Analysis of Correlation Between Contrast and Component of Polylatic Acid Composite for Fused Deposition Modeling 3D Printing.

Additive manufacturing or three-dimensional (3D) printing is considered a disruptive technology for producing components with topologically optimized complex geometries as well as functionalities that are not achievable by traditional methods. 3D printing is expected to revolutionize the manufacturing of components. While several 3D printing systems are available, printing based on fused-deposition modeling (FDM) using thermoplastics is particularly widespread because of the simplicity and potential applicability of the method.

A Deep Blue Organic Light Emitting Diodes Characteristic of Isomerically-Featured Phosphine Oxides Containing N-Phenyl Benzimidazole.

An isomeric series of phosphine oxides with N-phenyl benzimidazole such as 2-DPPI, 3-DPPI and 4-DPPI were synthesized for organic light emitting diodes (OLED). The thermal properties of DPPI isomers were determined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). OLED devices using DPPI isomers as the emitting material were fabricated, which configuration was ITO/MoOx [30 nm]/NPB [500 nm]/DPPI [300 nm]/Alq₃ [200 nm]/Liq[10 nm]/Al [120 nm].

Relation between work function and structural properties of triangular defects in 4H-SiC epitaxial layer: Kelvin probe force microscopic and spectroscopic analyses.

To understand the relationship between the work function and structural properties of sufficiently expanded triangular defects (size: ∼250 μm) in the 4H-SiC epitaxial layer, Kelvin probe force microscopy (KPFM) and spectroscopic [micro-Raman spectroscopy and photoluminescence (PL)] analyses were performed. Spectroscopic analysis demonstrated that the triangular defects mostly comprise the 3C polytypes and that it experiences internal stress, defects, and defect-induced carrier generation. The distinguishable areas in the triangular defects had surface potential values different from those of the 4H-SiC matrix; this could be explained by the work function difference, which arises from variations in the electron affinity of the 3C polytype as well as the positional variations of the Fermi energy level in terms of electron concentration.

Detection of Amyloid Using a Poly-L-Lysine Mediated Nanobiosensor.

Amyloid (A) peptide is secreted from the outside of neural cell by a neural signal pathway and it accumulated each other results in the highly toxicity amyloid plaque which is a critical causative factor in the pathogenesis of Alzheimer's Disease (AD). The peptide is considered to be a potential biomarker to diagnose AD. Here we introduce a novel poly-L-lysine (PLL) mediated nanobiosensor to detect A .

Development of Chemically Signal Amplified Nano-Biosensor Mediated by Poly-L-Lysine.

Amyloid (A) is considered to be one of a potential biomarker to monitor Alzheimer's Disease (AD) not only for diagnostic purposes but for early detection. Here we describe a novel nano-biosensor for A mediated by poly-L-lysine (PLL) which was used for the amplification of detection signal for A. The indirect enzyme-linked immunosorbent assay (ELISA) method was modified using PLL for the amplification of the A detection signal.

Detection of Actin Filament and Cofilin Interaction Change by Actin Filament Curvature Decreasing.

Actin filament senses mechanical forces and it is transduced into biochemical signals during many cellular processes. In the disassembling process of actin filaments, cofilin plays a central role as the actin filament depolymerization. In this study, we evaluated a quantitative analysis of the actin filament-cofilin interaction change dependent upon the actin filament curvature decrease using atomic force microscopy (AFM) and a fabricated wave-like substrate.

Probing Amyloid and the Antibody Interaction Using Atomic Force Microscopy.

Amyloid β (Aβ) peptide is considered to be the critical causative factor in the pathogenesis of Alzheimer's disease (AD) because the hydrophilic molecules accumulated outside of the neural cells and results in the formation of highly toxicity amyloid plaque. In this study, we probed the interaction between Aβ and the antibody using atomic force microscopy (AFM). We compared two kinds of antibodies which are the antibody for Aβ 1-42 (antibody42) and the antibody for Aβ 1-16 (antibody16).

Hybrid Structure White Organic Light Emitting Diode for Enhanced Efficiency by Varied Doping Rate.

Novel materials based on Zn(HPB)2 and Ir-complexes were synthesized as blue or red emitters, respectively. White organic light emitting diodes were fabricated using the Zn(HPB)2 as a blue emitting layer, Ir-complexes as a red emitting layer and Alq3 as a green emitting layer. The obtained experimental results, were based on white OLEDs fabricated using double emission layers of Zn(HPB)2 and Alq3:Ir-complexes.

Structural Stability and Phase Transitions of Octanethiol Self-Assembled Monolayers on Au(111) in Ultrahigh Vacuum.

