| Waterborne polyurethane(WPU)was used as the main material,diatomite(Diatomite,DME)was used as auxiliary material,and 1H,1H,2H,2H-perfluorooctyl trichlorosilane(PFOTS)was used as modifier.WPU film,DME/WPU film and super-amphiphobic DME modified SADME/WPU film with different surface wettability were prepared by casting method,and Eugenol(EG)was added as active antibacterial ingredient to the above films to prepare EGWPU film,DME-EG/WPU film and SA-DME-EG/WPU film.The powder and film were characterized by SEM,XRD,FT-IR and XPS,and the changes of the film's micro-morphology before and after DME modification and the interaction form of each component were studied.Taking Shewanella putrefaciens,the dominant spoilage bacteria of aquatic products,as the antibacterial object,the antibacterial properties and antibacterial mechanism of the above films were revealed.The preservation properties of Salmon fillets were studied.The results can provide theoretical support and technical guidance for the application of super-double phobic antibacterial materials in the field of food packaging.1.The microscopic morphology,surface wettability of DME and WPU films before and after modification and the slow-release performance of embedded EG films were studied.The results show that DME embeds EG by physical adsorption.After embedding EG,the structure of DME powder is destroyed.After being modified by PFOTS,DME agglomerates into particles,forming a micro-nano-scale structure on the surface,which has the characteristics of super-amphiphobic.The film surface becomes smoother and denser due to the reaction of EG and WPU.DME is dispersed in the WPU film through physical mixing,which significantly enhances the oleophobicity of the film.For SA-DME and SA-DME-EG powder,after adding to WPU to form SA-DME/WPU film and SA-DME-EG/WPU film,its crystal structure is destroyed,and a new crystal structure is formed on the surface of SA-DME-EG/WPU film.SA-DME-EG/WPU film has excellent hydrophobic and oleophobic properties,has a high embedding rate of EG to 82%,and has the highest total release rate in the PBS system and the optimal sustained-release performance.2.Taking S.putrefaciens as the objects,the antibacterial properties and antibacterial mechanism of SA-DME-EG/WPU film were studied.The results show that the surface of SADME-EG/WPU film is bound with EG,and its early release is larger,so its early antibacterial performance is better.At the same time,because the film has better embedding and slow-release properties for EG,it can continue to release EG for a long time and the bacterial cell membrane and cell wall are destroyed,the permeability of the cell membrane are increase,so as to inhibit the growth and reproduction of S.putrefaciens for a long time.3.Taking Salmon fillets as the preservation object,using the above films to wrap the fish fillets,and the preservation performances of the films on the Salmon fillets were studied.The results show that the film treatment can block the damage of external microorganisms,and water vapor to the fish meat,create an adverse environment for the growth of bacteria,and to a certain extent delay the changes in the freshness index,texture characteristics,color and moisture content of fish fillets.However,the surface wettability has no significant effect on the preservation properties of the films.The addition of EG significantly improves the preservation properties of the films,and the embedding method has a significant impact on the preservation properties of the films.In addition,the SA-DME-EG/WPU film has the best preservation properties.After DME embeds EG and undergoes super-amphiphobic modification,the loading and slow-release performance of EG is better,and it can inhibit the growth of microorganisms in fish fillets and the oxidation of protein and fat for a long time.Moreover,the surface-bound EG enhances the antibacterial properties of the film,so that it exhibits the best preservation effect during storage. |
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