Fabrication and properties of cellulose hydrated membrane with unique structure

By employing a pre-gelation processing of cellulose solution, this work has presented a new method to prepare cellulose hydrated membranes in NaOH/thiourea aqueous solvent system. The morphology and structure of the hydrated membranes obtained at different pre-gelation temperatures were studied by scanning electron microscopy (SEM), wide-angle X-ray diffractometry (WAXD), and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). The mechanical properties of the membranes were studied by tensile testing. Using a double-cell method, permeation of three model drugs (ceftazidine, cefazolin sodium, thiourea) through the hydrate membranes was determined in phosphate buffer solution at body-like temperature (37 degrees C). The results indicate that the membranes were packed densely by many hydrated nanospheres and exhibited good mechanical properties. At a relatively low pre-gelation temperature, the strain and the stress at break of the membranes are even up to 192% and 1.97 MPa, which are much larger than that of the hydrated membranes prepared by the general solution casting method. For the first time, the formation process of the hydrated membrane from gel state in water was investigated by ATR-FTIR spectrum, indicating a non-solvent-induced phase-separation mechanism.