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Featured researches published by Sangmo Kim.


Journal of The Korean Institute of Electrical and Electronic Material Engineers | 2008

Bending Effects of ITO Thin Film Deposited on the Polymer Substrate

Sangmo Kim; You Seung Rim; Hyung-Wook Choi; Myunggyu Choi; Kyung-Hwan Kim

ITO thin film was deposited on PC substrate in Facing Targets Sputtering (FTS) system with various sputtering conditions. After it is applied to external bending force, we investigated how change the surface and electrical property of as-deposited ITO thin film. As the L(face-plate distance) of substrate decreases, it found that the maximum crack density is increasing at the center position and decreasing crack density as goes to the edge. So to apply same curvature (r) and bending force to PC substrate with ITO thin film, we fixed the L that is equal to curvature radius (2r). Before bending test, ITO thin films that deposited in the input current of 0.4 A and thickness of 200 nm already had biaxial tensile failure because of each different CTE (Coefficient of Thermal Expansion) and Others had been shown no bending or crack. After bending test, all samples had been shown cracks at about 200 times and as increasing the crack density, resistivity increased.


Molecular Crystals and Liquid Crystals | 2018

Properties of ITO-stacked AgNWs films prepared on flexible substrates by low damage sputtering

Keon Yuep Shin; Sangmo Kim; Min Jong Keum; Yong Seo Park; Kyung Hwan Kim

ABSTRACT In this study, we fabricated the ITO-stacked AgNWs films on the various substrates and investigated their electrical, structural, and mechanical properties. Firstly, we coated Ag nanowires (AgNWs) layer on the soda-lime glass substrate and polymer substrate such as polyestersulfone (PES) and polycarbonate (PC) by using modified spin-coating method. And then, Indium Tin Oxide (ITO) film was deposited on coated-AgNWs layer by using facing targets magnetron sputtering (FTS) method at the room temperature. All samples prepared on various substrates have transmittance of about 80% in the visible range (300–800 nm) and low resistance of under 10 ohm/sq. And we investigated the properties of ITO-stacked AgNWs prepared on flexible substrate (PES, PC) by Lab-made bending machine. After substrate bending of 1000 times, the sheet resistance of prepared ITO single film 33.9 increased over 20000 ohm/sq and the sheet resistance of ITO-stacked AgNWs films increased from 8.38 to 19.33 ohm/sq in PES substrate and 6.69 to 24.42 ohm/sq in PC substrate.


Molecular Crystals and Liquid Crystals | 2018

Photocatalytic properties of transparent oxide thin films prepared by facing target magnetron sputtering

Sangmo Kim; Seung Hoon Kang; Hyung Wook Choi; Kyung Hwan Kim

ABSTRACT In this study, we fabricated indium tin oxide (ITO) films, which are well-known transparent oxide materials with low resistance and high transmittance. Their photocatalytic effect was investigated by using Rhodamine B (C28H31CIN2O3) solution. Facing target magnetron sputtering (FTS) was employed to deposit films on the substrate. The characteristics of the prepared films were analyzed using a UV-Vis spectrophotometer, a drop shape analyzer, a field emission scanning electron microscope, and a X-ray diffractometer. All samples exhibited optical transmittances of over 85% and resistance values under 50 ohm/sq. Moreover, as-prepared films were confirmed to have photocatalytic properties as seen from a decrease of Rhodamine B absorbance in their presence.


Archive | 2017

Effects of doping ratio of Cobalt and Iron on the structure and optical properties of ferroelectric bismuth titanates

