| With more and more attention paid to the human’s healthiness and environmental protection,oil pollution in water pollution problems,acid gas and inhalable particulate matter pollution in air pollution problems have become more and more concerned environmental issues.Oil entering into water body can hamper the substance and energy exchange between water and external environment,which is fatal to aquatic organisms.Oil can concentrate many harmful substances,and they can do great harm to human through natural circulation.Once acid gas is released into the atmosphere,it can form acid rain in a large spatial scope.Acid rain can destroy water,soil,vegetation and architecture.With the smog being identified as primary carcinogen,the harmfulness of inhalable particulate matter in air has been paid wide attention.Several studies have shown that inhalable particulate matter in air can cause respiratory,immune system,cardiovascular system diseases.These pollutions have seriously menaced the healthiness and life of mankind.Therefore,preparation of high-performance materials for oil adsorption,acid gas sensitive detection,and air filtration to solve these environmental issues has become an important topic related to the national economy and people’s livelihood.Because of the advantages of small diameter,large specific surface area,high porosity and good structural compatibility,electrospun nanofibers show excellent performance in oil adsorption,acid gas sensitive detection,and air filtration.Nanofibers with various structures can be prepared by adjusting the parameters of electrospinning.The functions can be enlarged through the structural advantages of these nanofibers,thus the applicability is enhanced.The advantages of electrospun nanofibers can be combined with the properties of the function materials through introducing function materials to electrospinning system by doping to realize the functionalization of electrospun nanofibers.Thus it can be seen that electrospun nanofibers have important research value and wide application prospect in oil adsorption,acid gas sensitive detection,and air filtration.In this thesis,we profoundly analyzed the corresponding relationship among structure,function and application on the basis of summarizing the research status of nanofibers with different structures prepared by electrospinning,the applications of nanofibers prepared by electrospinning in oil adsorption,gas sensitive detection,and air filtration and luminescent fibers prepared by electrospinning,and we found that porous nanofibers have advantages in oil adsorption and gas detection,and nanofibers with network structure display excellent performance when applied to air filtration,and luminescent fibers have distinctive indication performance.Therefore,we prepared polyethylene terephthalate（PET）nano-porous luminescence fibers,and applied the nanofibers to oil adsorption and acid gas detection.The oil adsorption and acid gas detection performances of PET nano-porous luminescence fibers were investigated.PET nano multilevel-network luminescence fibers have been also prepared,and applied the nanofibers to air filtration.The air filtration performance of PET nano multilevel-network luminescence fibers was investigated.In this thesis,we realized visual fluorescent-indicating to the process of oil adsorption,acid gas sensitive detection,and air filtration by utilizing the fluorescence properties of PET nano-porous luminescence fibers and PET nano multilevel-network luminescence fibers.The main results achieved are as follows:（1）PET nano-porous luminescence fibers have been prepared via one-step electrospinning on the basis of the mechanism of preparation of porous nanofibers.The forming process parameters have been determined by investigating the influence of solvent ratio,spinning solution concentration,relative humidity,voltage,receiving distance,feed rate and addition of rare earth luminescent materials to the morphology of PET nano-porous luminescence fibers.The structure and performances of PET nano-porous luminescence fibers have been tested and characterized.The results show that the surface of PET nano-porous luminescence fibers is covered with pores,and PET nano-porous luminescence fibers have a large specific surface area;there is coordination between rare earth luminescent materials and PET,and the rare earth luminescent materials are evenly distributed in PET nano-porous luminescence fibers;PET nano-porous luminescence fibers have good mechanical and thermal property;the breaking stress and elongation at break reaches 117 c N and 25 cm,respectively;the heat distortion temperature reaches 100°C;PET nano-porous luminescence fibers have good fluorescence property.The optimal addition amount of rare earth luminescent materials has been determined by introducing the fluorescence property of PET nano-porous luminescence fibers to CIE1931 chromaticity diagram.（2）PET nano-porous luminescence fibers have been applied to oil adsorption,and the adsorption of vacuum pump oil reaches 135.5 g/g.PET nano-porous luminescence fibers have good hot oil adsorption performance and the oil adsorption of vacuum pump oil reaches 80 g/g at 80°C;the correspondence between structure and performance is studied by investigating the oleophilicity and hydrophobicity and oil absorption performance of PET nano-porous luminescence fibers with different pore coverage and roughness;the corresponding relationship between oil adsorption and fluorescence property of PET nano-porous luminescence fibers has been established by determining the fluorescence properties at different oil adsorptions,and visual fluorescent-indicating to oil adsorption via fluorescence property have been realized.Visual fluorescent-indicating to the using degree of PET nano-porous luminescence fibers is realized via fluorescence property.By determining the fluorescence properties of PET nano-porous luminescence fibers after different times of use,it has been found that PET nano-porous luminescence fibers have good reusability,and oil adsorption and fluorescence intensity remain high after 20absorption and deoiling cycle times.（3）PET nano-porous luminescence fibers were applied to acid gas sensitive detection.It is found that PET nano-porous luminescence fibers have good acid gas detection performance by determining the fluorescence properties after absorbing acid gases with different concentrations and types,and the minimum response concentration and time to acid gas reaches 0.012 mmol/L and 10 s,respectively.PET nano-porous luminescence fibers have good fluorescent-indicating property to acid gases,and it can realize visual fluorescent-indicating to acid gases quantitatively and qualitatively via fluorescence property.The mechanism of PET nano-porous luminescence fibers fluorescent-indicating to acid gases was revealed from molecular structure and crystal structure.（4）PET nano multilevel-network luminescence fibers were prepared by adjusting the electrospinning parameters according to the forming theory of spider-web nanofibers.The morphology,air filtration performance,fluorescence property,mechanical and thermal property were tested and characterized by SEM,air filtration performance test instrument,spectrophotometer,electronic single fiber strength meter.The results show that PET nano multilevel-network luminescence fibers have distinctive structure of nano-interweave network.PET nano multilevel-network luminescence fibers have good air filtration performance,and the filtration efficiency and resistance pressure drop to PM0.3reaches 99.40%and 106 Pa,respectively.PET nano multilevel-network luminescence fibers have good fluorescent-indicating property to particulate matter in air.The correspondence between concentration of particle matter or using degree of PET nano multilevel-network luminescence fibers and fluorescence property was established by determining the fluorescence properties of PET multilevel-network structure luminescence fibers after air filtration under different particulate matter concentrations and different filtration times.Visual fluorescent-indicating to concentration of particle matter or using degree of PET nano multilevel-network luminescence fibers was realized.PET nano multilevel-network luminescence fibers have good mechanical and thermal property,and the breaking stress and elongation at break reaches 135 c N and 27 cm,respectively.The micromorphology of PET nano multilevel-network luminescence fibers has no significant changes at 180°C,and it still remain the structure of nano-interweave network. |
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