Photophysical And Photochemical Properties Of Organic Compounds In The Microemulsion

Uv-vis and fluorescence spectra of phenothiazine (PTZ) and anthracene are studied in different microemulsions. In sodium dodecyl sulfate (SDS)/benzyl alcohol (BA) /H2O O/W microemulsion, the absorption wavelength does not change with the increase of SDS but first remains unchanged then moves towards long wavelength with the increase of BA. The fluorescence intensity of anthracene increases first quickly then slowly with the increase of SDS but decreases with the increase of BA. In addition, in SDS/BA/H20 O/W microemulsion, the anthracene fluorescence decay is double exponential, from which two lifetimes are obtained. So anthracene exists both in the membrane phase and oil core. Compared with the case in O/W microemulsion, in SDS/BA/H20 W/O microemulsion, the absorption wavelength and fluorescence emission wavelength move towards long wavelength and the fluorescence intensity of anthracene increases a little with the increase of SDS. The fluorescence lifetime of anthracene with and without DEA in SDS/BA/H2O W/O microemulsion is almost the same as that in BA. So anthracene exists in the oil continuous phase in SDS/BA/H2O W/O microemulsion. In SDS/BA/H2O O/W microemulsion, the fluorescence intensity of PTZ increases with the increase of SDS and decreases with the increase of BA, So PTZ locates in the membrane phase. In SDS/BA/H2O W/O microemulsion, the increase of SDS content makes the fluorescence intensity of PTZ increase, so PTZ also locates in the membrane phase. In hexadecyltrimethylammonium bromide (CTAB) / 1-pentanol (n-C5H11OH) / H2O W/O microemulsion, the fluorescence intensity of anthracene decreases with the increase of CTAB and increases with the increase of n - C5H11OH, so anthracene exists in the membrane phase. The fluorescence intensity of PTZ increases with the increase of CTAB and decreases with the increase of n - C5H11OH in CTAB/n-C5H11OH/H2O W/O microemulsion, so PTZ also exists in the membrane phase, In Triton X-100/n-C5H11OH/H2O O/W microemulsion, the fluorescence intensity of anthracene increases with the increase of n-C5H11OH and Triton X-100, so anthracene locates in the membrane phase. In Triton X-100/n-C5H11OH/H20 W/Omicroemulsion, the fluorescence intensity of anthracene decreases with the increase of n -C5H11OH and increases with the increase of Triton X-100, so anthracene also locates in the membrane phase. In Triton X-l00/n-C5H11OH/H2O O/W microemulsion, the fluorescence intensity of PTZ decreases with the increase of Triton X-100 and increases with the increase of n-C5H11OH, so PTZ locates in the membrane phase, in Triton X-l00/n-C5H11OH/H2O W/O microemulsion, the fluorescence emission wavelength of PTZ moves towards long wavelength with the increase of Triton X-100 and moves towards short wavelength with the increase of n-C5H11OH, so PTZ locates in the membrane phase in Triton X?100/n-C5H11OH/H2O W/O microemulsion.In SDS/BA/H2O O/W microemulsion, only the excited anthracene existed in the membrane phase can be quenched by N, N-diethylaniline (DEA). In W/O microemulsion, this quenching reaction occurs in the BA continuous phase. Besides being the quencher of the excited anthracene, DEA could also change the system's structure. PTZ exists in the membrane phase because the rate for the photoinduced reaction between CHCl3 and PTZ in microemulsion is much slower than that in BA Anthracene locates in the membrane phase or the oil core of the O/W microemulsion and in the oil continuous phase of the W/O microemulsion. The quenching of the excited anthracene by PTZ occurs in the membrane phase either for the W/O microemulsion or for the O/W microemulsion. Photoinduced electron transfer reactions of anthracene with DEA and PTZ occur in the membrane phase of the CTAB/n -C5H11OH/H2O microemulsion. DEA and PTZ exist in the membrane phase of the microemulsion because the presence of vitamin - c (Vc) can change the quenching constant. The change of the quenching constant for the DEA - anthracene system with the presence of Vc is more obvious than that for the PTZ - anthracene system...