This study is focused on the preparation of
n-nonadecane-loaded calcium alginate capsules by coaxial
electrospray technique. The solution and process parameters
such as sodium alginate concentration, polymer feeding
rate, needle gauge, needle length, needle-to-collector
distance, and stirring speed were optimized through Taguchi
method. These parameters were selected as variables,
and three levels of them were introduced into L27 orthogonal
arrays. Taguchi’s signal-to-noise ratio and analysis of
variance were used to minimize the response and find the
effect of control factors on it, respectively. The setup of the
two-axial nozzle and feed rates of core/shell solutions were
studied, as well. Optical microscopy, scanning electron
microscopy (SEM), and Fourier transform infrared (FTIR)
spectroscopy were used for characterization of the capsules.
The results showed that the sodium alginate concentration
and the needle gauge are important factors for capsulated
alginate material. The optical microscope images
and the FTIR spectra confirmed that the alginate shell
successfully fabricated the n-nonadecane materials. SEM
analysis showed that at the optimal conditions, micro- and
nano-capsules were prepared with nearly spherical shape.
The results showed that when the inner needle tip was displaced 0.5 mm ahead of the tip of the outer needle, the
envelopment of the core polymer was better accomplished
by the outer polymer.