Chung Wung Bark; Sangmo Kim; Sung Kwan Shin; Hyung Wook Choi

A contact lens is ideal to monitor glucose levels in tear. We designed a contact lens-based biosensor comprised of glucose oxidase (GOX) and cerium oxide nanoparticle (CNP) to detect glucose levels in tear. GOX catalyzes the oxidation of glucose to hydrogen peroxide (H2O2) and gluconolactone. Then, CNP catalyzes the reduction of H2O2. At this moment, Ce 3+ being colorless shift to Ce4+ state that is shown yellow color. Glucose levels can be determined by analyzing the change of color. B value of RGB color is used to determine glucose levels, being shown the correlation with glucose concentration. To confirm the synthesized CNP structure, we perform the XPS, XRD, HR-TEM. GOX is immobilized on a modified-CNP using PEG spacer; it is CNP-PEG-GOX. The formation of CNP-PEG-GOX is determined via quantitative analysis of GOX. The contact lens sensor maintains its mechanical properties compared with HEMA contact lens. and has correlation with glucose levels in buffer and artificial tear.I the present study, the meshless Petrov–Galerkin (MLPG) method is adopted to study the free vibration and axial buckling characteristics of single-walled carbon nanotube (SWCNT) subject to magnetic field. In particular, a nonlocal shell model accounting for the small scale effect is utilized. In the theoretical formulations, a variational form of the Donnell shell equations is constructed over a local sub-domain which leads to derivation of the mass, stiffness and geometrical stiffness matrices. The resonant frequencies and critical axial buckling loads of SWCNT are presented. The influences of boundary conditions, nonlocal parameter and geometrical parameters on the mechanical behavior of SWCNT are investigated and discussed completely. Finally, the numerical results based on the present study are checked by finite element method, they show excellent agreement.T wide band gap of complex oxides is one of the major obstacles limiting their use in photovoltaic cells. Tunability of the bandgap for ferroelectric complex oxides is one of the key issues for photovoltaic applications. We report doped ferroelectric oxides with narrow bandgaps and photovoltaic effect. To identify an effective route for tailoring the band gap of complex oxides, this study examined the effects of cobalt and iron doping on lanthanum-modified Bi4Ti3O12-based oxides synthesized using a solid reaction. The structural and optical properties were analyzed by X-ray diffraction and ultraviolet-visible absorption spectroscopy. As a result, the optimal iron to cobalt doping ratio in bismuth titanate powder resulted in ~1.94eV decrease in the optical band gap. In the film form, the optical bandgaps of Co-doped Bi3.25 La0.25 Ti4O12 (BLT) and Fe, Codoped BLT films was narrower than that of non-doped BLT by more than 1 eV. Correlated with the bandgap reduction, the Fe,Co-doped BLT film shows largely enhanced the photocurrent density by 25 times that of than BLT films. The density functional theory (DFT) calculation confirms that intermixed transition metal dopants (Fe, Co) in BLT generate novel energy states under conduction band. This new route to reduce the optical bandgap can be adapted to the synthesis of other complex oxides. This approach to tune the bandgap by simple doping could be applied to other widebandgap materials, which have the potential to be used in solar energy conversion or optoelectronic applications.N lithium-ion hybrid supercapacitors (LIHSs) by virtue of a higher energy density and longer cycle life by the electrical and electronic industry wide attention. Because LIHSs special intercalation structure, it combines the lithium-ion battery and supercapacitor energy storage advantages. However LIHSs still face many challenges, such as poor rate capability and limited longterm cycling stability. Lithium vanadium phosphate (Li3V2(PO4)3) has a higher Li + diffusion coefficient, higher discharge voltage, higher energy density , higher specific capacity, it is the one of has great potential in the future Electrode material. In this work, we find that Li3V2(PO4)3 is the three-dimensional (3D) network that is built from the slightly distorted VO6 octahedra and PO4 tetrahedra sharing oxygen vertexes, because of this special structure will make the interlayer spacing of Li3V2(PO4)3 expand, reduce the resistance of the intercalation/de-intercalation of cations (e.g. Li+) in the bulk of active materials, more conducive to reflect the intercalation pseudocapacitive behaviour. However the phosphate family has been known to have poor conductivity. Carbon based nanocomposites have been broadly studied in electrochemical energy storage. We prepared the carbon-coated Li3V2(PO4)3 by hydrothermal method is one more time widen the interlayer spacing in the material, providing a wider channel for the rapid intercalation of cations, thus improving the electronic conductivity of the material and enhancing the overall performance of the lithium-ion hybrid supercapacitor. In addition, hydrothermal method uses water as the main reaction medium; it’s easy to obtain, in line with the concept of green chemistry.N solar cells of silicon have reached efficiencies of up to 25% for single crystal Si. But, the production of such material requires energetically demanding processes and relatively expensive production. Recently, a new class of perovskite was introduced as light harvesting material, showing strong absorption in a broad region of the visible spectrum, good electron and hole conductivity, delivering also high open circuit voltages in photovoltaic devices. The main advantage of such an organic-inorganic hybrid material is a high absorption coefficient, excellent long distance carriers