for the conductivity of graphene-filled composites. Using the derived equations, the interphase depth, percolation onset, and nanocomposite conductivity are graphed against various ranges of the aforementioned factors. Moreover, numerous experimental data points for percolation onset and conductivity are presented to validate the equations. The optimal levels for interphase depth, percolation onset, and conductivity are achieved through high interfacial conductivity and large graphene nanosheets. In addition, increased nanocomposite conductivity can be attained with thinner nanosheets, a larger tunneling distance, and a thicker interphase. The calculations highlight the considerable impacts of interfacial/interphase factors and tunneling distance on the percolation onset. The highest nanocomposite conductivity of 0.008 S/m is acquired by the highest interfacial conduction of 900 S/m and graphene length (D) of 5 μm, while an insulated sample is observed at D < 1.2 μm. Therefore, higher interfacial conduction and larger nanosheets cause the higher nanocomposite conductivity, but the short nanosheets cannot promote the conductivity.
        4,200원
        2.
        2024.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        식품 포장 분야에서 바이오센서와 바이오폴리머 기반 나 노복합체, 즉 바이오나노복합체의 통합이 점차 산업 전문 가들에 의해 인식되고 있으며, 이는 식품의 품질과 안전 에 대한 우려가 증가함에 따라 주도되고 있습니다. 식품 포장에 내장된 바이오센서는 포장된 상품의 미생물에 의 한 변질을 지속적으로 모니터링함으로써 식품의 완전성을 유지하는 핵심 요소로 업계를 변화시킬 준비가 되어 있다. 동시에, 탁월한 기계적, 열적, 광학적, 항균적 특성으로 인 해 바이오폴리머 기반 나노복합체의 연구와 적용이 크게 확대되었다. 이러한 특성은 이들을 혁신적인 포장 솔루션 에 적합한 주요 재료로 만든다. 그러나 지능형 식품 포장 시스템 발전에 바이오센서와 바이오나노복합체를 사용하 는 잠재적인 장애물과 전망을 탐구하는 것은 아직 충분하 지 않다. 바이오나노복합체와 바이오센서의 융합을 제안 하는 것은 스마트 포장 산업을 재정의하는 획기적인 단계 로, 이 기술들을 더 깊이 이해하여 지속 가능하고 경제적 으로 실행 가능한 스마트 포장 옵션의 개발을 촉진할 필 요성을 강조한다. 이 리뷰는 바이오센서와 바이오나노복 합체에 대한 기존 연구와 개발 동향을 철저히 검토하고, 가까운 미래에 스마트 식품 포장 산업에서 진전을 이끌어 낼 앞으로의 도전과 기회를 강조하는 데 전념하고 있다.
        5,700원
        3.
        2024.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study, a composite material suitable for flexible transparent electrodes was fabricated using Norland Optical Adhesive 68 (NOA 68), an ultraviolet (UV) curable polymer, and silver nanowires (Ag nanowire, AgNW). The mechanical behavior of this composite was then analyzed. A AgNW network structure was embedded in the NOA 68 polymer and cured using UV energy. The composite was prepared with an AgNW network structure formed approximately 4 μm from the top of the NOA 68 matrix. Tensile test specimens were prepared according to ASTM standards, and tensile tests were conducted at room temperature in air. Scanning electron microscopy (SEM) and tensile tests were used to analyze the changes in mechanical behavior according to UV exposure time and the presence of AgNW. The results showed that as UV curing time increased, the yield strength of the composite increased while the elongation decreased. Regardless of the presence of the AgNW filler, the stress-strain curves of the ductile polymer exhibited the typical mechanical behavior of semi-crystalline polymers as UV curing time increased, characterized by strain softening. It was also confirmed that the composite impregnated with AgNW exhibited higher strength in response to changes in mechanical properties due to UV curing.