To understand the structural stability of as-prepared octanethiol (OT) self-assembled monolayers (SAMs) with a fully covered c(4 x 2) phase on Au(111) in ultrahigh vacuum (UHV) conditions of 3 x 10(-7) Pa at room temperature, we examined OT SAM samples obtained as a function of storage period using scanning tunneling microscopy (STM). STM imaging revealed that phase transition of OT SAMs after storage in UHV for 3 days occurs from the c(4 x 2) phase to the mixed phase containing ordered c(4 x 2) and disordered phases. It was also observed that the disordered phase was mainly located at around vacancy islands and near step edges of Au(111) terraces, implying that desorption of OT molecules chemisorbed on Au(111) in UHV occurs more quickly in these regions compared with in the closely packed and ordered domains.

White OLED in Hybrid Structure for Enhancing Color Purity.

We synthesized the red emission material, bis(1,4-bis(5-phenyloxazol-2-yl)phenyl) iridium(picolate) [Ir-complexes] and the blue emission material, bis (2-(2-hydroxyphenyl) benzoxazolate)zinc [Zn(HPB)2]. White Organic Light Emitting Diodes were fabricated by using Zn(HPB)2 for a blue emitting layer, Ir-complexes for a red emitting layer and a tris (8-hydroxy quinoline)aluminum [Alq3] for a green emitting layer. The important experimental results obtained, white OLED was fabricated by using double emitting layers of Zn(HPB)2 and Alq3:Ir-complexes, and hole blocking layer of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline[BCP].

Characteristics of Intramolecular Charge Transfer by J-Aggregates in Merocyanine Dye LB Films.

In this study, for the development of future molecular electronic devices, we have investigated the characteristics of the aggregates of Langmuir-Blodgett films. The characteristics of intramolecular charge transfer by J-aggregates in merocyanine dye LB films have been studied experimentally by using UV irradiation and heat treatment. In addition to intramolecular charge transfer, we also studied the conjugation and energy changes of the molecules.

Nanolithography of Amyloid Precursor Protein Cleavage with β-Secretase by Atomic Force Microscopy.

Cleavage of the amyloid precursor protein (APP) by secretases is critical in neural cell processes including the pathway for neural cell proliferation and that underlying the pathogenesis of Alzheimer's disease (AD). Understanding the mechanism of APP cleavage and development of a convenient tool for the accurate evaluation of APP cleavage intensity by secretases are very important in the development of new AD therapeutic targets. In this study, we developed a sophisticated technology to evaluate the APP cleavage mechanism at the nano-molecular level by atomic force microscopic (AFM) nanolithography.

Effect of Substrate Temperature on Ti/TiO2 Layers Growth Using a Combined Sputtering/Sol-Gel Combustion Method.

A combined radio frequency sputtering/sol-gel combustion method was investigated in order to obtain optimum process condition for fabrication of a Titanium (Ti)/Titanium oxide (TiO2) films electrode of transparent conductive oxide-less dye-sensitized solar cells (TCO-less DSCs), Experimentally, the substrate temperature was changed from R.T. to 500 °C, and it was found that there existed an optimum value for efficient performance of the cell.

A Study on the Rectification Property of Self-Assembled Viologen Single Molecules Using a Scanning Tunneling Microscopy.

An ultrahigh vacuum scanning tunneling microscopy (UHV-STM) and a scanning tunneling spectroscopy (STS) are used measure the rectification property of self-assembled viologen single molecules (VC8SH, VC10SH, HSC8VC8SH, and HSC10VC10SH) in the previous study. Using STM we observe viologen single molecules in the self-assembled octanethiol (OT) SAM matrix. In the OT matrix a mixed phase that includes a c(4 x 2) superlattice of high-density standing up-phase is observed.

Ripple-Free Graphene Sheets on Alkanethiol Self-Assembled Monolayers Provided from Unzipped Multi-Walled Carbon Nanotubes.

Octanethiol (C8S, CH3(CH2)7SH) self-assembled monolayers/Au(111) were utilized as an inert surface to provide ripple-free graphene oxide layers provided from chemically unzipped multi-walled carbon nanotubes (MWCNTs). The resulting graphene oxide monolayers were characterized with atomic resolution by UHV-STM. The honeycomb structure for the graphene monolayer and "three-for-six" triangular pattern for the multi-layer graphene sheets on C8S SAMs were clearly observed without ripples by the high-resolution UHV-STM.

Fabrication of White Organic Light Emitting Diode Using Two Types of Zn-Complexes as an Emitting Layer.

