| Bacterial cellulose (Bacterial cellulose, abbreviated BC) is defined by the microbial synthesis of a nano cellulose, compared with plant cellulose, high purity, has many unique properties, such as ultrafine network structure has a high degree of crystallinity, good tensile strength, high water holding capacity, excellent biocompatibiliry characteristics. Bacterial cellulose has been used in various fields and continue to be expanded, is one of the hotspots of modern biomaterials research. This research involves screening high-yield strains of bacterial cellulose production, media and culture conditions to optimize the production of bacterial cellulose, using bacterial cellulose modified bacterial cellulose to improve the performance of the method, the use of bacterial cellulose membrane adsorption of heavy metals and bipolar aspects of the preparation, the main results are as follows:From Fujian Yongchun Laocu liquid fermented of vinegar of vinegar bacteria membrane isolated from breeding screened strains capable of synthesizing a bacterial cellulose, according to their growth characteristics, cell morphology and biochemical identification, the method performed sequence homology analysis, was identified as Acetobacter pasteurianus, bacterial cellulose production wet weight reached253g/L。Improved medium using lees liquid and rice koji mixed liquid fermentation to produce bacterial cellulose, greatly reduce the cost of production of bacterial cellulose. And through the single factor experiments,3main factors (sugar degree, pH value and the yeast extract), combined with Box-Behnken design, using central composite experimental design of response surface method analysis to optimize the production of bacterial cellulose process conditions. Sugar content is3.7°BX, yeast extract0.52g, pH value is6and optimization of process parameters to produce bacterial cellulose, increased from0.486g to0.798g before optimization, bacterial cellulose production increased by60.91%.The bacterial cellulose modification methods to improve the performance of bacterial cellulose, an in situ modified to add sodium carboxymethyl cellulose were in the process of fermentation of bacterial cellulose, sodium carboxymethyl cellulose and pectin mix and Pectin and other substances. Experimental results show that the added substances are conducive to increased production of bacterial cellulose. According to the results, sodium carboxymethyl cellulose, sodium carboxymethyl cellulose, pectin and pectin their appropriate mixing and were added in an amount of1.0%,1.25%,1.0%. Another chemical method, ie fermentation purified bacterial cellulose membranes were processed acrylic graft polymerization. Comparative results show that:Acrylic-modified bacterial cellulose crosslinking agent, the maximum ion exchange capacity of2.872meq/g-Application of bacterial cellulose:1. Study of modified bacterial cellulose adsorbed heavy metal ions。The modified bacterial cellulose was used to study the adsorption properties of the copper ions, hexavalent chromium and zinc ions.And Univariate adsorption experiments, combining Box-Behnken experimental design, optimization test using a central composite experimental design response surface method, adsorption of copper ions, heavy metal craft hexavalent chromium ions, zinc ions optimum parameters. And to study the properties of the modified cellulose regenerated adsorption。Experimental results show that bacterial cellulose and modified cellulose Cu2+, Cr6+, Zn2+best adsorption effect is:LMP-BC membrane adsorption of Cu2+, AA-MBA-BC membrane Cr6+adsorption and membrane LMP-BC the adsorption of Zn2; and adsorption conditions were optimized for their performance and conduct analytical studies modified cellulose adsorption and regeneration, the experimental results show that the modified bacterial cellulose regenerated adsorption of heavy metal ions good adsorption efficiency.2. Modified bacterial cellulose prepared bipolar membranes and analyzed their electrochemical properties. |
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