Jin Woong Kim

Abstract Electronic skin (E‐skin) imitates human skin by converting external stimuli into electrical signals. E‐skin requires high flexibility and a high level of device integration. Unlike conventional E‐skin creation methods, a highly sensitive pressure sensor matrix (100 pixels cm −2 ) made of position‐registered elastic conductive microparticles (MPs) is created. The MPs form a Schottky junction with the bottom electrode and the current through the junction is sensitive to external pressure,

Intense interest has been shown in the development of “smart nanofluids” because they can dramatically change their flow properties in complex fluid systems. We introduce a robust and straightforward approach to develop a smart nanofluid system, in which associative silica nanoparticles (ASNPs) were incorporated to regulate their flow properties in rock pores. ASNPs were synthesized by covalently coating a hydrophobically associative hygroscopic zwitterionic poly[2-methacryloyloxyethyl phosphory

A microfluidic technique is described to encapsulate living cells in alginate hydrogel microparticles generated from monodisperse double-emulsion templates. A microcapillary device is used to fabricate double emulsion templates composed of an alginate drop surrounded by a mineral oil shell. Hydrogel formation begins when the alginate drop separates from the mineral oil shell and comes into contact with Ca(2+) ions in the continuous phase. Alginate hydrogel microparticles with diameters ranging f

Abstract Due to the increasing interest in wearable devices, flexible and stretchable film heaters have been widely studied, as alternatives to heaters with conventional rigid shapes. Herein, a highly stretchable film heater (SFH) based on the silver nanowire (Ag NW)–single‐walled carbon nanotube composite with a thermochromic display on a polydimethylsiloxane (PDMS) substrate is successfully fabricated. The SFH shows excellent electrical conductivity, high mechanical stretchability, and outstan

This study reports a Pickering emulsion flooding system, in which the oil–water interface is structurally stabilized by a complex colloidal layer consisting of silica nanoparticles, dodecyltrimethylammonium bromide (DTAB), and poly(4-styrenesulfonic acid- co -maleic acid) sodium salt (PSS- co -MA). The colloidal layer was generated by adsorption of PSS- co -MA on the silica nanoparticles as a result of the van der Waals attraction and by adsorption of DTAB onto the PSS- co -MA layer as a result

Colloid surfactant catalysts are synthesized for the production of Pickering emulsion microreactors that exhibit outstanding catalytic activity and magnetic-responsive recovery performance.

Janus particles endowed with controlled anisotropies represent promising building blocks and assembly materials because of their asymmetric functionalities. Herein, we show that using the seeded monomer swelling and polymerization technique allows us to obtain bi-compartmentalized Janus microparticles that are generated depending on the phase miscibility of the poly (alkyl acrylate) chains against the polystyrene seed, thus minimizing the interfacial free energy. When tetradecyl acrylate is used

We herein propose a polymeric nanovehicle system that has the ability to remarkably improve cellular uptake and transdermal delivery. Cell-penetrating peptide-patchy deformable polymeric nanovehicles were fabricated by tailored coassembly of amphiphilic poly(ethylene oxide)- block-poly(ε-caprolactone) (PEO- b-PCL), mannosylerythritol lipid (MEL), and YGRKKRRQRRR-cysteamine (TAT)-linked MEL. Using X-ray diffraction, differential scanning calorimetry, and nuclear magnetic resonance analyses, we re

Luteolin (3',4',5,7-tetrahydroxyflavone), a type of flavonoid found in medicinal herbs and vegetables, has been of great interest due to its antioxidative, anti-inflammatory, and anticarcinogenic effects. Despite these beneficial biological properties, the ease with which luteolin forms molecular crystals in conventional aqueous formulations has hampered much wider applications. In this study, we introduce an oil-in-water (O/W) nanoemulsion vehicle system for enhanced follicular delivery of lute

We present a straightforward and robust method for the synthesis of Janus colloid surfactants with distinct amphiphilicity and magnetic responsiveness. To this end, hydroxyl-functionalized amphiphilic Janus microparticles (JMPs) are synthesized by seeded monomer swelling and subsequent photopolymerization. By incorporating controlled amounts of hydroxyl groups on poly(styrene- co -vinyl alcohol) seed particles, we adjust the interfacial tension between the seed polymer and the poly(tetradecyl ac

Cellulose fibrils, unique plant-derived semicrystalline nanomaterials with exceptional mechanical properties, have significant potential for rheology modification of complex fluids due to their ability to form a physically associated semiflexible fibrillary network. Here, we report new associative cellulose nanocrystals (ACNCs) with stress-responsive rheological behaviors in an aqueous solution. The surface-mediated living radical polymerization was employed to graft poly(stearyl methacrylate-co

Abstract There is an increasing demand for control over the dimensions and functions of transition metal dichalcogenides (TMDs) in aqueous solution toward biological and medical applications. Herein, an approach for the exfoliation and functionalization of TMDs in water via modulation of the hydrophobic interaction between poly(ε‐caprolactone)‐ b ‐poly(ethylene glycol) (PCL‐ b ‐PEG) and the basal planes of TMDs is reported. Decreasing the hydrophobic PCL length of PCL‐ b ‐PEG from 5000 g mol −1

Abstract A new platform for designing 2D colloidal arrays by using Janus microparticles (JMPs) with tunable anisotropic particle geometry is introduced. The JMPs are synthesized by the photopolymerization of biphasic emulsion droplets produced by capillary‐based microfluidics while adjusting the spreading coefficient between −4.4 and −7.2 mN m −1 . The unidirectional rubbing of JMPs leads to their exact positioning in the stencil holes. The ratio of the hole diameter to the bigger bulb diameter