We have studied white OLED using two types of Zn-complexes as an emitting layer. We synthesized brand new two emissive materials, Zn(HPQ)2 as a yellow emitting material and Zn(HPB)2 as a blue emitting material. The Zn-complexes are low-molecular compounds and stable thermally.

Thin Film Passivation Properties of Using Atomic Layer Deposition in Organic Light-Emitting Diodes.

In this paper, a thin film passivation for a gas barrier is performed using Al2O3. The passivation film shows a thickness of 50 nm. We deposit an Al2O3 layer using ALD.

Synthesis and electroluminescent properties of a novel electroluminescence material of bis-2-(4-(diphenylphosphino)phenyl)benzo[d]oxazole (DPB).

A new light-emissive material, bis-2-(4-(diphenylphosphino)phenyl)benzo[d]oxazole (DPB), has been synthesized and characterized by FT-NMR, FT-IR, UV-Vis and elemental analysis. DPB has the band gap of 4.3 eV between HOMO and LUMO levels.

Electrical characterization of organic monolayers at a nanoscale.

This study investigates the electrical properties of viologen derivatives at a nanoscale and analyzes it using a scanning tunneling microscopy (STM) in order to apply viologen molecules that represent a function in electron transfer mediators as a molecular electronic device. In addition, we measure conformational changes in the viologen molecular protrusions using STM and investigate changes in the width and height of the alkyl group that are due to the change in the polarity of viologen molecules by electron charges. In this experiment, high peak current is observed, such as a rectification at +1.

White organic light-emitting diodes with Zn-complexes.

This paper reviews OLEDs fabricated using Zn-complexes. Zn(HPB)2, Zn(HPB)q, and Zn(phen)q were synthesized as new electroluminescence materials. The electron affinity (EA) and ionization potential (IP) of Zn complexes were also determined and devices were characterized.

Optical and electrical properties of merocyanine dye LB films by various time of UV irradiation and heat treatment.

The Langmuir-Blodgett (LB) technique provides many possibilities for the control of film thickness, dimensions, and molecular structures on the nanometer scale. Various kinds of dye molecules have been found to form the J-aggregation which has been used as sensitizers of silver halide photography for long time. In recent years, they attract attention as model systems for investigating the ultra-fast exciton dynamics, materials for ultra-fast nonlinear optical devices, fluorescence probes for mitochondrial membranes.

Photolysis properties of merocyanine dye LB films by various time of UV irradiation.

We fabricated the merocyanine dye LB films with arachidic acid (MD LB films). We compared absorption peak of before and after added Cd2+. The optical absorption peak of the MD LB films was shifted to 610 nm at 535 nm, when Cd2+ ions were added.

Polyaniline-based conducting polymer compositions with a high work function for hole-injection layers in organic light-emitting diodes: formation of ohmic contacts.

It is a great challenge to develop solution-processed, polymeric hole-injection layers (HILs) that perform better than small molecular layers for realizing high-performance small-molecule organic light-emitting diodes (SM-OLEDs). We have greatly improved the injection efficiency and the current efficiency of SM-OLEDs by introducing conducting polymer compositions composed of polyaniline doped with polystyrene sulfonate and perfluorinated ionomer (PFI) as the HIL. During single spin-coating of conducting polymer compositions, the PFI layer was self-organized at the surface and greatly increased the film work function.

Characterization of the electrical and optical properties of viologen devices using chlorophyll a as an electron excimer.

This paper uses self-assembled monolayers (SAMs) on an Au(111) substrate to detect the unique characteristics of viologen molecules using scanning tunneling microscopy (STM), and reports the orientation and surface changes of molecules at the nano level in real-time. In particular, the rectification characteristics of the viologen molecule were observed at the molecular level using scanning tunneling spectroscopy (STS). After verifying the rectification characteristics of viologen molecules, an experiment was carried out to demonstrate the possibility of applying viologen to photodiodes and switching devices by forming a thin film of chlorophyll a on the viologen SAMs using the Langmuir-Blodgett (LB) method.

J-aggregation characteristics of merocyanine dye with arachidic acid LB films by heat treatment.

For a measurement of J-aggregation characteristics by heat treatment, we fabricated arachidic acid (AA)-Merocyanine dye mixed Langmuir-Blodgett (LB) films. pi-A curves were used to investigate the surface pressure of the LB film from a liquid to a solid state while the pressure ranged from 35 and 40 mN/m. When the surface pressure reached 40 mN/m, a monolayer was deposited onto the hydrophilic glass substrates by Y-type deposition.