Study On Functional Nanomaterials And Their Pan (PVA) Based Composite Fibers

Functional nanomaterial is the frontier of material science. Fabrication and structural control are the important topics. This dissertation aims at the fabrication of functional nanomaterials and their PAN (PVA) composite fibers. The main works are as follows:Lipase nano-gel (lipase NG) is prepared through surface modification and in-situ polymerization. Nanofibrous PAN membrane is fabricated by electrospinning of polyacrylonitrile (PAN) solution dispersed with lipase NG The membrane is characterized by structural analyses and the bioactivity of lipase NG is investigated. The lipase NG phase appears more stable at high temperature and organic solvents compared with lipase, and can be well dispersed in PAN nanofibers. This lipase NG containing PAN nanofibrous membrane shows more bioactive than its native lipase containing counterpart.The fluorescent marked bovine serum albumin (ab., L-BSA) and fluorescent marked bovine serum albumin nanogels (ab., L-BSA NG) are used as protein and protein nanogel models, and, PAN and poly(styrene-co-acrylonitrile)(ab., PSAN) are adopted as polymer templates for fabrication of fibers by electrospinning. The dispersion of L-BSA and L-BSA NG in the fibers is analysed by fluorescence microscopy and laser scanning confocal microscope. A nano-gel layer is observed on its surface due to gelation of L-BSA through the surface acrylation and the in situ polymerization. The L-BSA NG is well dispersed in organic solvents, and most of them distributed in the surface region.Indium tin oxide/MWCNTs composites (ab., ITO/MWCNTs) are prepared from MWCNTs, indium nitrate and tin chloride through co-precipitation, hydrothermal or solvent-thermal methods and the following heat treatment. The influence of process conditions to MWCNTs and according ITO/MWCNTs composites are studied, and the electrochemical property of ITO/MWCNTs composites is tested. The results show that, the structure of MWCNTs i significantly affected by acid treatment, and the surfactant modification is better for functional combination. Those studies provide a fundamental basis for biosensor research.MWCNTs is a kind of wide frequency and efficient microwave absorbing materials. The PVA/MWCNTs spinning solution is prepared by mixing selected MWCNTs with polyvinyl alcohol (PVA). The microwave absorbing functional PVA/MWCNTs fibers are prepared through wet spinning method by design and control of spinning parameters. The structure, electromagnetic, mechanical properties and thermal stability are investigated. Finally, a kind of soft, light, thin and flexible fabric with certain electromagnetic wave absorbing property is woven from the above fibers. Those studies provide a basis for study on novel high efficient microwave absorbing materials.