to move the hole diffusion length. Mixed halide perovskite materials, which electron hole diffusion length is ten times longer than those only containing iodide. Which presents efficient charge transport, low recombination rates and also good pore filling of the TiO2 layer enhancing device performance with respect to Spiro-OMeTAD (HTM). Trivalent rare-earth (RE) ions activated materials have kept booming in the past decades owing to their wonderful applications in phosphor-converted white light-emitting diodes (WLEDs), solar cells, temperature sensors, and drug deliveries. RE ion-doped inorganic phosphors revealed intense luminescent properties and showed potential applications in WLEDs. The conversion luminescence of a phosphor from the ultraviolet region to the visible region can enhance the light harvesting in Perovskite solar cells (PSCs), because many perovskites can only absorb visible light. In this work, to explore the influence of phosphor additives on the conversion efficiency of PSC, we introduce the YAG:Ce3+ phosphor layer. The samples were characterized by XRD, SEM, UV–vis, PL and IV-curves. Photoelectrode DSSC with light-to-electric energy conversion efficiency was achieved under a simulated solar light irradiation of 100 mW/cm2 (AM 1.5).T approach using localized surface plasmon resonance (LSPR) from metallic nanoparticles is attractive as one of the promising method to enhance the internal quantum efficiency of an organic light emitting diode (OLED) or power conversion efficiency of an organic solar cell (OSC), where the various shapes and geometrical arrangements of the nanoparticle and the nanostructures affects their performances. LSPR increases electromagnetic density of states which contribute to more efficient light emission of OLEDs. In order to investigate the light extraction from metallic nanoparticle array, we have compared the monodispersed silver nanoparticles (randomly dispersed onto substrates by spin-coating) with the ordered gold metallic arrays (formed by the phase separation of block copolymer; BCP). Gold nanoparticles arrays were given a particular morphology, which is driven by self-assembly of polystyreneblock-poly (2-vinyl pyridine) BCP thin film by solvent-annealing process. Controlling the annealing time and solvent type of the block copolymer results in the various nano-morphologies. In case of OLED, light emission efficiency (internal quantum yield) shows notable improvement (about 43.8%) in terms of current efficiency for line patterns of Au nanoparticles array developed by BCP selfassembly. Those plasmonic nanostructures of gold were almost similar scales of BCP patterns, formed at the on the surface of anode (ITO) at both OLED and OSC, showing notable enhancements of the light extraction and power conversion efficiency. The size and the anisotropy of gold nano-patterns were changed from a simple dispersion of dot through an integrated dot-line pattern, finally to a contour line pattern with higher percolation of particle array.Statement of Problem: Medical Waste Incinerators are used in destroying medical waste such as blood-drenched bandages, culture containers, abandoned surgical equipment’s, needles, removed body organs, lancets, surgical gloves and removed body organs. If not incinerated properly they are capable of transmitting diseases such as HIV, Hepatitis, and life taking infections. Medical waste being rich in high calorific value and chlorine, on combustion these wastes produces chlorides of sodium and chlorides which attacks the metallic parts of incinerators. The purpose of this study is to summarize the results of available research for prevention of hightemperature corrosion in incinerators.Statement of the Problem: Nowadays, superhydrophobic surfaces (Figure 1) are a hot topic of coatings research, due to their waterrepellent and self-cleaning potential, first observed on lotus leaves. Biomimetic artificial coatings intend bringing together the double/ multiple roughness of the natural self-cleaning surfaces and a hydrophobic coating that could mimic the wax properties covering the lotus leaves. The roughness of the surface plays an important role in obtaining high contact angles (> 150°); otherwise, it is impossible to exceed angles of 120°. This work proposes an innovative method to produce durable superhydrophobic coating films with selfcleaning features.Results: New bone formation onto GDF-5 coated Zr (Zr/GDF-5) surface was confirmed by in vitro test including cell proliferation, alkaline phosphatase activity and calcium deposition assays, and in vivo test including real-time polymerase chain reaction (qPCR) assay including osterix (OSX), runt-related transcription factor 2 (Runx 2), COL 1 (type I collagen) and osteocalcin (OC). Cell proliferation, alkaline phosphatase activity, and calcium deposition of MC3T3-E1 cells were significantly enhanced when the cells were cultured on Zr/GDF-5. Additionally, the results of qPCR revealed that genes related with osteogenic differentiation were up regulated when the cells were cultured on Zr/GDF-5.S (Si)-based solar cells have a market share of more than 90%, and are expanding in this market. However, high purity Si is very expensive and would be the risks of short supply and price fluctuation. Recently, Cu(In.Ga)Se2(CIGS) based thin film solar cells have been attracted as high conversion efficiency as a high efficiency thin film solar cell of the next generation and achieved the highest conversion efficiency of 20% over. The top electrode material for CICS based solar cell is widely used ZnO:Al and is required to be low resistivity (under 10-3 Ωcm) and optical transparency (larger than 80% in transmittance). Moreover, the preparation of good crystallinity ZnO:Al