Synthesis And Properties Of Gelatin-based Nanocomposite Films

Gelatin is a low cost and abundant fibrous protein, and has been widely applied for tissue engineering, drug delivering and functional membranes. In this work, we investigated the fabrication process for gelatin-based nanocomposite films in detail and exploited the potential application for catalysts, sensors of heavy metal ions, purification of water and photoluminescence.The contents of this research are as follows:1. The gelatin films were prepared by using copper hydroxide nanostrands as both the assembling frames and the pore generators. gelatin/Au nanoparticles (NPs) composite thin films were successfully prepared by formation of Au NPs in gelatin films through in situ reduction of HAuCl4at room temperature. It was found that both the trace aldehyde groups of the glutaraldehyde cross-linker and the reduction groups of gelatin contributed to the formation of Au NPs. These gelatin/Au NPs composite films demonstrated superior catalytic properties for reduction of o-nitroaniline to1,2-benzendiamine.2. Gelatin/[Fe(CN)6]4" composite films were prepared by incorporating [Fe(CN)6]4-ions into the gelatin films through electrostatic interaction. According to the different color of the PB nanoparticles and its analogues, the Gelatin/[Fe(CN)6]4-composite films demonstrated colorimetric sensor ability for probing the corresponding metal ions with sufficient sensitivity and quite short response time. Moreover, this Gelatin/[Fe(CN)6]4-composite films show tens times higher adsorption ability for heavy metal ions in water than that of activated carbon.3. Ultrathin gelatin films and gelatin/carbon nanotube composite thin films were prepared by filtration technique and cross-linked by glutaraldehyde. The gelatin/carbon nanotube composite thin films had superior separation properties under pressure up to18bars and present more than90%rejection for2-3nm molecules. It was found that the carbon nanotube layer dramatically increased the mechanical properties of the gelatin layer.4. Free-standing fluorescent gelatin/Si NPs composite film is facilely prepared by means of a filtration technique. This film demonstrates fast and reversible detection of amines from water. Meanwhile, gelatin/Si-Au NPs composite film is also successfully prepared by formation of Au NPs in gelatin/Si nanoparticles composite film through in situ reduction of HAuCl4. The photoluminescence quenching and blue shift in the peak of emission spectra occur due to the energy transfer from Si NPs to Au NPs. By varying the amount and size of Au NPs incorporated in the gelatin/Si NPs composite film, the energy transfer efficiency can be controlled.