Microstructures and functional group properties of nano-sized chitosan prepared by ball milling

Nano-sized chitosan has been prepared by ball mill (High Energy Milling) with 1500 rpm to determine itsgrainz size and functional group. A nanopowder sample was prepared in the various milling time of the precusor. The milling time were 60, 120, 180, 240, 300 and 360 minutes. The Scanning Electron Microscopy (SEM)images indicated that the microstructures and grain size of as-prepared chitosan changed by increasing the milling time. The average of grain size is 15,1 nm. The Fourier Transform Infra-Red (FTIR) spectra showedthat the-OH bond shifted after milling process. The new C=O groups formedduring the milling process, because of the ordered microstructures in the nano-sized chitosan granules weredestroyed after ball millingThe surface area of the nano-sized chitosan was high, the particles tend to agglomerate since the ionic electrostatic could not prevent to form the agglomeration. The ball milling treatment was an effective method to reduce the grain size of chitosan, and functional groups will not automatically change during the milling process. © 2019 Trans Tech Publications Ltd, Switzerland.