Jong-Man Kim

Hanyang University, Sŏul, Seoul, South Korea

Are you Jong-Man Kim?

Claim your profile

Publications (110)391.29 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: A challenge in developing photovoltaic devices is to minimize the loss of electrons, which can seriously deteriorate energy conversion efficiency. In particular, minimizing this negative process in dye-sensitized solar cells (DSCs) is imperative. Herein, we use three different kinds of siloxanes, which are adsorbable to titania surfaces and polymerizable in forming a surface passivation layer, to reduce the electron loss. The siloxanes used are tetraethyl orthosilicate (TEOS or compound A), 1-(3-(1H-imidazol-1-yl)propyl)-3-(3-triethoxysilyl) propyl) urea (compound B), and N-(3-triethoxysilylpropyl)-N'[3-(3-methyl-1H-imidazol-3-ium) propyl] urea iodide (compound C). Titania surface passivation by either compound B or C was comparatively more effective in increasing the electron lifetime than TEOS. In the case of small-sized TEOS combined with either large-sized compound B or C, a thinner and denser passivation layer was presumably developed, thus increasing electron lifetime further. Intriguingly, device AB shows the longest electron lifetime, whereas device AC has the highest energy-conversion efficiency among these experimental conditions. These results suggest that, in this special case, the electron lifetime may not be a dominant parameter in determining the energy conversion efficiency.
    ACS Applied Materials & Interfaces 07/2014; · 5.01 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Fabrication of 3D biological structures reveals dynamic response to external stimuli. A liquid-crystalline bridge extrusion technique is used to generate 3D structures allowing the capture of Rayleigh-like instabilities, facilitating customization of smooth, helical, or undulating periodic surface textures. By integrating intrinsic biochemical functionality and synthetic components into controlled structures, this strategy offers a new form of adaptable materials.
    Advanced materials (Deerfield Beach, Fla.). 06/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: A highly sensitive, tunable, flexible and microfluidic compatible gas sensor was developed based on a photochromic spiropyran-embedded PDMS composite.
    Chemical Communications 03/2014; · 6.38 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: An electrothermochromic paper display composed of colorimetrically reversible polydiacetylenes (PDAs), utilizing screen printing on photopaper and patterning of electrically conductive wires on the reverse side, was developed. Heat generated by passing a current through the wires on the back of the photopaper induced a blue-to-red color transition of the PDA on the front at regions corresponding to the wires. This resulted in the generation of red-colored images, which disappeared when the supplied electric current was removed. The voltage at which the PDAs changed color could be controlled by using structured diacetylene (DA) monomers. A PDA-based seven-segment display has also been developed. By applying voltages, red-colored numeric digits from 0 to 9 can be displayed on the surface of the PDA layer.
    Nanotechnology 02/2014; 25(9):094011. · 3.84 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A biphenyl derivative containing two D-Ala-D-Ala moieties was found to form fluorescent nano/microfibers when subjected to self-assembly conditions in aqueous EtOH. Incubation of the nano/microfibers with vancomycin results in the disappearance of the fibers along with a significant decrease in the fluorescence intensity. The detection limit of vancomycin determined by the fluorescence quenching strategy was calculated to be ca. 57 μM. Regeneration of the original fiber structures were obtained in the presence of Ac-Lys(Ac)-D-Ala-D-Ala, a substance known to bind tightly to vancomycin. Other proteins including bovine serum albumin (BSA), casein, elastase, and chymotrypsin were found to cause no morphological and fluorescence changes in the supramolecules. The unique vancomycin-induced phase transition and fluorescence change were not observed with a biphenyl derivative having L-Ala-L-Ala moiety.
    Journal of Nanoscience and Nanotechnology 01/2014; 14(10). · 1.15 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Hydrochromic materials have been actively investigated in the context of humidity sensing and measuring water contents in organic solvents. Here we report a sensor system that undergoes a brilliant blue-to-red colour transition as well as 'Turn-On' fluorescence upon exposure to water. Introduction of a hygroscopic element into a supramolecularly assembled polydiacetylene results in a hydrochromic conjugated polymer that is rapidly responsive (<20 μs), spin-coatable and inkjet-compatible. Importantly, the hydrochromic sensor is found to be suitable for mapping human sweat pores. The exceedingly small quantities (sub-nanolitre) of water secreted from sweat pores are sufficient to promote an instantaneous colorimetric transition of the polymer. As a result, the sensor can be used to construct a precise map of active sweat pores on fingertips. The sensor technology, developed in this study, has the potential of serving as new method for fingerprint analysis and for the clinical diagnosis of malfunctioning sweat pores.
