Jiwon Kim

Hanbat National University · Department of Chemical and Biological Engineering

In this study, a hollow-structured plate-type titania (HL-Plate@TiO2) is fabricated using a glass plate (GL-Plate) and applied as electrorheological (ER) materials dispersed in an insulating medium. First, titania is coated onto the surface of GL-Plate using titanium tetrachloride as a precursor by the sol-gel method, followed by a calcination proc...

This study aimed to recycle coffee waste, a type of biomass, as a carbonaceous active material for electric double layer capacitor (EDLC) in industrial applications. Firstly, coffee waste was collected, washed, and carbonized to produce carbon material (C-CW). Subsequently, graphene oxide (GO) was mixed with C-CW at different concentrations of 5–15...

A novel LiDAR-detectable plate-like hollow black titanium dioxide (HbTiO2) is developed by recycling silicon sludge generated from silicon wafer sawing. By employing TiCl4 sol-gel synthesis, hydrofluoric acid etching, and NaBH4 reduction, the hollow-structured black TiO2 is successfully synthesized. Plate-like HbTiO2 readily mixed with hydrophilic...

A novel LiDAR-detectable plate-like hollow black titanium dioxide (HbTiO2) is developed by recycling silicon sludge generated from silicon wafer sawing. By employing TiCl4 sol-gel synthesis, hydrofluoric acid etching, and NaBH4 reduction, the hollow-structured black TiO2 is successfully synthesized. Plate-like HbTiO2 readily mixed with hydrophilic...

Autonomous driving relies on the precise recognition of objects using light detection and ranging (LiDAR) technology, that operates at a specific wavelength of 905 nm. Black objects, such as carbon black used in vehicle coating, tend to absorb this specific wavelength significantly, which limits the performance of LiDAR sensors. To address this iss...

This study presents the synthesis of silica-embedded carbon nanofibers (SiO2/eCNFs) as additives to enhance the heat dissipation properties of epoxy molding compounds (EMCs) for semiconductor packaging. Three different sized SiO2 nanoparticles were prepared and added to the precursor solution for polyacrylonitrile (PAN) nanofibers. Through electros...

Colloidal nanocrystals with a narrow band gap offer a low-cost infrared photodetection platform but often suffer from surface defects due to their incomplete surface passivation. Such defects can generate mid-gap trap states and reduce the carrier transport. Thus, revealing the trap-mediated transport could be important to attain a fast photodetect...

Light detection and ranging (LiDAR) sensors emit pulsed near-infrared (NIR) lasers toward targets and detect the reflected signals to measure the distance between LiDAR-equipped autonomous vehicles and surrounding objects. However, LiDAR sensors have difficulty recognizing black and dark objects owing to their intrinsic light absorption characteris...

One-dimensional lithium-ion transport channels in lithium iron phosphate (LFP) used as a cathode in lithium-ion batteries (LIBs) result in low electrical conductivity and reduced electrochemical performance. To overcome this limitation, three-dimensional plasma-treated reduced graphene oxide (rGO) was synthesized in this study and used as an additi...

One-dimensional lithium-ion transport channels in lithium iron phosphate (LFP) used as a cathode in lithium-ion batteries (LIBs) result in low electrical conductivity and reduced electrochemical performance. To overcome this limitation, three-dimensional plasma-treated reduced graphene oxide (rGO) was synthesized in this study and used as an additi...

A plasma-reduced graphene oxide/lithium titanate oxide (PrGO/LTO) composite is prepared as anode material to enhance the performance of lithium-ion capacitors (LICs). The 17 PrGO/LTO composite is synthesized by mixing graphene oxide (GO) and LTO, followed by a series of freeze-drying and plasma-treatment processes. PrGO forms a porous three-dimensi...

We synthesize an etchant solution designed to remove polydimethylsiloxane (PDMS) residues from semiconductor wafers during wafer-to-wafer processing in advanced semiconductor packaging (AVP). The etchant solution is produced by combining hexane, a nonpolar swelling solvent, with tetrabutylammonium fluoride (TBAF), a fluorine based compound, to enha...

This study presents the synthesis of silica-embedded carbon nanofibers (SiO2/eCNFs) as additives to enhance the heat dissipation properties of epoxy molding compounds (EMCs) for semiconductor packaging. Three differently sized SiO2 nanoparticles were prepared and added to the precursor solution for polyacrylonitrile (PAN) nanofibers. Through electr...

