|Preparation and properties of ground cellulose nanofibers|
|ساعت ۱:٥٧ ب.ظ روز پنجشنبه ۱٢ امرداد ۱۳٩۱|
Preparation and properties of ground cellulose nanofibers
Mohamad Mehdi Hadilam, Elyas Afra, Ali Ghasemian, Hossein Yousefi
The alpha cellulose of softwoods (microfibers) was turned into cellulose nanofibers using 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 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.