Papers by Keyword: Particle Coating

Abstract: The incorporation of protein based polymeric materials with calcium phosphate (CaP) coatings can provide excellent biological characteristics and biocompatibility with its bone-like protein-CaP composition. Calcium chloride-ethanol catalysed hydrolysis reaction and wet precipitation method was used to prepare silk solution and to precipitate brushite respectively to produce the brushite/silk composite powder. FTIR analyses showed that brushite absorption bands were prominent, overlapping the less intense N-H bands in silk. The most distinct absorptions from the silk were N-H bands. 1g of silk additive to the 300 ml of solution media resulted in arbitrary particle attachment onto brushite crystal surface; most of the brushite particles were covered by the silk β-sheets phase.

Abstract: Tristructural-isotropic (TRISO) coated fuel particles with spherical ceramic fuel kernels followed by three layers of pyrolytic carbon and one layer of silicon carbide (SiC) is successfully used in high temperature gas cooled reactor (HTGR) system. In this paper, an improved design concept of fully ceramic fuel is proposed. The kernels were coated by SiC layers with different densities. Two kinds of SiC coatings, namely porous SiC and dense SiC were prepared by a fluidized bed chemical vapor deposition method. The densities of porous SiC and dense SiC were 1.40 g/cm³ and 3.20 g/cm³, respectively. By controlling experimental parameters, densities of the SiC layer can be adjusted. The structure and micromorphology of the coated particles were investigated by various technologies such as XRD, SEM, and EDX. The coated particles were dispersed in SiC matrix and further sintered to dense compacts. High temperature oxidation test confirmed the robustness of the fuel elements.

Abstract: This paper describes the use of Taguchi Method in optimizing coating hardness in a tangential fluidized bed coater using modified biopolymer. During the coating process, granular ureas collide among themselves and the wall surface at high velocity. This led to excessive attrition and likely to break the granular ureas into smaller sizes. Hence, hardness is the critical properties during operations such as packaging and stacking. A series of coating experiments were carried out by using the L₉ orthogonal array with 3 levels to determine the effect of inlet air temperature (40, 60 and 80^OC), disc rotation speed (40, 60 and 80 rpm) and spraying rate (0.5, 1.0 and 2.0 rpm) on hardness of coated granular urea. The optimized operating parameters in this work were 60^OC for inlet air temperature, 60 rpm for disc rotation speed and 2 rpm for spraying rate. The results show that the spraying rate was the most significant factor affecting the hardness of the coated granular urea since the contribution was 69.2 %. No confirmations run for this work were necessary since the optimized operating parameters that were discovered was one of the experiments operating parameters.

Abstract: In this research, glass beads with size range between 1.68 and 2mm were coated with 5 polymeric suspensions. The suspensions formulations differ in relation to their employment and physical properties (solids concentration, surface tension and rheology), generating different characteristics of wettability and adhesion with the nucleus. The aim of this study was to evaluate particle coating in a spouted bed through analysis of particle growth in terms of solid surface energy, wettability, and adhesion before and after the formation of the first layer of polymeric film on the particle. The solid-suspension and film-suspension systems were characterized by contact angle and surface energy. The operating conditions were fixed for all suspensions: 1.5 kg of beads, air velocity of 0.369 m/s, air temperature of 60 °C, suspension flow rate of 4 ml and atomizing pressure of 10 psig. Analyzing particle growth kinetics, different behaviors were observed and related not only to glass-suspension wettability, but also to polymeric film-suspension surface properties.

Abstract: The high temperature abrasive wear resistant of the composites with different Al2O3 volume fractions, particle coating and size were investigated and the failure action of composites under different conditions at high temperature was analyzed. The results showed that the high temperature abrasive wear resistant of composite with Ni coating and wide size and 39% volume fraction of particle is the best among all composites examined.