Study On The Preparation Of KGM/Nano-ZnO Blend Films And Its Antibacterial Activity

Currently the material that mainly used in food packaging is plastic film,with the widespread interest focus on food packaging and environmental issues,green,healthy and environmentally friendly packaging materials,has always been a long-term research focus.Gradually attentions are that polysaccharide with excellent performance can be readily biodegraded,which is a good substitute for plastic wrap.In this study,we utilized Konjac glucomannan(referred KGM)as the main material to make a thin film with a renewable,biodegradable,etc.,is one of the most promising food packaging materials.However,limitations are that the natural single KGM film has some drawbacks such as long time of film formation,the low strength of the film,antibacterial weak and suck humidity,etc.In this paper,nano-zinc oxide(Nano-ZnO)is added,in the study of membrane performance and membrane structure to it,and finally to study the antibacterial activity of KGM/Nano-ZnO blend film,the results of the study are as follows:(1)Through the KGM/Nano-ZnO complex process of research,determination of rheological properties of the composite membrane liquid,indicating that within the scope added,KGM Sol complex has a certain viscosity increase.Research for the mechanical properties of the blend films found that with the increasing of Nano-ZnO doping ratio,the mechanical properties of KGM/Nano-ZnO increased at first and then decreased.When adding a small amount,the mechanical properties of the composite films can significantly improve;the nano particles hold together when a large amount added,resulting in lower mechanical properties.And with the increase in the amount of Nano-ZnO,Barrier properties of the composite film becomes wet,the water vapor permeation coefficient decreases.(2)The adding of Nano-ZnO makes the molecules form more hydrogen bond,so film formation can form a more orderly and compact,which is good for the improvement in the performance of the membrane.In the ultraviolet and visible wavelengths of 300-600nm,wavelengths in the absorption of the film showed a linear dose,can easily block ultraviolet and visible light.Seen from the blend film scanning electron micrograph of the different levels of Nano-ZnO,pure KGM has a neat smooth membrane surface,nanoparticles are prone to gather,a phenomenon called BaoTuan in the presence of high concentrations of Nano-ZnO,producing a diameter of zinc oxide particles about 100nm,which can be indicated by the results of X-ray energy dispersive spectroscopy.DSC curves are analyzed for each membrane corresponds to the crystalline melting transition temperature(Tm,taking all the peak temperature),it can be seen clearly form the curve that the crystalline melting temperature of the laminating film is higher than that of pure KGM,Tm move to higher temperature,thermal stability enhancements.(3)KGM/Nano-ZnO blend films against Staphylococcus aureus,Salmonella,E.coli,Pseudomonas and Bacillus subtilis significantly and the strength of the inhibition of various bacteria is:Staphylococcus aureus>E.coli>Salmonella>B.subtilis>aeruginosa.When the amount reach 1%,a variety of bacteria have shown good antibacterial effect In the pH test,a composite film of the five kinds of bacteria inhibition differences,and within this range pH has great influence on antibacterial effect,overall,pH acidity antibacterial effect better.