2.2. Preparation of GLS/alginate (GLS/A) suspension
GLS/A suspension was prepared by adding commercial GLS powder
into alginate solutions (2% w/v). 80/20 (w/w%) GLS/A suspension
was used to establish the relationship between the various processing
parameters on the microstructure of GLS beads, which was prepared
by adding 2 g of alginate and 8 g of GLS powders into 100 mL of deionized
water.
2.3. Preparation of GLS/A hydrogel beads
A schematic diagram illustrating the fabrication of GLS/A beads
using ES is shown in Fig. 1. Stainless steel needles with outer and
inner diameters of 1000 μm and 800 μm, respectively, were used for
the experiment. The ES processing parameters, such as the concentration
of calcium chloride crosslinking solutions (0.01 to 0.5 M),
crosslinking durations (1 to 300 min), working distance between the
needle exit and the collecting beaker (150 to 350 mm), flow rates (30
to 1000 μL/min) and applied voltage (0 to 10 kV) were varied and tested.
In order to achieve reproducible and consistent results, all process
parameters, which were kept constant while optimizing the others.
The dimensions of beads (placed on a glass slide) were measured after
crosslinking and washing (5 times with deionized water) and the
beads were stored at 4 °C until further analysis or processing.