عنوان مقاله [English]
نویسندگان [English]چکیده [English]
The alpha cellulose of softwoods (microfibers) was turned to cellulose nanofibers using ultra-fine friction grinding process, as a simple, fast and one-step downsizing method. The effect of grinding on fiber diameter, crystallite size, crystallinity, suspension stability, together with the transparency and air permeability of sheets made from micro-and nanofibers was investigated. The average diameter of microfibers and nanofibers was 33±10 µm and 28±11 nm, respectively. The results of X-ray scattering demonstrated that the crystallinity and crystallite size of microfiber was 79% and 5.1 nm, respectively. During grinding process, the crystallinity and crystallite size decreased to 73% and 4.6 nm, respectively. The suspension of microfibers was unstable over checking stability time, while the nanofiber suspension had a long-term stability. The air-permeability of microfiber and nanofiber sheets was 320 and 1.06 µmPa-1s-1, respectively. The qualitative transparency of microfiber sheet was distinguishably lower than that of nanofiber sheet.