The conductivity measurements in the low frequency region (3300 Hz) were performed with a conductivity meter Crison microCM 2202 (cell constant = 1.09 cm−1). The sample with an initial volume fraction ?o was placed in a glass vessel with double wall to facilitate the thermostatization of the system. An inert GDC0941 (N2) was created by pouring the system with continue gas stream. The solid volume fraction dependence of the suspension conductivity was measured by extracting a determined volume of the sample and replacing it with the same volume of the liquid phase. The extracted volume was used to determine the solid volume fraction drying tracheids in hot air stuff.
The rheological measurements were performed in a Haake Rheostress-600 rheometer (Thermoelectron, Germany). Cone-plate geometry (20 mm/1°) was utilized. To avoid the undesirable influence from different mechanical histories, fresh samples were homogenized by shearing at an identical rate of 50 s−1 for 1 min and left standing for an additional 1 min before measurement. Steady-shear flow curves were carried out through stepwise ascending shear rate from 10−5 to 150 s−1. Samples were prepared, at a constant volume fraction of ?=0.2?=0.2. All measurements were recorded at 25.0±0.1 °C.