| Summary: | 碩士 === 國立臺灣大學 === 化學工程學研究所 === 105 === Bacterial Cellulose (BC) of unique nano-fibers structure and strong hydrophilicity is noted for its high water holding capacity (WHC). In this study WHC was measured by a draining method proposed by Chen (2015) with a slight modification.
Experimental results suggested that a convenient set of draining criteria: time interval between draining droplets (∆T) = 6 min and the size of BC (A) = 16 cm2 to measure. WHC would satisfactorily result in less than 5 % coefficient of variation, and evaporation loss is less than 1.5 % within 30 mins.
Furthermore, GHC (glycerol holding capacity) of gly/BC membrane was measured via this draining method by soaking BC memebrane in glycerol solution of various concentrations. The results showed that as the concentration of glycerol solution increased, GHC of gly/BC increased. Meanwhile, as the concentration of glycerol solution increased, up to 12 % swelling effect was noted.
As to WRC (water rehydration capability) of BC dried by hot air, the experimental results showed that the WRC of gly/BC (glycerol concentration 10 wt % or more) could retain at least 90 % of capability compared to only 5 % by hot-air dried BC and 20~40% by freeze-dried BC.
The porosity of rehydrated gly/BC was higher than 99.3 % and the permeability was about 6*10-6 ~6.5*10-6 cm2/sec, which were slightly lower than never-dried BC, but far greater than the hot-air dried BC and freeze-dried BC.
|
|---|
