ABSTRACT
In this paper, a comparison of cellulose nanofiber (CNF) fabrication from Gelidium amansii using two kinds of grinding processes is presented. The cellulose from Gelidium amansii is pretreated with hydrogen peroxide and sodium carbonate in a separating and bleaching process. Then, two grinding processes (method A and B) are used to fabricate CNFs. The first is a traditional method of fabricating CNFs using a disc grinder, whereas the second method is identical to the first, but includes an additional step involving a planetary ball mill. In the new method (method B), dry cellulose powder is prepared using a planetary ball mill, which has the advantage of long-term storage and maintains the original quality of the cellulose. The morphological changes of the dry cellulose powder and CNFs are determined using scanning electron microscopy and field emission scanning electron microscopy. The physical characteristics of the CNFs are found to be significantly different when we change the disc grinder used in the grinding method to produce nanometer scale where the best result is homogeneous, uniform CNFs with a fabricated width of 19 nm.
ABSTRACT
Carbon nanotubes (CNTs) have received interest as an attractive reinforcing agent metal matrix composites regarded as an increase to mechanical properties of the final product. Aluminum/carbon nanotubes (Al/CNTs) nanocomposites were observed with different raw material at the optimized experimental condition. In this study, Al-based CNTs composites were three different samples, including un-milled Al, un-milled Al with CNTs, and milled Al with CNTs nanocomposites in the presence of additional CNTs with various experimental conditions while using a traditional ball mill (TBM). The particle morphology and CNT dispersions of milled composites were respectively analysed by scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM), and the mechanical properties of the fabricated composites were tested. In each sample, CNTs were well dispersed on the surface of Al powder at different experimental conditions for milling in a TBM. The Al/CNTs nanocomposites were processed by compacting, sintering and rolling process. The Vickers hardness was used to characterize the mechanical properties. The hardness of Al/CNTs nanocomposites that were fabricated with milled Al with CNT was higher than the reached to in the nanocomposites prepared with the use of un-milled Al with CNT nanocomposites. Therefore, the discrete element method (DEM) simulation was used to complete quantitative analysis. The flow pattern, impact force, and energy at various experimental conditions are considered. The results of the simulations are compared with experimental data.
