Sodium bicarbonate microcapsules (SBCM) were prepared by phase separation method using glycerol monostearate (GMS) and konjac glucomannan (KGM) as wall materials. Microscope micrographs clearly showed that SBCM microcapsules were spherical shapes, and the microcapsule morphology could not be changed at 40℃, while it could be destroyed at temperature above 60℃. DSC thermograms implied that SBCM wall materials could be melted at temperature about 59℃. Size distribution indicated that the particle size of SBCM was mainly distributed in the range of 50 μm to 300 μm. SBCM stability was evaluated using the percentage of SBC (sodium bicarbonate) retention, i.e. retention ratio. SBC retention ratio showed that SBCM was highly stable in the temperature range 40-80℃. Furthermore, carbon dioxide (CO 2) release efficiency of SBCM was investigated by pairing the microcapsules with monopotassium phosphate. The CO 2 release ratio of SBCM was very low at temperature below 60℃. However, the release ratio was sharply increased at temperature above 60℃, and CO 2 was almost completely released at 60℃ for 10 min. According to the results, the CO 2 release of SBC could be effectively controlled by encapsulating into microcapsules based on GMS/KGM wall materials.
Ammonium bicarbonate microcapsules (AMBCMC) were prepared by phase separation method using palm stearin/carnauba wax (CNW) as wall materials. The morphology of AMBCMC showed that the microcapsules were mainly spherical shapes. DSC analysis results suggested that the microcapsule shells began melting at the temperature 47.9 °C, while the shells were thoroughly destructed at the temperature above 78.1 °C. The particle sizes of AMBCMC were chiefly distributed in the range of 30 ~ 300 μm. Ammonium bicarbonate (AMBC) in microcapsules was highly stable under different relative humidity, and AMBCMC was hardly damaged even at 95% relative humidity. The thermal stability of AMBC increased, while AMBC encapsulated in microcapsules still could decompose and release gas at 70 °C as well as free AMBC. Furthermore, AMBC encapsulated in microcapsules showed strong survivability in the presence of citric acid. The results indicated that the stability and compatibility of AMBC were effectively increased after microencapsulation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.