Publications by authors named "Sujin Yoon"

There is a growing demand for adsorption technologies for recovering and recycling precious metals (PMs) in various industries. Unfortunately, amine-functionalized polymers widely used as metal adsorbents are ineffective at recovering PMs owing to their unsatisfactory PM adsorption performance. Herein, a star-shaped, hydrazide-functionalized polymer (S-PAcH) is proposed as a readily recoverable standalone adsorbent with high PM adsorption performance.

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Efficient support materials are crucial for maximizing the efficacy of nanomaterials in various applications such as energy storage, drug delivery, catalysis, and environmental remediation. However, traditional supports often hinder nanomaterial performance due to their high weight ratio and limited manageability, leading to issues like tube blocking and secondary pollution. To address this, a novel grapefruit-inspired polymeric capsule (GPC) as a promising carrier platform is introduced.

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A gold nanourchin (AuNU) probe with a novel sensing mechanism for monitoring HS was developed as a feasible colorimetric sensor. In this study, AuNUs that are selectively responsive to HS were fabricated in the presence of trisodium citrate and 1,4-hydroquinone using a seed-mediated approach. Upon exposure of the AuNU solution to HS, the hydrosulfide ions (HS) in the solution are converted into oligomeric sulfides by 1,4-hydroquinone used as a reducing agent during the synthesis of AuNUs.

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The accumulation of plastic debris in aquatic organisms has raised serious concerns about the potential health implications of their incorporation into the food chain. However, conventional water remediation techniques are incapable of effectively removing nanoplastics (NPs) smaller than 200 nm, which can have harmful effect on animal and human health. Herein, we demonstrate the "on-the-fly" capture of NPs through their enlargement (approximately 4,100 times) using self-propelled nanobots composed of a metal-organic framework.

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The polymer electrolytes are considered to be an alternative to liquid electrolytes for lithium-ion batteries because of their high thermal stability, flexibility, and wide applications. However, the polymer electrolytes have low ionic conductivity at room temperature due to the interfacial contact issue and the growing of lithium dendrites between the electrolytes/electrodes. In this study, we prepared gel polymer electrolytes (GPEs) through an in situ thermal-induced cationic ring-opening strategy, using LiFSI as an initiator.

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Rechargeable lithium-ion batteries have drawn extensive attention owing to increasing demands in applications from portable electronic devices to energy storage systems. In situ polymerization is considered one of the most promising approaches for enabling interfacial issues and improving compatibility between electrolytes and electrodes in batteries. Herein, we observed in situ thermally induced electrolytes based on an oxetane group with LiFSI as an initiator, and investigated structural characteristics, physicochemical properties, contacting interface, and electrochemical performances of as-prepared SPEs with a variety of technologies, such as FTIR, 1H-NMR, FE-SEM, EIS, LSV, and chronoamperometry.

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UV-cured cross-linked polymer electrolytes are promising electrolytes for safe Li-ion batteries (LIBs) application due to their excellent conduction ability, low glass-transition temperature (), and high discharge capacity. Herein, we have prepared novel fluorosulfonylimide methacrylic-based cross-linked polymer electrolyte membranes for LIBs via UV-curing process, which is a well-known, easy, low-cost, fast, and reliable technique. The synthesized UV-reactive novel methacrylate monomer with directly attached fluorosulfonylimide functional group methacryloylcarbamoyl sulfamoyl fluoride (MACSF) was used as a precursor for UV curing along with poly(ethylene glycol) dimethacrylate (PEGDMA) and lithium bis(fluorosulfonyl)imide (LiFSI).

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Concave gold nanocubes are viable optical nanoprobes for the determination of nitrite ions. Herein, a novel approach was developed, based on the measurement of localized surface plasmon resonance absorption. The addition of nitrite ions selectively induced the etching of concave gold nanocubes, abrading the sharp vertices to spherical corners, which resulted in blue-shifted absorption accompanied by a color change from sapphire blue to light violet.

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Improved proton conductivity and high durability are now a high concern for proton exchange membranes (PEMs). Therefore, highly proton conductive PEMs have been synthesized from branched sulfonimide-based poly(phenylenebenzophenone) (SI-branched PPBP) with excellent thermal and chemical stability. The branched polyphenylene-based carbon-carbon backbones of the SI-branched PPBP membranes were attained from the 1,4-dichloro-2,5-diphenylenebenzophenone (PBP) monomer using 1,3,5-trichlorobenzene as a branching agent (0.

