Papers by Keyword: Dispersion

Abstract: Graphene nanoplatelets (GnP) reinforced styrene-butadiene rubber (SBR) nanocomposites were produced by two different methods. For reference purpose carbon black (CB) reinforced formulations served. In the first method the components were mixed on a two roll open mill directly. In the second method, GnP was subjected to milling in an attritor mill together with cyclic butylene-terephthalate oligomer (CBT) powder prior to the mixing on two roll mill. Samples were cured in a hot press. The rubber sheets were characterized by tensile and tear tests, and their fracture surfaces inspected in scanning electron microscopy (SEM). Results showed that GnP outperformed CB with respect to reinforcing effect. Previous co-milling of GnP with CBT caused a slight decrease in mechanical properties. SEM images proved, that the co-milling process did not affect significantly the dispersion of GnP, its particles were shredded into smaller pieces, which caused the slight decrease in the mechanical properties.

Abstract: MWCNTs were dispersed in acetone solution of styrene-acrylonitrile copolymer (SAN). Four factors which had effect on the average particle size, including the ratio of MWCNTs to SAN, the mass percent of MWCNTs, the ultrasonic power and the ultrasonic time, were studied. The optimal dispersion conditions of MWCNTs in acetone solution of SAN were the ratio of MWCNTs to SAN 1:3, the mass percent of MWCNTs 0.25%, the ultrasonic power 100%, and the ultrasonic time 30 min.

Abstract: Increasing production of nanomaterials makes the study of nanoparticles fate in the environment of immediate interest. Nanomaterials are known to radically change their properties when released into the environment. In this work, the ability of nanoparticles to form stable dispersions in physiological solutions has been demonstrated. The dispersions were prepared by mixing nanopowders of zinc (13.58 m²/g), copper (24.66 m²/g), aluminum oxides (54.75 m²/g), and zirconium dioxide (8.10 m²/g) with phosphate buffered saline, an isotonic solution of glucose and artificial lysosomal fluid. With the help of laser diffraction method and transmission electron microscopy it was shown that unstable suspensions (with the dispersoid size of 6...49 μm) and aggregative-stable lyosols (with the particles size of 20...300 nm) were formed in dispersions of nanoparticles in physiological media.

Abstract: The results of studies to determine the parameters affecting the morphology of the particle formation in certain conditions plasma chemical synthesis are present. On the example of oxides of cerium and yttrium were determined kinetic characteristics of plasmachemical process for their preparation, calculated characteristic times of the main stages occurring in the plasma-chemical reactor (t₁, t₂, t₃, t₄). Have been proposed parameter K₀, characterizing the modes of hollow and solid particles formation and determining the process of salt diffusion in the droplet volume and solvent evaporate from the surface.

Abstract: The white ink commonly serves as render ink in printing, and its covering property (CP), which is assumed to be influenced by the dispersion, plays a key role in color reproduction on the film surface. In order to research on the relations between dispersivity and CP, inks with different dispersion are prepared by changing the preparation process. The inks’ particle size and distribution are tested before it is coated onto the surface of covering property test paper. The morphologies of inks film are studied through SEM to examine the white ink’s dispersion and its influence on CP. The result shows that well dispersed inks have fine particle size and tend to uniformly distribute. There is hardly any agglomeration found on the well dispersed ink’s SEM image which is supposed to account for its high CP.

Abstract: The application prospect of conductive rubber composite is introduced. The mechanism of resistance relaxation of conductive rubber composite was expounded. Several representative mathematical models of the resistance relaxation effect of conductive rubber composite were introduced. The influence of external temperature, heat treatment temperature, the amount of conductive filler, the type and the size of stress, nanomodified materials and dispersing additives on the resistance relaxation effect of the conductive rubber composite were discussed respectively. Finally, a brief description of the application status of conductive rubber composite and its summary and outlook were made.

Abstract: Dispersion of carbon nanotubes in water largely determines the excellent properties of carbon nanotubes can be fully exhibited in the composite material. Summarizes the characteristics of all kinds of surface active agent, select several can represent various types of surfactant reagents to test and comparing the several kinds of surfactants on the dispersion of carbon nanotubes, and focus on the effects of polyvinylpyrrolidone special molecular structure on the surface of the carbon nanotubes.

Abstract: The research of improving thermal properties of cool storage medium using nanocomposite technology is proposed in this paper. The nanocomposite cool storage material was prepared by the method of mixing directly. The effect of dispersant, ultrasonic time and concentration of dispersant were deeply researched. The optimizing concentration of dispersant and the optimizing dispersion process conditions are confirmed. The results show that thermal conductivity of TiO₂ /HS-6 nanofluids is noticeably enhanced to compare base fluid HS-6, the increasing extent is 21.5%. The results provide the basic data for the application research of TiO₂ nanoparticles in PCM for air-conditioning system.

Abstract: In the present work, glasses of the As-S-I system have been synthesized, the region of glasses stable in moist air has been investigated, the properties of the glasses have been determined.

Abstract: To achieve well dispersion of carbon nanotubes (CNTs) and increase the interactions between CNTs and thermoplastics polyurethane (TPU) matrix,a new type of fluorinated carbon nanotube (f-CNT) was modified by fluorine plasma grafting with fluoropolymer. A series of f-CNTs/TPU nanocomposites were prepared by one-step in situ bulk polymerization method. The morphology, thermal property and chemical resistance of nanocomposites were characterized and compared. Results indicated thermal degradation temperature was largely increased and the glass-transition temperature increased from-51.7°C to-42.3°C. Moreover, the chemical resistance was apparent improved.