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Next-generation devices and systems require the development and integration of advanced materials, the realization of which inevitably requires two separate processes: property engineering and patterning. Here, we report a one-step, ink-lithography technique to pattern and engineer the properties of thin films of colloidal nanocrystals that exploits their chemically addressable surface. Colloidal nanocrystals are deposited by solution-based methods to form thin films and a local chemical treatment is applied using an ink-printing technique to simultaneously modify (i) the chemical nature of the nanocrystal surface to allow thin-film patterning and (ii) the physical electronic, optical, thermal, and mechanical properties of the nanocrystal thin films. The ink-lithography technique is applied to the library of colloidal nanocrystals to engineer thin films of metals, semiconductors, and insulators on both rigid and flexible substrates and demonstrate their application in high-resolution image replications, anticounterfeit devices, multicolor filters, thin-film transistors and circuits, photoconductors, and wearable multisensors.

The synthesis and characterization of poly(phenylene polysulfide) networks (PSNs) with controlled average sulfur ranks, from elemental sulfur (ES) and

The AlN substrate was fabricated by the tape casting process, and its thermal conductivity and electrical conductivity were investigated for various ball milling times and types of milling media. The oxygen content was measured after ball milling, de-binding process, and sintering. The oxygen content after the de-binding process was 1.2–2.3 wt%, similar to that after milling. After the de-binding process, the specimens were sintered at 1850 ℃ for 3 h in nitrogen atmosphere. The thermal conductivity of the sintered specimens decreased from 158 W m−1 K−1 to 100 W m−1K−1 with increasing milling time. Simultaneously, the electrical conductivity decreased from approximately 10−7 Ω−1 cm−1 to 10−9 Ω−1 cm−1 at 500 °C when Al2O3 or ZrO2 balls were used, whereas the electrical conductivity did not decrease when Si3N4 balls were used.

For the evaluation of the residual image suppression, the amorphous indium-gallium-zinc-oxide thin film transistor was manufactured with electric field shield metal on silicon oxide multi-buffer layer, without the need for a silicon crystallization process through the excimer laser process, and is advantageous for the manufacture of large-scale plastic organic light-emitting display. We conducted a study on the propensity to suppress a residual image according to the temperature of the annealing process in amorphous indium gallium zinc oxide. The evaluation divided by the ambient process temperature conditions to measure the change and restoration tendency of the gray current by the black/white current of thin film transistors, and for precise measurement of the current change intervals, the current was analyzed in 0.004 seconds per point. Through the study, residual image of amorphous Indium Gallium Zinc Oxide transistor was found to be suppressed as the temperature of the annealing crystallization increased from 250°C to 325°C, and there was no improvement effect on the 325°C or higher. The trend of threshold voltage shift of thin film transistors according to the two process temperature conditions, 250°C and 325°C, was analyzed by Two sample T analysis method, and the analysis confirmed that the trend of current deterioration is different through p-value 0.007.

Plastic organic light emitting diode displays suffer from residual image, which is closely connected with the hysteresis of the driving thin-film transistor in the pixels. Therefore, in researching paper, we manufactured an OLED display comprise a polyimide substrate and an amorphous indium gallium zinc oxide thin film transistor active layer. Paper proposed a solution for reducing hysteresis through oxygen partial pressure control and evaluated it using hysteresis analysis. The results showed that hysteresis is strongly dependent on the threshold voltage is settled by the oxygen partial pressure while active layer deposition of the TFT. Moreover, hysteresis decreases with increasing temperature.

We fabricated the AlN substrate using tape casting method and investigated the effect of carbon content on sinterability and thermal conductivity. The carbon residue content was measured after the debinding of the AlN green sheet containing 1 wt% Ca–Al–Si–O glass (CAS glass) in the range of 300–1000°C in atmospheres of air, N2, vacuum, and wet N2. The carbon residue content was 0.21 wt% after debinding in the wet N2 atmosphere at 800°C, 0.59 wt% after debinding at 1000°C in the N2 atmosphere, and 1.1 wt% after debinding in the N2 atmosphere at 700°C. The debinded specimen was sintered at 1850°C for 3 h in the N2 atmosphere. As a result, when the residual carbon content was 0.2 wt%, the bulk density was found to be highest with 3.22 g/cm3, and the thermal conductivity was 93 W/m∙K. When the residual carbon content was 0.59 wt%, the bulk density was almost the same at 3.21 g/cm3, and the thermal conductivity was significantly increased to 161 W/m∙K. When the residual carbon content was 1.1 wt%, the bulk density was 2.71 g/cm3, and the thermal conductivity was 60 W/m∙K, degrading the sintered properties.

The synthesis and characterization of poly(phenylene polysulfide) networks (PSNs) with controlled average sulfur ranks, from elemental sulfur (ES) and p-diiodobenzene (DIB), are investigated. The P...

