Preparation and characterization of NaCS-CMC/PDMDAAC capsules.
A novel capsule system composed of sodium cellulose sulfate (NaCS), carboxymethyl cellulose (CMC) and poly[dimethyl(diallyl)ammonium chloride] (PDMDAAC) was prepared for improving the properties of NaCS/PDMDAAC capsules. The process parameters, such as CMC concentration (0, 2, 4, 6 and 8 g/L), NaCS concentration (20, 25, 30, 35 and 40 g/L), PDMDAAC concentration (20, 30, 40, 50, 60, 70 and 80 g/L), reaction time and temperature were investigated to understand their effects on the diameter, membrane thickness and mechanical strength of capsules. The optimum operation conditions for preparing NaCS-CMC/PDMDAAC capsules were determined as 6-8 g/L CMC, 35-40 g/L NaCS, 60 g/L PDMDAAC and polymerization for 30-40 min. Diffusion of substances with low molecular weight into capsules was investigated, and diffusion coefficients were calculated according to the developed model. The yeast of Candida krusei was chosen as representative cell to evaluate the effects of different cell loading on capsule mechanical strength. Meanwhile the encapsulated osmophilic C. krusei cells were cultured in 250 mL shaking flasks for 72 h to determine the cell leaking properties in short and long term.
Chen
Guo
G
Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027, PR China.
Yao
Shan-jing
SJ
Guan
Yi-xin
YX
Lin
Dong-qiang
DQ
D002214:Capsules / Q000138:chemical synthesis / Q000737:chemistry; D002266:Carboxymethylcellulose Sodium / Q000737:chemistry*; D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D015394:Molecular Structure; D010316:Particle Size; D011095:Polyethylenes / Q000138:chemical synthesis / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000138:chemical synthesis / Q000737:chemistry; D012964:Sodium / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors
D002214:Capsules; D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; D002482:Cellulose; C020254:cellulose sulfate; D012964:Sodium; D002266:Carboxymethylcellulose Sodium