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A tetraphenylethene (TPE) derivative was designed and synthesized upon conjugation with bis(thiophen-2-ylmethyl) amine (BTA) containing a mercury-binding moiety and further characterized by using Nuclear magnetic resonance (NMR), LC-MS, UV-Vis, and fluorescence spectroscopic methods. The resulting TPE-BTA exhibited comprehensive aggregation-induced emission while expressing a high quantum yield and emission intensity at 70% water fraction. The probe exhibited a good photochromic effect with a Stokes shift of 178 nm, and the emission intensity at 550 nm increased considerably with the color turning from dark green to bright green under a UV lamp upon the addition of 5 μM Hg.

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A highly sensitive and selective colorimetric assay for the dual detection of Hg and As using gold nanoparticles (AuNPs) conjugated with d-penicillamine (DPL) was developed. When Hg and As ions coordinate with AuNP-bound DPLs, the interparticle distance decreases, inducing aggregation; this results in a significant color change from wine red to dark midnight blue. The Hg4f and As3d signals in the X-ray photoelectron spectra of Hg (As)-DPL-AuNPs presented binding energies indicative of Hg-N(O) and As-N(O) bonds, and the molecular fragment observed in time-of-flight secondary ion mass spectra confirmed that Hg and As coordinated with two oxygen and two nitrogen atoms in DPL.

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Polymer membranes, having improved conductivity with enhanced thermal and chemical stability, are desirable for proton exchange membranes fuel cell application. Hence, poly(benzophenone)s membranes (SI-PBP) containing super gas-phase acidic sulfonyl imide groups have been prepared from 2,5-dichlorobenzophenone (DCBP) monomer by C-C coupling polymerization using Ni (0) catalyst. The entirely aromatic C-C coupled polymer backbones of the SI-PBP membranes provide exceptional dimensional stability with rational ion exchange capacity (IEC) from 1.

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Thermally and chemically stable, sulfonyl imide-based polymer blends have been prepared from sulfonimide poly(arylene ether sulfone) (SI-PAES) and sulfonimide Parmax-1200 (SI-Parmax-1200) using the solvent casting method. Initially, sulfonimide poly(arylene ether sulfone) (SI-PAES) polymers have typically been synthesized via direct polymerization of bis(4-chlorophenyl) sulfonyl imide (SI-DCDPS) and bis(4-fluorophenyl) sulfone (DFDPS) with bisphenol A (BPA). Subsequently, SI-Parmax-1200 has been synthesized via post-modification of the existing Parmax-1200 polymer followed by sulfonation and imidization.

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This study aims to develop a one-dimensional (1D) computational fluid dynamics (CFD) model with dynamic airway geometry that considers airway wall compliance and acinar dynamics. The proposed 1D model evaluates the pressure distribution and the hysteresis between the pressure and tidal volume () in the central and terminal airways for healthy and asthmatic subjects. Four-dimensional CT images were captured at 11-14 time points during the breathing cycle.

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Although bariatric surgery is the best treatment modality for morbidly obese patients, a 10-30% rate of weight recidivism has been reported in various specialized centers. We examined changes in energy and macronutrients after bariatric surgery and performed analysis to establish appropriate nutritional guidelines for reaching the target percentage of weight loss after surgery. A total of 189 subjects who underwent bariatric surgery were classified into success and failure groups depending on whether or not they reached 50% loss of excess weight at 12 months after bariatric surgery.

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The synthesis of boron nitride nanodisks (BNNDs) with reducing the size and having fewer disk layers, and low optical band gap (E ) is essential for practical applications in electronics and optoelectronic devices. So far, the large-scale preparation of hydroxyl (-OH) and hydroperoxyl (-OOH) functionalized boron nitride nanosheets and BNNDs with reduced E is still a challenge. This research demonstrates the scalable and solution process synthesis of hydroxyl (-OH) and hydroperoxyl (-OOH) functionalization of BNNDs at the edges and basal planes from pristine hexagonal boron nitride (h-BN) by the combination of modified Hummer's method and Fenton's chemistry.