In this study, silane compound treatment for hybrid bonding was conducted to enhance the bonding performance between the insulating layers (SiO2-SiO2) in Cu/SiO2 hybrid bonding (Cu/SiO2-patterned chip) for the semiconductor packaging process. In detail, surface treatment of Cu/SiO2-patterned chip was performed through spin coating using 10.0 wt% of...

In this paper, we present the concept of traceback analysis to identify the origins and mechanisms of non-wet defects caused by hydrophobic unknown nanoparticles in the semiconductor packaging process. Traceback analysis consists of five steps, i.e., practical observation of failure mode, detailed physical and chemical analysis, investigation of pr...

In this study, the contamination of gold (Au) wire according to the types of rinse applied for surface treatment in the wire bonding process is investigated and confirmed. For the surface treatment, rinses containing silicon (Si) or those based on organic materials are mainly employed. To identify their effects, surface treatment is conducted on Au...

Novel LiDAR-detectable black double-shell hollow nanoparticles (BDS-HNPs) with internal white shell are successfully utilized as materials for autonomous vehicle paint for the first time. These BDS-HNPs are carefully designed to achieve excellent near-infrared (NIR) reflectance, blackness, hydrophilicity, and applicability as monolayer coatings. An...

In this study, ester co-solvents and fluoroethylene carbonate (FEC) were used as low-temperature electrolyte additives to improve the formation of the solid electrolyte interface (SEI) on graphite anodes in lithium-ion batteries (LIBs). Four ester co-solvents, namely methyl acetate (MA), ethyl acetate, methyl propionate, and ethyl propionate, were...

(Hypothesis) The development of highly NIR reflective black single-shell hollow nanoparticles (BSS-HNPs) can overcome the Light Detection and Ranging (LiDAR) sensor limitations of dark-tone materials. The crystalline phase of TiO2 and the refractive index can be controlled by calcination temperature. The formation of hollow structure and the ref...

Plate-type hollow black TiO2 (HL/BT) with a high NIR reflectance was fabricated for the first time as a LiDAR-detectable black material. A TiO2 layer was formed on commercial-grade glass by using the sol−gel method to obtain a plate-type structure. The glass template was then etched with hydrofluoric acid to form a hollow structure, and blackness w...

In this study, LiDAR-detective black material is synthesized by recycling silicon sludge (SS) that is generated from semiconductor manufacturing process, and its recognition is confirmed using two types of LiDAR sensors (MEMS and Rotating LiDAR). In detail, metal impurities on the surface of SS is removed, followed by coating of titanium dioxide (T...

Hypothesis: Surface modification of dielectric materials changes the dipole-dipole interactions under electric fields, thereby controlling the electrorheological (ER) response. The introduction of metal oxides onto mica templates and further coating of dyes is expected to simultaneously improve the color clarity and ER performance. Experiments: Dye...

The use of plate-like materials to induce a percolation gel-like effect in electrorheological (ER) fluids is sparsely documented. Hence, we dispersed plate-like materials, namely natural mica, synthetic mica, and glass, as well as their pulverized particles, in various concentrations in silicone oil to form ER fluids. Subsequently, the rheological...

In this study, Al paper and cellulose acetate (CA) filters derived from heated tobacco waste were successfully converted into current collectors and active materials for a supercapacitor device. Typically, heated tobacco contains electrically discontinuous Al paper. First, Al was extracted from the tobacco waste using HCl to produce Lewis acid (AlC...

In this study, Al paper and cellulose acetate (CA) filters derived from heated tobacco waste 16 were successfully converted into current collectors and active materials for supercapacitor device. 17 Typically, heated tobacco contains electrically discontinuous Al paper. Firstly, Al was extracted 18 from the tobacco waste using HCl to produce Lewis...

In this study, silicon sludge from semiconductor dicing process is recycled to fabricate silica nanoparticles, which are applied as dispersing materials for electro-responsive (ER) smart fluid. In specific, metal impurities are removed from silicon sludge by acid washing to obtain the high-purity silicon powder. And then, silica nanoparticles are s...

In this study, silicon sludge generated in semiconductor manufacturing process is recycled and applied as materials for pigments and paints. In detail, metallic impurities are removed from silicon sludge to obtain plate-like silicon sludge powder (SW-sludge), which is then coated with titanium dioxide via sol-gel method (TCS-sludge). SW-sludge and...

