Study On Preparation And Properties With Vermiculite Supramolecular Assembly Fluorescent Films

Solid-state luminescent materials are attracting attention for their cutting-edge applications in areas such as sensors,displays,data storage,and security marking.However,fluorescent materials are easy to aggregate in the solid state,causing them to fluorescence to quench,affecting the luminescence efficiency of fluorescent materials,limiting the application of fluorescent materials in solid-state luminescent materials and optoelectronic devices.Two-dimensional layered materials can give nanostructured materials interesting functions and structural properties,in order to solve the problem of aggregation and quenching of fluorescent molecules,fluorescent materials and two-dimensional layered inorganic matrix can be supermolecular assembly or fluorescent materials can be introduced into a two-dimensional inorganic matrix with a rigid plane,to achieve uniform distribution at the molecular level,thereby improving the photothermal stability of solid fluorescent materials,which is conducive to the preparation of thin film materials with clear structure and uniform luminescence.This paper strips the two-dimensional layered vermiculite into single-layer or few-layer vermiculite nanosheets,from the perspective of supramolecular design,combined with the problems existing in the application and development of fluorescent molecules,the stripped vermiculite nanosheets are assembled with fluorescent molecules for supramolecular assembly,and the thin film material with continuous uniform luminescence is obtained,which realizes the regulation and structural control of thin film materials at the molecular scale.The main research contents and results of the paper are as follows:(1)The particle size distribution of vermiculite nanosheets prepared by high-speed shear method is40-450 nm,the potential is-33 m V,and the negative potential is presented.By assembling vermiculite nanosheets with cationic organic fluorescent dyes rhodamine 6G and rhodamine B by electrostatic interaction,organic and inorganic film materials with periodicity,order and continuous uniform luminescence were prepared(of which: VMT/R6G@PVA film fluorescence fit can reach more than 99%,AND the ultraviolet fit of VMT/RB@PVA film is also more than 99%),overcoming the problem of dense accumulation of organic fluorescent dyes in solid form leading to fluorescence quenching,Organic fluorescent dyes are fluorescent in the solid state,expanding the application range of solid fluorescent materials.(2)Applying additional shear stress to peel off vermiculite to obtain a single-layer or small-layer vermiculite nanosheet particle size distribution between 20-300 nm,the layer plate is negatively charged,and the CdTe quantum dots synthesized by aqueous phase method and modified with polycationic PDDA are self-assembled layer by layer to obtain a vermiculite-based composite film with ordered luminescence,and the highest peak fit of the fluorescence spectrum of the film reaches more than 99%,which realizes the orderly assembly and structural regulation of the film,(VMT/CdTe@PDDA)n VLFs exhibit periodic uniform structure and controllable film thickness at the nanoscale,the addition of VMT increases the fluorescence life of(VMT/CdTe@PDDA)n VLFs by about 2 times,and flexible transparent thin film materials can be obtained by transferring the substrate,which shows that VMT layered structures with rigid planes can effectively block and limit interlayer interactions and aggregation of CdTe@PDDA,helping(VMT/CdTe@PDDA)n Potential applications of VLFs in multicolor optical display lasers and optoelectronic devices.(3)Using the special layered structure of vermiculite,the vermiculite is structured and split,the tetrahedral structure of vermiculite is retained,and the octahedral structure is intercalated with organic fluorescent dyes(rhodamine 6G,rhodamine B and fluorescein sodium)to obtain a solid luminous hydrotallite colloidal solution.High-speed shear-peeled vermiculite nanosheets are assembled with organic fluorescent dye intercalation hydrotalite to construct a thin film material with solid luminescence by supramolecular assembly method.The results showed that the particle size of the peeled vermiculite nanosheets was distributed at 20-600 nm,and the Zeta potential was-33.5 m V,which was negatively charged;the organic fluorescent dye intercalation was successfully inserted into the surface of the hydrotalite by hydrothermal method to synthesize the intercalated hydrotallocylide with fluorescent characteristics,and the intercalation of organic fluorescent dye did not destroy the typical hexagonal structure of hydrotalumite,and showed a positive potential.Organic fluorescent dye intercalation hydrotalite(MgAl-LDH@R6G,MgAl-LDH@PG and MgAl-LDH@Fl-Na)are alternately assembled with vermiculite to obtain a film material with periodicity,order and structural tunables based on the supramolecular assembly method.At the same time,during the assembly process,it was found that the introduction of vermiculite would cause fluorescein sodium or fluorescein sodium intercalation hydrotalgalc to fluorescence quenching,which is due to the non-radiative energy transfer between VMT and fluorescein sodium to form a stable complex leading to its fluorescence quenching.(4)The particle size of vermiculite obtained by high-speed shear is distributed between 40-400 nm,and the Zeta potential is-37.1 m V,showing a negative potential.The aqueous synthesis of CdTe quantum dots with green fluorescence and red fluorescence showed a negative potential,the Zeta potential of the CdTe quantum dots after the addition of polycationic PDDA was +37.47 m V,showing a positive potential,and the MgAl-LDH@APPP synthesized by hydrothermal method had blue fluorescence,and the Zeta potential was +34.0 m V,showing a positive potential.Through the principle of three primary colors,the fluorescent materials of red,green and blue fluorescent colors are used as the construction unit and the peeled vermiculite nanosheets are self-assembled layer by layer to obtain a thin film material with white luminescence,the film material exhibits periodicity and order,and the fit of the film is high,which can reach more than 99%,and the surface of the obtained film is relatively smooth,and the root mean square roughness is 27.1 nm.By adjusting the assembly sequence and layer number of different color light emitting units,multicolor assembly is realized to obtain white luminous thin film materials(wherein: CIE coordinates are(0.3345,0.3651),near white luminescence).Through characterization,it is found that the thin film material exhibits good order and uniform luminescence,which can be applied to white light-emitting devices and other fields.