Preparation and characterization of collagencoclotriphosphazene and its action in flame-retardant viscose fiber

Abstract

In order to develop a flame retardant using the phosphazene derivative of a natural polymer, hexachlorocyclotriphosphazene and collagen were used as the raw materials to synthesize collagencoclotriphosphazene. The Fourier transform infrared results indicate that flame retardant collagencoclotriphosphazene(CGCP) was successfully synthesized. Thermal properties of CGCP were evaluated using thermogravimetry. The thermal analysis shows that the introduction of phosphazene into collagen lowered the primary decomposition temperature, increased the decomposition rate, and caused less weight loss. The viscose fibers blended by CGCP were prepared by the wet spinning method, and the properties of the fiber were investigated. Limiting oxygen index of the flame-retardant fiber containing 12% CGCP was 28.3%, which increased greatly comparing to the fiber sample without CGCP and just decreased slightly to 27.6% after 30 washing cycles. The thermal analysis shows that the introduction of CGCP increased the decomposition rate of viscose fiber at a lower temperature, and caused less weight loss. After burning, the scanning electron microscopy image showed an inflated carbonized coat on the fiber surface. The effect of CGCP on the mechanical properties of the fibers was insignificant. CGCP was compatible with cellulose, and the flame retardancy of the viscose fiber was significantly improved. Due to the introduction of CGCP, moisture regain of the fiber is a little higher than that of viscose fiber.     

Effect of Cationic Modification on the Color Absorption Properties of Viscose Fibers

Abstract

The aim of this work is to determine the dyeing process of the cationic modified viscose fiber. The results indicated that cationic modified viscose fiber greatly improved the dyeing ability and dyeing rate. Sodium chloride and urea have little effect on the dyeing process. The degree of fiber dyeing gradually increased with the dyeing time increasing. The dyeing temperature and fixing time has little effect on the cationic modified viscose fiber. It was also found that the morphology of the viscose fiber had no obvious change after cation modification. The dyeing process had no influence on the mechanical property.     

Preparation and Characterization of Flame-Retardant Viscose Fiber Treated with TAECTP

In this paper, hexachlorocyclotriphosphazene (HCCTP) was used as a raw material to synthesize triaminoethyloxy cyclotriphosphazene (TAECTP). After-finishing method was applied to the preparation of flame-retardant viscose fibers. LOI results showed that TAECTP was intrinsically flame retardant. After burning, inflated carbonized coat was found on the fiber surface. Thermogravimetric analysis (TG) indicated that primary decomposition temperature of the fiber moved up about 30°C, as compared with untreated viscose fiber. Loss on mechanical properties of fibers was insignificant. The introduction of TAECTP was compatible and the flame retardancy of viscose fiber was greatly improved with limited negative impact.     

多晶铁纤维吸波材料的微波磁性研究

实验研究了纤维组分、直径和长径对比对多晶铁纤维微波磁导率的影响。结果表明,选择具有高本征磁导率和低电导率的材料制备多晶铁纤维有利于提高多晶铁纤维的微波磁导率;多晶铁纤维的微波磁导率随纤维直径的增大而减小,随长径比的增大而增大。介绍了一种高性能多晶铁纤维的研制及其微波磁性。     

Development of anisotropic phantoms using wood and fiber materials for diffusion tensor imaging and diffusion kurtosis imaging

Objective

Several studies have demonstrated that anisotropic phantoms can be utilized for diffusion magnetic resonance imaging. The purpose of our study was to examine whether wood is suitable as an anisotropic phantom material from the viewpoints of affordability and availability. In the current study, wood was used for restricted diffusion, and fibers were used for hindered diffusion.

Materials and methods

Wood and fiber phantoms were made. Diffusion kurtosis images were acquired with three magnetic resonance scanners. Fractional anisotropy, radial diffusivity, axial diffusivity, radial kurtosis and axial kurtosis values were measured. The wood phantom was imaged, and its durability was confirmed. The phantoms were imaged in varying orientations within the magnetic field. The wood was observed using an optical microscope.

Results

Ten kinds of wood and the fiber had a diffusion metrics. The wood diffusion metrics suggested low variation over a period of 9 months. Changing the orientation of the phantoms within the magnetic field resulted in changes in diffusion metrics. Observation of wood vessels and fibers was conducted.

Discussion

Wood and fibers have anisotropy and are promising as phantom materials. The development of anisotropic phantoms that anyone can use is useful for diffusion magnetic resonance imaging research and clinical applications.

