Insulating Liquids for Antenna Measurement

I am conducting some measurement for implanted antennas.
And I need some insulating liquids (to insulate antenna with environment) which have permittivity 10 and 18?
Can you suggest me some liquids like that?

Many thanks

Distillate water gives around ε≈68. Dependently from frequency.

E.g. butanol (≈18) or pentanol (≈15), to name some of the less harmful substances. I doubt that it's a reasonable approach.

I know that people use castor oil as a dielectric coolant for overclocking. Just putting all the PCB in the bowl with it. (It was used in capacitors in the past). However ε is not high (wikipedia tells about 4.7)

what about using:
Silicon epsilon = 11 - 12.
BUTANOL Eps =17.8 (at 68 degree K)
ALCOHOL, INDUSTRIAL Eps = 16 -31;
AMYL ALCOHOL Eps =15.8 (at 68 degree K)
CASTOR OIL (HYDROGENATED) Eps =10.3 (at 80 degree K).

These liquids need to be almost perfect insulating. The test is conducted at 400 MHz, 20-25 degree C.
How can I know the electrical conductivity of organic substances? I have a table for dielectric constant of many substances.
Many thanks

short-molecule spirits are good in theory, but in reality they are bad dielectrics. they easily absorb water from the air. I don't know about higher spirits, but I believe they should repel water.

Hardly. Alcohols are polar molecules, which is also the reason for their relative large permittivity. Respectively they mix well with water or are even hygroscopic.

Alcohols, while polar, follow the same rule of thumb as other organic compounds with a polar functional group. The short chain alcohols (n≤3) are completely miscible with water. With n≥6, solubility decreases substantially. Cholesterol (n=27) is quite insoluble (<0.1 mg/L).

Here's a small table of solubilities in mol/100mL of water (source: http://www.solubilityofthings.com/water/alcohols ).

Although I can't comment on this approach from an electronic point of view, I find the chemical and biological questions posed intriguing. If I understand the question, nvt088 needs to electrically insulate an antenna from a synthetic biologic medium with a minimum number of interfaces to reduce losses. So, I assume putting the antenna in an alcoholic solution in a plastic bag is out of the question. One, because of the interfaces, and two, because of osmotic exchange.

Polyvinyl alcohols and similar polyols can be crosslinked to become quite insoluble in water. So-called "waterproof" woodworker's glue is based on that principle. There are also resorcinol and formaldehyde-urea glues that provide polarity and water resistance.

Before spending much time trying to figure out some practical suggestions, is the concept of using such a paint worth pursuing for the insulating layer?

John

Water & water
Interesting μ is not equal to 1, it means some magnetic magics . And conductivity very depends and nothing about ThΔ.
With brain is OK μ=1 ε by Voxel model and finally we have: somebody trust to the UFOs, somebody to the 8 polarization for antennas