maniachalengineer
Mechanical
I am trying to formulate silicone compounds that ultimately will have higher dielectric (e) properties for radio and antenna applications. Many formulas and "recipes" exist for liquid (water/salt/sugar) solutions with high dielectric but these are quite problematic for storage, mold, leakage, etc. Thus I'd prefer to have a "solid" high dielectric polymer or silicone based solution. I've been able to add moderate amounts of high dielectric (e= approx 90) powders such as barium titanate to conventional polymers (e=approx 3) resulting in composite materials with medium dielectric constant (e=approx 10). The complex dielectric properties are measured with an Agilent vector network analyzer and dielectric probe.
As one might suspect, the upper and lower limits of this "mixing" approach are defined by the percentage of the high dielectric "guest" material (barium titanate) incorporated into the low dielectric "host" material (ex silicone. In other words the effective dielectric constant of the resultant compound can never go lower than silicone or higher than barium titanate.
I have located a few public research papers online that show mixing low percentages (5%-10%) of various carbon powders and fibers into polymer with very high dielectric constant of the resultant compound. Unfortunately my experiments with commercially available carbon powders and fibers have not produced similar results. I suspect that I'm doing something wrong or using the wrong types of carbon additives. I'm assuming that the polymer "host" is unimportant and simply performs the role of a "carrier" for the dielectric modifying additives.
Has anybody encountered any experimental results or formulations for high dielectric solid/polymer materials? I'm targeting dielectric constants from 20 to 100 and I'd like to tailor the dielectric conductivity, permittivity, and loss to specific values for various radio frequencies...
Any ideas? Suggestions?
Thanks in advance!
As one might suspect, the upper and lower limits of this "mixing" approach are defined by the percentage of the high dielectric "guest" material (barium titanate) incorporated into the low dielectric "host" material (ex silicone. In other words the effective dielectric constant of the resultant compound can never go lower than silicone or higher than barium titanate.
I have located a few public research papers online that show mixing low percentages (5%-10%) of various carbon powders and fibers into polymer with very high dielectric constant of the resultant compound. Unfortunately my experiments with commercially available carbon powders and fibers have not produced similar results. I suspect that I'm doing something wrong or using the wrong types of carbon additives. I'm assuming that the polymer "host" is unimportant and simply performs the role of a "carrier" for the dielectric modifying additives.
Has anybody encountered any experimental results or formulations for high dielectric solid/polymer materials? I'm targeting dielectric constants from 20 to 100 and I'd like to tailor the dielectric conductivity, permittivity, and loss to specific values for various radio frequencies...
Any ideas? Suggestions?
Thanks in advance!