Papers by Keyword: Composite Particle

Abstract: The microstructure of an Al-Ti-C-Ce alloy was studied by XRD, SEM, and EDS. This mother alloy consisted of α (Al),(AlTi),(TiC), and (Ti₂Al₂₀Ce) phases, and there was a second phase of a composite structure in the alloy. The TiC phase was the primary crystal nucleus, and the (TiAl) phase was segregated on the surface of TiC phase to form a TiC-(TiAl) composite crystal nucleus. Al formed a fine TiC-(TiAl)-α (Al) primary composite crystal nucleus by a peritectic reaction.The primary composite crystal nucleus with higher energy and larger cluster size was taken as the core,and other composite crystal nuclei were segregated on its surface to form a secondary composite crystal nucleus. Next, the secondary composite crystal nucleus formed the tertiary composite crystal nucleus, and so on, to form the titanium-enriched area of composite particles.

Abstract: Composite particles with ultra-high molecular polyethylene (UHMWPE) matrix core and acetylene black (ACB) shell were produced by particle composite system (PCS), and molded into conductive polymer composites. Morphology of these composite particles was investigated by SEM. Matrix particles were coated by ACB nanoparticles very well. Conductive networks of ACB in polymer composites were seen by SEM. The results of electrical behavior study show that the polymer composites exhibit low percolation threshold and its electric conductivity is less affected by temperature due to unusual ACB distribution. Related mechanism is discussed.

Abstract: Microcrystalline Cellulose and Herba Sarcandrae were used to study the properties and relationship of powders before and after blending. The theoretical values of the physical quantities of the binary mixture were calculated based on the random mixing theory, The measured values of particle size specific surface area, pore volume and angle of repose of binary mixture had larger values than that of theoretical calculations. Whereas, tapped density and bulk density had a smaller value. The results suggested that the mixing behavior was not a complete random, arbitrary or simple superposition of the operation for coarse and sticky particles. The mixing process would create novel particles and physical quantities of novel particles exist regular changes.

Abstract: A novel ultrafine polyethylene/silica composite particle with core-shell structure was prepared by the sol-gel method in the presence of the melt polyethylene emulsion. A series of samples with different polyethylene content were prepared to investigate the unique characteristics of this original composite particle. The core-shell structure and composition of the composite particle was proved by the transmission electron microscopy observation and Fourier transform infrared spectra. The composite particles possess a spherical morphology and the mean size is about 160nm, presented by the scanning electronic microscope observation and nanoparticle tracking analysis, respectively.

Abstract: In this paper raspberry-like composite particles were prepared via cationic soap-free emulsion polymerization with silica sol as stabilizer and 2-(methacryloyl) ethyltrimethylammonium chloride (MTC) as cationic auxiliary monomer. According to the TGA and TEM results we could find that the electrostatic attraction supplied by MTC played a vital role in the adsorption of silica particles as well as the generation of raspberry-like morphology. The silica content and appearance of composite particles were found to be improved with the increasing amount of silica sol and MTC while varied little with changes of AIBA amount.

Abstract: Nano-TiO₂/Micron size Cu composite particles were prepared in ambient conditions by bio-inspired method. Observation by field emission scanning electronic microscope shows TiO₂ particles of 3-5 nm covers on copper powder surfaces to form nanometer/micron composite particles. XPS analysis shows that the element C, O, Ti, Sn and Cu existed on the surfaces of the composite particles. UV-vis spectra show a red shift of the absorption edge and a significant increase of absorption intensity in the visible region. The degradation experiment taking methyl orange demonstrates the photocatalysis activation of powder with good body made. At the same time, the apparent kinetics model for degradation reaction was established.

Abstract: Nano-TiO2/micro-Cu composite particles were prepared by peptization method using Ti(OBu)4 and SnCl2•2H2O as the raw materials. The effect of the content of HNO3 on the morphology and composition was investigated. The results showed that when the mole ratio of HNO3 and Ti(OBu)4 was 0.5:1, about 100nm TiO2 of amorphous phase grew on the surface of Cu forming strawberry like particles. When the mole ratio of HNO3 and Ti(OBu)4 was 1:1, Cu powders were coated with TiO2 crystals of several nanometers in size, meanwhile particles of several microns in size was absorbed on the Cu surface, which can be easily removed by water cleaning. The possible mechanism was discussed in the end.

Abstract: Silver myristate/AgBr composite particles were prepared by using silver nitrate, sodium hydroxide, myristic acid, and sodium bromide as raw materials and PVP as surfactant in water-alcohol system and characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), ultraviolet-visible spectroscopy (UV) and differential scanning calorimetry (DSC). The results showed that silver myristate/AgBr composite particles are composed of rod-like silver myristate grains with a layer structure and small silver bromide particles formed on the surface of silver myristate. Silver bromide can extend the ultraviolet absorbance range of silver myristate. The size of silver myristate is about 260nm and the average size of silver bromide is about 44nm. TG and DSC analysis showed that the reaction was carried out completely. The composite particles start to decompose at about 210oC. Silver bromide of the composite particles melts at 418.2oC.

Abstract: We introduce a case study of “high sphericity” and “high uniformity” generated through flame synthesis. Recently, cosmetics need to solve 1) UV-protective effect, 2) transparence, and 3) smooth-textured touch. However, the best recipe and usable evaluation methods are not established. This research is a result combined with a theoretical approach of flame formation process, and a strategic regional alliance of the “AIST” grant venture. A new manufacturing and evaluation method has been commercialized in the forms of a highly original cosmetics and a new evaluation device.

Abstract: Nano-TiO2/micro-Cu composite particles were prepared by hydrolysis of Ti(OBu)4 in abundant acidic aqueous solution and subsequent reflux in the presence of micron size Cu powders. The preparation process was optimized using response surface design with the degradation of TiO2/Cu particles to Methyl orange as target. The particle morphology and composition were characterized by FE-SEM, XPS and XRD. The photon absorption properties of composite particles was investigated by the UV-VIS DRS experiments, and the results show the photoabsorption property of composite particles is intermediate between TiO2 particles and Cu powders, showing cooperative effect by the combination of oxide semiconductor particles with metal substrate.