Characteristics of field-induced-drain (FID) poly-Si TFTs with highon/off current ratio

The characteristics of polycrystalline silicon thin-film transistors (poly-Si TFTs) with a field-induction-drain (FID) structure using an inversion layer as a drain are investigated. The FID structure not only reduces the anomalous leakage current, but also maintains a high on current. An off current of 1.5 pA/μm and an on/off current ratio of 10⁷ (V_d=10, V_g =-20 V) are successfully obtained. These characteristics result from good junction characteristics between the p channel and n⁺ inversion layer. Reducing the threshold voltage of the FID region allows a simple circuit configuration for the FID TFTs     

High-performance liquid chromatographic determination of zinc pyrithione in antidandruff preparations based on copper chelate formation

A simple and rapid method for the determination of zinc pyrithione (ZPT) in antidandruff preparations by high-performance liquid chromatography (HPLC) has been developed. ZPT in samples was converted into a stable copper(II) complex by mixing with cupric sulphate solution followed by extraction with chloroform. HPLC was carried out on a Nucleosil 5 C18 column (15 cm X 4.6 mm I.D.) using methanol-water (3:2) as the mobile phase with UV detection at 320 nm. The calibration graph was linear from 0.1-0.5 micrograms for ZPT. The recoveries from four shampoos were 98.0-100.6% with high accuracy.     

Surface activity of myristic acid in the poly(methyl methacrylate)/supercritical carbon dioxide system

To confirm the surface activity of myristic acid in the dispersion polymerization of vinyl monomers in scCO2, the interfacial tension (IFT) at the polymer/supercritical carbon dioxide (scCO2) interface has been measured. For the IFT measurements, a high-pressure pendant drop apparatus was constructed. The IFT data was obtained by the axisymmetric drop shape analysis of melt polymer droplets formed at the tip of a capillary. The reliability of the apparatus was confirmed by measuring the IFT of polystyrene (PS)/scCO2 and polypropylene (PP)/CO2 systems. The IFT of the poly(methyl methacrylate) (PMMA)/scCO2 system with and without myristic acid was also measured. The IFT decreased on addition of myristic acid. The magnitude of the IFT depression due to the myristic acid was comparable to that of PS/scCO2 systems with the block copolymer surfactant, PS-b-poly(fluorooctyl acrylate). The surface activity of the myristic acid was confirmed by the decrease of IFT.     

The viscoelasticity of spinnable solutions of alkyltrimethylammonium salicylates

The viscoelasticity has been measured for aqueous solutions of tetradecyl-and hexadecyltrimethylammonium salicylates (C₁₄TASal, C₁₆TASal). The aqueous solutions of C₁₄TASal without salt displayed the gel-like behavior at 10.0×10^–2 g cm^–3, but those more dilute than 3.2×10^–2 g cm^–3 presented the viscoelasticity similar to that of a Maxwell liquid. The Maxwell-like behavior was converted to the polymer-like one on the addition of (0.1–0.2) M NaBr or (0.02–0.2) M NaSal. The gel-like viscoelasticity can be connected with the spinnability of cohesive fracture failure, and the Maxwell-like and polymer-like viscoelasticities are concerned with the spinnability of ductile failure. The gel-like and Maxwell-like viscoelasticities originate in the pseudo-network formed by the pseudo-linkages between rodlike micelles, while the polymer-like viscoelasticity is caused by the entanglement of long rodlike micelles in semidilute and concentrated solutions. The aqueous solutions of C₁₆TASal behaved very similar to those of C₁₄TASal.