Study On Room Temperature Phosphorescent Materials Based On Supramolecular Gel Composite Matrix

Room temperature phosphorescence?RTP?has attracted much attention due to its advantages such as long lifetime,large Stokes displacement and good selectivity.At present,the strategy to develop room temperature phosphorescence mainly based on the design of phosphorescent molecules or construction of matrices to protect phosphorescent molecules.Due to the complexity of the design and synthesis of phosphorescent molecules,the research of room temperature phosphorescence focused on the construction of protective matrices for phosphorescent molecules.However,the conventional protective matrices of room temperature phosphorescence are mostly based on a single component,which leading to the disadvantages such as low intensity,poor stability and non-responsive.In order to overcome these shortcomings,we developed the composite matrices based on supramolecular gel to induce room temperature phosphorescence of phosphorescent molecules.The composite matrices owned the advantages such as high-intensity phosphorescence,good stability and stimuli responsiveness.The results are as follows:In the first part,A composite matrix??-CD/DBS?was constructed by a supramolecular gel formed by gelator of 1,3?R?:2,4?S?-dibenzylidene-D-sorbitol?DBS?and?-cyclodextrin??-CD?to induce RTP of?-bromonaphthalene??-BrNp?.The results showed that the?-CD/DBS composite matrix can induce high-intensity RTP of?-BrNp.Compared with the single matrix formed by?-CD,the RTP stability of?-BrNp in?-CD/DBS composite matrix is greatly improved.Excellent stability of RTP is beneficial to expand its application.The optimum conditions for the system to induce RTP are the concentration of?-CD is 1.0×10^-4mol/L,the concentration of DBS is 1.2wt%,the sequence of reagent addition is DBS/?-BrNp/?-CD.The mechanism of RTP of?-BrNp induced by?-CD/DBS composite matrix was characterized by transmission electron microscopy,polarized phosphorescence and other methods.The results indicated that?-CD and?-BrNp formed inclusion compounds,which increased the dispersion of?-BrNp;DBS self-assembled to form ordered three-dimensional network which can immobilize the inclusion compounds,in this case,?-BrNp was double protected by the composite matrix,resulting in the decrease of its non-radiative transition,so?-BrNp in?-CD/DBS composite matrix can produce strong and more stable RTP.In the second part,A composite matrix?GA/DBC?was constructed based on the supramolecular gel formed by self-assembly of gelator N,N'-dibenzoyl-L-cystine?DBC?and biocompatible gelatin?GA?.GA/DBC composite matrix can induce strong RTP of meso-tetra?carboxyl phenyl?porphin palladium?Pd-TCPP?.The optimum conditions for the system to induce RTP are the concentration of GA is 9.5wt%,the concentration of DBC is 1.0wt%,the sequence of reagent addition is Pd-TCPP/GA/DBC.The mechanism of RTP of Pd-TCPP induced by GA/DBC composite matrix was characterized by circular dichroism,X-ray diffraction,infrared spectroscopy and other methods.The results showed that Pd-TCPP entrapped in the hydrophobic micro domain formed by the secondary folding of GA.The interaction of DBC aggregates with GA and Pd-TCPP enhanced the fixation and dispersion of Pd-TCPP in composite matrix.The non-radiative deactivation of the excitation triplet of Pd-TCPP in composite matrix is greatly reduced,so that high intensity RTP can obtained.It was found that RTP intensity of Pd-TCPP in GA/DBC decrease with the increase of the concentration of Cr³⁺,it has potential application for sensing of Cr³⁺.