        4,000원
        4.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper explores the potential application of carbon nanotubes (CNTs) in the construction industry, as CNTs can effectively serve as nano-fillers, bridging the voids and holes in cement structures. However, the limited dispersibility of CNTs in water necessitates the use of dispersing agents for achieving uniform dispersion. In this study, two kinds of cement superplasticizers, polycarboxylate ether (PCE) and sulfonated naphthalene formaldehyde (SNF) were employed as dispersing agents to improve the interfacial affinity between CNTs and cement, and to enhance the strength of the cement nanocomposites. Contact angle experiments revealed that the utilization of PCE and SNF effectively addressed the interface issues between CNTs and cement. As a result, the cement nanocomposite with a CNT to PCE ratio of 1:2 exhibited an approximately 6.6% increase in compressive strength (73.05 MPa), while the CNT:SNF 1:2 cement composite showed a 4.7% increase (71.72 MPa) compared to plain cement (68.52 MPa). In addition, the rate of crack generation in cement nanocomposites with CNTs and dispersing agents was found to be slower than that of plain cement. The resulting cement nanocomposites, characterized by enhanced strength and durability, can be utilized as safer materials in the construction industry.
        4,600원
        6.
        2024.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Ni-CNT nanocomposites were synthesized via the electrical explosion of wire (EEW) in acetone and deionized (DI) water liquid conditions with different CNT compositions. The change in the shape and properties of the Ni-CNT nanopowders were determined based on the type of fluids and CNT compositions. In every case, the Ni nanopowder had a spherical shape and the CNT powder had a tube shape. However, the Ni-CNT nanopowders obtained in DI water exhibited irregular shapes due to the oxidation of Ni. Phase analysis also revealed the existence of nickel oxide when using DI water, as well as some unknown peaks with acetone, which may form due to the metastable phase of Ni. Magnetic properties were investigated using a Vibrating Sample Magnetometer (VSM) for all cases. Nanopowders prepared in DI water conditions had better magnetic properties than those in acetone, as evidenced by the simultaneous formation of super paramagnetic NiO peaks and ferromagnetic Ni peaks. The DI water (Ni:CNT = 1:0.3) sample revealed better magnetic results than the DI water (Ni-CNT = 1:0.5) because it had less CNT contents.
        4,000원
        7.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Determination of Idarubicin (IDA) as an anthracycline derivative and extensively used treatment of leukemia was investigated by electrochemical method using carbon paste electrode (CPE) modified with NiO/SWCNTs nanocomposite and 1-ethyl-3-methylimidazolium chloride (EMCl). The NiO/SWCNTs nanocomposites and EMCl play an important catalytic role in improving the electron transfer process at surface of CPE to monitoring of IDA. Electrochemical method was used to investigation redox behavior of IDA at surface of the NiO/SWCNTs/EMCl/CPE. The oxidation signal of IDA amplified by modification of CPE by NiO/SWCNTs and EMCl was about 4.3 times and NiO/SWCNTs/EMCl/CPE detected IDA in concentration range of 0.001–160 μM with detection limit of 0.5 nM, respectively. The evaluation of analytical and recovery data confirms the mentioned method was completely validated and successfully employed for the determination of IDA in real samples.
        4,000원
        8.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hybrid nanocomposites of aluminium (NHAMMCs) made from AA5052 are fabricated via stir casting route by reinforcing 12 wt% Si3N4 and 0.5 wt% of graphene for usage in aeronautical and automotive applications due to the lower density and higher strength to weight proportion. The wear characteristics of the NHAMMCs are evaluated for different axial load, rotational speed, sliding distance and sliding time based on Box-Behnken design (BBD) of response surface methodology (RSM). Orowan strengthening mechanism is identified from optical image which improves the strength of the composite. Outcomes show that with higher axial load and rotational speed, there is substantial increase in wear loss whereas with increased sliding distance and sliding time there is no considerable increase in wear loss due to the lubricating nature of the reinforced graphene particles since it has higher surface area to volume ratio. Besides, artificial intelligence approach of neuro-fuzzy (ANFIS) model is developed to predict the output responses and the results are compared with the regression model predictions. Prediction from ANFIS outplays the regression model prediction.
