Research on CdSe Quantum Dot Doped in Polymer Matrix for Pressure Sensing

Abstract

In this study CdSe quantum dots (QDs) doped in Toluene/PMMA/PDMS/Epoxy polymer matrix for pressure sensing are studied It is found that photoluminescent (PL) spectra of sample are sensitive to applied pressures from 0 - 180 psi The emission intensity PL shift and response times of QDs doped into matrixes with different pressure are characterized in different polymer matrix Furthermore CdSe QDs doped with different volume of carbon tube in different polymer matrixes for improving sensitivity and QDs doped in different matrixes for thermal effect are also studied As compared to sensitivities to applied pressure of the QDs doped in four different matrixes QDs doped in PMMA are most sensitive to applied pressure The maximum response (I0/I) of the QDs doped in PMMA can be seen to be approximately 1 48 in Stern–Volmer equation corresponding to sensitivity as (I0/I)/pressure = 2 67×10-3/psi Besides CdSe QDs doped in different matrix under different temperature at 0 psi were tested and it is concluded that PL quenching and redshift majorly depend on the temperature-sensitive of QDs instead of some interaction between QDs and matrix which means the distance Spectral characteristics of QDs doped in matrixes exhibit resembling change behavior with different pressure Experiment result indicated QDs doped with carbon tube into Toluene/PMMA do not remarkably improve sensitivity to applied pressure from 0-180 psi However QDs doped with carbon tube into PDMS improve sensitivity from 1 38×10-3/psi to 3 5×10-3/psi The change of Spectral characteristics of QDs doped in different matrixes with different pressure can be attributed to the resonance phenomenon cause by dipole-dipole interaction between QDs or between QDs and matrix molecules and the phenomenon could be described by F?rster energy transfer theory With further study QDs-polymer matrix composite may be applied to a new type of optical strain gauges and pressure sensors

Date of Award	2014 Jul 30
Original language	English
Supervisor	Yu-Lung Lo (Supervisor)