A catalytic hydrolysis rate of nerve agents can be a significant issue because of their severe toxicity which can lead to severe damage to human life. Regarding the issue, much effort has been given rise to the development of the various design of Zr(IV)-based MOF catalysts so that high catalytic performance. However, we still have feasibility issues. To this end, we turned our attention to develop the method for facile, scalable, and efficient synthesis of Zr(IV)-based MOFs (UiO-66) with high-performance hydrolysis by imparting enriched active sites to the catalysts, as well as to examine its feasibility using the combination of UiO-66 with the organic bases including 4-ethylmorpholine (4-EM) and linear-/ branch-type polyethyleneimine (PEI). The modulated UiO-66 catalysts were synthesized by varying the total reaction concentration. The synthesized three different UiO-66 catalysts were characterized and then applied for hydrolysis rates of the methylparaoxon (MPO) nerve agent simulant. From these investigations, we found that the highest concentration led to the smallest particle size (ca. 100 nm) and highest defect density (1.8 per cluster), resulting in 3-times higher catalytic activity (0.548 s−1) in turnover frequency (TOF) relative to that of the uncontrolled UiO-66 (ca. 580 nm and 1.6 per cluster) (0.188 s−1) which is prepared by the reported procedure. In addition, the reaction process significantly influenced on the catalytic activity of UiO-66, in which the simple change of the reagent mixing method led to a ca. 182-times difference in the catalytic activity for MPO hydrolysis despite using the same reagents including catalysts and bases. Importantly, we found that the reaction process-dependent catalytic activity of UiO-66 can be significantly associated with the chelation of Zr(IV) Lewis acidic active sites by base materials of 4-EM and PEI (Lewis base). Furthermore, the solid-state catalytic system based on the polymer composite of UiO-66S/LPEI10k on the cotton fabric was also examined for MPO hydrolysis at various relative humidity and temperature conditions to create actual atmosphere conditions, which gave the possibility for actual military applications such as protective suits and equipment. In addition, we schematically demonstrated the loss of active sites on UiO-66 by chelation effects based on experimental and density functional theory (DFT)-derived computational simulation because it is highly correlated to the feasibility of Zr(IV)-based MOF catalysts for detoxification of nerve agents. In addition, we carefully propose a plausible reaction mechanism step on the nucleophilic attack by hydroxide group on the basis of the computational simulation.

Cordierite is an alumina-magnesia-silica compound widely used as a thermal shock resistant material due to its high thermal shock resistance, low coefficient of thermal expansion (CTE), low dielectric constant, and good electrical insulation. However, its narrow sintering temperature range and low mechanical strength hinder its application in ceramic heaters. Although mullite shows excellent thermal and chemical stability, heat resistance, and mechanical strength, it has the disadvantages of high sintering temperatures (1600-1700 °C) and poor thermal shock resistance. In this study, a composite phase was prepared by mixing cordierite and mullite to expand the narrow sintering temperature range of cordierite and adjust its CTE to be similar to that of Si. Furthermore, Y₂O₃ was added to reduce the sintering temperature and to increase the mechanical strength. Therefore, the composite showed the highest density of 2.5 g/cm³ at 1380 °C when the ratio of mullite to cordierite was 20 wt%. When 11 wt% Y₂O₃ was added to this composition, the highest density was 2.8 g/cm³ for a sintering temperature of 1320 °C, and the mechanical strength was relatively good as 180 MPa of 3-points bending strength was comparatively good. The CTE was 2.6×10-6.K-1, which was similar to that of Si.

A plastic organic light-emitting diode display is a device that emits light in an organic layer in proportion to the amount of current applied from a thin film transistor, which constitutes a pixel. However, it was confirmed that the residual image was shown by the operation of the thin film transistor. To suppress residual image, the effect of electric field was studied in operation of a-IGZO thin film transistor. The a-IGZO thin film transistor, in which a polyimide film was used as a substrate, was applied as a driving thin film transistor for pixel circuits in a plastic organic light-emitting diode display, and the effect of the electric field behavior inside the film on residual images was studied. Residual images were strongly connection with the electric field distribution characteristics inside the polyimide substrate, and they were reduced by introducing an electric field shield metal layer in the a-IGZO thin film transistor. The correlation between residual image generation and the operation of the a-IGZO thin film transistor was further explained through technology computer-aided design simulation (Silvaco Group Inc.).

Various failure modes derived from the electrochemical migration (ECM) through the dielectric polymer layers have been considered critical issues in the electronic devices. Herein, we for the first time suggested the rationally designed epoxy/zeolitic imidazolate framework-8 (ZIF-8) nanocomposite materials for efficient suppression of copper ion migration based on the plausible reaction mechanisms of metal metathesis addressed by sequential cleaving and ligating between metal ions (Zn2+ and Cu2+) and 2-methylimidazole (2-mim) ligands. The fabrication process for epoxy/ZIF-8 (EZ) nanocomposites was first examined to optimize the crosslinking system. The capability of the metal ion capture in the EZ nanocomposites was examined using the aqueous solution containing Cu2+ ions. In addition, the ECM suppression properties were evaluated using the thermal humidity bias (THB) model testing. The representative model investigations with the EZ nanocomposites exhibited substantially enhanced copper ion adsorption and suppression of copper migration in comparison to those of epoxy. Hence, the EZ nanocomposites can be one promising material to alleviate the undesired ECM behavior in electronic device applications.

