Publications by authors named "Song Jung-Il"

Article Synopsis
  • A novel and cost-effective method for extracting cellulose nanofibers (ECNFs) from Imperata cylindrica grass was developed, resulting in high yield and purity.
  • The extracted ECNFs exhibited impressive characteristics, including a uniform diameter, high crystallinity, and small crystal size, confirmed through advanced analytical techniques.
  • ECNFs were shown to significantly improve the mechanical properties of chitosan composite films, while incorporating graphene nanoplatelets further enhanced their thermal stability, flame retardancy, and electromagnetic shielding capabilities.
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  • Polymeric foams are lightweight and flexible 3D sponges traditionally used for cushioning and insulation, but now they are being applied in advanced technologies requiring properties like flame retardancy and energy storage.
  • The review covers recent developments in surface coating strategies for these foams, outlining their unique characteristics, synthesis methods, and various high-value applications.
  • It also discusses both the advantages and challenges of these new coating techniques, aiming to inspire future research and innovation in polymeric foam design for modern applications.
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Biobased-functionalized metal-organic frameworks (Bio-FUN-MOFs) stand out from the crowd of candidates in the flame-retardant field due to their multipathway flame-retardant mechanisms and green synthesis processes. However, exploring and designing Bio-FUN-MOFs tend to counteract the problem of compromising the flame-retardant advantages of MOFs themselves, which inevitably results in a waste of resources. Herein, a strategy in which MOFs are ecologically regulated through acid-base balance is presented for controllable preparation of Bio-FUN-MOFs by two birds with one stone, i.

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The purpose of this study is to design and evaluate a series of porous hydrogels by considering three independent variables using the Box-Behnken method. Accordingly, concentrations of the constituent macromolecules of the hydrogels, Polyvinyl Alcohol and Gelatin, and concentration of the crosslinking agent are varied to fabricate sixteen different porous samples utilizing the lyophilization process. Subsequently, the porous hydrogels are subjected to a battery of tests, including Fourier Transform Infrared spectroscopy, morphology assessment, pore-size study, porosimetry, uniaxial compression, and swelling measurements.

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Self-healing panels were prepared using vinyl ester (VE) and vascular abaca fibers (unidirectional) through the hand lay-up process. Initially, two sets of abaca fibers (AF) were prepared by filling the healing resin VE and hardener and stacking both core-filled unidirectional fibers in a 90° direction to obtain sufficient healing. The experimental results demonstrated that the healing efficiency increased by approximately 3%.

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The current study focused on abaca fiber lumens with a thermoset healing resin mechanism integrated into high-performance carbon prepreg composites. Self-healing composites with a fiber orientation of [0°/90°] and similar fiber volume fractions were manufactured and tested using a compression after impact (CAI) test to assess the post-impact behavior. The experimental results showed that the healed composites had an improved restoration strength of 19.

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Two-component self-healing carbon/epoxy composites were fabricated by incorporating healing agents between to carbon fiber laminates via the vacuum bagging method. Vinyl ester (VE), cobalt naphthalene (CN), and methyl ethyl ketone peroxide (MEKP) were encapsulated in a polyacrylonitrile (PAN)/Poly(vinylidene fluoride) (PVDF) shell via co-axial electrospinning. Varying nanofiber compositions were fabricated, namely, 10, 20, 30, and 40% PAN in PVDF nanofibers.

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  • A new palladium catalytic system (PdAc-5) effectively oxidizes primary and secondary alcohols to aldehydes and ketones using oxygen at moderate pressures.
  • The catalyst's performance was evaluated using various analytical techniques and demonstrated high yields (70-85%) with cost-effective, non-toxic solvents and additives.
  • Comprehensive studies compared PdAc-5 against commercial catalysts and explored different conditions, ensuring the synthetic process of alcohol oxidation was reliable and thoroughly analyzed through advanced methods like H NMR and GC-mass.
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The development of highly durable, stretchable, and steady triboelectric nanogenerators (TENGs) is highly desirable to satisfy the tight requirement of energy demand. Here, we presented a novel integrated polymeric membrane that is designed by PEDOT: PSSa-naphthalene sulfonated polyimide (PPNSP)-EMI.BF Electronic skin (e-skin) for potential TENG applications.

