The gel was cut into rods
after 24 h of gelation. The rods were re-immersed into the
same solution of calcium ions for further gelation. The
height of the rods was always approximately 1.8 cm and the
diameter of the rods was 1.4 cm. In the case of pre-cut
samples, the alginate rods were cut in half on the following
day and re-placed in the calcium chloride solution. In the
case of freshly cut samples, the alginate rods were cut in
half just before conducting the experiments. Special care
was taken to ensure the bottom and top half of the rod
fitted together, i.e. the topography of the two half rods
matched perfectly so that surface of contact remained
constant for all the samples studied. The purpose of this
was to enable comparison between samples.