توليد و مشخصه يابي نانو الياف سلولز بامبو

Bamboo is an incredible plant that has important properties such as biodegradability, renewable, anti-bacterial an‎d anti-allergenic, permeable an‎d hydro‎philic, anti-ultraviolet radiation, etc, an‎d is used for a wide range of applications. One of the fields of research about this plant is the production of electrospun nanofibers. Bamboo cellulose can be used as a raw material for this process, which leads to the production of very fine fibers with unique properties. In this research, the chemical-electrospinning method was used to extract cellulose an‎d produce bamboo cellulose nanofibers. Also, the green wooden stem of the bamboo plant was used as the raw material. The chemical part includes the stages of dewaxing, delignification an‎d alkaline hydrolysis, which finally leads to obtaining pure cellulose. Dewaxing was done in order to remove wax an‎d fat, as well as the initial washing of the plant using a benzene/ethanol solution at a ratio of 1/2. Delignination was done with acidified sodium chlorite solution in order to remove lignin an‎d also whiten the raw powder obtained from the previous step. Alkaline hydrolysis was done with the aim of removing hemicellulose an‎d residual starch using sodium hydroxide solution of 5% by weight. It should be noted that depending on the frequency of lignin removal from the sample, the alkaline hydrolysis step can be omitted. In this way, at first, lignin was removed from the dewaxed sample 5 times, But after examining the structure of the sample, a small amount of impurities under the name of hemicellulose an‎d insoluble lignin were observed in the structure, which were removed by performing 8 times of lignin removal, an‎d therefore, it was not necessary to perform alkaline hydrolysis after the lignin removal stage. Finally, the white an‎d pure powder of bamboo cellulose was prepared an‎d electrospun under the name of primary polymer in trifluoroacetic acid solvent with concentrations of 1 to 7% w/w. At concentrations lower than 3%, the electrospraying process was observed with nanofibers with uneven diameter distribution, an‎d at concentrations higher than 6%, electrospinning was not possible due to the gelation of the polymer solution. In order to improve electrospinning conditions, 5% by weight of methylene chloride was added to the polymer solution. The best solution concentration for electrospinning was 6% by weight, in which the average fiber diameter was 254 nm. The removal of non-cellulosic materials from the polymer structure was investigated by XRD an‎d FTIR tests. The morphology an‎d diameter distribution of nanofibers were investigated by scanning electron microscope images. The contact angle of the nanofiber layer was 56.8 degrees, which indicates the hydro‎philic property of the bamboo cellulose nanofiber layer. Also, biodegradability, water absorption an‎d thermal gravimetric analysis tests were performed for the nanofiber sample an‎d it was observed that the obtained nanofiber layer had no biodegradability feature within three months an‎d had 4.92 % water absorption. Finally, the antibacterial test of non-growth halo was performed by Staphylococcus aureus bacteria an‎d Escherichia coli bacteria, an‎d the results of this test showed that bamboo cellulose nanofibers have antibacterial properties

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كميل نصوري , حسن محمدي