Team:TUST China/Results/More BC
BC Property Testing
Overview
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After the experiments above, we processed the bacterial cellulose film formed by the co-culture of the modified E. coli and G.xylinus, we would like to know whether this culture method of mixed bacteria will change the microstructure of BC? Therefore, we observed the morphological characteristics of the bacterial cellulose produced by the co-culture of the bacteria by scanning electron microscopy (SEM), infrared spectroscopy (FTIR) and atomic force. The results are as below: :
1. Scanning electron microscopy (SEM)
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We first used a scanning electron microscope to observe the formation of bacterial cellulose samples under different electric field strength. The results are shown in the figure
The microstructure, fiber detail and fiber width of the bacterial cellulose samples can be analyzed by scanning electron microscopy after freeze-drying. We found no significant difference between them.
2.Infrared Spectroscopy (FTIR)
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The use of Fourier transform infrared spectroscopy can help us understand the chemical structure of cellulose. Bacterial cellulose has an absorption peak for a particular wavelength of infrared, so that the composition of its chemical group can be analyzed.
Respectively, we analyzed BC film under the two conditions after the natural drying by the infrared spectrum scan, the results shown in Figure. The absorption peak at about 1060 cm-1 reflects the vibration of the C-O-C group, which is the characteristic absorption peak of the cellulose. The absorption peak at 1428 cm-1 is caused by the bending vibration of the C-H bond, and the depth is related to the crystallinity of the cellulose. Although the infrared spectrum is a simple method, it can only give a relative value, it can show whether is a crystalline phase or non-crystalline phase at one time. It can be seen that the BC film produced under these two conditions are not much different in the composition of the structure.
3. For the quality of wound dressings
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Bacterial cellulose is well suited for wound dressings due to its good biocompatibility, high mechanical strength in wet state, good liquid and gas permeability, and inhibition of skin infections. For secondary and tertiary burns, ulcers have been successfully used as temporary substitutes for artificial skin. For the application of bacterial cellulose in medical materials, our team visited the BC factory and learned more about what conditions are required for the products of BC films used as wound dressings.
The above test content：
Test Items Technical Requirements Clause Technical Requirements Test Result Conclusion Water Content 2.2.3 ≦5 5 qualified pH 2.2.5 6.0±2.0 6.3 qualified Heavy Metals 2.2.6 ≦10 <10 qualified Residue 2.2.7 <4.0 0.3 qualified At the same time we would like to thank xx company for providing the conditions of the test of our BC films . After a variety of tests of specifications, size, permeability, water content and others, data shows that the bacterial cellulose produced after the co-culture meet the technical requirements of wound dressings.