    Nature Communications 01/2014; 5:3736. · 10.02 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Low temperature reactive plasmas have been widely used in various nanofabrication processes. We have developed a large area wafer-type colorimetric plasma diagnostic system based on a polymerizable supramolecular sensor (PSS). The supramolecular diacetylene based PSS allows efficient mapping of the ion density distribution. The colour change of the thin PSS film was found to be very sensitive to plasma and afforded a real time colorimetric and fluorometric monitoring of spatial ion density distribution. This PSS method, which does not require electrical circuits and batteries, will find great utility in the field of plasma diagnostics.
    Sensors and Actuators B Chemical 01/2014; 203:130–134. · 3.54 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: As they have been designed to undergo colorimetric changes that are dependent on the polarity of solvents, the majority of conventional solvatochromic molecule based sensor systems inevitably display broad overlaps in their absorption and emission bands. As a result, colorimetric differentiation of solvents of similar polarity has been extremely difficult. Here we present a tailor-made colorimetric and fluorescence turn-on type solvatochromic sensor that enables facile identification of a specific solvent. The sensor system displays a colorimetric transition only when a thin protective layer, which protects the solvatochromic materials, is destroyed or disrupted by a specific solvent. The versatility of the strategy is demonstrated by designing a sensor that differentiates chloroform and dichloromethane colorimetrically and one that performs sequence selective colorimetric sensing. In addition, the approach is employed to construct a solvatochromic molecular AND logic gate. The new strategy could open new avenues for the development of novel solvatochromic sensors.
    Nature Communications 09/2013; 4:2461. · 10.02 Impact Factor
  • In Sung Park, Hye Jin Park, Jong-Man Kim
    [Show abstract] [Hide abstract]
    ABSTRACT: The majority of polydiacetylenes (PDAs) described to date display thermochromic transitions above room temperature. By following a strategy that employs headgroups that do not participate in strong interactions, we have designed and prepared a liquid diacetylene (DA) monomer that solidifies at a temperature near 0 °C. The isocyanate-containing DA monomer, DA-NCO, having this property does not undergo polymerization in its liquid state at room temperature. However, UV irradiation of frozen DA-NCO at 0 °C causes the instantaneous formation of a blue PDA (PDA-NCO). Interestingly, PDA-NCO was found to display a sharp blue-to-red color transition at a temperature near 11 °C. By taking advantage of its room temperature liquid-phase property, we were able to readily transfer the DA monomer to solid substrates by using common stamping and writing methods used for creating patterned PDA images. In addition, PDA-NCO dissolves in chloroform, giving a yellow solution that becomes red and simultaneously generates polymer aggregates when hexane is added. Finally, the isocyanate moieties present in PDA-NCO have been utilized to differentiate 1° from 2° and 3° amines owing to the fact that a chloroform solution of PDA-NCO undergoes a rapid yellow-to-red color change associated with an insoluble urea-forming reaction with primary amines.
    ACS Applied Materials & Interfaces 08/2013; · 5.01 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Biological systems provide us with a diverse source of peptide-based ligands for cellular adhesion. Controlling and assessing the ligand surface density as well as tailoring the surface chemistry to have specific cellular adhesion properties are important in biomaterials design. In the following work, we provide a means for displaying peptide-based ligands on magnetic liposomes in which the surface density and chemistry may be controlled. Simultaneously, the conjugated vesicles provide a fluorescent signal for examining steric hindrance among surface ligands. In addition, the inherent magnetic and fluorescence features of this system revealed potential for magnet-based cell isolation and fluorescent labeling of adhered cells, respectively. Adhered cells were found to remain viable and proliferative, thereby allowing them to be used for subsequent evaluation. In a specific demonstration, we control the density of fibronectin-mimetic ligands on the polydiacetylene liposome surfaces. We find that steric limitation occurring at over 20% surface density result in decreased cell adhesion, in accord with related techniques. The magnetic-liposome system offers the means for not only separating cells adhered to the biomaterial but also providing the ability to control and assess the biomaterial surface. This may prove particularly useful for examining combinations of peptide-based ligands or for evaluating the molecular-level ligand accessibility and its effect on cell attachment to a biomaterial surface.
