Papers by Author: Tai Qi Liu

Abstract: Due to the absence of the functional group in the poly (p-xylylene) (PPX) based tube, there is limitation of its application such as a catalyst supporter. In this paper a functional tube with a modification of the PPX tube by coating with polyacrylonitrile (PAN) was successfully prepared and its dielectric constant was measured. The results show that the PAN coated PPX tube has an obvious dielectric relaxations, which has no great different with that of a pure PAN film.

Abstract: Electrospinning of PVA can be performed from aqueous solution leading to the generation of homogenous nanofiber webs. PVA nanofibers are generally required to be modified because of its poor stability in water. The water stability of PVA nanofibers was improved by heat treatment in this paper. The test results showed that the crystallinity of the PVA nanofibers increases after heat-treatment. The crystallinity which is the largest increased by 12% when they were treated at 150°C for 10 min. The heat-treated fibers don’t dissolve in water and show certain degree of agglutination and swelling. PVA nanofibers were taken as the inner layer of the sandwich structure purification material prepared with the hot pressing technology. The filtering experiment showed that the filtration properties were better when the area density of PVA nanofibers is 2.5g/m2. The filtration efficiency of materials and retention rate of PVA nanofibers decreased after being used for 5 times.

Abstract: Coaxial electrospinning has been recognized as an efficient technique for fabrication of composite fibers with especial circular cross-section in a diameter from micrometers to nanometers. In this paper, PS hollow submicro-fibers have been successfully prepared by electrospinning two polymer liquids through a coaxial, two spinneret, followed by selective removal of the core. Moreover, the influence of the relative (inner-to-outer) flow rate on the morphology and the average diameter of the fibers have been studied. The hollow submicro-fibers are particularly attractive for use in catalysis, purification, separation, gas storage, energy conversion, drug release, sensing, and environmental protection.

Abstract: The clothing containing phase change material (PCM) with function of absorbing the body-released heat has wide applications. In this paper, a novel protective clothing based phase change material was investigated. The results show that PCM has suitable melting temperature, large heat flow, stability after repeating applications, and it is convenient for application in cooling. Moreover, the manufacturing process has a great affect on the property of the titled material. The above inorganic composite was selected to prepare the temperature self-operating protective clothing, which can efficiently lighten the demic thermal stresses at high and low temperatures.

Abstract: PVA nanofibers are generally required to be modified because of its poor stability in water. The water stability of PVA nanofibers was improved by heat treatment in this paper. The DSC test results showed that the crystallinity of heat-treated PVA nanofibers at 150°C for 10 min reached the maximum which increased by 12% compared with PVA nanofibers. From the SEM images it was observed that the heat-treated fibers didn’t dissolve in water but showed certain degree of agglutination and swelling. PVA nanofibers were taken as the inner layer of the sandwich structure purification material prepared with the hot pressing technology. The filtering experiments showed that the filtration properties were better when the area density of PVA nanofibers was 2.5 g/m2.

Abstract: Nano-TiO2 is a high efficient and no poisonous light induced catalyst. It is important how to immobilize it on some supporter for its application. In this paper, The Nylon-6 (PA-6) nanofibres bearing TiO2 nano-particles were prepared via gas-jet/electrospinning technique. The resulted materials were characterized by XRD, SEM, TEM, EDX and TG techniques, and antibacterial activities of the resulted fibers were tested by Shake Flask method. The results show that fibers bearing nano-TiO2, in an average diameter from 60 to 65nm were prepared, and the antibacterial efficiency of these gas-jet/electrospun nanofibers can reach 99.74%. The titled fibers can be loaded in a sandwich structure nanofiber super-cleaning material by hot-press process, and its filtration efficiency can reach 99.50% with 1µm polystyrene microspheres as the filter media.

Abstract: In this paper, metallocene based LLDPE (mLLDPE) extra-fine fiber , which can not be processed by a common solution electrospinning method.was successfully prepared via a melt electrospinning method. First, a self-designed melt electrospinning device was manufctured and it was used to produce mLLDPE fibers . Then LLDPE extra-fine fiber was successfully prepared by addition of viscosity-reducing additive such as wax, and the resulted fiber was charctered by SEM. Last, the optimal parameters for the preparation of mLLDPE fiber was determined. The experimental results show that commercial mLLDPE can hardly be processed to fibers because of its high viscosity. The diameter and morphology of resulted mLLDPE electrospun fibers depend on the electrospinning parameters such as electric field strength and collecting distance.

Abstract: a novel fibrous catalyst containing palladium nano-particles was produced via electrospinning technique. The fibrous catalyst was characterized by scanning electron microscopy and transmission electron microscopy respectively, the results showed that the diameter of fiber was about 200 nm and the palladium (Pd) particles were in the range of 30~40 nm. The catalyst was tested in hydrogenations of α-olefins, cyclohexene and nitrobenzol in ethanol at room temperature under 1 atmosphere hydrogen. The results showed that the titled catalyst had high activity in the hydrogenations of α-olefins, cyclohexene and nitrobenzol.

Abstract: Rare-earth metal-organic frameworks [Tb2(pdc)3(H2O)9]n3nH2O, were synthesized and characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. The title compound consisted of one-dimensional dual-chains, in which each metal atom is nine-coordinated with oxygen atoms. The carboxylate groups of pdc provided two kinds of coordination ways as bidentate and monodentate. The solid-state photoluminescence measurement exhibited green light-emitting characteristic of terbium (III) coordination polymer, and the fluorescence intensities were stronger than that of the europium compound with the same ligand.

Abstract: Chitosan grafting acrylic copolymer (CTS-g-AA) supported Nano palladium catalyst was obtained in this paper. Chitosan grafting acrylic copolymer (CTS-g-AA) was prepared firstly and palladium was supported on CTS-g-AA; then nano fibrous catalyst was gained via electrospinning technique. The title catalysts were characterized by TEM, SEM and IR, the diameter of nanofiber was about 70~200 nm, the size of metal particles were in a range of 10~40 nm, and palladium particles dispersed on nanofibers homogeneously. The catalyst was applied to catalyze α-octene hydrogenation in normal temperature and pressure. The results showed that the conversion of α-octene was 99%, and the yield of octane was 65% by double-metal catalyst.