Measurements of the Temperature Dependent Diamagnetism of Liquids.

Measurements of temperature dependence of the diamagnetism of various liquids performed using a high precision. (10 to the 10th power SI) superconducting magnetic susceptometer are reported and discussed. A microprocessor-based signal processing system was developed allowing the elimination of systematic error due to the background signal from the quartz sample holder and due to linear output drift. Partly to evaluate the temperature regulation of this protype susceptometer, a measurement of the change in volume susceptibility at the well-studid gel to liquid crystal phase transition of dipalmitpyphosphatidylcholine vesicle dispersions was performed. The observed change is consistent with the known density change of the phospholipid bilayer and the assumption that the mass susceptibility of the system is constant through the transition. The measurements of methanol, acetic acid, deuterium oxide, chloroform, acetone, carbon tetrachloride, carbon disulfide, cyclohexane, and nitrobenzene indicate that hydrogen bonding is not a necessary condition for temperature dependent diamagnetism in liquids.