    Langmuir 05/2013; · 4.19 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Novel, stimulus-responsive supramolecular structures in the form of fibers, gels and spheres, derived from an azobenzene-containing benzenetricarboxamide derivative, are described. Self-assembly of tris(4-((E)-phenyldiazenyl)phenyl)benzene-1,3,5-tricarboxamide (Azo-1) in aqueous organic solvent systems results in solvent dependent generation of microfibers (aq. DMSO), gels (aq. DMF) and hollow spheres (aq. THF). The results of a single crystal X-ray diffraction analysis of Azo-1 (crystallized from a mixture of DMSO and H2O) reveal that it possesses supramolecular columnar packing along the b axis. Data obtained from FTIR analysis and density functional theory (DFT) calculation suggest that multiple hydrogen bonding modes exist in the Azo-1 fibers. UV irradiation of the microfibers, formed in aq. DMSO, causes complete melting while regeneration of new fibers occurs upon visible light irradiation. In addition to this photoinduced and reversible phase transition, the Azo-1 supramolecules display a reversible, fiber-to-sphere morphological transition upon exposure to pure DMSO or aq. THF. The role played by amide hydrogen bonds in the morphological changes occurring in Azo-1 is demonstrated by the behavior of the analogous, ester-containing tris(4-((E)-phenyldiazenyl)phenyl)benzene-1,3,5-tricarboxylate (Azo-2) and by the hydrogen abstraction in the presence of fluoride anions.
    Langmuir 04/2013; · 4.19 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Technological advances made in constructing high-resolution instrumentation have enabled fabrication of sophisticated counterfeit products. As a result, the need to develop novel anti-counterfeiting materials and systems is greatly increasing. Accordingly, various functional materials that display distinct chemical, physical as well as optical and electrical properties have been investigated for preventing and detecting counterfeiting. In this feature article, we describe recent strategies that have been devised for anti-counterfeiting purposes that focus on colorimetric and fluorometric approaches that are employed in the determination of the authenticity of banknotes, documents, medicine, etc. In addition, methods of incorporating organic electronics on banknotes as active authentication tools as well as molecular imaging techniques based on mass spectrometry are briefly described.
    J. Mater. Chem. C. 03/2013; 1(13):2388-2403.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Inkjet-printable diacetylene (DA) supramolecules, which can be dispersed in water without using additional surfactants, have been developed. The supramolecules are generated from DA monomers that contain bisurea groups, which are capable of forming hydrogen-bonding networks, and hydrophilic oligoethylene oxide moieties. Because of suitable size distribution and stability characteristics, the single DA component ink can be readily transferred to paper substrates by utilizing a common office inkjet printer. UV irradiation of the DA-printed paper results in generation of blue-colored polydiacetylene (PDA) images, which show reversible thermochromic transitions in specific temperature ranges. Inkjet-printed PDAs, in the format of a two-dimensional (2D) quick response (QR) code on a real parking ticket, serve as a dual anticounterfeiting system that combines easy decoding of the QR code and colorimetric PDA reversibility for validating the authenticity of the tickets. This single-component ink system has great potential for use in paper-based devices, temperature sensors, and anticounterfeiting barcodes.
    ACS Applied Materials & Interfaces 03/2013; · 5.01 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Inkjet-printed paper-based volatile organic compound (VOC) sensor strips imaged with polydiacetylenes (PDAs) are developed. A microemulsion ink containing bisurethane-substituted diacetylene (DA) monomers, 4BCMU, was inkjet printed onto paper using a conventional inkjet office printer. UV irradiation of the printed image allowed fabrication of blue-colored poly-4BCMU on the paper and the polymer was found to display colorimetric responses to VOCs. Interestingly, a blue-to-yellow color change was observed when the strip was exposed to chloroform vapor, which was accompanied by the generation of green fluorescence. The principal component analysis plot of the color and fluorescence images of the VOC-exposed polymers allowed a more precise discrimination of VOC vapors.
    Macromolecular Rapid Communications 02/2013; · 4.93 Impact Factor
  • Bora Yoon, Justyn Jaworski, Jong-Man Kim
    [Show abstract] [Hide abstract]
    ABSTRACT: The structure of polydiacetylene (PDA) supramolecules offers carboxylic acid-terminated alkyl side-chains around a π conjugated polymer backbone. Exposure of these supramolecules to alkylamines induced disruption of the conjugated PDA backbone via intercalation as revealed by a colorimetric/fluorometric response. This response is demonstrated to be dependent on the length of the alkylamine, offering a new view on intercalation in PDA systems with respect to supramolecules. It is found that this critical carbon chain length of alkylamine required to induce a colour change response must be greater than the alkyl side-chain length of PDA in order to interact with the conjugated backbone. Intercalation of longer species is also found to induce supramolecule aggregation resulting in destabilised PDA suspensions.