     

Research on the application of preparation of conductive nanofibers on coal gas sensors

Abstract

In recent years, gas sensitivity devices with high sensitivity have been applied to develop coal mine gas sensor. What’s more, the application of electrospinning method in preparing gas sensitivity devices has drawn more and more attention. Utilizing electrospinning method, this paper prepared polyaniline nanofiber membrance, which can be used for the development of new gas sensor. The process parameters were also systemically studied. To be specific, reasonable solution parameters were explored by changing preparation condition; moreover, the impact of process parameters on polyaniline electrospun fibers was explored, thereby improving the controllability of electrospun fiber morphology; finally, the structure and conductive properties of the fiber membrane were characterized by FTIR, WARD, conductivity detection.     

Preparation and performance of PMMA/R-TiO2 and PMMA/A-TiO2 electrospun fibrous films

ABSTRACT

In this paper, the PMMA/R-TiO₂ and PMMA/A-TiO₂ nanofiber membranes were prepared by electrospinning and its photocatalytic performance was studied. Accordinly, the obtained composites nanofibers were characterized by SEM, Porosity and TG in order to characterize morphologically the nanostructures and their distribution in the polymeric matrix, thermal properties. The R-TiO₂ and A-TiO₂ content of 5%, the minimum average fiber diameters of 436 nm and 409 nm, the fibers appear smooth and continuous, and the two kinds of composite fibers have higher porosities. The TG curve showed that PMMA/R-TiO₂ nanofibers residual amount was higher than PMMA/A-TiO₂, which indicated that R-TiO₂ could improve thermal stability of the composites. It evaluated their photocatalytic activity by degradation of some dyes and methyl orange in an aqueous medium. The results showed that with the increase of TiO₂ content, the composite nanofibers degradation rate of methyl orange improved. At the same conditions, when the TiO₂ content was 10%, the photocatalytic degradation rate of PMMA/R-TiO₂ and PMMA/A-TiO₂ composite nanofibers were 21.8% and 51.3% respectively.     

电纺制备PEO nm纤维过程参数的试验研究

电纺丝技术是一种能制备连续纤维的简单而直接的加工方法,其所得纤维的直径一般为几十至几千nm。为研究电纺丝过程参数对所得纤维直径与形态的影响关系,采用聚氧化乙烯(PEO)/水体系作为研究对象,进行了电纺丝法制备PEO纳米纤维的试验,制得了直径为100-1000 nm的纤维。对溶液质量浓度(0.04-0.06 kg/L)和纺丝电压(5.7-15 kV)两个过程参数的研究表明,低质量浓度PEO水溶液在该实验条件下无法获得均匀光滑的纤维,纤维有打结现象。质量浓度为0.05、0.06 kg/L的PEO水溶液在纺丝电压为5-15 kV条件下可制得形态良好的纤维,且纤维直径随着溶液质量浓度增高而变大,随着纺丝电压升高而变小。     

Preparation of MoP2 nanoparticles as a novel anode material for sodium ion batteries

ABSTRACT

We identify the most important factor affecting the delay precision detonators by orthogonal experiments, thus optimize formulations to expect to get a better precision detonator recipe. Ultrafine ms delay due to the small particle size drug, the distance between the particles is small, a small gap, in the natural body of air the air is delayed relatively small, although the moisture absorption, but the overall water was reduced, and therefore can effectively avoid vibration combustion and second volume drift, therefore burning more stable, so the delay time stability, high delay precision, good storage performance.     

One step synthesis of Fe3O4/GO nanocomposites at 100°C and its magnetic properties

ABSTRACT

In the research work, we had planned a one-step procedure to prepare magnetite/graphene oxide (Fe₃O₄/GO) nanocomposites by using chemical co-precepitation method. The polycrystalline phase formation of the magnetite nanoparticles was confirmed by using X-ray diffraction setup. Structural and surface morphology properties of Fe₃O₄/GO nanocomposites are analysed by scanning electron microscopy and transmission electron microscopy. The Raman spectrum of Fe₃O₄/GO nanocomposites shows the enhancement of D and G band, which are associated with GO sheets due to the presence of Fe₃O₄ nanoparticles. Magnetic property measurement was carried out by physical property measurement system (PPMS), which shows its superparamagnetic behaviour.     