thin films is expected for improvement of the conversion efficiency of CIGS based solar cells. In this study, we tried to prepare ZnO:Al thin films with good crystallinity by helicon wave excited magnetron sputtering method and aimed to establish conditions for preparation. ZnO:Al thin films prepared by this method were evaluated for crystallinity, optical transmittance, and thickness by X-ray diffraction (XRD), recording spectrophotometer, and stylus surface profiler. Figure1 shows (a) XRD patterns and (b) optical transmittance spectra of ZnO:Al thin films prepared at various the target bias voltages. RF power, substrate temperature, and deposition time were 400 W, 2000c, and 3 hours, respectively. ZnO:Al thin film prepared at -300 V exhibited the wurtzite structure (α-ZnO), optical absorption edge of 360 nm (3.37 eV) and good optical transparency.T differences lines of researches within of the Engineering and Materials Sciences have developed new materials, which can be applied in different industrial sectors, Energy, Health and Transportation. For nuclear industry for example, the W alloy, is of great interest because of their excellent mechanical properties, excellent corrosion resistance and high cross sections to γ radiation. The tungsten and cooper, has great chemical affinity with oxygen and nitrogen, oxides and nitrides may form during the sintering process and heat treatment, changing the physic-chemical properties of material. This experiment work shows the results of microstructure evolution of the W20Cu alloy obtained by powder metallurgy method, where it was possible to obtain the crystallographic parameters and confirmation of the absence of formation of oxides and nitrides on the alloy as excellent homogeneity of the phases and great distribution of porous, confirming the reliability of sintering and heat treatment process experimental of the W20Cu alloy which can be used on sector nuclear industry in device manufacturing to transport radioactive substance.Introduction: In recent years, research interest in nickel has grown due to its increasing industrial significance and the growing environmental concerns regarding industrial effluents. Nickel (Ni2+) contamination of water bodies have led to efforts for the development of various treatment technologies for its removal. This paper characterized and utilized Terminalia catappa L. Fruit Shells (TCF) in adsorbing Ni2+ in synthetic wastewater at varying pH conditions.T effect of titanium dioxide (TiO2) nanoparticles (NPs) concentrations on spectroscopic measurements for a novel 3(2H)pyridazinone; 5-(5-bromo-2-hydroxy-phenyl)-2-phenyl-2H-pyridazin-3-one (BHP) molecule in ethanol solvent has been investigated using UV-Visible spectrophotometer, fluorescence spectrophotometer and time correlated single photon counting techniques at room temperature. The values of absorption, fluorescence intensity and fluorescence lifetime of BHP molecule decreases with increase in TiO2 NPs concentration. The association constant (ka) of BHP molecule with TiO2 NPs in the ground state is estimated using the Benesi–Hildebrand relation. A linear Stern–Volmer (S-V) plot is obtained in steady state and transient state studies. In addition, we have estimated the binding constant and number of binding sites. Results revealed that there is a strong interaction between investigated molecule with TiO2 NPs, fluorescence quenching in the said system is purely dynamic in nature and also there exist one binding site in BHP molecule for TiO2 NPs. Furthermore, we studied the energy transfer in fluorescence quenching by the Forster’s non-radiative energy transfer (FRET) theory it reveals that there is an energy transfer from BHP molecule to TiO2 NPs. The results of present investigations may shine in variety of applications, such as to sensitize the TIO2 for solar energy conversion and biological sensing etc.Recently, a new class of hybrid organic halide perovskite was introduced as light harvesting material, showing strong absorption in a broad region of the visible spectrum, good electron and hole conductivity, delivering also high open circuit voltages in photovoltaic devices. The perovskite absorber was initially used as the sensitizer to replace dye molecules in the dye-sensitized solar cell by using the liquid of iodide-based electrolyte. The solution-based device fabrication in solid-state perovskite solar cell (PSC) is very attractive advantage of manufacturing compared with other solar cell. PSCs are consist of CH3NH3PbX3 loaded on a mesoporous TiO2 layer in conjunction with the hole transporting material between the two electrodes. The PSCs based on CH3NH3PbX3 thin films processed by various methods show quite different device performances. High power conversion efficiency was observed from PSCs based on high quality deposited CH3NH3PbX3 thin films. Moderate power conversion efficiency was observed from PSCs based on low quality solution-processed CH3NH3PbI3−xClx layer. In this study, we studied the correlations between the efficiencies of PSCs and the film thicknesses of CH3NH3PbI3−xClx layers. We investigate the device performance of X-ray diffraction (XRD) patterns, atomic force microscopy (AFM) and scanning electron microscopy (SEM) images of CH3NH3PbI3−xClx films. The incident photocurrent conversion efficiency was measured using a solar simulator (100 mW/cm2). [email protected] Res. Rev. J Mat. Sci. 2017, 5:7 DOI: 10.4172/2321-6212-C1-012Methods & Materials: 40 commercially made pure titanium discs were prepared to produce Ti oxide machined surface (M) and Mg-incorporated Ti oxide machined surface (MM). Surface properties were analyzed using a scanning electron microscopy (SEM). On each surface, alkaline phosphatase (ALP) activity, alizarin