Papers by Author: Mei Niu

Abstract: For a long time, discoloring PET/cotton blend fabric is a difficult topic in textile industry. For it, this search work was carried out to stripping PET/cotton fabric dyed by disperse/direct dye with dimethyl formamide. Though experiment, results is discovered as follows: firstly, the PET/cotton fabric dyed by disperse/direct dye is swelled in the home-made swelling liquid. Then, put it into striping liquid which is mainly contain dimethyl formamide, and heat to 140°C，and keep 30 minutes. The stripping rate of three kinds of test samples can be over 80 percent, and some can reach 95 percent. While the strength retention rate also can reach about 90 Percent.

Abstract: PET fiber was preprocessed by means of microwave radiation. Different reaction parameters such as the time, the power and the Ph value of solution were optioned to study the degree of the fiber hydrolysis. The changes of mechanical performance and hygroscopicity of the fiber were analyzed, which showed that the best power of microwave radiation was the 250W, the best reaction time was 5 min, and the Ph value of solution was 9. Compared with the untreated fiber, the fracture strength of treated fiber is 1.686cN/dtex and the moisture regain is 0.58%. The morphology structure were characterized by SEM and the fracture strength were tested by filament electronic strength tester. The results showed that the surface of PET fibers became rough and the quantities of the -OH and -COOH functional groups on the surface increased after etching. Meanwhile the hygroscopicity of the treated fibers had been enhanced obviously and the fiber strength had been reduced.

Abstract: Carbon microspheres (CMSs) were used as the carrier to prepare the Ag-loading CMSs (Ag/CMSs) antibacterial agent through the method of chemical adsorption. The morphologies and structures of modified CMSs were characterized by using the field emission Scanning Electron Microscope (SEM). The results showed that silver was absorbed on the surface of CMSs. The bacterial inhibition ring experiment showed that Ag/CMSs had good antibacterial activity against Staphylococcus aureus and Escherichia coli, meanwhile the diameters of the bacterial inhibition rings were 19 mm against Staphylococcus aureus and 21 mm against Escherichia coli, respectively.

Abstract: Using the capillary rheometer to study the effect of shear rate, shear stress and temperature of Japanese and domestic PPS resin( fiber grade) on the apparent viscosity, index of non-Newtonian and viscous flow activation energy.The results show that with the increase of shear rate and temperature,compared to the domestic sample, Japanese sample has higher apparent viscosity, smaller non-Newtonian index(n),lower viscous flow activation energy,and smaller sensitivity to temperature.The Japanese specimens are suitable for processing and forming under high shear rate and spinning speed, but the domestic specimens are suitable for processing and froming under low shear rate and spinning speed.

Abstract: Chitosan (CTS) and Ag-loading nano-SiO2 (SLS) are excellent antibacterial materials. However, when used alone, these monocomponent antibacterial agents are sometimes far from meeting requirements in special conditions. In this study, crosslinked chitosan-coated Ag-loading nano-SiO2 composites (CCTS-SLS) were synthesized by adsorption crosslinking reaction. Then Escherichia coil (ATCC 8099) was taken as the experimental bacteria for antibacterial tests. The experimental results indicate that the mass ratio of SLS to chitosan had the greatest influences on the value of MIC (minimal inhibitory concentration) for CCTS-SLS composite. However, the heating temperature had a weak influence on the antibacterial performance of CCTS-SLS composite.

Abstract: Using capillary rheometer to study PPS temperature, shear rate, activation energy of viscous flow. Experiments show that with the increase of shear rate, apparent viscosity decreased. As the apparent viscosity is affected by temperature, so when the temperature increased, the apparent viscosity also decreased. It also indicates that the higher the shear rate comes, the lower the impact of temperature on the apparent viscosity is. As the temperature increased, non-Newtonian index (n) increased and tended to 1, PPS melt is pseudoplastic fluid. The activation energy of viscous flow of PPS decreased with the increasing of the shear rate. In addition, with the increasing of temperature, structural viscosity index felt regularly.

Abstract: The MWNTs-OH/PET composite fibers were prepared by the masterbatch melt blending spinning drawing one-step process (FDY), and the structure and properties of different contents of MWNTs-OH of the PET FDY fiber were studied. The results showed that the interaction between MWNTs-OH and PET matrix was enhanced after the modification of terephthalic acid (TPA), resulting in the improved interface compatibility. Also, the crystallinity of the composite fibers was raised 7% after the addition of modified MWNTs-OH. The fracture strength of composite fibers had firstly increased and then decreased with increasing of the content of MWNTs-OH, the strength of the composite fiber was largely improved by 60.5% with 0.2% (wt) of TPA/MWNTs-OH.

Abstract: Abstract. Multiwall carbon nanotubes (MWNTs) were modified by grafting the maleic anhydride (MAH). The morphologies and structures of modified multiwall carbon nanotubes (MWNTs) were characterized by using Scanning Electrohic Microscope (SEM) and Fourier Transformation Infrared (FTIR). The results showed that a layer of maleic anhydride was grafted on the surface of MWNTs by covalent bonding.

Abstract: Wool fiber was firstly pretreated by nano-SiO2/Ag antibacterial agent, and then dyed with an acid dyes at low temperature by ultrasonic dyeing. Many factors had an important influence on the dye ability and the antibacterial behavior during the dyeing process of antibacterial wool fiber. The experimental results indicate that the dye-takeup rates of antibacterial wool fiber were enhanced with the increase of the concentration of nano-SiO2/Ag, the dyeing temperature, the dyeing time and the ultrasonic frequency (less than 60Hz). However, the antibacterial ratios of wool fiber were declined in the impact of these factors other than the concentration of antibacterial agent.

Abstract: The antibacterial PET (polyethylene terephthalate) masterbatch was extruded from twin screw extruder, using silver and zinc-loading Nano-SiO2 antibacterial agent (SLSZ) as the functional material. The content of SLSZ and extruding techniques were investigated. The dispersion and compatibility of antibacterial agent in antibacterial PET masterbatch were further characterized using Scanning Electron Microscopy and Transmission Electron Microscopy. The antibacterial performances and adsorption process of the antibacterial PET masterbatch against Escherichia coli (E. coli) were tested using alive-bacteria-counting method. The experimental results indicate that when the content of SLSZ was 30 wt. %, the antibacterial agent with an average diameter of 150nm showed excellent dispersion and compatibility in antibacterial PET masterbatch, and had excellent antibacterial performances. The adsorption process of antibacterial PET masterbatch against E. coli was controlled by Coulomb force between them. As the amount of the antibacterial PET masterbatch increased, the adsorbing rate and capacity were increased.