关键词: 醋酸纤维素, 丝素蛋白, 液体分离, 静电纺丝, 复合材料, 环境友好

Abstract: At present, oil spills and oily wastewater discharges have a great negative impact on our natural ecological environment and human living environment, and leaked oily wastewater is also a misplaced natural energy source. Many wastewater treatment devices themselves also have certain negative impacts on the environment. In this case, it is necessary to find an environmentally friendly material for the preparation of filter materials. This paper, with cellulose acetate (CA) and silk fibroin (SF) as raw materials, employed the electrospinning technique to fabricate CA/SF porous fiber membranes.
Natural macromolecular fibers, cellulose acetate and silk fibroin are environmentally friendly, and the modification of the two fibers has received extensive research and attention. After degumming, dialysis and freeze-drying, the finished silk fibroin has a broad application prospect as a flexible textile. As the most abundant source of natural macromolecular polymers, cellulose has a rich and diverse structure and has diverse applications, making it suitable as a filter material. Electrospinning is a simple and efficient technique for preparing nanofiber materials. Electrospinning spins molten polymers into nanofibers or ultrafine fibers under the action of a controllable high-voltage electric field. It can be seen from the scanning electron microscopy that smooth, uniform, continuous and bead-free nanofibers were successfully prepared. From the tensile strain-tensile strength curve of the porous fiber membrane, it can be judged that the fiber membrane has basic self-sustaining mechanical properties. Porosity decreases as the proportion of ethanol in the treatment solvent decreases, and porosity increases with increasing temperature and time in the mixed treatment solvent. Through the analysis of air permeability, the results show that when the proportion of ethanol or water in the treatment solution is high, the air permeability of the fiber membrane is high, and the air permeability increases with the increase of temperature and time. Through the analysis of the wettability of the composite porous fiber membrane, as the proportion of water in the mixed processing solvent increases, the water contact angle of the fiber membrane prepared shows an increasing trend. 
Porosity, air permeability, and wettability results indicate that the performance parameters of the composite porous nanofiber membrane can be changed by changing the treatment conditions during the post-processing of the fiber membrane. The porous composite nanofiber membrane produced under different treatment conditions of the fiber membrane can facilitate selective permeation and separation of various mixtures, including oil-water and oil-oil mixtures. The results show that the porous CA/SF fiber membranes obtained through simple solution treatments exhibit tunable performance parameters. These membranes, tailored to different performance specifications, hold promise for effective liquid separation applications.

Key words: cellulose acetate, silk fibroin protein, liquid separation, electrospinning, composite materials, environmentally friendly