Conductivity anisotropy inp−n-nonyloxybenzoic acid

Ionic conduction in the nematic phase of $p-n$-nonyloxybenzoic acid can be a maximum in a direction parallel (positive conductivity anisotropy) or perpendicular (negative anisotropy) to the nematic director. The presence of acetone can change a sample which exhibits a positive conductivity anisotropy to negative anisotropy. Experimental evidence indicates that there are many other dopants that can change the sign of anisotropy. It is suggested that the dopant may disrupt one of the hydrogen bonds of the dimer in some of the molecules, which makes it easier for trimers and higher polymers to form. This process should favor a smecticlike structure.