Electrokinetic and electrorheological properties of poly(vinyl chloride)/polyindole conducting composites

In this study, poly(vinyl chloride) (PVC), polyindole (PIN), and PVC/PIN conducting composites having five different compositions were used. Particle sizes, densities, dielectric constants, and sedimentation ratios of the materials were determined. The zeta‐potentials of the samples were measured in aqueous and nonaqueous (silicone oil [SO]) media. The dispersions prepared in SO were subjected to external electric field strength, and their electrorheological properties were investigated. Then the effects of dispersed particle volume fraction, shear rate, external electric field strength, frequency, and temperature onto electrorheological activities of the dispersions were examined. Further, creep and creep‐recovery tests were applied to the PIN/SO and PVC/PIN/SO dispersions, and reversible viscoelastic deformations were observed. Finally, the vibration damping capacity of PVC (66%)/PIN (34%)/SO dispersion system was tested by using an automobile shock absorber. Copyright © 2011 John Wiley & Sons, Ltd.     

A novel high‐contrast ratio electrochromic material from spiro[cyclododecane‐1,9′‐fluorene]bicarbazole

A novel electroactive spirocyclododecylfluorene monomer named 2,7‐bis(carbazol‐9‐yl)‐9,9′‐spiro[cyclododecane‐1,9′‐fluorene] (SFC) was synthesized and electrochemically polymerized to give a very stable multi‐electrochromic polymer (poly‐SFC). Two separate oxidation processes were observed for both SFC monomer and poly‐SFC that carries two carbazole units. The polymeric film of poly‐SFC was coated onto ITO/glass surface, and it shows different colors (transparent, yellowish green, green, and dark green) upon stepwise oxidations. An electrochromic device based on poly‐SFC was assembled in the sandwich cell configuration of ITO/poly‐SFC//gel electrolyte//PEDOT/ITO. Poly‐SFC exhibits 90% of transparency at neutral state and a high contrast ratio (ΔT = 58% at 800 nm). This device constructed from it represents a response time of about 1 s, high coloration efficiency (1377 cm² C^–1) and retained its performance by 96.4% even after 1000 cycles. Exhibiting high transparency at neutral state, reversible redox behavior, resistance to overoxidation, and especially high contrast ratio at near IR region can make poly‐SFC be useful and promising candidate for electrochromic applications despite having a relatively slow response time. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010     

Revealing the Spin-Hamiltonian and Characteristic Parameters of Paramagnetic Centers in Cu2+-Doped Potassium Metabisulfite (K2S2O5) Single Crystal by Electron Paramagnetic Resonance Technique

The present study is mainly related to finding out spin-Hamiltonian parameters of Cu²⁺-doped potassium metabisulfite [K₂S₂O₅] single crystals using electron paramagnetic resonance (EPR) technique which has been applied in the temperature range from 297 to 113 K for single and powder crystals of the title compound. The existence of two complexes and two Cu²⁺ sites for each complex was concluded from the angular variation of the EPR spectra. Having constructed the g and the hyperfine tensors, the spin-Hamiltonian parameters have been obtained for these two complexes. Using these parameters, the covalency parameter (α ²), mixing coefficients (α and β) and Fermi contact term (K) have been calculated.     

DIBUTADIENYL PIPERAZINE,DIBUTADIENYL HOMOPIPERAZINES AND BUTADIENYL-SUBSTITUTED PIPERIDINES FROM MONOSUBSTITUTED HALODIENES

Compounds 3a–k were obtained from the reactions of compounds 1a–k with homopiperazine (2) in CH ₂ Cl ₂ . Compounds 1a–b, 1d–f, and 1h–l gave compounds 5a–b, 5d–f, and 5h–l with 2-methylpiperazine (4) in dichloromethane. Compounds 7c and 9c were obtained from the reactions of compound 1c with 4-ethoxycarbonyl piperazine (6) and 4-piperidinol (8) in CH ₂ Cl ₂ . Compounds 1a and 1f gave compounds 11a and 11f with 4-methylpiperazine (10), and compound 13f was obtained from the reactions of compound 1f with 4-methylpiperidine (12) in CH ₂ Cl ₂ .     

New N,S-Substituted Dienes from the Reactions of Some Aliphatic Mono(thio)substituted Nitrodienes with Aromatic Primary Amines and Cyclic Amines

Reaction of 2-nitropentachlorobutadiene with thiols and amines gave new N,S- and S,S-substituted nitrodiene compounds is discussed.     

Synthesis,Characterization, and Spectroscopic Properties of Hexa(4-Bromo-2-Formyl-Phenoxy)Cyclotriphosphazene and Hexa(4-Chloro-2-Formyl-Phenoxy)Cyclotriphosphazene and Fully Substituted Cyclotriphosphazene Derivatives Bearing a Schiff Base at Room Temperature

Abstract

Hexa(4-bromo-2-formyl-phenoxy)cyclotriphosphazene (2) and hexa(4-chloro-2- formyl-phenoxy)cyclotriphosphazene (3) were obtained from the reactions of hexachloro- cyclotriphosphazene (1) with 5-bromosalicylaldehyde and 5-chlorosalicylaldehyde in the presence of (C₂H₅)₃N and K₂CO₃ at room temperature, respectively. The new two organocyclotriphosphazenes bearing formyl groups were reacted with 4-cyano aniline, 2-phenyl aniline, 4-aceto aniline, 5-chloro-2-hydroxy aniline, 2-hydroxy aniline, 4-hydroxy aniline, 2-(4-morpholino)ethyl amine, 4-carboxy aniline, 4-carbomoyl aniline, 2-mercapto aniline, and 5-amino isoquonoline to prepare cyclotriphosphazene derivatives containing a Schiff base at room temperature. However, fully phenoxy-substituted cyclotriphosphazenes containing a Schiff base were isolated from the reactions of the compound 2 and 3 with 5-chloro-2-hydroxy aniline, 2-hydroxy aniline, 4-hydroxy aniline, and 2-(4-morpholino)ethyl amine. The structures of the synthesized compounds were characterized by elemental analysis, IR, and NMR (¹H, ¹³C, ³¹P) spectroscopy. According to the results of the analysis, all synthesized compounds were found to be fully substituted organocyclotriphosphazenes, such as hexa[4-bromo-2-(5-chloro-2-hydroxy-pheyliminomethyl)phenoxy]cyclotriphosphaze (2a). All cyclotriphosphazene derivatives synthesized gave fluorescence emission peaks in range between 300 nm and 410 nm.