TY - JOUR
T1 - Dynamic shear modulus of glycerol
T2 - Corrections due to instrument compliance
AU - Schröter, K.
AU - Hutcheson, S. A.
AU - Shi, X.
AU - Mandanici, A.
AU - McKenna, G. B.
PY - 2006
Y1 - 2006
N2 - A recent article by Shi [J. Chem. Phys.123, 174507 (2005)] reports results from mechanical measurements on three simple inorganic glass formers: glycerol, m -toluidine, and sucrose benzoate. The experiments carried out were stress relaxation, aging, and dynamic (all in shear) using a torsional rheometer, an advanced rheometric expansion system (TA Instruments). The original force rebalance transducer (2KFRT) supplied with the system was replaced with a custom-made load cell (Sensotec) that had a capacity of 20 000 g cm in torque and 5000 g in normal force. The replacement of the load cell was done due to the belief that the main source of compliance in this instrument was from the 2KFRT. With this assumption, the authors published their results for the three materials of interest and compared their results with the techniques of Schröter and Donth [J. Chem. Phys.113, 9101 (2000)] for the measurements on glycerol and reported important differences. These differences were disputed by one of the present authors (Schröter), and the present report shows that the results from Schröter and Donth are correct. We show that the reasons have to do with the instrument compliance being greater than originally thought by Shi Here we examine the effects of platen diameter/geometry on the glycerol dynamic moduli, describe a means to correct dynamic data, present a revised comparison of the corrected data with that of Schröter and Donth, and provide a discussion of future work and conclusions.
AB - A recent article by Shi [J. Chem. Phys.123, 174507 (2005)] reports results from mechanical measurements on three simple inorganic glass formers: glycerol, m -toluidine, and sucrose benzoate. The experiments carried out were stress relaxation, aging, and dynamic (all in shear) using a torsional rheometer, an advanced rheometric expansion system (TA Instruments). The original force rebalance transducer (2KFRT) supplied with the system was replaced with a custom-made load cell (Sensotec) that had a capacity of 20 000 g cm in torque and 5000 g in normal force. The replacement of the load cell was done due to the belief that the main source of compliance in this instrument was from the 2KFRT. With this assumption, the authors published their results for the three materials of interest and compared their results with the techniques of Schröter and Donth [J. Chem. Phys.113, 9101 (2000)] for the measurements on glycerol and reported important differences. These differences were disputed by one of the present authors (Schröter), and the present report shows that the results from Schröter and Donth are correct. We show that the reasons have to do with the instrument compliance being greater than originally thought by Shi Here we examine the effects of platen diameter/geometry on the glycerol dynamic moduli, describe a means to correct dynamic data, present a revised comparison of the corrected data with that of Schröter and Donth, and provide a discussion of future work and conclusions.
UR - http://www.scopus.com/inward/record.url?scp=33845415296&partnerID=8YFLogxK
U2 - 10.1063/1.2400862
DO - 10.1063/1.2400862
M3 - Article
C2 - 17166033
AN - SCOPUS:33845415296
SN - 0021-9606
VL - 125
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
IS - 21
M1 - 214507
ER -