Two series of water-soluble metalloporphyrin-cored amphiphilic star block copolymers were synthesized by controlled radical polymerizations such as atom transfer radical polymerization (ATRP) and reversible addition fragmentation chain transfer (RAFT), which gave eight amphiphilic block copolymer arm chains consisting of poly(n-butyl acrylate-b-poly(ethylene glycol) methyl ether methacylate) (PnBA-b-PEGMEMA, Mn,GPC = 78,000, Mw/Mn = 1.2, 70 wt% of PPEGMEMA) and poly(styrene-b-2-dimethylamino ethyl acrylate) (PS-b-PDMAEA, Mn,GPC = 83,000, Mw/Mn = 1.2, 67 wt% of PDMAEA), yielding porphyrin(Pd)-(PnBA-b-PPEGMEMA)8 and porphyrin(Pd)-(PS-b-PDMAEA)8, respectively. Obtained metalloporphyrin polymer photocatalysts were homogeneously solubilized in water to apply to the removal of chlorophenols in water, and was distinguished from conventional water-insoluble small molecular metalloporphyrin photocatalysts. Notably, we found that the water-soluble star block copolymers with hydrophobic–hydrophilic core–shell structures more effectively decomposed the chlorophenol, 2,4,6-trichlorophenol (2,4,6-TCP), in water under visible light irradiation (k = 1.39 h−1, t1/2 = 0.5 h) in comparison to the corresponding water-soluble star homopolymer, because the hydrophobic core near the metalloporphyrin effectively captured and decomposed the hydrophobic chlorophenols in water.

The carbon fiber reinforced plastics (CFRP) are still limited the used in the automotive industry mainly by the weak interfacial adhesion between the fiber and polymer matrix. Herein, to improve interfacial interactions between the carbon fiber (CF) and polypropylene (PP) matrix, poly(dimethylaminoethyl methacrylate)-b-poly(methyl methacrylate) (PDMAEMA-b-PMMA, PDM) compatibilizers are applied to functionalize the CF surface through a covalent bonding with epoxide groups on the chemically modified CF surface with tertiary amines in the PDMAEMA block, which induced intermolecular entanglement with PP chains with the PMD compatibilizers. The acquired compatibilizer-functionalized CF (CECF) was applied to fabricate PP composites by a melt-mixing method. The highly improved interfacial adhesion between the CECF and PP was confirmed by evaluating thermal, morphological, rheological, and mechanical properties. Based on the significantly enhanced interfacial adhesion, notably, the tensile strength and modulus of the CECF/PP composite exhibited a massive increase by ca. 312% and 664%, respectively, relative to those of the PP resin. The Ashby plot facilitated understanding that the acquired mechanical properties of the CECF/PP composite showed a relatively ideal position compared to reported PP composites and centered on the commercially available region in automotive components.

The facile tuning of the gate size and the chemical functionalization of zeolitic imidazolate frameworks (ZIFs) have been considered efficient strategies for various potential applications including gas membranes, sensors, and catalysts. Herein, we demonstrate the synthesis of amine-functionalized ZIF-8 (ZIF8-A) with 3-amino-1,2,4-triazole (Atz) by postsynthetic modification (PSM) towards two objectives: (1) CO2 selective adsorption by a combination of chemical interactions and controlled gate sizes and (2) potential for further chemical modifications. The acquired ZIF8-A substantially enhanced CO2/N2 and CO2/CH4 selectivity at 35 °C compared to ZIF-8 since the Atz conversion enhanced chemical interactions with CO2 due to the introduction of amine moieties while reducing both the surface area and pore volume. The gate size control of ZIF-8 by the replacement of Atz was thoroughly investigated by extensive transport experiments and density functional theory (DFT)-based computational simulations. In addition, the vinyl-functionalized ZIF-8, another versatile starting material, was successfully prepared by further chemical modifications of ZIF8-A with either methacrylic anhydride or glycidyl methacrylate through nucleophilic substitution reactions. As such, we believe that our current work can provide promising platforms for designing ZIF-based materials with versatile properties including precise control of the gate size and the incorporation of various functional groups.