    Supramolecular Chemistry 01/2013; 25(1). · 1.55 Impact Factor
  • Source
    Jung Lee, Wha Kyung, Oh, Jong-Man Kim
    [Show abstract] [Hide abstract]
    ABSTRACT: Owing to the ever growing interest for the human health against infectious bacteria, various substances that dis-play antimicrobial activity have been developed. 1-7 For instance, inorganic silver nanoparticles have been actively investigated as antibacterial agents although the mecha-nism for the activity is not clearly understood. 8-12 Recently, photochemically triggerable organic antimi-crobial substances have received significant attention since these materials can be formulated with fabrics to produce self-decontaminating clothes. 13-18 In addition, the irradiation-induced antimicrobial activity is attractive because of the readily available light source (eg. Sun). Among var-ious candidates, benzophenone derivatives have been most actively investigated as photoactive antimicrobial agents owing to the some salient features including facile syn-thesis and generation of reactive radicals via photosensi-tization. 13-15 Thus, benzoquinone with diverse substituents have been prepared and applied to the antimicrobial screening. It has been well known that photoinduced oxidation of certain electron donating group-substituted triphenyl-methane derivatives produces brilliantly colored ionic species. 19 Owing to this property, triphenylmethane deriv-atives have been investigated as precursors of colorants. A mechanistic pathway to the photochemical genartion of an ionic iminium product from a triphenyl methane dri-vative, 4,4',4''-tris(dimethylaminophenyl) methane (TPM, 1) is presented in Scheme 1. The first step of this process involves excited state single electron transfer (SET) from the triphenylmethane donor to presumably molecular oxygen. The radical cation intermediate 2, produced in this fashion, subsequently undergoes hydrogen atom loss to yield the iminium ion 3. Since the iminium ion 3 is fully conjugated, formation of the ionic moiety can be readily monitored by visible absorption spectroscopy and most often with naked eyes. The generation of reactive ionic/radical species from the photochemical oxidation of TPM is very intriguing since these reactive species might be able to retard the growth of microbes or destroy them. If TPM displays the antimicrobial activity, a new class of photoactive antimi-crobial agent can be developed. In order to test the feasibility of TPM as a photoactive antimicrobial agent, a thin (ca. 1 m) polystyrene (PS) film containing TPM was prepared by spin-coating of a chlo-roform solution containing PS (MW: 280,000, 5 wt%) and TPM (1.5 wt%, based on the weight of PS polymer pow-der) on a glass substrate. 20 Irradiation of UV light (254 nm, 1 mW/cm 2) to the film resulted in the gradual increase of the absorption in the visible region, confirming the suc-cessful generation of iminium product 3 in the polymer film (Fig. 1). In addition, the colorless transparent TMP-containing film became pale purple after UV irradiation. We next investigated antimicrobial properties of the TPM containing PS films against Staphylococcus aureus Scheme 1. Proposed mechanism of photoinducediminium ion formation from TPM.
    Journal of the Korean Chemical Society 04/2012; 56(2):185.
  • Imsung Yoo, Simon Song, Bora Yoon, Jong-Man Kim
    [Show abstract] [Hide abstract]
    ABSTRACT: A microfluidic technique was employed to fabricate polydiacetylene (PDA)-embedded hydrogel microfibers. By taking advantage of calcium ion-induced insoluble hydrogel formation, supramolecularly assembled diacetylene (DA)-surfactant complexes were successfully immobilized in the calcium alginate fibers. Thus, instantaneous microfiber formation was observed when the core flow of DA supramolecules-containing alginate solution met the sheath flow of calcium ions. UV irradiation of the resulting fibers afforded blue colored PDAs, and the formation of a conjugated polymer was confirmed by heat-induced phase transition and by Raman spectroscopy. By adjusting the core and sheath flow rates, PDA-embedded hydrogel fibers of various sizes were obtained.