        6,400원
        9.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present studies explored the possibility of immobilizing phosphocholine (PC) liposomes on the surface of graphene oxide (GO) which was pre-adsorbed with two kinds of enzymes, horseradish peroxidase and glucose oxidase. The transmission electron microscope images showed that the PC liposomes adsorbed onto the GO surface kept integrity. By using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)-encapsulated liposomes, a one-step colorimetric assay for glucose was developed. In the presence of glucose, the GO nanocomposites catalyzed the cascade enzymatic reaction producing colorimetric signals directly. Under the optimal conditions, the GO nanocomposites produced linearly increased colorimetric signal with increased concentrations of glucose ranging from 50 to 500 μM. The detection limit was 33 μM. The GO nanocomposites also exhibited good selectivity for the detection of glucose and were able to detect glucose in human serum.
        4,200원
        10.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        나노복합재료는 다기능성과 고성능을 가지는 혁신적인 복합재료이다. 나노 스케일 필러의 혼입함으로써 복합재료의 전기적, 역학 적 및 열적 특성이 크게 향상될 수 있기 때문에 나노 스케일 필러를 이용한 나노복합재료의 특성화에 관한 다양한 연구가 광범위하게 수행되어 왔다. 특히, 탄소계 나노 필러(탄소나노튜브, 카본블랙, 그래핀 나노판 등)를 활용하여 전기/역학적 특성을 향상시킨 나노복 합소재 개발에 관한 연구들이 복합재료 분야에서 큰 관심을 받고있다. 본 논문은 실제 응용에 필수적인 나노복합재료의 전기/역학적 특성을 문헌조사를 통해 고찰하는 것을 목표로 한다. 또한, 나노복합재료의 전기/역학적 특성 예측을 위한 최신 멀티스케일 모델링 연 구들에 대해서 검토하고, 멀티스케일 모델링에 대한 과제와 향후 발전 가능성에 대해서 논의한다.
        4,000원
        11.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Epoxy resin (EP) is a thermosetting resin with excellent properties, but its application is limited due to its high brittleness and poor flame retardancy. Therefore, to solve this problem, a dispersion system of imidazole-containing ionic liquid ([Dmim]Es) and graphene in epoxy resin is designed based on the π–π stacking effect between imidazole and graphite layers. The study on the thermal and flame-retardant properties of the composites show that the modified [Dmim]Es–graphene nanosheets improved the flame retardancy, smoke suppression and thermal stability of epoxy resin. With the addition of 5wt% [Dmim]Es and 1% Gra, the exothermic rate (HRR) and total exothermic (THR) of the composites decrease by 35% and 30.2% compared with the untreated epoxy cross-linking, respectively. The limiting oxygen index reaches 33.4%, the UL-94 test rating reaches V-0. The characterization of mechanical properties shows that the tensile properties and impact properties increased by 13% and 30%, respectively. Through SEM observation, the addition of [Dmim]Es improves the dispersion of graphene in the EP collective and changes the mechanical fracture behavior. The results show that ionic liquid [Dmim]Es-modified graphene nanosheets are well dispersed in the matrix, which not only improves the mechanical properties of epoxy resin (EP), but also has a synergistic effect on flame retardancy. This work provides novel flame-retardant and graphene dispersion methods that broaden the range of applications of epoxy resins.
        4,900원
        13.
        2022.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Tin-antimony sulfide nanocomposites were prepared via hydrothermal synthesis and a N2 reduction process for use as a negative electrode in a sodium ion battery. The electrochemical energy storage performance of the battery was analyzed according to the tin-antimony composition. The optimized sulfides exhibited superior charge/discharge capacity (770 mAh g-1 at a current density of 100 mA g-1) and stable lifespan characteristics (71.2 % after 200 cycles at a current density of 500 mA g-1). It exhibited a reversible characteristic, continuously participating in the charge-discharge process. The improved electrochemical energy storage performance and cycle stability was attributed to the small particle size, by controlling the composition of the tin-antimony sulfide. By optimizing the tin-antimony ratio during the synthesis process, it did not deviate from the solubility limit. Graphene oxide also acts to suppress volume expansion during reversible electrochemical reaction. Based on these results, tin-antimony sulfide is considered a promising anode material for a sodium ion battery used as a medium-to-large energy storage source.
