Immobilization Of Pyrene Functional Membrane Preparation And Its Solvent Sensitivity

In the first part of this dissertation, a medium polarity sensitive films was prepared byembedding pyrene (Py), a polarity sensitive fluorescence probe, into a glutaraldehyde(Glu)cross-linked chitosan(CS) film. The composition and thermo-stability of the films werecharacterized by FTlR and TGA analysis. It is shown that the composition of the films isc1ose to that of CS. The introduction of micro-amount of Py and cross-linker has littIeeffect upon the compokition of the films. However, the Glu cross-linked CS films is morestable toward heating than the uncross-linked CS films. In addition, the cross-linked CSfilms is also stable in acidic and basic media. The CS-Glu films containing Py wassuccessfully used to monitor the po1arities of various soIvents including water, ethanol, andethanol-water mixtures. Based upon the measurement of po1arity, the prepared films wasalso used to monitor the micelle formation in the surfactant solutions of sodium dodecyIsuIfate(SDS) and sodium lauryl sulfonate(SLS), respectively. Compared with thetraditional solution fluorescence probing method, this new method is more simple andconvenient.In the second part of the thesis, pyrenesulfonylchloride(PSC) was prepared andconvalently bound to glutaraldehyde(Glu) cross-linked chitosan(CS) fiIms by a postmodification method. The monomer emission of pyrene(Py) immobilized on the CS filmswas weak both at dry and wet State if super-water was used to wet the films Howevef, uponaddition of salts or replacing the super-pure water with tap water the monomer emissionincreased dramatically whereas the change in the excimer emission was hardly observed.Furthermore, the increasing process could Iast as long as 7hr. In contrast, the emissionreturned to the original intensity at once when the fi1ms were washed with super-purewater for 3-4 times. The process could be repeated for at least 5 times.