Effect of carbonization temperature and chemical pre-treatment on the thermal change and fiber morphology of kenaf-based carbon fibers

Abstract

Kenaf fibers, cellulose-based natural fibers, were used as precursor for preparing kenafbased carbon fibers. The effects of carbonization temperature (700 o C to 1100 o C) and chemical pre-treatment (NaOH and NH 4 Cl) at various concentrations on the thermal change, chemical composition and fiber morphology of kenaf-based carbon fibers were investigated. Remarkable weight loss and longitudinal shrinkage were found to occur during the thermal conversion from kenaf precursor to kenaf-based carbon fiber, depending on the carbonization temperature. It was noted that the alkali pre-treatment of kenaf with NaOH played a role in reducing the weight loss and the longitudinal shrinkage and also in increasing the carbon content of kenaf-based carbon fibers. The number and size of the cells and the fiber diameter were reduced with increasing carbonization temperature. Morphological observations implied that the micrometer-sized cells were combined or fused and then reorganized with the neighboring cells during the carbonization process. By the pre-treatment of kenaf with 10 and 15 wt% NaOH solutions and the subsequent carbonization process, the inner cells completely disappeared through the transverse direction of the kenaf fiber, resulting in the fiber densification. It was noticeable that the alkali pre-treatment of the kenaf fibers prior to carbonization contributed to the forming of kenaf-based carbon fibers.

Production of bioadsorbent from phosphoric acid pretreated palm kernel shell and coconut shell by two-stage continuous physical activation via N 2 and air

“…Approximately 63.83 and 69.01% of the mass for CS and PKS bioadsorbent, respectively, are still not volatilized at 1000°C. The greater thermal stability of the activated bioadsorbents is also thought to be because they have more stable structures with higher carbon assay [88]. Thus, TGA result displays that both bioadsorbents prepared via N 2 > Air activation achieved high amount of residue.…”

Cellulose‐Derived Supercapacitors from the Carbonisation of Filter Paper

“… 1 , 2 In addition, control of the macro- and microstructure of cellulose-derived carbon materials offers routes towards the tailored control of properties known to affect performance, such as material porosity, surface area, and nanoshape (e.g., fibres, sheets, etc.). 1 – 3 Previously, natural resources have been investigated as a source of these alternative carbon materials, such as disposable cashmere, 4 sisal fibre, 5 filter paper (FP), 6 wool fibres, 7 coconut shell, 8 wood, 9 , 10 and honeycomb. 2 A resource common to laboratories worldwide is FP, and here we consider it as an easily accessible source material for cellulose-derived supercapacitors.…”

Influence of calcium chloride impregnation on the thermal and high-temperature carbonization properties of bamboo fiber

“…More than 80% of cellulose- or rayon-based carbon fibers are known to shrink and lose weight after carbonization [5]. Further, the carbon yield of these fibers is relatively low.…”