A NEW TORSIONAL ROD INSTRUMENT FOR HIGH-FREQUENCY DYNAMIC VISCOELASTIC MEASUREMENTS

In studies of the viscoelastic properties of biopolymer solutions the total amount of polymer needed is often a crucial limiting factor. We here report on a new high-Q quartz torsional rod design that reduces t he required sample volume to about 1 ml, while maintaining the instrum ent sensitivity. This corresponds to a reduction in the amount of poly mer needed by more than a factor of ten compared to other existing ins truments for measurements of high frequency dynamic viscoelasticity. T he frequency range of this new instrument is 8-150 kHz (about eight di fferent frequencies for each of several resonators).