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Harvesting of flow current through implanted hydrophobic surface within silicone pipe as liquid nanogenerators where Tap water (TW), and DI water (DIw) as liquid reservoirs to successfully convert induced mechanical energy into electrical energy. Here, we used a commercial PTFE film for the generation of a hydrophobic surface as a source of mechanical energy. The surface roughness of the hydrophobic surface is confirmed using atomic force microscopy, and contact angle analyses.

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This study aimed to produce a new potential flame retardant thermoset resin from epoxidised corn oil through a one-pot method using liquid inorganic catalysed with hydrogen peroxide. Using a gas chromatography-mass selective detector, attenuated total reflectance-fourier transform infrared spectroscopy, proton nuclear magnetic resonance imaging, optical microscopy, and scanning emission microscopy, we synthesised a bio-based resin based on newly designed parameters. The flame retardant capacity was fully established using thermogravimetric analysis and a micro calorimeter.

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The use of halogen-based materials has been regulated since toxic substances are released during combustion. In this study, polyurethane foam was coated with cationic starch (CS) and montmorillonite (MMT) nano-clay using a spray-assisted layer-by-layer (LbL) assembly to develop an eco-friendly, high-performance flame-retardant coating agent. The thickness of the CS/MMT coating layer was confirmed to have increased uniformly as the layers were stacked.

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In this report, layer by layer (LBL) fire retardant coatings were produced on wood ply and Polypropylene Homopolymer/Flax fiber composites. FE-SEM and EDAX analysis was carried out to analyze the surface morphology, thickness, growth rate and elemental composition of the samples. Coatings with a high degree of uniformity were formed on Polypropylene composite (PP/flax), while coatings with highest thickness were obtained on wood ply (wood).

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Self-healing on the engineering applications is smart, decisive research for prolonging the life span of the materials and the innovations have been mounting still smarter. Connecting to advancements in self-healing carriers, in altering the chemical structure by optimizing the brittleness for self-healing performance and introducing the bio-degradability, for the first time TPS was blended to PVDF for the synthesis of nanofibers, as carriers of a vinyl ester (VE) resin (medication), by the coaxial electrospinning technique. TPS was mechanically mixed with PVDF base polymer and optimized the TPS content (10 wt%) based on mechanical performance.

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We report the synthesis of thermally heated pop-up reduced graphene oxide (Pop-rGO) and its nanofluid (Pop-rGO-Nf) in DI water for extended critical heat flux (CHF) in a nucleate pool boiling experiment. When Pop-rGO-Nf is boiled over a nichrome (NiCr) wire heater the CHF values were increased up to 132%, 156%, and 175% with increasing concentrations of 0.0005 vol%, 0.

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The study reveals the fabrication of eco-friendly bio-composites by employing natural, widely available biopolymers such as starch, chitosan (CS) and flax fabric (FF). In a typical process, starch was used in the form of thermoplastic starch prepared via mechano ball milling and subsequently, composites were fabricated via compression with CS and FF. The nature of the composites was analysed using FTIR.

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This article highlights the development of biodegradable flame-retardant composites using a compression technique on low-cost starch, flax fabric (FF) and ammonium polyphosphate (APP) raw materials. The starch was plasticized into thermoplastic starch through a mechano-ball milling process and composites were developed by reinforcing the FF and incorporating varying amounts of APP. The effects of APP on the flammability and thermal properties of the composites were studied.

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Peening is mainly used as a method of surface treatment for microstructural modification in order to improve surface mechanical properties. The ultrasonic shot peening (USP) technique can cause severe plastic deformation with its high strain rate on the surface of metallic parts. However, systematic studies of microstructural refinement mechanism upon plastic deformation with consideration of alloy systems are rare.

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Alumina/zirconia (Al2O3/ZrO2) multilayer thin films were deposited on Si (100) substrates at an optimized oxygen partial pressure of 3 Pa at room temperature by pulsed laser deposition. The Al2O3/ZrO2 multilayers of 10:10, 5:10, 5:5, and 4:4 nm with 40 bilayers were deposited alternately in order to stabilize a high-temperature phase of zirconia at room temperature. All these films were characterized by X-ray diffraction (XRD), cross-sectional transmission electron microscopy (XTEM), and atomic force microscopy.

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