Construction Of Composite Materials Based On Inverse Opal Structure And Its Application In Optical Anti-counterfeiting

The forgery of circulating currency,high-value goods and value documents seriously damages the interests of the government,enterprises and individuals,causing tens of billions of dollars of economic losses every year.The work of anti-counterfeiting and combating counterfeiting has become more and more serious.Generally,the anti-counterfeiting label chooses to hide the encrypted information in the normal state and selectively disclose it under specific conditions.However,for a single anti-counterfeiting mark,materials with low information level and anti-counterfeiting level are easy to be stolen and counterfeited.In order to solve the above problems,we constructed a composite material based on quantum dot fluorescence color and photonic crystal structure color,which was used for optical anticounterfeiting and information encryption decryption.The main contents were as follows:Firstly,the Methacryloyl based gels(GelMA)were physically mixed with CdTe quantum dots(QDs)to crosslinked the CdTe QDs gel to obtain the luminescent behavior and optical anti-counterfeiting applications of CdTe QDs gels.Then,the SiO2 photonic crystal template was prepared.The polyethylene glycol diacrylate(PEGDA)and tetra(3-mercaptoacetic acid)pentaerythritol(PETMP)monomers were filled into the SiO2 photonic crystal template and then were photocurable.After the HF etching,PEGDA-PETMP inverse opal hydrogels were obtained,and the size dependence,angle dependence and wetting response of PEGDAPETMP inverse opal hydrogels were studied.Finally,the CdTe QDs and GelMA precondensate were filled into the PEGDA covered reverse opal gel holes,and then the CdTe QDs gel and PEGDA-PETMP inverse opal hydrogel composites were prepared by UV curing.Through the simple combination of CdTe QDs,photonic crystals and different CdTe QDs,more complex and higher dimensional optical recombination coding effects was obtained,which provided a good platform for exploring the two-mode luminescence coupling effect.Moreover,the preparation process was simple and flexible.It only rerquired to provide visually confused structural color and fluorescent color,such as "100",which quickly identified and authenticated hidden signals through relevant spectral detection.Therefore,this work opens up a simple way to encode the complex information of a single composite platform,and provides a method to realize fast information decoding,which has important theoretical significance and practical value for the construction of anti-counterfeiting composite materials for product anti-counterfeiting and information confidentiality.