        4,000원
        14.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pentachlorophenol (PCP), as one of the common pesticide and preservatives, is easily accumulated in living organisms. Considering the high toxicity of PCP, the development of an effective and sensitive inspection method to determine the residual trace amounts of PCP continues to be a significant challenge. Herein, a convenient and sensitive electrochemical sensor is constructed by modifying glassy carbon electrode with cerium dioxide ( CeO2) nanoparticles anchored graphene ( CeO2-GR) to detect trace PCP. Benefiting from the two-dimensional lamellar structural advantages, the extraordinary electron-transfer properties, as well as the intensive coupling effect between CeO2 nanoparticles and graphene, the afforded CeO2- GR electrode nanomaterial possesses excellent electrocatalytic activity for the oxidation of PCP. Under the optimum synthetic conditions, the PCP oxidation peak currents of developed CeO2– GR sample exhibit a wide linear range of 5–150 μM. Moreover, the corresponding detection limit of PCP on the CeO2– GR electrode is as low as 0.5 μM. Apart from providing a promising electrochemical sensor, this work, most importantly, promotes an efficient route for the construction of highly active sensing electrode materials.
        4,000원
        15.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This work reported the electrochemical and photoelectrochemical (PEC) properties of a new photoelectrode based on hematite Co-Fe2O3@NiO, a photoactive semiconductor, was prepared using a process involving a combination of the co-precipitation and microwave-assisted synthesis of Fe2O3, Co-Fe2O3 and Co-Fe2O3@NiO, respectively. The obtained products were characterized by X-Ray powder Diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray analysis (EDX), Ultraviolet–Visible (UV–vis) analysis, Fourier Transform Infrared spectroscopy (FT-IR). X-ray diffraction (XRD) pattern of the sample determined the crystal structure of α-Fe2O3 nanoparticles. The SEM image shows spherical nanoparticles. FTIR spectrospy spectrum confirmed the phase purity and chemical bond for the sample. Optical studies show a variation of band gap from 2.118 to 2.07 eV. The electrochemical and photoelectrochemical (PEC) performance of the films were examined by cyclic voltammetry, linear sweep voltammetry and chronoamperometry. The electrochemical oxidation of water achieved by Cobalt-doped Fe2O3@ GCE modified electrode exhibited the current density of 21 mA/g at 0.5 V vs. SCE for 5 at% of Co and reveals enhanced specific capacitance of 352.11 F/g. The catalytic performance of urea oxidation was measured by cyclic voltammetry on Co-Fe2O3@NiO nanoparticles modified glassy carbon electrode (GCE) in alkaline medium. The electrode Co-Fe2O3@NiO without annealing showed a peak current density of 1.59 mA/cm2 at 0.1 M urea in 1.0 M NaOH, which was 3.6 fold higher than that of Co-Fe2O3@NiO with annealing. In another part, this work reported the photoelectrochemical (PEC) properties of photoanode prepared by spin coating. The highest photocurrent 0.042 mA/cm2 at 0.5 V Vs SCE was obtained for 5% Co-Fe2O3@NiO while the photocatalytic oxidation of urea.
        5,100원
        16.