    Macromolecular Rapid Communications 04/2012; 33(15):1256-61. · 4.93 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Owing to their flexible, light-weight and disposable properties, paper-based electronic and sensor systems have gained much attention. Efficient immobilization and patterning of functional materials on paper substrates are critical to device performance. Herein, we report an inkjet printable and photopolymerizable diacetylene (DA) containing microemulsion system that can be readily transferred to paper substrates using a common office inkjet printer. UV-induced polymerization afforded clean formation of polydiacetylene (PDA) supramolecules on paper and the polymer displayed a typical thermochromism. The resolution of the printed PDA images was found to be equivalent to that of conventional black ink. The randomly oriented DA in the oil phase was found to be transformed to self-assembled layered structures upon printing. The printed PDA supramolecules derived from 5,7-dodecadiyne-1,12-diol bis[((butoxycarbonyl)methyl)urethane] (4BCMU) displayed a blue-to-red-to-yellow color transition upon heating. Thus, the blue colored 4BCMU-derived polymer was converted to a red colored PDA at 100 °C and further heating to 180 °C resulted in the generation of a yellow colored PDA. Upon cooling to room temperature, the yellow colored PDA became red and a complete colorimetric reversibility was observed between red (30 °C) and yellow (180 °C). The thermally promoted reversible PDA phase transition was successfully applied to a banknote to demonstrate an application to a potential counterfeit prevention method.
    Journal of Materials Chemistry 04/2012; 22(17):8680-8686. · 5.97 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: While a large variety of conjugated polymers exist, polydiacetylenes (PDAs) remain a major research area among scientists due to their interesting optical, spectral, electronic, and structural properties. Heavily reviewed in regards to their stimuli responsive properties, much is known about the assortment of sensing and detection capabilities of PDAs. In this article, we look more upon the structural diversities of polydiacetylenes that have been achieved in recent years, particularly from a hierarchical perspective of 1, 2, and 3-dimensional configurations. In addition, we examine how these different dimensional arrangements of PDAs have heralded clear applications in several key areas. Successful integration of these stimuli-responsive "smart" materials into various geometries has required researchers to have a comprehensive understanding of both the fabrication and synthesis processes, as well as the signalling mechanism for the optical, fluorogenic or spectral transitions. The on-going discovery of new PDA formulations continues to provide interesting structural manifestations such as liposomes, tubes, fibres, organic/inorganic incorporated hybrids and composite structures. By highlighting some of the recent conceptual and technological developments, we hope to provide a measure of the current pace in new PDA derivative development as core components in efficient sensor, imaging and display systems.
    Chemical Communications 02/2012; 48(19):2469-85. · 6.38 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We describe the results of electrophoretic deposition characteristics of a conjugated polymer, polydiacetylene (PDA), that reveal film forming behavior, polymerization effects, pattern transfer capabilities, and fluorescence based thermo/mechano-responsive features of the deposited layer. The electric field applied in a two electrode system promotes the oriented motion of diacetylene (DA) supramolecules in aqueous solution in a direction that is determined by the charge polarities of tailorable pendant groups on the DA monomers. Through this mechanism, electrophoretic deposition of DA supramolecules on a conductive layer takes place to yield vesicular clustered aggregates with continuous leaf-like morphologies. In addition, unusual conformational changes of the DA monomers during the deposition result in the formation of polymerized blue colored PDAs on the working electrode. Based on these properties, selective deposition of the supramolecules on pre-patterned templates and consequent pattern transfer to a flexible substrate can be utilized to fabricate PDA-based microarray sensors. The chromatic change of the vesicles induced by an applied mechanical stress during pattern transfer is found to be dependent on the side groups of the DA monomers. Owing to inherent non-fluorescence to fluorescence transition features of PDA supramolecules occurring as a response to thermal perturbations, electrophoretically deposited PDAvesicles are employed to monitor the temperature of a heat dispensing micro-heater device.
    Journal of Materials Chemistry 11/2011; 21(46):18605-18612. · 5.97 Impact Factor

Publication Stats

713 Citations
391.29 Total Impact Points

Institutions

  • 2002–2014
    • Hanyang University
      • • Division of Chemical Engineering and Bioengineering
      • • Division of Mechanical Engineering
      • • College of Engineering
      Sŏul, Seoul, South Korea
  • 2006–2011
    • Korea Advanced Institute of Science and Technology
      • • Department of Electrical Engineering
      • • Department of Chemical and Biomolecular Engineering
      Seoul, Seoul, South Korea
  • 2009
    • University of Ulsan
      • Department of Chemistry
      Ulsan, Ulsan, South Korea
  • 2003–2008
    • Korea University
      • Department of Chemical and Biological Engineering
      Seoul, Seoul, South Korea
  • 1998–2007
    • Korea Institute of Science and Technology
      • Center for Biomaterials
      Sŏul, Seoul, South Korea
  • 2001
    • Heinrich-Heine-Universität Düsseldorf
      • Institut für Organische Chemie und Makromolekulare Chemie
      Düsseldorf, North Rhine-Westphalia, Germany