Cellulose/microalgae composite films prepared in ionic liquids

Using 1-allyl-3-methylimidazolium chloride (AmimCl) as the solvent, cellulose/microalgae (C/M) composite films with microalgae content ranging from 19.14 to 78.83 wt% were prepared by solution-mixing and subsequent casting. The structure and properties were characterized by element analysis, Fourier transform infrared (FTIR) spectra, scanning electron microscopy (SEM), thermogravimetry, tensile test, hydrolytic degradation, and cell cultivation test. SEM and FTIR results indicated good compatibility between the microalgae and cellulose due to strong hydrogen bonding interaction. These composite films possessed good mechanical properties and thermal stability that are better than those of other microalgae based materials. The hydrolytic degradation rate of C/M composite films with microalgae content higher than 33.97% was faster than cellulose, and increased significantly with the increase of microalgae content. The cell culture experiments confirmed that the C/M composite films could support cell adhesion and proliferation, consequently exhibit good biocompatibility. Therefore, the C/M composite films can be considered as novel functional films with applications as biodegradable materials even in medical fields.