Polarized light microscope method for the determination of asbestos fiber of textile

ABSTRACT

Optical spectrogram and optical characteristic parameters of six kinds of asbestos standard products were established by polarizing microscope to analyze the asbestos fiber, and utilized horizon estimation to get the semi-quantitative asbestos content in the samples. The sample had been observed form, refractive index, interference color, dispersion, ductility, color, pleochroism, cleavage, contour lines, bumps, rough, baker characteristics under different refractive index of oiled, to compare with standard optical spectra and characteristic parameters. Comparison between the situation of asbestos fiber particles and the standard map of mineral chips in the field of view, the percentage of asbestos fibers in the sample is estimated. The results showed that this method is accurate, simple and fast.     

Percolation Behavior of Conductor-Insulator Composites with Varying Aspect Ratio of Conductive Fiber

The electrical properties of composite electroceramics are determined by the concentration, shape and distribution of filler phase in matrix. The carbon fiber-filled polymer was chosen as a model system and the electrical conductivity was measured as a function of carbon fiber content and the aspect ratio (AR) of the fibers to understand the percolation behavior of the composites. The composites of carbon fiber (19 vol.%) and thermoplastic polymer were fabricated in a mold press with the aspect ratio of carbon fiber varying between 4 and 10. The percolation threshold volume concentrations (V _c) of transition from the insulator to the conductor decreased as the fiber aspect ratio increased. With the fibers segregated at the polymer-polymer interfaces in the present study, V _c values were much smaller than those with the fibers randomly distributed in the matrix shown in other studies. The inverse relation between V _c and AR was found as expected. From the comparison with other experimental and simulated data, we concluded that the slope in 1/V _c versus AR plot is a strong function of fiber segregation.     

Effect of Molding Temperature on Shape Memory Performance of SMPC

Abstract

Carbon fiber reinforced shape memory polymer composite (SMPC) is a kind of smart material with shape memory characteristics, which is widely used in aerospace, biomedicine, robotics and other fields. In this paper, SMPC was prepared by heating molding process at five different molding temperatures. The effect of molding temperature on the shape memory performance of SMPC was studied. The results show that the shape memory properties of SMPC are closely related to the infiltration effect during the preparation process. When the molding temperature is 70?°C, SMPC has an optimum penetration effect and the preparation defects are effectively controlled. The shape fixing rate is 84.3%, and the shape recovery rate is 94.7%, which lays a foundation for the better application of shape memory composite.     

Growth and structural characterization of lanthanum doped lead titanate fiber

Abstract

Lanthanum doped lead titanate Pb_1?x La_x Ti_1?x/4 O₃ fibers (x '0, 5 and 15 at%) were grown by sol-gel technique and characterized for their phase formation behavior and crystal structure. The precursor sol was concentrated upon heating at 100°C to make it spinnable and used for fiber drawing. For heat treatment, a two-step heating schedule was designed on the basis of DSC analysis of the as drawn fibers. X-ray diffraction analysis showed that the tetragonality of the Lead Titanate (PT) fibers reduces with La doping and the structure is changed to pseudocubic from tetragonal. MicroRaman Spectroscopy confirms these observations of change in crystal structure and distortion in the material due to La doping. Dense and elongated grains of about 1 μm diameter were observed at the surface and at the cross section of PT fibers. La doped fibers show a porous fracture surface and also the grain size reduces dramatically with the addition of La. Strain energy is believed to play a major role in the observed changes in the microstructure.     

Self-Heating Composite Fabric and Its Application in Sports Injury Protection of Athletes

Abstract

This work is mainly focused on developing a self-heating composite fabric using the PVF and PPP. Prepare a new functional composite self-heating fabric through core spun method based on the synergy of hygroscopic heating principle and the characteristics of piezoelectricity of tourmaline. PVF with good hygroscopicity and PPP with piezoelectric effect were blended to produce fabrics with continuous heating function. Spandex fiber filament was set as a core to introduce elasticity, and the PVF and PPP were set as a sheath. In order to test the heating insulation properties of the fabric better, an athlete volunteer to be test foe the self-heating properties of fabrics during exercise. The heart rate was used to characterize the athlete’s exercise intensity. The fever effect was not particularly obvious when the exercise intensity was low because the human body sweats less, but with the increase of exercise intensity, the heating effect increases obviously. And when the exercise intensity continues to increase, the body releases a lot of heat, which made the heat released by the fabric becomes less obvious. Therefore, the functional composite self-heating fabric is promising materials in sports injury protection of athletes applications.     