To data, combination of Pt-based bimetallic nanocrysatals and the graphene support have significantly contributed to enhance the oxygen reduction reaction (ORR) performance relative to electrocatalysts based on monometallic Pt nanoparticles (NPs) primarily due to the unique ligand effects and benefits of the carbon support. In this study, we propose a new structure of bimetallic electrocatalysts to realize the synergistic effects on the ORR performance through effective integration of the fine-sized Pt NPs, PdPt bimetallic nanocrystals, and non-covalently functionalized graphene with ionic polymers. The facile wet-chemical methods were applied to synthesize fine-sized (2–5 nm) spherical Pt NPs doped large-sized (20–50 nm) non-spherical PdPt bimetallic NPs on the electronically negative ionic polymer-functionalized graphene support (Pt-on-PdPt/fG). This Pt-on-PdPt/fG with synergistic effects based on enlarged active surface area, ligand, and interfacial linking effects, exhibits substantially enhanced ORR activity (specific activity: 1.89 mA c m Pt − 2 at 0.9 VRHE) and durability in comparison to the commercial Pt/C (specific activity: 0.23 mA c m Pt − 2 at 0.9 VRHE). To this end, the effective integration of newly designed fine-sized Pt NPs doped bimetallic nanocrystals and unique graphene supports with the well-interactive ability could be a good platform to develop the advanced electrocatalysts for the efficient ORR.

In this work, we investigated the effects of the flow modifier addition on the rheological behavior and mechanical properties of high-filled polyamide 66 composites prepared from melt compounding. The flow modifiers were prepared from various amine monomers and fatty acids, and their structures were analyzed by Fourier transform infrared spectroscopy. The synthesized flow modifiers were added simultaneously during melt compounding. The presence of flow modifiers significantly reduced torque in neat polyamide 66 polymer and glass fiber-reinforced polyamide 66 composites, respectively, while the torque during compounding in composites with glass fiber contents of 50 wt% has decreased by approximately 12% after the addition of 1 phr of hexamethylene bis -stearamide indicating the simultaneous enhancement in flowability. The presence of the synthesized flow modifiers in matrix polymers improves flowability of the composites during injection molding without compromising the mechanical properties.

Thermadapt shape memory polymers (SMPs), utilizing a variety of dynamic covalent bond exchange mechanisms, have been extensively studied in recent years but it is still challenging to address several constraints in terms of limited accuracy and complexity for constructing 3D shape memory structures. Here, an effective and facile preparation of thermadapt SMPs based on elemental sulfur-derived poly(phenylene polysulfide) networks (PSNs) is presented. These SMPs possess intrinsic near-infrared (NIR)-induced photothermal conversion properties for spatiotemporal control of their plasticity and elasticity. The NIR-controllable plasticity and elasticity of the PSNs enable versatile shape manipulation of 3D multi-shape memory structures, including building block assembly, reconfiguration, shape fixing/recovery, and repair.

Porous-structured noble metal electrocatalysts offer activity and durability benefits based on a high surface area and interconnected nanostructure, respectively. However, conventional technical methods used for synthesizing a porous structure are still difficult as well as resulting in defects in the structure. Here we report a facile route for the synthesis of uniform, large-area mesoporous platinum thin films based on ionic polymer doped graphene, which exhibit substantially enhanced activity and durability for oxygen reduction relative to commercial Pt/C. Notably, a remarkable durability (≥95% retention of electrochemical activities after 30 000 cycles of intensive accelerated durability tests) is acquired which is ascribed to the synergistic effects derived from the interconnected Pt structure (morphology) and ionic polymer-doped graphene (support). The suggested robust concept for a controlled mesoporous-structured platinum thin film on graphene could be a great breakthrough for obtaining a highly durable electrocatalyst.

Palladium nanoparticles on ionic polymer-doped graphene (Pd–IPG) nanocomposite catalysts have been investigated for efficient Suzuki coupling reactions. This combination effected highly accelerated Suzuki coupling reactions due to several advantageous features associated with the flanking ionic polymer part of the catalyst system. These include a high level of Pd incorporation, excellent dispersion stability, and increased accessibility and diffusion of the substrates onto the surface of Pd NPs. The enhanced availability of the Pd catalyst to the reacting substrates is believed to allow for ca. 16-fold higher catalytic activity than that of Pd–graphene without the ionic polymer. Moreover, high recycling capability of the catalyst (10 times) in combination with excellent product yields (>96%) and no significant leaching of the catalyst upon hot-filtration test suggest that the Pd–IPG nanocomposite catalysts have high reusability with significant retention (>95%) of the Pd species.

The incorporation of pyrene-functionalized poly(methyl methacrylate)-b-poly(dimethylaminoethyl methacrylate) (PMMA-b-PDMAEMA) ionic block copolymer-wrapped carbon nanotubes (PBCNTs) with graphene oxide (GO) allows compact decoration of metal nanoparticles (NP) for use as robust catalysts. This well-tailored concept of the PBCNT-GO functional carbon support provides various features, including a two-dimensional (2D) structure, dimensional stability, versatile solubility (from toluene to water), enhanced diffusion of reagents, and recyclability. Among the various compositions of GO and PBCNT, 50 wt% of the PBCNT additive-containing support (PBCGO55) showed great hybridization potential for Ag, Au, and Pd NPs. In particular, the hybridization of PBCGO55 with Pd NPs (Pd-PBCGO55) displayed superior morphological features with compact decoration of ultra-fine NPs (1–3 nm), larger surface area, higher density of edge and corner atoms, better dispersion stability, and lesser aggregation of the decorated Pd NPs in comparison with the other hybrid catalysts. In the catalytic reduction of 4-nitrophenol (4-NP), the Pd-PBCGO55 hybrid catalyst exhibited the best catalytic performance, resulting in highly enhanced reaction rate constant (k) of 9.73 min−1 and catalytic activity of 141.8 mol mol−1 min−1, exhibiting a 50-fold increased rate constant and 30-fold increased catalytic activity in comparison to Ag-GO without PBCNT (k = 0.19 min−1, catalytic activity = 4.58 mol mol−1 min−1).

