The Preparation And Application Of Aggregation Induced Luminescent Molecules @ Polymer/LDHs Composite Luminescent Thin Films

In this paper,a supramolecular composite luminescent film is constructed by employing three components containing 1,2-bis[4-(3-sulfonatopropoxyl)-phenyl]-1-,2-diphenylethene sodium salt(BSTPE),layered double hydroxides(LDHs)and poly(acrylic acid)(PAA),which uses the electrostatic layer-by-layer assembly method.The assembly process of the composite film was monitored through its optical properties,and the surface morphology and structure of the film were investigated.The sensing response and mechanism of BSTPE@PAA/LDH film to external pressure were studied,and its response to volatile organic solvents and its discussion in the field of temperature sensors were studied.The specific research content of this paper is as follows:1)The construction of BSTPE@PAA/LDH composite luminescent film and its reversible response to external pressure:The constructed BSTPE@PAA/LDH film exhibits uniform and orderly blue fluorescence,showing excellent anisotropy and fluorescence quantum yield with high stability(UV resistance,adhesion and storage capacity).Due to the uniform array arrangement of BSTPE in inorganic-organic hybrid matrices.The constructed BSTPE@PAA/LDH film has a reversible fluorescent response to external pressure.As the external pressure increases,the fluorescence intensity gradually increases.Due to pressure induction,the BSTPE between layers of LDHs is more ordered and tighter.The fluorescence properties of the film include fluorescence intensity,anisotropy,fluorescence lifetime,and fluorescence quantum yield are improved.By the AFM,small angle XRD,fluorescence polarization,fluorescence lifetime to study the principle of pressure response.When the film compressed,the layer spacing of LDHs reduced,the BSTPE dispersed tightly and orderly in the layer,thereby suppressing the vibration or rotation of BSTPE,and then non-radioactive transitions are suppressed and fluorescence intensity is enhanced.The repeatability and stability of the film provide good conditions for its use as a pressure sensing material.The design concept of the supramolecular layer successfully avoids the contradiction between the stiffness and flexibility of the AIE material in the pressure design and greatly expands the practical application of the AIE material.2)Response of the BSTPE@PAA/LDH film to volatile organic solvents and temperature sensing:The BSTPE@PAA/LDH film exhibits reversible fluorescence responses to volatile organic solvents such as acetone,toluene,tetrahydrofuran and chloroform.The quartz chip loaded with BSTPE@PAA/LDH film was placed in a volatile organic solvent atmosphere,then measure its fluorescence intensity.The fluorescence intensity of the film was reduced.When the film was taken out and placed in dry air,the fluorescence intensity of the film was restored to initial state.The mechanism was studied by measuring the small angle XRD,fluorescence polarization,and fluorescence lifetime.VOCs diffused into the layered double hydroxides layer and between the organic molecules and the polymer guest.The distance between layered double hydroxides layers increased,and the arrangement orderliness of BSTPE which was in the two-dimensional system of supramolecular decreases,non-radiative transitions increase,and the fluorescence intensity decreases.This allows the detection of volatile organic gases in the environment.At the same time,the influence of temperature on the optical properties of the film was also studied.The film' fluorescence also responds to temperature.In summary,this paper mainly constructs an inorganic/organic composite light-emitting film,and studies pressure sensing and VOCs sensing,respectively,which has potential applications in the sensing of fluorescent materials.