EFFECTS OF PH OF NA5P3O10/NAOH REACTION SOLUTION ON THE PROPERTIES OF CHITOSAN MICROSPHERES

With an attempt to expand the versatilities and applications in chitosan microspheres, chitosan were first converted into micro-droplets by using a high voltage electrostatic field system, and then treated with Na 5 P 3 O 10 /NaOH solution of volume ratio of 17/3, 19/1, 1/0 (pure Na 5 P 3 O 10 ) or 0/1 (pure NaOH) to fabricate chitosan microsphere. By varying the pH values of these reacting agents, distinct morphological structures and properties of chitosan microspheres were further be changed. Chitosan microsphere prepared in this study exhibited a good spherical shape and was in a range of 185.8 ± 13.8 μm to 380.9 ± 11.5 μm in diameter. The size of chitosan microspheres varied by treating with various pH values of these reaction reagents. The prepared chitosan microspheres upon treatment with pH 7 of various ratios Na 5 P 3 O 10 /NaOH solution, all exhibited a shrunken surface morphological structure. This densely shrunken structure of microspheres yielded a stronger mechanical strength and a slower release rate of drug (5-FU), no matter what the ratios of Na 5 P 3 O 10 /NaOH solution was used. From the data of FTIR analyses, the protonated amino peak of NH 3 + at around 1562 cm −1 has decreased significantly after treated with various pH values of these reaction reagents. It could be attributed to the linkage between phosphoric and ammonium ion of the protonated chitosan molecules. Besides, another boarder absorption at about 3366cm −1 of treated chitosan microspheres (under the employed range of pH values), which represented the hydrogen bonding was enhanced as compare with the pure chitosan material.