Preparation Of Graphene/Titania And Application On Oxygen Indicator

Oxygen indicator is a new type of intelligent packaging technology for modified atmosphere packaging(MAP),which is economical,simple,reliable and sensitive.It has a good application prospect in the field of food packaging.Therefore,an oxygen indicator based on series of graphene-titania(GN/TiO2)composite materials was designed and prepared,applied for intelligent package.The result was as follow.(1)X-ray diffraction(XRD),transmission electron microscopy(TEM),infrared spectroscopy(FT-IR)and Raman spectroscopy(Raman spectroscopy)were used to characterize the structure of the graphene oxide(GO)prepared by the modified Hummers method.The results indicated that there were many polar oxygen groups in the graphene oxide layer,and the graphene oxide was successfully prepared.(2)The composite photo-catalysts were prepared by hydrothermal method with different reaction times proportions using self-made graphene oxide and butyl titanate(Ti(OBu)4)as raw materials.And they were characterized by XRD,SEM and TEM.The results pointed out that the crystal form of the composites was only anatase type,and the graphene and titanium dioxide are compounded together in the form of chemical bonds.The preferred reaction time is 6 h and the preferred ratio is 3%.(3)Oxygen sensitivity indicator ink was obtained following the preferred ink formulation,which mixed methylene blue(MB),composite photocatalyst(GNT),polyvinyl alcohol(PVA)or hydroxyethyl cellulose(HEC)and glycerol in ball mill.Its photocatalytic rate and recovery rate were both faster than a single titanium dioxide(TiO2).The recovery time decreased with the increase of graphene ratio,which indicated that the exist of graphene improved the catalytic activity of the photocatalyst and also helped to improve the reaction rate of the recovery process.(4)The color recovery process of GNT3%ink matched with the first reaction kinetics and the recovery rate was so high that affecting the dynamic analysis of the photocatalytic process.The GNT3%E ink maintained its original activity after repeating five times of photocatalytic and color recovery process.The oxygen indicator based on composite photocatalyst can be used as an intelligent packaging technology with non-destructive indication of oxygen leakage due to its high photocatalytic activity,fast color recovery and high sensitivity.