red S staining for mineralization of MC3T3-E1 cells, and quantitative analysis of osteoblastic gene expression, were evaluated. Actin ring formation assay and gene expression analysis of TRAP and GAPDH performing RT-PCR were performed to characterize osteoclast differentiation on mouse bone marrow-derived macrophages (BMMs).D to an ongoing pursuit to replace fossil fuels with renewable energy sources, there is a high demand for large-scale electrical grid storage. Computational chemistry methods can be used to predict redox potentials of benzoquinones and hydroquinone’s; the potentials of which can be tailored by the addition of electron withdrawing groups and electron donating groups. Quinones are an attractive organic material for aqueous flow batteries because they are low cost and undergo a reversible two-electron, twoproton redox reaction. Therefore, these organic species can be stored as chemical energy in electrolyte tanks, and be pumped into a regenerative fuel cell to undergo oxidation and reduction, when electric power is needed. This study has two objectives: 1) find a theory and functional pair that accurately predicts redox potentials, 2) find potential organic species for an aqueous flow battery. This presentation will report geometry optimizations using different theories and functionals, to determine which experimental set up most accurately predicts redox potentials. Quantum chemical calculations were performed using the 2012 MOLPRO software package. Accuracy is measured by the linear correlation between calculated potentials and experimental potentials. Experimental values are from Wedege’s 2016 scientific report, Organic Redox Species in Aqueous Flow Batteries: Redox Potentials, Chemical Stability and Solubility. Quantum chemical methods can thus aid electrochemists in the effort to make an all organic aqueous flow battery, provided accurate redox potentials are ensured by calculations.Z oxide is a n-type semiconductor which has wide and a direct band gap of 3.37ev with large exciton binding energy of 60meV. In addition, ZnO is also accessible material, which has many applications, such as transductors, gas sensors, and optical devices. However, zinc oxide has large band gap, which contributes to the efficiency of photovoltaic devices. Thus, we incorporate ZnS into ZnO structures because zinc sulfide is able to modulate band gap. In this study, we electroplate the ZnO seed layer to cover on the copper grid as the first step. Secondly, we adopt the hydrothermal method to grow the ZnO nanorods, and then prepare the solution of zinc sulfide to do the hydrothermal method for the second time. In order to characterize the material properties, several analytical methods such as FESEM, TEM, PL and so forth have been conducted. The TEM images indicate that ZnO nanorods are completely covered by ZnS layer. The Photoluminescence (PL) analysis illustrates that this nanocomposite materials contain good optical property. In this research, to conduct the TEM analyze directly, we attempt to fabricate ZnO/ZnS core/shell nanostructure on the copper grid. This paper provides a simple three-step process to synthesize ZnO/ZnS core/shell nanostructure and also affords a possibility to apply to optical sensor, solar cell, gas sensor and so on.I the field of micro systems technology, e.g. for sensors or actuator applications, polymeric materials with functional properties (e.g. electrical conductivity or magnetic properties) are an interesting alternative to common metallic materials due to their highefficient fabrication techniques. The desired functional property spectrum is often realized by addition of functional fillers, which inevitably influences the injection molding process. Especially the flow-ability and the mold filling behavior change dramatically due to the fillers. This behavior is critical for the quality of the final part, but cannot be predicted sufficiently until now. At present, the current standard process monitoring technologies are not adequate to provide enough information to analyze and optimize the filling behavior. In the presented study, the flow behavior of the highly-filled polymeric materials is characterized with a glass-insert mold which is designed for direct visual analysis of the flow phenomena. The investigation is carried out using polyamide (PA 6) with ferrite micro particles of 150μm size. These particles are admixed to the polymer matrix with filler contents of 50 vol.-%, 60 vol.-% and 65 vol.-%, respectively. The flow front is observed during the filling stage with a high-speed camera. The filling behavior is simulated with commercial software (Mold Flow®), and validated with the real experiment. Based on these investigations, the process ability of highly filled polymer melts are characterized both by experiment and simulation, with evaluation of the conventional simulation tools for application in highly-filled polymeric materials.A novel Up-conversion ytterbium material was doped with titanium dioxide (YbT) nanoparticles (NPs) for to analyze the effect on antibacterial activities in two conditions (without UV-irradiated and with UV-irradiated) against two Gram strain bacteria’s (Staphylococcus aureus and Escherichia coli). For the synthesis of YbT NPs, we have employed a bottom-up approach in that the green route was adopted. In the green route, there are a number of bioreductants were used due to their potentiality. In our synthetic route, a novel Piper Betel leaf extract was chosen due to their rich constituents (Phytochemicals). In order to confirm their optical, functional, surface morphological, structural and thermal stability observations, YbT NPs was subjected to various characterization techniques. The obtained