Hydrocarbon resins, which are defined as low molecular weight, amorphous, and thermoplastic polymers, are widely used as tackifiers for various types of adhesives, as processing aids in rubber compounds, and as modifiers for paint and ink products, and for use in plastics polymers such as isotactic polypropylene. Recently, the quantities of the hydrocarbon resin׳ raw materials which are the side products from naphtha cracking process have decreased because of light-feed cracking such as gas cracking, so new raw materials for hydrocarbon resin production are essential. To be satisfied with the previously mentioned factors, the substitution of hydrocarbon resin raw materials with renewable resources is a worthy consideration. Moreover, new hydrocarbon resin having high adhesion performance, low specific gravity, and good compatibility with various polymers has been requested in various adhesives. To meet those requests, in this study, propylene instead of side product from naphtha cracking as main raw material of hydrocarbon resin were partially used. The propylene serves as a new, sustainable raw material and was successfully grafted onto dicyclopentadiene. The reaction of the propylene with dicyclopentadiene was confirmed because, according to NMR and FT-IR analyses, a pendant methyl-propylene group exists in the structure of the propylene-grafted, hydrogenated dicyclopentadiene hydrocarbon resin. To establish an optimal production condition regarding the propylene-grafted, hydrogenated dicyclopentadiene hydrocarbon resin, numerous experiments were conducted according to the mole ratio of the raw materials and the polymerization temperature. The propylene-grafted, hydrogenated dicyclopentadiene hydrocarbon resin that was manufactured according to optimal conditions results in a lower specific gravity and a high molecular weight, whereby the advantages of the adhesion properties of an SIS-based pressure-sensitive-adhesive are exploited. When the propylene-grafted, hydrogenated dicyclopentadiene hydrocarbon resin was formulated with the SIS-based pressure-sensitive-adhesive, both the heat stability and the shear-adhesion strength are sound.

Cordierite is an alumina-magnesia-silica compound widely used as a thermal shock resistant material due to its high thermal shock resistance, low coefficient of thermal expansion (CTE), low dielectric constant, and good electrical insulation. However, its narrow sintering temperature range and low mechanical strength hinder its application in ceramic heaters. Although mullite shows excellent thermal and chemical stability, heat resistance, and mechanical strength, it has the disadvantages of high sintering temperatures (1600-1700 °C) and poor thermal shock resistance. In this study, a composite phase was prepared by mixing cordierite and mullite to expand the narrow sintering temperature range of cordierite and adjust its CTE to be similar to that of Si. Furthermore, Y₂O₃ was added to reduce the sintering temperature and to increase the mechanical strength. Therefore, the composite showed the highest density of 2.5 g/cm³ at 1380 °C when the ratio of mullite to cordierite was 20 wt%. When 11 wt% Y₂O₃ was added to this composition, the highest density was 2.8 g/cm³ for a sintering temperature of 1320 °C, and the mechanical strength was relatively good as 180 MPa of 3-points bending strength was comparatively good. The CTE was 2.6×10

A series of well-defined hard–soft–hard triblock copolymers were synthesized by Ru-based atom transfer radical polymerization (ATRP) (MWD < 1.26) in order to examine their electromechanical properties under electric fields. The obtained methacrylate based triblock copolymers consisted of poly(dodecyl methacrylate) (PDMA) soft middle block segments and three different hard block segments with poly(methyl methacrylate) (PMMA), poly(tert-butyl methacrylate) (PtBMA), and their random copolymers (PMTDTMTs). Polar acidified triblock copolymers were also prepared by deprotecting tert-butyl groups in tBMA-incorporating hard block segments through simple thermal treatment at 200 °C for 120 min, which in situ gave poly(methacrylic acid) (PMAA) and its random copolymers (PAMDMA) in the hard block segments. SAXS and AFM studies indicated that these triblock copolymers showed well-organized phase separations with different domain sizes, which were strongly dependent on the amount of bulky PtBMA or polar PMAA in the hard block segments. In addition, these triblock copolymers had a variety of morphologies affecting their mechanical (elastic modulus) and electrical (dielectric constant) properties, leading to a tuning of their electromechanical properties. The transverse strains of these triblock random copolymers as a function of an applied electric field indicated that the PTMDMT series possessed the best electromechanical properties, exhibiting an 11-fold enhancement relative to the corresponding acidified polymer PAMDMA at 50 Vpp μm−1 due to a dramatic decrease of the elastic modulus from 4.04 to 0.05 MPa in spite of an increase of the dielectric constant from 3.6 to 5.1. In situ SAXS analysis under an electric field showed that these bulk strains originated from nano-structured microdomain changes.

