Study On Nanoparticles/Nanofibers Layer-By-Layer Assembly Mats

Nanoparticles possessed various excellent properties for its unique size and specific spectrum poverties.It is widely applied in biomedicine and chemical analysis field.In this study, CdTe quantum dots, gold nanoparticles were assembled to the Negatively charged electrospun cellulose acetate (CA) fibrous mats via layer-by-layer (LBL) self-assembly technique, and Konjac glucomannan and CdTe quantum dots are blended to obtain the blending film. The special poverties of these films were researched by FT-IR, SEM, XPS, XRD, DSC, TG. This could provid theoretical basis for the development of a fast and efficient portable detection materials and antibacterial packaging materials.The main results indicated as follows:1. Oppositely charged CdTe QDs and PDDA in aqueous media were deposited onto the negatively charged electrospun cellulose acetate mats alternatively, and the properties of the different cellulose acetate mats was studied. It was manifested that there is a good linear relationship between the fluorescence intensity of the films and the assembled layers. The peaks of carbon, nitrogen, oxygen, cadmium and tellurium were found in the XPS spectrum to confirm the existence of CdTe and PDDA in the samples after the layer-by-layer coating. The coatted nanofibrous mats just exihibited the diffraction patterns of CdTe. It was confirmed only Electrostatic interaction occurred in the process of coating. The layer-by-layer films-showed a relatively high surface roughness on each fiber, which could be attributed to the deposition of QDs and PDDA. With the layers increasing, the thermal stability of the films became stronger.2. The properties of CdTe/KGM casting films with different proportion was studied. It was manifested that CdTe/KGM casting films did not occure Forster resonance energy transfer. When the mixing ratio was 4:6, the fluorescence intensity of the casting films was the highest. The addition of QDs could improve the crystallinity of the KGM, and lowered the thermal stability casting films. With the concentration of QDs increased, the thermal stability of the films became weaker.3. Negatively charged electrospun cellulose acetate fibrous mats were modified with multilayers of the positively charged lysozyme (LY)-and the neatively charged gold nanoparticle via layer-by-layer (LBL) self-assembly technique. The antibacterial poverties of these films were investigated. The emergence of gold element and increasing percentage of nitrogen element from the XPS Energy-dispersive X-ray spectroscopy,the rough surface of the nanofiber from the Scanning Electron Microscopy, the characteristic crystalline peak from Wide angle X-ray diffraction all verifies that lysozyme and gold nanoparticle are successful incorporated into the composite nanofibrous mats. The thermal stability and antibacterial effect of composites became stronger with increasing of assembled layers, but the difference of the outer layer has little effect on antibacterial poverty of the composite nanofibrous mats.