Effect of Processing and Particle Size on the Properties and Morphology of MWCNT-Polymer and SiC-Polymer Composites

Author(s):  
MORGAN R. WATT ◽  
ROSARIO A. GERHARDT
1997 ◽  
Vol 7 (8) ◽  
pp. 1581-1585 ◽  
Author(s):  
Sonia Granado ◽  
Victoria Ragel ◽  
Victoria Cabañas ◽  
Julio San Román ◽  
María Vallet-Regí

2008 ◽  
Vol 1138 ◽  
Author(s):  
Silvia Liong ◽  
Ricky Lamar Moore

AbstractThis paper discusses preparation, characterization and measurement of linear DC and AC magnetic properties of magnetite (Fe3O4) nanoparticles (size ranges of 7-50 nm and 5 microns) and polymer composites of those particulates. Selected data and analysis are taken from the PhD thesis of Liong [1]. The goal of this research is to obtain magnetic data, specifically magnetization, anisotropy and coercivity as functions of particle size. These will be used as inputs to non linear magnetic simulations and in planning for future nonlinear magnetic measurements. Magnetite nanoparticles were synthesized by chemical coprecipitation, a method that allowed for the production of samples in gram quantities. Vibrating sample magnetometry was used to measure the room-temperature DC magnetization and coercivity of the particulates. Coaxial line impedance measurements were used to measure low frequency and dispersive AC permeability of Fe3O4–polymer composites from 1 Megahertz to 10 Gigahertz. AC data are applied to infer particulate magnetic susceptibility and anisotropy field change with particle size. Particle size was calculated from XTD data and supported by TEM images.Measured DC saturation magnetization and coercivity decreased with particle dimension while anisotropy was calculated to increase. Magnetization data are consistent with models that calculate nanoparticle magnetization as a volumetric average of a spherical bulk material core and a passive outer shell. The shell thickness was calculated at 0.84 nm, very near one lattice constant of bulk Fe3O4, 0.8394 nm. Composites containing particulate volume fractions less than 20% were fabricated. Effective media theory was applied to measured AC composite permeability to extract particle magnetic properties and thereby anisotropy field, which increased by an order of magnitude from the bulk. Permeability decreased with particulate size.


2015 ◽  
Vol 76 (3) ◽  
Author(s):  
Petr VALÁŠEK

Composites are materials which synergically combine properties of each phase – matrix and filler. Polymer materials can be used as matrix while inorganic and organic particles can be used as fillers. Composite systems based on renewable resources can be designed as an interesting material for engineering. This paper describes on the tribological and other mechanical properties of biocomposites based on polymer resins and microparticles - seed cakes, which were obtained from seeds of the plant Jatropha Curcas L. during pressing. The particle size obtained was 573 µm.The results confirmed that the epoxy and polyurethane resins were capable of forming which corresponds to the interaction with the organic particles prepared from the seeds of Jatropha Curcas L. The presence of particles however, changed the mechanical properties of the resins. In the case of epoxy resins and polyurethane (Sika Force 7723), the hardness according to Shore D identically decreased with a maximum of 1.9. Abrasion resistance decreased due to the presence of particles of 0.0393 cm3 for Glue Epox Rapid, 0.0449 cm3 for Epoxy 1200/324 and 0.0567 cm3 for Sika Force 7723.


2015 ◽  
Vol 103 (8) ◽  
pp. 1641-1651 ◽  
Author(s):  
Edna M. Prieto ◽  
Anne D. Talley ◽  
Nicholas R. Gould ◽  
Katarzyna J. Zienkiewicz ◽  
Susan J. Drapeau ◽  
...  

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