Showing 3 results for Zeolite
S. Vaezifar, H. Faghihian, M. Kamali,
Volume 30, Issue 1 (6-2011)
Abstract
DP803, an industrial catalyst used in petrochemical industry for dehydrogenation of isobutane to isobutene, was characterized in the current study. The results showed that zeolite Y is a high performance catalyst. This catalyst was then synthesized using a platinum source (hexachloro platinic acid) and two different tin sources (tributyl tin chloride and SnCl2.2H2O) all on zeolites Y, and then the synthesized catalysts were used in the dehydrogenation of isobutane in a reactor designed for dehydrogenation reaction. XRF, XRD, TG/DTG, FT-IR, and SEM techniques were used for the characterization and determination of the composition of catalysts. The wet analysis of samples under different reaction conditions were investigated as well.
S.m.h. Mirbagheri, R. Tafteh, K. Sardashti,
Volume 30, Issue 1 (6-2011)
Abstract
In this paper, the effect of TiH2 and CaCO3 blowing agents was investigated on the structure and energy absorption of Al-7%Si-3%SiC composite metal foam by powder compact route. Composition of the foam was prepared from a mixture of Al, SiC and Si powders. Then, precursors were consolidated in H13 die mould by cold and uni-axial pressing at 110 MPa and at room temperature. The pressed precursors were extruded at 500oC, in a 12*24 mm2 cross-section. Then, the precursors were foamed in a 316L-stainless steel tube with diameter and height of 20 mm and 100 mm, respectively, in an electrical resistance furnace. Finally, for micro-structural investigation the samples were cut and polished, and a scanning electron microscope was used to observe the cell wall and surface topology. For calculation and comparison, energy absorption was used in an Instron Hydraulic test machine and the foam samples were compressed at the ramp velocity of 50 mm/minute. Results showed that foams with CaCO3 agent due to having high porosities are more stable than foams with TiH2 agent. Also, the energy absorption for foam with CaCO3 agent is more than foams with TiH2 agents. However, its drainage due to less thickness of wall porosities is better than the foam with CaCO3 agent.
N. Zakeri, H.r. Rezaie, J. Javadpour, M. Kharaziha,
Volume 39, Issue 4 (2-2021)
Abstract
In recent years, nanoceramics have been used in scaffolds to emulate the nanocomposite with a three-dimensional structure of natural bone tissue. In this regard, polycaprolactone biopolymer is widely used as a scaffold in bone tissue engineering. The goal of this research is to produce porous scaffolds of polycaprolactone - zeolite biocomposite with suitable mechanical, bioactive and biological properties for bone tissue engineering applications. The nanocomposite scaffolds were synthesized by solvent casting/particulate leaching and freeze-drying approaches. Microscopic investigations showed generation of pores with an average size of 200-400μm after addition of ceramic phase. Energy dispersive X-ray analysis confirmed uniform distribution of ceramic phase in polycaprolactone matrix. FTIR results determined the binding type of zeolite nanoparticles to the polycaprolactone matrix as physical bonding. The results of mechanical tests showed the increase in young’s modulus after addition of ceramic phase (from 0.04 to 0.3 and 3 to 7 MPa, respectively). The hydrophilicity of polycaprolactone increased after adding nanozeolite and more weight loss was observed for scaffold containing 20% zeolite (53.52 6 1.6%) with an increase in the rate of hydroxyapatite formation. The results showed that the prepared scaffolds have potential for cancellous bone tissue engineering application.
