Materials Science Forum Vol. 996

Abstract: 32in full high definition display devices based on back-channel etch IGZO TFTs were prepared. The mechanism of interlayer peeling defect in IGZO TFTs formation was studied. It turns out that the passivation layer was peeling with the underlying source electrode, which caused an interruption in signal transmission. Relevant process improvements were implemented, and the interlayer peeling defect in IGZO TFTs was solved.

Abstract: Manganese-based solid solution ceramics of transition metal with spinel-type crystal structure have generated much interest as NTC thermistors in various domestic and industrial applications. Doping has been considered as one of the most important method to improve their electrical properties. In this work, Cr doped Mn-based solid solution NTC ceramics Ni_0.7Mn_2-xCu_0.3Cr_xO₄ (x = 0.1, 0.2, 0.3 and 0.4) were prepared by solid-state reaction method. X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray energy dispersive spectrometer (EDS) were applied to study the phase structure, surface morphology and surface element content. The results indicate that the resistance and B value increase as the substituted Cr content increases.

Abstract: The geometrical and electronic properties of B-doped ZnO monolayer with the concentrations of 12.5% and 25% have been calculated using the first-principles method. B-doped ZnO monolayer leads to the structural distortion around the doped atoms compared with the pure ZnO sheet. The B-B pair or two B-B pairs doped ZnO monolayer present nonmagnetic metal.

Abstract: Novel fluorescent nanomaterials have attracted enormous interests in the applications of illumination and display besides the traditional organic fluorophors. As potential alternatives, the environmental friendly fluorescent ultra-small organic-inorganic hybrid metal nanoclusters (size < 2 nm) is a series of powerful competitors used in illuminating field, on account of the non-poisonous, large amount of storage in earth, simple synthetic route, and relative low cost. The most important one, facile regulation of the fluorescence intensity and emission colors makes metal nanoclusters more attractive candidates for illumination application. Here, through ingeniously designing the structures of capping ligands, the highly bright copper nanoclusters are obtained, which further assemble into 2D ribbons with fluorescence quantum efficiency ascending to 36.4%. Last, the light emitting diodes with excellent performance are constructed, the emission wavelength locates at 650 nm in red region, which is suitable for plant illumination.

Abstract: Thermosensitive conducting composite particles were synthesized using the unsulfonated P(St-NIPAm) as a thermosensitive substrate. A series of characterizations have been performed to study the effects of thermosensitive PANI@poly (St-NIPAm) conductivity performance. Aniline diffused into P(St-NIPAm) particles in solution, and then polyaniline (PANI) was in-situ produced in P(St-NIPAm) particles through oxidation polymerization. The samples showed different particle sizes at different temperatures. The content of conducting polyaniline is dependent on NIPAm feed ratios. The particle electrical conductivity was improved with the increasing NIPAM feed ratios and exhibited thermal responsive electrical conductivity. The thermosensitive conducting composite particles will have wide applications in sensors, for example, they could be used to fabricate smart conductive gel responsive to temperature and moisture.

Abstract: Thermal treatment of polyacrylonitrile (PAN) with different molecular weights pre-irradiated by electron beam was prepared to study the radiation effects on thermal behaviors. Thermal properties were characterized by thermogravimetric analyses. Char yields (800 oC) of PAN samples are increased remarkably with the increase of irradiation dose, and all samples can obtain the similar high char yields (~57 %) at the dose of 300 kGy. FTIR and UV-visible absorption spectra of pre-irradiation PAN illustrate the formation of –HC=N-N=CH-crosslinking conjugation across the polymeric chains, which can improve PAN’s thermal behaviors. Char yields of pre-irradiated PAN samples are mainly dominated by their gel contents, and they are almost independent of the molecular weights of PAN samples.

Abstract: The CNTs/Al2009 composite powders were prepared by cryogenic milling. The CNTs were uniformly dispersed on the surface of Al2009 powders. And then the CNTs/2009Al composites were fabricated by hot extrusion/hot isostatic pressing method. The effects of CNTs content and cryogenic milling process on the dispersion of CNTs in Al2009 matrix, the microstructure of powders and the properties of composites were studied by Scanning electron microscopy, Raman spectroscopy and tensile strength testing at room temperature. The results showed that the dispersion of CNTs was improved with the extension of ball milling time (1h~4h), but the damage degree of CNTs was intensified. In comparison, CNTs had the highest damage rate at the beginning of ball milling. As the milling time increased, the mechanical properties began to increase slightly and then decreased. When the ball milling time was 2h, the mechanical properties reached the highest. Cryogenic milling could achieve good dispersion in the Al2009 matrix for mixed powders with low CNTs content. When the CNTs content increased to 1.0%, a small amount of agglomeration appeared, but for composites, the strengthening effect of CNTs was more dominant. When CNTs were further added, the dispersion was remarkably lowered and the performance was deteriorated. CNTs (1.0wt.%)/Al2009 composites had excellent mechanical properties. The tensile strength reached 560MPa, which was 25% higher than Al2009.

Abstract: In order to make rational use of waste cattle hair, the protein filler was prepared by using chitosan modified keratin which hydrolyzed waste cattle hair, then used in retanning and filling process. The optimal modification conditions of keratin: chitosan: keratin was 20:80, pH value was 2, time was 5h, chitosan modified keratin product zeta potential was 31.3mV, nanometer particle size was 482d·nm. Chitosan-modified keratin can be used as chrome auxiliaries in the retanning process to significantly reduce total chromium in the waste liquid. At the same time, the modified keratin had good filling performance. Moreover, the softness, tearing force and tensile strength of the shoe upper leather which filled with chitosan modified keratin were improved.

Abstract: In the present study, oligopeptide (TEA) and modified Pluronic F127 (M-Pluronic F127) with different mass fraction composited by intermolecular forces. And the oligopeptide/M-Pluronic F127 composite membranes were prepared and investigated. The structural parameters of the membranes were characterized by fourier transform-infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) measurements. It was found that there had strong interaction between TEA and M-Pluronic F127 and the composite films with different proportions had different surface morphology and thermal stability. The characteristics of the membranes were related to the significant changes of the self-assembly behavior of the TEA modified by M-Pluronic F127.