Black TiO2@Mica 소재를 제조하였다. 이후, 도료로서 응용 가능성을 확인하기 위해 친수성 투명 바니시에 혼합하고 유리 기판에 분사하였다. 그 결과, 제조한 Black TiO2@Mica 기반의 도료는 실제 검은색의 명도(L* = 12.1)와 높은 근적외선 반사 율(30.2 R%)을 나타내었다. 더불어, 제조한 판상형 검은색 소재는 성공적으로 라이다 센서에 인식되는 것을 확인하였다. 이는, 굴절률이 다른 천연 마이카와 이산화티타늄 간의 계면에서 빛의 반사가 일어나는 프레넬의 반사 법칙에 기인한 것이다. 본 연구 결과를 통해, 라이다

In this study, a comparative study is conducted on the synthesis methods for silica nanoparticle employing the silicon sludge waste generated from the semiconductor manufacturing processes. Specifically, acid-washed silicon sludge wastes with no impurities are employed as the precursors of sol-gel and hydrothermal methods for silica nanoparticles p...

In this study, various plant-based biomass are recycled into carbon materials to employ as anode materials for lithium-ion batteries. Firstly, various biomass of rice husk, chestnut, tea bag, and coffee ground are collected, washed, and ground. The carbonization process is followed under a nitrogen atmosphere at 850°C. The morphological and chemica...

Herein, unique three-dimensional (3D) hierarchically structured carbon nanofiber (CNF)/metal oxide/conducting polymer composite materials were successfully synthesized by combinations of various experimental methods. Firstly, base CNFs were synthesized by carbonization of electrospun PAN/PVP fibers to attain electric double-layer capacitor (EDLC) c...

In this study, coffee waste was recycled into nitrogen-doped porous carbon fibers as an active material for high-energy EDLC (Electric Double Layer Capacitors). The coffee waste was mixed with polyvinylpyrrolidone and dissolved into dimethylformamide. The mixture was then electrospun to fabricate coffee waste-derived nanofibers (Bare-CWNF), and car...

This study describes the successful synthesize strategy for the silica nanoparticles utilizing various water sources, including tap, industrial, and stream waters without using deionized water. Also, as-synthesized silica nanoparticles are employed as dispersive materials for the electro-responsive smart fluid application. Specifically, homogeneous...

In this study, LiDAR-reflective black hollow-structured silica/titania(B-HST) materials are successfully synthesized by employing the NaBH 4 reduction and etching method on silica/titania core/shell(STCS) materials, which also effectively enhance near-infrared(NIR) reflectance. Moreover, core-etched supernatant solutions are collected and recycled...

In this study, the sludge formation in the wastewater drain from the advanced packaging process mechanisms are revealed as well as the key factors, materials, and sludge prevention methods using surfactant. Compared with that of conventional packaging process, advanced packaging process employ similar process to the semiconductor fabrication proces...

In this study, a flexible all-solid-state asymmetric supercapacitor (FASC) device has been successfully fabricated via full recycling of heated tobacco waste (HTW). Tobacco leaves and cellulose acetate tubes have been successfully carbonized (HTW-C) and mixed with metal oxides (MnO 2 and Fe 3 O 4) to obtain highly active materials for supercapacito...

Light detection and ranging (LiDAR) sensors utilize a near-infrared (NIR) laser with a wavelength of 905 nm. However, LiDAR sensors have weakness in detecting black or dark-tone materials with light-absorbing properties. In this study, SiO2/black TiO2 core/shell nanoparticles (SBT CSNs) were designed as LiDAR-detectable black materials. The SBT CSN...

Hollow TiO2 nanoparticles (HNPs) capped with conducting polymers, such as polythio-phene (PT), polypyrrole (PPy), and polyaniline (PANI), have been studied to be used as polariza-bility-tunable electrorheological (ER) fluids. The hollow shape of TiO2 nanoparticles, achieved by the removal of the SiO2 template, offers colloidal dispersion stability...

Herein, the electrorheological (ER) performances of ER fluids were correlated with their colors to allow for the visual selection of the appropriate fluid for a specific application using naked eyes. A series of TiO2-coated synthetic mica materials colored white, yellow, red, violet, blue, and green (referred to as color mica/TiO2 materials) were f...

This study suggests the effective recycling method of sludge waste from various industrial fields to synthesize uniform colloidal silica nanoparticles. In detail, polymers are removed from the sludge waste to attain sludge-extracted silica (s-SiO 2) micron-sized particles, and ammonia assisted sonication is applied to s-SiO 2 , which has effectivel...

In this study, heated tobacco biomass was prepared as an active material for supercapacitor device. Retrieved tobacco leaf from the heated tobacco was carbonized at various temperature(800/850/950°C). Carbonized tobacco leaf material synthesized at 850°C exhibited the highest C/O ratio, indicating the finest carbon quality. In addition, polypyrrole...