It is necessary for ferrite sheets to be fabricated with high packing density for excellent electrical properties and high strength. In this study, the relationship between the warpage and the packing density of ferrite green sheet, was investigated with amount variation of organic additives. With 0.4 wt% of dispersant, the packing density was about 48% and warpage appeared 0.5~1.3 mm high. With 1.4 wt% of dispersant, the packing density increased up to 57% and warpage appeared 0.8~2.1 mm high. With high packing density, warpage appeared along the edges of specimen, while with low packing density, deformation appeared over whole specimen inhomogeneously. It is thought that inhomogeneous deformation after sintering came from the inhomogeneity in green sheet prepared with badly dispersed slurry. With good homogeneity in green sheet from well-dispersed slurry, isotropic shrinkage is thought to have occurred along the distance from center to edges of specimen during sintering.

Poly(vinylidenefluoride-co-trifluoroethylene) (PVDF-TrFE)/SWCNT nanocomposites with ultra-low percolation threshold were prepared by interfacial control using a block copolymer comapatibilizer. For this, a well-defined block copolymer of poly(3-hexylthiophene) (P3HT) and poly(methyl methacrylate) (PMMA) (P3HT-b-PMMA) was synthesized by combination of GRIM and ATRP (Mn = 24 K, Mw/Mn = 1.25), where the P3HT block segment wrapped the SWCNTs by π–π interaction and the resulting PMMA block segment dangled from the SWCNTs, which gave de-bundled SWCNTs without any aggregations for over 5 months in most common organic solvents for PMMA. The block copolymer coated SWCNT (TMCNT) was then mixed with PVDF-TrFE to prepare PVDF-TrFE/SWCNT nanocomposites (PVT-TMCNT), which enabled excellent dispersion of SWCNT in a PVDF-TrFE matrix without aggregation due to the miscibility of the PMMA on TMCNT and PVDF-TrFE. Obtained PVT-TMCNT showed large enhancements of the electrical conductivity and the dielectric constant with ultra-low percolation threshold (fc = 0.07 wt.%) due to excellent interfacial control by the block copolymer comapatibilizer between SWCNT and PVDF-TrFE. Improved ferroelectric properties of PVT-TMCNT were also observed by an increase of field-induced polarization response, which was almost over 10-times higher than for neat PVDF-TrFE.

Compatible hybrid composites (PVLPMA) comprising of poly(vinylidene fluoride) (PVDF) and UV-curable ladder-like polysilsesquioxane (LPMASQ) were investigated for maximizing synergetic effects in various properties. The PVDF fluoropolymer was found to be well-incorporated with the LPMASQ inorganic filler because of good hydrogen-bonding, and the compatibility rigorously investigated by FT-IR, DSC, and WAXS studies. In addition, the crosslinkable function arising from the methacryl-group of the LPMASQ inorganic filler with the aid of the radical source was evaluated from the analysis of various properties. After UV-crosslinking, PVLPMA hybrid composites showcased enhanced mechanical properties such as elastic modulus, surface modulus, and surface hardness with accordance to the increasing the LPMASQ quantity. In addition, hydrophobicity was observed through the increase in the water contact angle up to 115°, a value much larger than that of neat PVDF and cured LPMASQ. Furthermore, the enhanced electrical stability of PVLPMA hybrid composites was obtained through examination of dielectric properties and breakdown strength in comparison to neat PVDF. These PVDF-LPMASQ organic-inorganic compatible hybrid composites with enhanced properties arising from the good compatibility and synergetic effects can be applicable in the various fields supplanting neat PVDF.

Poly(ethylene-co-ethyl acrylate) (EEA)/multiwalled carbon nanotubes (MWCNTs) master batches are prepared via melt mixing to investigate the effect that blending low density polyethylene (LDPE) into the master batch has on their electrical properties. Blending LDPE into the EEA/MWCNT master batches with a relatively low ratio of LDPE to EEA improves the electrical conductivity and lowers the percolation threshold as a result of the increase in the dielectric constant of EEA/LDPE blend resin and a better dispersion of MWCNTs. The electrical conductivity of the blend composite peaks at 20% LDPE and is inversely proportional to the degree of crystallinity of the composite. The average size and the number of the MWCNT aggregates decreases after LDPE blending, thus the better distribution is obtained for the MWCNTs without disturbing the formation of conducting paths caused by the presence of crystallites.

The morphologies, crystalline structures, and thermal and rheological behaviors of isotactic polypropylene (iPP) blended with dicyclopentadiene based hydrogenated hydrocarbon resin (HCR) were investigated using scanning electron microscopy (SEM), wide-angle X-ray diffractometry, and differential scanning calorimetry in detail. Furthermore, the transparency, mechanical properties, and water vapor and oxygen permeability of biaxially oriented polypropylene films, fabricated from these iPP/HCR blends using a biaxial drawing machine, were examined. It was found that crystallinity varies with the HCR content of the iPP/HCR blend. In addition, amorphous HCR with its high glass transition temperature (T g ) upon blending with iPP’s amorphous structure affords improvements in various film properties, such as mechanical properties, transparency, and gas permeabilities.

