Photo-Luminescence Response Of Quantum Dots-Epoxy Resin Composite On Stress-strain

Stress and strain are two important parameters for measuring the integrity of structure,so monitoring stress and strain of structure in real time is an effective method to ensure the safe operation of mechanical equipment. Recently, luminescent nanocrystal stress-strain gauge has been developed based on the response of Quantum Dots (QDs)’fluorescence to the stress and strain.Based on the QDs-Epoxy resin nano-composite, the factors that affect the photo-luminescence(PL) drift were inspected; the relationship between the PL intensity and load were summarized; then the mechanism of the PL response to stress and strain was discussed; by the evaporation of chloroform droplet, the QDs’concentric rings fluorescence patterns was got. Concentric rings fluorescence patterns were formed via the evaporation of chloroform droplet. The purpose is to establish the rule of PL intensity and stress or strain, which can become the theoretical foundation of strain gauge based on the PL response of quantum dots.The main conclusions of this thesis are summarized below:(1) The PL drift of QDs-Epoxy resin composite is affected by temperature, concentration, excitation light intensity. This finding provides a theoretical basis for solving the problem of fluorescence drift in QDs.(2)The relationship between the PL intensity and the stress and strain was examined, four types of the PL response to stress and strain were established, which shows a great prospect of the in-situ strain gauge based on PL intensity.(3)The mechanism of PL intensity response was explained:the concentration of the QDs and QDs agglomeration are the main reasons for these four change rules. By controlling the QDs agglomeration, the unification of the relationship between the fluorescence and strain is expected to be realized.(4) The QDs’ concentric rings fluorescence patterns was formed via the evaporation of chloroform droplet, which provide a new study direction for the stress and strain detection technology based on the PL response of QDs.