results were signified that they having an absorption maximum around at 373 nm, the presence of N-H, C-H, C=O and C-O on YbT FT-IR spectrum indicates that the possible presence of bioreductants which are responsible for the reduction and stabilizing the YbT NPs. The size of the particles was in nano nature and they consist size of about 7 nm. They are having a tetragonal crystal structure, later compared the crystalline size from Scherrer’s and Williamson-Hall (W-H) methods, this may signify that estimated crystalline size from the W-H method is more appropriate for the TEM image as compared to the Scherrer’s method. The YbT NPs are thermally stable. After the satisfactory results, we have further studies their antibacterial activities. The obtained results may indicate that YbT NPs have shown more potent antibacterial activities against Staphylococcus aureus and Escherichia coli bacteria in both the conditions. But we have got more zone of inhibition for with UV-irradiated YBT NPs. So this may indicate that YbT NPs can be used for various biological activities. Furthermore, this synthesis route can be utilized for the mass productions of NPs; it may help for the industrial uses.T work is focused on the characterization of sintered valve seat insert (VSI) after heat treatment. Such VSI was obtained by powder metallurgy technique and fulfilled the requirement to replace cobalt and lead, used in the original alloy, due to their high cost and toxicological effect, respectively. The studied VSI is composed of a high-speed steel (AISI M3:2) powder admixed with iron powder and additives such as manganese sulphide, zinc stearate, graphite, carbides and copper, which was added through the metallic infiltration process. These powders characterization were carried out analyzing its particle size distribution and morphological aspects. The VSI was air quenched, and after that, it was double tempered at seven equidistant different temperatures, ranging from 100 °C until 700 °C. The VSI physical and mechanical properties were determined by means of its apparent hardness, apparent density and radial crush strength tests. The microstructural evaluation was performed etching the samples with Nital and then evaluating it with the support of the optical microscopy, scanning electron microscopy and energy dispersive spectroscopy. The chemical composition of the VSI was determined using the energy dispersive X-ray fluorescence spectrometer. The VSI best results was achieved, regarding its final application, by air quenching and double tempering it at 600 °C.T direct carbon fuel cell (DCFC) is a power generation device that converts carbonic chemical energy directly into electricity by electrochemical oxidation. Because of well-known characteristics of coal-fired power plants, such as relatively low efficiencies, considerable contributions to greenhouse gas emissions, acid rain, and particulate and heavy metal pollution, improvement in coal utilization technology remains an important issue. The direct carbon fuel cell has some advantages such as the high theoretical efficiency, concentrated CO2 product off-gas, and the high energy density of solid carbon fuel. The molten hydroxide direct carbon fuel cell is a kind of the direct carbon fuel cell. Compared to other direct carbon fuel cells, the molten hydroxide direct carbon fuel cell has more superiorities and it will become a research trend in the future. The performance and characterization of a batch direct carbon fuel cell employing molten hydroxide electrolytes will be affected by many factors. For example, temperature, different carbonaceous fuels, the type of catalysts and the proportion of molten hydroxide electrolytes will have a significant impact. At present, some research groups have started this research. I believe that it will have more space of development and benefit to human in the near future. Because of catalytic oxidation of carbon in the process, I will do some research about catalytic performance. Efficiency of the direct carbon fuel cell with molten alkaline electrolyte can be obviously improved.S therapy for cancer is greatly hampered by its poor water-solubility, difficulties in controlling and predicting the drug release, and non-specific delivery to the target tissue that limited to the clinical application. In order to overcome these limitations, a novel self-assembled nanoparticle platform based on pectin-multi-arm-polyethylene glycol-dihydroartemisinin conjugate (PecMultiarm-PEG-DHA) was first presented. This conjugate was synthesized by introducing hydrophobic drugs dihydroartemisinin to hydrophilic polymer molecules eight-arm polyethylene glycol, and then was linked to pectin via ester linkages. Moreover, another anticancer drug hydroxycamptothecin (HCPT) was encapsulated into the self-assembled nanoparticles (Pec-Multiarm-PEG-DHA/ HCPT NPs). The obtained nanoparticles possessed appropriate size (~ 85 nm), high drug-loaded efficiency (~9.12 wt% DHA), encapsulation efficiency (~ 12.11 wt% HCPT), good stability and pH-dependent. The time-dependent cytotoxic of the Pec-MultiarmPEG-DHA/HCPT NPs was only 4% 4T1 cell and 2% MCF-1 cell survived after 72 h. Pec-Multiarm-PEG-DHA/HCPT NPs exhibited a higher cytotoxicity, longer blood retention time of free drug (8.0-fold DHA, 7.4-fold HCPT) and more effective cellular uptake than free drugs. 4T1 tumor-bearing mice treated with the nanoparticles also showed a 90.6% survival advantage in comparison with 15.5% free DHA and14.1% free HCPT. In addition, it is clearly an elaborate certification that nanoparticles could reduce the risk of hypersensitivity reactions substantially. Therefore, Pec-Multiarm-PEG-DHA/HCPT NPs is a promising potential for anticancer combination therapy.