        2022.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        NiMoS2 is a promising material for various functional applications and highly compatible with GO to make hybrid nanocomposites with excellent characteristics for supercapacitor electrode material. Deposition of NiMoS2 was achieved on the rGO(reduced Graphene Oxide) surface to form a NiMoS2− rGO nanocomposite by the method of the facile hydrothermal synthesis process. XRD pattern shows the crystalline nature of composites. Raman and EPMA result interpreting the composites formation and elements compositions, respectively. The sheet-like morphology of rGO was found in the composites by FESEM images. Particles distribution was confirmed by HR-TEM. The electrochemical properties of the pure NiMoS2 and NiMoS2– rGO composites have been studied by cyclic voltammetry analysis. The results revealed that the NiMoS2/ 5% rGO nanocomposites exhibit high specific capacitance compared to pure NiMoS2 due to the synergistic effects of NiMoS2 and rGO in the composite material. The photocatalytic behavior of the prepared nanocomposites for dye degradation was tested. The quantity of rGO has significantly improved the photocatalytic behavior of NiMoS2/ rGO composites. The studies on degradation mechanism, the N2 adsorption/desorption isotherms, pore size distribution behavior and % of removal of MB reveal the enhanced photocatalytic performance of sysnthesised composites.
        4,500원
        17.
        2022.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Silver/graphene core/shell nanocomposites were synthesized through a one-step electric explosion of wire method using only silver wires and ethanol. The morphology of the graphene shell structures can be easily formed by alternating the solvent from deionized water to ethanol. Transmission electron microscopy revealed that the size of the prepared silver/graphene core/ shell nanocomposites was in the 10–110 nm range. The Raman spectra showed the formation of graphene shells on silver. A possible formation mechanism of the silver/graphene core/shell nanocomposites is proposed in this study. The crystallinity of the nanoparticles was investigated via X-ray diffraction. The graphene on the surfaces of the nanocomposites containing functional groups was analyzed through Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses. Zeta potential and dynamic light scattering analyses were performed to determine the dispersion characteristics of the nanocomposites when redispersed in other solvents.
        4,000원
        18.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the arsenide removal by using mesoporous CoFe2O4/ graphene oxide nanocomposites based on batch experiments optimized by artificial intelligence tools. These nanocomposites were prepared by immobilizing cobalt ferrite on graphene oxide and then characterized using various techniques, including small angle X-ray diffraction, high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy. Artificial intelligence tools associated with response surface methodology were employed to optimize the conditions of the arsenide removal process. The results showed that back propagation neural network combined with genetic algorithm was suitable for the arsenide removal from aqueous solutions by the nanocomposites based on the minimum average values of absolute errors and the value of R2. The optimal values of the four variables (operating temperature, initial pH, initial arsenide concentration, and contact time) were found to be 25.66 °C, 7.58, 10.78 mg/L and 46.41 min, and the predicted arsenide removal percentage was 84.78%. The verification experiment showed that the arsenide removal percentage was 86.62%, which was close to the predicted value. Three evaluation methods (gradient boosted regression trees, Garson method and analysis of variance) all demonstrated that the temperature was the most important explanatory variable for the arsenide removal. In addition, the arsenide removal process can be depicted with pseudo-second-order kinetics model and Langmuir isotherm, respectively. The thermodynamics investigation disclosed that the adsorption process was of a spontaneously endothermic nature. In summary, this study showed that ANN-GA was an efficient and feasible method in determining the optimum conditions for arsenic removal by CoFe2O4/ graphene oxide nanocomposites.
        4,900원
        19.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, the performance evaluation of Al-graphene nanoplatelets (GNP) composites surface engineered by a modified friction stir processing (FSP) is reported. Here, multiple micro channels (MCRF) are used to incorporate GNPs in the aluminium matrix instead of a single large groove (SCRF) that is usually used in conventional FSP. With the MCRF approach, ~ 18% higher peak temperature (compared to SCRF) was observed owing to the presence of aluminium sandwiched between consecutive microgrooves and higher heat accumulation in the stir zone. The MCRF approach have significantly reduced the coefficient of friction and wear rates of the processed composites by ~ 14% and ~ 57%, respectively as compared to the SCRF approach. The proposed reinforcement filling method significantly improves the particle dispersion in the matrix, which in turn changes the adhesion mode of wear in SCRF to abrasive mode in MCRF fabricated composites. The uniformly squeezed out GNP tribolayer prevented the direct metal to metal contact between composite and its counterpart which have effectively reduced the deterioration rates.
        4,600원
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