Advanced Materials Research Vols. 881-883

Abstract: A 1,8-naphthyridine modified rhodamine B derivative, one Cu²⁺-selective chemosensors was designed, synthesized and characterized, which display a high selectivity for Cu²⁺ among environmentally and biologically relevant metal ions. It can detect Cu²⁺ in aqueous solution selectively with a dramatic colour change from colorless to magenta. The detection mechanism involves a ring-opening process as a consequence of metal complex formation. Jobs plots study indicated that the chemosensor chelated Cu²⁺ with 2:1 stoichiometry.

Abstract: Graphene oxide with high degree of oxidation and peelable has been prepared by two-step oxidation method used large flake graphite. The expanded graphite was prepared firstly and then prepared graphene oxide via further oxidation. The influence of oxidation time, oxidant dosage and high temperature reaction on the structure and degree of oxidation were studied. The morphology and structure of graphene oxide were characterized by X-ray diffraction, fourier transform infrared spectra, scanning electron microscope and transmission electron microscope. It was found that high degree of oxidation and large specific surface area graphene oxide was prepared at the ratio of sulfuric acid and expanded graphite was 75 mL : 1 g, the ratio of potassium permanganate and expanded graphite was 4 g : 1 g and the oxidation time at 35 °C was 24 h. This technology is simple without high-temperature reaction process, and solved the problem of low oxidation efficiency when used the large flake graphite as raw materials.

Abstract: This paper emphasis has researched the microstructure, mechanics properties of multi alcohol modification particles ER fluid,compared the difference of microstructure and properties modification by multi alcohol, it has grasped the law of microstructure and mechanics properties of multi alcohol-Ti-O particles ER fluid.

Abstract: In this article, Cu-H₂O, Co-H₂O, MWCNT-H₂O nanofluids were prepared through two-step method. The transmittance of nanofluids over solar spectrum (250 to 2500nm) was measured by the UV-Vis-NIR spectrophotometer based on integrating sphere principle. The factors of various particle size, mass fraction and optical path influencing transmittance of nanofluids were investigated. The experimental results show that the transmittance of the three nanofluids is much less than that of deionized water. The transmittance decreased with the nanoparticle size and mass fraction increasing, but increased with the optical path length reducing. With the same mass fraction, the transmittance of MWCNT-H₂O nanofluids is the minimum. The transmittance of Co-H₂O nanofluids is higher than that of Cu-H₂O nanofluids within 250~775nm wavelength range, while inverse in 775~1370nm wavelength range. It indicates that different particle has diverse light absorption properties in different wavelength range.

Abstract: In this work, flower-like ZnIn₂S₄ microspheres were synthesized using a solvothermal method. The as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and ultraviolet-visible diffuse reflectance spectroscopy (DRS) techniques. The photocatalytic activity of the ZnIn₂S₄ microspheres was investigated. The ZnIn₂S₄ microspheres exhibit much higher photocatalytic activity than pure P25 TiO₂.

Abstract: PDLC films are very useful materials and can apply in flexible displays, intelligent switchable windows, information storage and adaptive optical devices. In this paper we focus on its color display characteristic in reflective display and firstly we fabricated PDLC films by polymerization induced phase separation method and measured its transmissivity and spectral reflection curves of the printing ink layer and PDLC covered color by X-Rite DTP41 Spectrophotometer. From the result, it demonstrates that PDLC films show different optical transmission properties in long and short wavelength.

Abstract: Magnetic FeCoSiB thin films have been prepared and annealed at 300 °C and 400 °C for 1 hour. The as-prepared films and films annealed at 300 °C are found in amorphous states and to be anisotropic in static magnetic properties. Nanocrystalline grains have been found in the films annealed at 400 °C, which are isotropic in magnetic properties. With increasing the annealing temperature, the coercivity and saturation magnetic fields are found decreasing. The resonance frequency shows the same varying trend as the saturation magnetic fields. Large microwave magnetic losses have been found in all the films, which indicate that these films have potential applications in microwave noise attenuation.

Abstract: The transmission spectra of 1-D quasi-periodic photonic crystal of positive-negative index structure at angular incidence was studied by transfer matrix method. The results show that the photonic band gap structure changes along with different incidence angles, a new photonic band gap corresponding to ω/ω_pe=1 will appear, whose centric position is invariant with the changes of incidence angle, but the width broadens as the incidence angle increases; likewise, for a Bragg gap, the centric position and width of band gap also change, which provides conditions for achieving complete phase matching for the second harmonic effect.

Abstract: ZnO thin films with different thickness (the sputtering time of AlN buffer layers was 0 min, 30 min,60 min, and 90 min, respectively) were prepared on Si substrates using radio frequency (RF) magnetron sputtering system.X-ray diffraction (XRD), atomic force microscope (AFM), Hall measurements setup (Hall) were used to analyze the structure, morphology and electrical properties of ZnO films.The results show that growth are still preferred (002) orientation of ZnO thin films with different sputtering time of AlN buffer layer,and for the better growth of ZnO films, the optimal sputtering time is 60 min.

Abstract: Textile-based electrodes are a potential choice for wearable and continuous monitoring of electrocardiogram measurements. In this paper, we present a novel composite textile electrode for ECG measurement. We chosen cotton jersey knit fabric as the substrate. Based on the substrate, polypyrrole (PPy) was coated chemically only and plated chemically electrochemically successively, respectively, to form PPy/cotton fabric composite electrode. The obtained results suggest that, first, both the composite electrodes can measure the ECG signals including P-waves, QRS complex and T-waves clearly, second, both the composite electrodes are poorer frequency dependence than Ag/AgCl electrode, and the one deposited chemically only is the poorest, whats more, the composite electrode deposited chemically only obtains the highest signal to noise ratio (SNR).