Journal of The Korean Institute of Electrical and Electronic Material Engineers | 2007

Properties of AZO Thin Film deposited on the PES Substrate

Sangmo Kim; Kyung-Hwan Kim

We prepared the Al doped ZnO (AZO) thin film on polyethersulfon (PES) without any substrate heating by Facing Targets Sputtering (FTS) system. FTS system has two different facing targets. One is ZnO doped the content of Al 2 wt% and the other is Zn in order to decrease resistivity. The electrical, structural and optical properties of AZO thin films were investigated. To evaluate the as-deposited thin film properties, we employed four-point probe (CMT-R100nw, Changmin), Surface profiler (Alpha-step, Tencor), UV/VIS spectrometer (HP), X-ray diffractometer (XRD, Rigaku) and Field Emission Scanning Electron Microscopy (FESEM, Hitachi S-4700). As a result, We obtained that AZO thin film deposited on PES substrate at a DC Power of 150 W, working pressure of 1 mTorr and gas flow ratio of 0.2 exhibited the resistivity of and the optical transmittance of about 85 % in the visible range.


Journal of Electroceramics | 2009

Study on the electrical and optical properties of ITO and AZO thin film by oxygen gas flow rate

Sangmo Kim; You Seung Rim; Min-Jong Keum; Kyung-Hwan Kim


Journal of the Korean Physical Society | 2009

Influence of a Ag Layer on AZO/Ag/AZO Multilayer Thin Films Prepared by Facing Targets Sputtering

Sangmo Kim; You Seung Rim; Min-Jong Keum; Kyung-Hwan Kim


Journal of the Korean Physical Society | 2007

Deposition of an Al Cathode for an OLED by Using Low-Damage Sputtering Method

Sangmo Kim; Kyung-Hwan Kim; Min-Jong Keum


Science of Advanced Materials | 2017

Two-Dimensional Nanomaterials: Their Structures, Synthesis, and Applications

Sangmo Kim; Kyung Hwan Kim; Chung Wung Bark


Science of Advanced Materials | 2017

ITO/Ag Multilayer Films Fabricated by Low-Damaging Facing-Target Sputtering

Keon Yuep Shin; Sangmo Kim; You Seung Rim; Kyung Hwan Kim

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You Seung Rim

University of California

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Myunggyu Choi

Catholic University of Daegu

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