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This research demonstrated the development of a simple, cost-effective, and label-free immunosensor for the detection of α-synuclein (α-Syn) based on a cystamine (CYS) self-assembled monolayer (SAM) decorated fluorine-doped tin oxide (FTO) electrode. CYS-SAM was formed onto the FTO electrode by the adsorption of CYS molecules through the head sulfur groups. The free amine (-NH) groups at the tail of the CYS-SAM enabled the immobilization of anti-α-Syn-antibody, which concurrently allowed the formation of immunocomplex by covalent bonding with α-Syn-antigen.

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A series of new self-standing gel polymer electrolytes (SGPEs) were fabricated by ultraviolet (UV) curing and investigated for application in flexible lithium-ion batteries. Compared with traditional gel polymer electrolytes (combine with solvents or plasticizers), these new SGPEs were prepared simply by curing different weight ratios of lithium bis(fluorosulfonyl)imide (LiFSI) with a methacrylic linear monomer, poly (ethylene glycol) dimethacrylate (PEGDMA). Noticeably, there were no solvents or plasticizers combined with the final SGPEs.

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Single-ion conducting polymer electrolyte (SICPE) is a safer alternative to the conventional high-performance liquid electrolyte for Li-ion batteries. The performance of SICPEs-based Li-ion batteries is limited due to the low Li conductivities of SICPEs at room temperature. Herein, we demonstrated the synthesis of a novel SICPE, poly(ethylene--acrylic lithium (fluoro sulfonyl)imide) (PEALiFSI), with acrylic (fluoro sulfonyl)imide anion (AFSI).

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This study aimed to introduce a one-dimensional (1D) computational fluid dynamics (CFD) model for airway resistance and lung compliance to examine the relationship between airway resistance, pressure, and regional flow distribution. We employed five healthy and five asthmatic subjects who had dynamic computed tomography (CT) scans (4D CT) along with two static scans at total lung capacity and functional residual capacity. Fractional air-volume change ( ) from 4D CT was used for a validation of the 1D CFD model.

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Polymer containing isatin was synthesized by super acid-catalyzed carbon-carbon coupling reaction. Propylsulfonic acid was grafted on isatin unit by substitution reaction with potassium salt of 3-bromo-1-propanesulfonic acid. The sulfonic acid composition was regulated at 25~80 mol% of propylsulfonic acid in order to achieve expected ion exchange capacity of maximum 2.

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Gold nanoparticles (AuNPs) and quantum dots (Qdots) were clicked into doxorubicin nanoclusters that showed enzyme-dependent dissociation behaviors for differential cellular uptakes and imaging. The AuNPs were co-functionalized with doxorubicin (DOX) and azide-terminated polymer (DOX/azide@AuNP), while an enzyme-cleavable peptide and alkyne-terminated polymer were sequentially conjugated on Qdot surface (Alkyne-MMP@Qdot). Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and fluorescence imaging detected the azide and alkyne groups on DOX/azide@AuNP and Alkyne-MMP@Qdot, respectively, and the click-reactivity was also confirmed.

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Self-assembled nanoaggregates co-encapsulating doxorubicin (DOX) and oligonucleotide are prepared for dual-responsive breakdown of the nanostructure with complete disappearance characteristics. Four-arm poly(ethylene glycol) is co-conjugated with DOX and anti-bcl-2 oligonucleotide with reducible linkers and acid-cleavable linkers, respectively. The conjugate is hydrophobically self-assembled into nanoaggregates in aqueous solution.

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Although it is assumed that most patients with terminal cancer are reluctant to receive life-sustaining treatment, there is a paucity of evidence supporting this assumption. We retrospectively analyzed the advance directives of terminal cancer patients to determine the preferences of patients. Patients with cancer who had life expectancy of less than 6 months were admitted to a palliative care unit in Seoul Medical Center from March 2008 to February 2010.

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This study evaluated the antioxidant activities of kimchi at different fermentation times: short-term fermented kimchi (SK; less than 7days) and over-ripened kimchi (OK; greater than 2 years). In conclusion, antioxidant activity of the OK was significantly higher than the SK. The results of this study suggested that there was an increase in the antioxidant activity of fermented kimchi during the fermentation and ripening processes.

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