석유수지는 분자량이 작고 무정형인 열가소성 수지로써 다양한 접착제 및 고무의 가공조제, 필름의 첨가제 등으로 사용되고 있다. 석유수지의 단점은 비극성이기 때문에 비극성의 폴리머와의 상용성은 우수하나 아크릴 및 우레탄, 폴리아마이드와 같은 극성기를 포함하는 폴리머와의 상용성은 좋지 않다. 그뿐만 아니라, 최근 석유수지의 원료로 사용되는 나프타 크래킹 공정에서 나오는 부산물의 양이 가스 크래킹의 확대 적용으로 인해 줄어들고 있는 상황이다. 이러한 문제를 해결하기 위해 본 연구에서는 석유수지 원료로 극성기를 포함하면서 지속 가능한 신규 원료인 소르빅산으로 일부 대체하고자 하였다. 기존 석유수지 원료인 DCPD 모노머와 블루베리로부터 생성되는 소르빅산은 열중합에 의해 Diels-Alder 반응으로 성공적으로 공중합하였다. 소르빅산 변성 수소첨가 DCDPD계 석유수지는 아크릴계 접착제 배합에 적용되어 다양한 점 접착 물성이 측정되었으며, Polarity에 따른 상용성 및 연화점에 따라 최적 물성이 결정되었다. 【Hydrocarbon resins, which are defined as low molecular weight, amorphous, and thermoplastic polymers, are widely used as tackifier for various types of adhesives, as processing aids in rubber compounds, and as modifiers for plastics polymers such as isotactic polypropylene. Typically, hydrocarbon resins are non-polar, and thus highly compatible with non-polar rubbers and polymer. However, they are poorly compatible with polar system, such as acrylic copolymer, polyurethanes, and polyamides. Moreover, recently the raw materials of hydrocarbon resin from naphtha cracking had been decreased because of light feed cracking such as gas cracking. To overcome this problem, in this study, novel hydrocarbon resins were designed to have a highly polar chemical structure which material is sustainable. And, it was successfully synthesized by Diels-Alder reaction of dicyclopentadiene monomer and sorbic acid from blueberry as renewable resources. Acrylic resins were formulated with various tackifiers solution including sorbic acid grafted hydrogenated dicyclopentadiene hydrocarbon resins in acrylic adhesive and rolling ball tack, loop tack, $180^{\circ}$ peel adhesion strength, and shear adhesion strength were measured. The properties depend on the softening point and polar content of tackifiers.】

We synthesized an ultra-fine Pd nanocatalyst supported by ionic block copolymer doped reduced graphene oxide (Pd-PIBrGO) for ultra-accelerated nanocatalysis. This hybrid catalyst exhibited exceptionally advanced catalytic performance for the reduction of methylene blue using miniscule quantities of Pd-PIBrGO due to facilitated diffusion of reagents, resulting in full reduction within a few seconds and showing a 280-fold increase of the rate constant over Pd-rGO without ionic block copolymers.

Volume resistivity and tensile properties of ethylene ethylacrylate (EEA)/carbon nanotube (CNT) composites were studied in conjunction with the dispersion of CNT in EEA. The EEA/CNT composites were prepared by a kneading internal mixer. The effect of fumed silica on these properties was also investigated. The volume resistivity of EEA/CNT compounds was found to be less than 10 Ohmcm at 4 wt% of mWcNT. Interestingly, peroxide crosslinking increased the volume resistivity of EEA/CNT compound dramatically, though no particular chemical change was observed. The extent of change was found to depend on the dispersity of CNT. The finer dispersion resulted in a smaller increase of volume resistivity, from 2–5 Ohm cm before crosslinking to 8–10 Ohmcm after crosslinking, whereas poor dispersion changes drastically, from ∼10 Ohmcm before crosslinking to >107 Ohmcm after crosslinking. This change becomes much less when fumed silica was mixed with EEA and CNT. Both tensile strength and elongation were also improved when fumed silica was mixed together with EEA and CNT.

Efficient removal of heat accumulation from electronic devices has been considered an important issue because it is prone to induce reduced lifetime, heat shock, ignition, and malfunction during their operation. To that end, optimized epoxy composites, which are fabricated by dispersing a mesogen-containing polymer compatibilizer (BPIB)-applied multi-layered graphene nanoplate (MGNP) filler into a mesogen-containing epoxy (DGEBP) matrix (BPIB-MGNP/epoxy), are designed toward high thermal conductivity at the low filler loading content. Various effects on its thermal conductivity, including size, thickness, and dispersion of fillers along with the crystalline property of epoxy, are systematically investigated by comparing with their intermediate counterpart materials. The extended micromechanics model, which was modified using a power law from its initial one, was employed to address the filler size effects on its thermal conductivity as well as an exponential increase of thermal conductivity with increasing filler loading content. Thickness effects of carbon fillers are examined by comparing GNP/epoxy composites with single-layered graphene filler-based epoxy composites. The effects of dispersion properties of the fillers in the epoxy composites are also investigated using the theory prediction plot based on the extended micromechanics model. The comparison between experimental and theoretical prediction led us to study crystalline properties of the BPIB-MGNP/epoxy composites because it was unexpected and beyond the theoretical traces. An Ashby plot is prepared to evaluate the state of our results by comparing them with the reported state-of-the-art composite performances.

