Jinseok Park

Abstract This work demonstrates the low‐temperature operation of solid‐state lithium metal batteries (LMBs) through the development of a fluorinated and plastic‐crystal‐embedded elastomeric electrolyte (F‐PCEE). The F‐PCEE is formed via polymerization‐induced phase separation between the polymer matrix and plastic crystal phase, offering a high mechanical strain (≈300%) and ionic conductivity (≈0.23 mS cm −1 ) at −10 °C. Notably, strong phase separation between two phases leads to the selective

Millimeter-wave beamforming front-end ICs have been studied intensively as the service of 5G wireless communication is scheduled to begin in the near future [1-4]. The ICs include circuit elements such as PAs, LNAs, phase shifters, variable gain blocks, and switches to support antenna arrays for RF/hybrid beamforming. Due to the large number of antennas required for beamforming, the beamforming IC should include as many circuit elements as possible in a chip. The IC also needs high phase- and ga

We use single-particle tracking (SPT) to explore the role of nanoparticles/polymer interactions and polymer molecular weight on nanoparticle (NP) diffusion in unentangled polymer melts. The very dilute NP concentrations (∼10–7 wt %) in SPT measurements enable tuning NP/polymer interactions so that the systems with unfavorable or neutral NP/polymer interactions in polymer melts can be studied without nanoparticle aggregation. Here, the diffusion coefficients of weakly interacting (methyl-capped,

We investigated the nanoscale morphologies and ionic conductivities of polyethylene-based multiblock copolymers as single-ion conducting polymer electrolytes. These polymers contain short polar blocks with a single sodium sulfonate group separated by polyethylene blocks of fixed length (PESxNa, x = 10, 12, and 18). At room temperature, these multiblock copolymers exhibit layered ionic aggregates with semicrystalline polyethylene backbones. For PES12Na and PES18Na, the layered ionic aggregate mor

We demonstrate enhanced Li+ transport through the selectively solvated ionic layers of a single-ion conducting polymer. The polymer is a precisely segmented ion-containing multiblock copolymers with well-defined Li+SO3– ionic layers between crystallized linear aliphatic 18-carbon blocks. X-ray scattering reveals that the dimethyl sulfoxide (DMSO) molecules selectively solvate the ionic layers without disrupting the crystallization of the polymer backbone. The amount of DMSO (∼21 wt %) calculated

The double gyroid structure was first reported in diblock copolymers about 30 years ago, and the complexity of this morphology relative to the other ordered morphologies in block copolymers continues to fascinate the soft matter community. The double gyroid microphase-separated morphology has co-continuous domains of both species, and the minority phase is subdivided into two interpenetrating network structures. In addition to diblock copolymers, this structure has been reported in similar syste

We investigated the temperature-dependent phase behavior and interaction parameter of polyethylene-based multiblock copolymers with pendant ionic groups. These step-growth polymers contain short polyester blocks with a single Li⁺SO₃^- group strictly alternating with polyethylene blocks of <i>x</i>-carbons (PES<i>x</i>Li, <i>x</i> = 12, 18, 23). At room temperature, these polymers exhibit layered morphologies with semicrystalline polyethylene blocks. Upon heating a

A method of microalgae-templated spray drying to develop hierarchical porous Fe3O4/C composite microspheres as anode materials for Li-ion batteries was developed. During the spray-drying process, individual microalgae serve as building blocks of raspberry-like hollow microspheres via self-assembly. In the present study, microalgae-derived carbon matrices, naturally doped heteroatoms, and hierarchical porous structural features synergistically contributed to the high electrochemical performance o

We demonstrate that ionic functionality in a multiblock architecture produces highly ordered and sub-3 nm nanostructures in thin films, including bicontinuous double gyroids. At 40 °C, precise ion-containing multiblock copolymers of poly(ethylene-<i>b</i>-lithium sulfosuccinate ester) _<i>n</i> (PES<i>x</i>Li, <i>x</i> = 12 or 18) exhibit layered ionic assemblies parallel to the substrate. These ionic layers are separated by crystalline polyethylene blocks with the polymer backbones pe

Polymer electrolytes (PEs) have emerged as alternatives to conventional liquid electrolytes in lithium metal batteries (LMBs) by addressing critical safety and performance challenges, including flame hazards, dendrite growth, and interfacial instability. While oxygen-based PEs, such as poly(ethylene oxide), have been widely investigated, their limited ionic conductivity and susceptibility to electrochemical degradation under high-voltage operation have prompted the exploration of heteroatom-func

Searching prior art is a key part of the patent application and examination processes. A comprehensive prior art search gives the inventor ideas as to how he can improve or circumvent existing technology by providing up to date knowledge on the state of the art. It also enables the patent applicant to minimise the likelihood of an objection from the patent office. This article explores the characteristics of prior art associated with software patents, dealing with difficulties in searching prior

CC는 평가보증등급에 따라 정보보호제품의 보안취약점을 최소화할 수 있도록 지원하는 제도이다. 소프트웨어 개발보안은 소프트웨어의 개발 생명주기에서 보안취약점을 발생시킬 수 있는 보안약점을 제거하는 방법이다. 하지만 CC는 정보보호제품이 인증된 시점 이전의 보안취약점에 대해선 고려하지만 인증된 시점 이후에 발생할 수 있는 새로운 보안취약점에 대해서 고려하지 않기 때문에 정보보호제품의 안전성과 신뢰성에 대한 문제가 발생할 수 있다. 또한, 국가 및 공공기관의 정보화사업에 도입되는 정보보호제품은 CC와 소프트웨어 개발보안을 모두 만족시켜야 되기 때문에 개발자, 평가자에게 부담이 된다. 따라서 본 논문은 CC에서 소프트웨어 개발보안을 활용해야하는 당위성을 검증하기 위해 CC와 소프트웨어 개발보안이 제거할 수 있는 보안약점 및 보안취약점의 상관관계를 비교하였다. 또한, CC에서 소프트웨어 개발보안을 활용하기 위한 평가방법을 제안하여 정보보호제품의 안전성과 신뢰성을 극대화하고 개발자와 평가자의

This paper presents a transistor level design of a current mode 4 switch buck boost converter (4SBBC) for polar modulation. The reference signal of this 4SBBC is the envelope signal of EDGE (Enhancement Data-rate for GSM Evolution) standard which has more than 200kHz bandwidth. In order for output voltage to follow this fast varying reference signal, this 4SBBC uses current mode control with 10MHz fixed switching frequency which demands high bandwidth circuit design. This paper will show how to