Date Published: February 28, 2019
Publisher: Public Library of Science
Author(s): Dali Cheng, Tao Li, Gregory Smith, Jing Yang, Cheng Hang, Zhenyue Miao, Zicheng Wu, Markus Metsälä.
In this study, bamboo fiber was pretreated with calcium chloride (CaCl2) solution by using an ultrasonic method, and then heat-treated at 250°C and carbonized at 1000°C. The effect of impregnation with CaCl2 on the thermal and chemical properties and morphology of bamboo fiber was determined using thermogravimetric and differential thermogravimetric analyses, in situ Fourier transform infrared spectroscopy, and scanning electron microscopy. The pore structure of the carbonized bamboo fiber was investigated. The results revealed that bamboo fiber pretreated with 5% CaCl2 (BFCa5) showed a downward shift in the temperature of the maximum rate of weight loss253°C and increase in char residue to 31.89%. BFCa5 was expected to undergo dehydration under the combined effect of oxygen-rich atmosphere and CaCl2 catalysis from 210°C, and cellulose decomposition would be remarkable at 250°C. Pretreatment with 5% CaCl2 promoted the formation of porous structure of the carbonized fiber, which exhibited a typical Type-IV isotherm, with the Brunauer–Emmett–Teller specific surface area of 331.32 m2/g and Barrett–Joyner–Halenda adsorption average pore diameter of 13.6440 nm. Thus, CaCl2 was found to be an effective catalyst for the pyrolysis of bamboo fiber, facilitating the formation of porous carbonized fiber.
In recent years, biomass-based products from naturally renewable resources have been attracting considerable attention. Cellulose-based carbon fibers and corresponding reinforced composite materials are good examples of materials developed using renewable resources such as bamboo [1, 2]. Bamboo has several advantages over other plant fibers such as low density; low cost; high mechanical strength, stiffness, and growth rate; and ability to fix atmospheric carbon dioxide [3, 4]. In China, bamboo, especially Moso Bamboo, is one of the most important and abundant resources of fibers having relatively high mechanical strength. Bamboo-derived rayon fiber is a new promising environmental fabric material that has gained acceptance for manufacturing and processing textiles. It was named “Chinese Fiber” because of its good strength, wear resistance, and flexibility. These fibers are non-toxic, non-carcinogenic, biocompatible, and non-toxic to the biological environment.
(1) Bamboo fiber pretreated with CaCl2 shows a decrease of the temperature of the maximum rate of weight lossi to <300°C and a decrease of the overall weight loss, whereas increase in the formation of char residue. The char residue is increased to 13.04%, 31.89%, and 36.92% at 800°C after pretreatment with 1%, 5%, and 10% CaCl2. Source: http://doi.org/10.1371/journal.pone.0212886