短切磁性碳纤维泡沫复合材料吸波性能研究

采用溶胶-凝胶技术对碳纤维磁性涂层改性,并研究了纤维含量、盐雾试验、环境温度对短切磁性碳纤维聚氨酯吸波泡沫复合材料2~18GHz吸波性能的影响以及夹层结构复合吸波材料平板的吸波性能。结果表明,磁性涂层碳纤维性能均匀、吸波效果良好;纤维含量的增加有利于频带的展宽,吸波泡沫在Ku频段具有较好的吸波性能,反射率达-27.06dB;吸波泡沫的耐盐雾性和热稳定性较好;夹层结构具有更好的吸波效果,反射率在-8dB以下的带宽为8.64GHz。     

Synthesis of monodispersed pH-sensitive Ni0.5Zn0.5Fe2O4 magnetic nanoparticles and the potential medical application of adsorption for bovine serum album

We synthesized Ni_0.5Zn_0.5Fe₂O₄ magnetic nanoparticles (MNPs) by co-precipitation method and performed its adsorption of bovine serum albumin V(BSA (V)). The Ni_0.5Zn_0.5Fe₂O₄ MNPs in nitrogen atmosphere annealed at 400, 500, 600, 700 and 800°C, respectively. X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer(VSM) were used to characterize the resulting powders of the structure and properties. XRD results show that the Ni_0.5Zn_0.5Fe₂O₄ powder is a typical single-phase cubic spinel structure, and has no impurity phases. TEM results show that the Ni_0.5Zn_0.5Fe₂O₄ crystalline size is approximately 30–50 nm, which is similar with the XRD estimate results. The magnetic measurements show that Ni_0.5Zn_0.5Fe₂O₄ samples, super paramagnetic material, have high saturation magnetization and small coercivity properties. Moreover, We adopted ultraviolet spectrophotometer to analysis adsorption of BSA(V) on the Ni_0.5Zn_0.5Fe₂O₄ MNPs at room temperature, which show that annealed temperatures, pH, and stirring time can affect BSA(V) adsorption on the Ni_0.5Zn_0.5Fe₂O₄ MNPs. Most importantly, when ultrasonic stirring 2 hours in the liquor BSA(V) at pH = 7.0, the Ni_0.5Zn_0.5Fe₂O₄ samples annealed at 600°C has a highest value of 39.81mgg^?1. From above these results, Ni_0.5Zn_0.5Fe₂O₄ MNPs reveals a great adsorbing ability for BSA(V) that probable are a potential BSA-carrier candidate.     

双复纤维长径比对其吸波性能的影响

采用电加热和化学气相沉淀(CVD)法合成双复纤维材料,研究了双复纤维含量一定的条件下长径比对吸波性能的影响.结果表明,双复纤维长径比的增大导致复磁导率和复介电常数都有所增大,其中复介电常数的实部显著增大,而且双复纤维长径比为15∶1左右时,吸波效果较好,吸收峰为-19.1dB,11.2～1 8GHz范围反射率低于-5d...     

Novel waveguide structures for enhanced fiber grating devices

An emerging class of fiber waveguide structures is being used to increase the functionality of fiber gratings, enabling new devices critical to the performance of next generation light-wave communications systems. These devices rely on advances in the fabrication of optical fiber waveguides, which go beyond the conventional doped silica design and fall into two general categories: 1) local modifications to the waveguide after fabrication and 2) fibers drawn with modified claddings that include nonsilica regions throughout their length. This paper provides a comprehensive review of emerging fiber waveguide structures that enhance the functionality of optical fiber grating devices. Two examples of technologies that fall into the first category are thin metal films deposited onto the cladding surface, which can be used for thermal tuning and infusion of nonsilica materials into the air regions, which change the waveguide structure and can provide enhanced tunability. The second category is typified by air-silica microstructured optical fibers, which contain air-voids that run along the length of the fiber. These fibers have unique cladding mode properties that can be exploited in fiber grating based devices     

FeZrNbBCu非晶和纳米晶合金高温磁性能研究

利用单辊熔淬法制备了FeZrNbBCu非晶薄带,然后通过非晶晶化方法得到纳米晶合金.研究了FeZrNbBCu非晶和纳米晶合金的磁性能与温度的关系.非晶态合金晶化升温过程中磁导率~温度曲线中出现了一个Hopkinson峰,而在晶化后的样品中没有出现,并根据各向异性的变化和磁化强度与温度的关系进行了合理的解释.对于非晶样品和晶相体积分数小的合金样品,当温度接近残余非晶居里温度时,磁导率急剧减小;而对于非晶相含量很少的样品,其磁导率随温度升高而缓慢下降,根据双相合金中交换作用模型进行了解释.