For example, coconut oil and olive oil have a dielectric constant of 3.25¹.  Oils that have a low DEC are lipophilic and will need surfactants with a high HLB value in order to work as an emulsifier.

For example, pine oil has a DEC of 4.67 and it is reported that a HLB of 13 is required to make an oil in water (o/w) emulsion².

Mixed surfactant systems can be prepared by combining nonionic surfactants with known HLB values in controlled ratios to make a mixture with a desired HLB value.

Gorman and Hall demonstrated the relationship between the weight percent of Tween in Span to the log of the DEC and the approximate equivalent HLB value². They concluded “the DEC of surfactant required for producing an o/w emulsion of any oil can be approximated from the graph by determining the DEC of the oil”.

The BI-870 is an ideal choice to quantify the dielectric constant of cannabinoids oils, extracts, and select nonionic surfactants for the optimization of a cannabinoid nanoemulsion.

How is Dielectric Constant Measured?

The dielectric constant is a measure of the ability of an insulator to store electric energy.  It is determined by applying a stable voltage at a specific frequency to a probe made of two concentric cylinders.

The conductivity of the liquid is compensated by an 180^o phase shift of a reference signal.  Once the conductive current is compensated then it is possible to measure the capacitive current. The measurement is performed by placing the probe into a glass cylinder, which is then filled with enough liquid to cover the immersion probe.

A coarse and fine adjustment knob are then utilized to dial in to a final value., These fine adjustments are used to compensate for the conductivity component of the solution. The DEC can then be determined and the result is displayed on the LED display.  This can be used quite effectively for oils, and other nonpolar liquids with very low conductivity.