Ceramic–resin hybrid materials can be used as solutions to overcome the limitations of pure ceramic materials such as their high sintering temperature and no material compliancy. These hybrid materials have been applied to electronic components for 3-dimensional system integration, especially passive circuits that tend to be embedded into multilayered packages. In this study, low noise amplifier (LNA) module was fabricated with BaTiO 3 -DCPBCy and Al 2 O 3 -DCPBCy hybrid films by an inkjet printing process. These inkjet-printed hybrid films were used as high-k and low-k dielectric layers for embedded capacitor and insulating layer, respectively. The dielectric properties of the inkjet-printed hybrid films were investigated in order to confirm their feasibilities as dielectric layers; in the case of the Al 2 O 3 -DCPBCy hybrid film: e r ≈6, tan δ 3 -DCPBCy hybrid film: e r ≈49, tan δ

Carbon nanotubes (CNTs) coated by compatibilizer (P3HT-PMMA) imparted sta-ble dispersion in organic solvents and polymer matrix (P(VDF-TrFE)). The compatibility be-tween CNTs with P3HT-PMMA was con rmed by measuring Raman spectroscopy. CoatedCNTs were then blended with P(VDF-TrFE) (70:30 mol%) to obtain polymer nanocompositesby solution- casting process. Polymer nanocomposites showed enhanced electrical characteris-tics, as nanocomposites near the threshold of the transition between P(VDF-TrFE) insulatorand CNT conductor revealed great improvement of electrical conductivity up to 10-6 S/cmat 1 KHz. Electromechanical properties of the polymer nanocomposite were examined as afunction of electric eld.

In this study, the effects of multi-walled carbon nanotube (MWCNT) dispersion and poly(styrene-co-acrylonitrile)-g-maleic anhydride (SAN-g-MAH) as a compatibilizer on the electrical conductivity, electromagnetic interference shielding effectiveness (EMI SE), and rheological properties of polycarbonate (PC)/poly(acrylonitrile–butadiene–styrene) (ABS)/MWCNT composites were investigated. The morphological results from the scanning and transmission electron microscope images showed that the droplet size of the ABS decreased when the SAN-g-MAH (5 phr) was added to the PC/ABS (80/20) blend. This result suggests that the SAN-g-MAH acts as an effective compatibilizer in the PC/ABS blend. Also, the MWCNT appeared to be located more in the ABS phase (dispersed phase) than in the PC phase (continuous phase). The interfacial tension of the ABS/MWCNT composite was lower than that of the PC–MWCNT composite, and the lower value of interfacial tension of the ABS/MWCNT composite affected the preferred location of the MWCNT in the ABS phase more than in the PC phase. The electrical conductivities and EMI SE of the PC/ABS/MWCNT composite with the compatibilizer were higher than those of the composite without compatibilizer. The complex viscosity of the PC/ABS/MWCNT composite containing the SAN-g-MAH increased with the frequency compared to that of the composite without SAN-g-MAH. This result is possibly due to the increased degree of MWCNT dispersion. The result of rheological properties is consistent with the results of the morphology, electrical conductivity, and EMI SE of the PC/ABS/MWCNT composite.

The effects of hybrid conductive fillers on the electrical conductivity and electromagnetic interference shielding effectiveness (EMI SE) of polyamide 6 (PA6)/conductive filler composites were investigated. Nickel-coated carbon fiber (NCCF) was used as the main filler and multi-walled carbon nanotube (MWCNT), nickel-coated graphite, carbon black, and titanium dioxide (TiO2) were used as the second fillers in this study. From the results of morphological studies of the PA6/NCCF/second filler composites, NCCF easily formed an electrical pathway since it has a high aspect ratio and random orientation, and the second fillers seemed to disperse evenly in the PA6 matrix. The electrical conductivity and EMI SE of the PA6/NCCF composites were increased with the increase of NCCF content. Among the second fillers used in this study, TiO2 appeared to be the most effective second filler with regard to increasing the EMI SE and electrical conductivity of the PA6/NCCF composite. This was probably because TiO2 has a high dielectric constant with dominant dipolar polarization, consequently leading to greater shielding effectiveness due to the absorption of electromagnetic waves. From the above results of EMI SE and electrical conductivity, it was suggested that the TiO2 produced a synergistic effect when it was hybridized with the NCCF of the PA6/NCCF/TiO2 composites.