Preparation and performance as PEM of sulfonated pre-oxidized nanofiber/SPEEK composite membrane

Building proton transfer channel is an important strategy to optimize the proton transfer process of the proton exchange membrane (PEM). In this work, sulfonated pre-oxidized nanofibers were prepared by solution blowing of polyacrylonitrile (PAN) nanofibers followed by pre-oxidization and sulfonating, and the nanofibers were composited with SPEEK to enhance its performance as PEM. The results of the proton conductivity verified that the employment of sulfonated pre-oxidized nanofibers improved the proton conductivity. Meanwhile, the introduction of the sulfonated pre-oxidized nanofibers realized the upgrades of the thermostability and water absorbency of the membrane, and led to the decrease of the swelling property and methyl alcohol’s permeability of the material. It is indicated that the composite membrane is promising materials for PEM fuel cells.     

Metal ion adsorbability of electrospun wool keratose/silk fibroin blend nanofiber mats

In this study, electrospun wool keratose (WK)/silk fibroin (SF) blend nanofiber was prepared and evaluated as a heavy metal ion adsorbent which can be used in water purification field. The WK, which was a soluble fraction of oxidized wool keratin fiber, was blended with SF in formic acid. The electrospinnability was greatly improved with an increase of SF content. The structure and properties of WK/SF blend nanofibers were investigated by SEM, FTIR, DMTA and tensile test. Among various WK/SF blend ratios, 50/50 blend nanofiber showed an excellent mechanical property. It might be due to some physical interaction between SF and WK molecules although FTIR result did not show any evidence of molecular miscibility. As a result of metal ion adsorption test, WK/SF blend nanofiber mats exhibited high Cu²⁺ adsorption capacity compared with ordinary wool sliver at pH 8.5. It might be due to large specific surface area of nanofiber mat as well as numerous functional groups of WK. Consequently, the WK/SF blend nanofiber mats can be a promising candidate as metal ion adsorption filter.     

Sound absorption of multiple layers of nanofiber webs and the comparison of measuring methods for sound absorption coefficients

Textile sound absorbents are getting more and more popular on the market as noise reduction is a major requirement for human comfort today. In this paper we focus on a new textile material for sound absorption, by investigating the acoustic characteristics of nanofibers. Through impedance tube method we measured the sound absorption coefficients of multiple layers of nanofiber webs and compared those with microfiber materials per fabric weight. We also examined the effect of layers of nanofiber webs on regularfiber knitted fabric on sound absorption. The test results showed that the sound absorption coefficients of nanofiber layers were superior that of microfiber fabrics in the frequency range 1000–4000 Hz. In this range, the sound absorption of nanofiber webs improved with numbers of layers. Also, adding nanofiber web plies to regularfiber fleece increased the sound absorption coefficient with 85 % at 4000 Hz. From our results we could observe differences in the sound absorption coefficients between two test methods, which are higher absorbance coefficients through the reverberation room method than impedance tube method.     

单仓高效平筛制备菜籽浓缩蛋白的研究

为了提高菜籽浓缩蛋白的生产效率以及蛋白含量,以预浸压榨菜籽粕为原料,研究单仓高效平筛制备菜籽浓缩蛋白的工艺。通过对原料的粒径分布以及不同粒径原料的成分分析得到原料粒径分布的R-R分布函数;对原料蛋白质与植酸的含量进行了相关性分析,结果显示两者具有显著的相关性（r=0.994 1）。利用单仓高效平筛制备菜籽浓缩蛋白,以筛下物得率和筛下物蛋白含量为指标研究进料流量和平筛旋转速度对筛分效果的影响,确定制备菜籽浓缩蛋白的最佳工艺为：进机流量为2kg/min,平筛回转速度为260r/min,在最优工艺条件下得到的菜籽浓缩蛋白的蛋白含量为56.99%(干基),得率为26.66%,经醇洗脱毒后得到的菜籽浓缩蛋白的蛋白含量可达60.155%。     

Sound absorption properties of spiral vane electrospun PVA/nano particle nanofiber membrane and non-woven composite material

In this research, we fabricated a series of PVA membranes loaded with 0 wt.%, 1 wt.%, 3 wt.%, 5 wt.% ZrC and 0 wt.%, 1 wt.%, 3 wt.%, 5 wt.% TiO₂ using a spiral vane electrospun machine respectively. There were 2 sizes of TiO₂ nano particles: 10 nm and 200 nm. We tested sound absorption properties of needle-punched nonwovens as well as the composite of nano membranes and needle-punched nonwovens by an impedance tube at the frequency range from 500 Hz to 6500 Hz. Besides, we tested morphological characterization of nano membranes by scanning electron microscope (SEM) and crystalline properties by X-ray diffraction (XRD). We investigated the sound absorption properties of composites as well as the effect of ZrC, TiO₂, nano particle sizes and cavity depth on sound absorption properties. Results showed that sound absorption properties of composites increased at the whole range of frequency compared to those of needle-punched nonwovens. When loaded with ZrC nano particles, sound absorption properties of composite shifted to a higher frequency region, and with increasing content of ZrC, sound absorption properties were better above 2500 Hz. However, when loaded with TiO₂, sound absorption properties were better at lower frequency. With 3 wt.% TiO₂, sound absorption coefficient reached the best at the frequency range from 500 Hz to 1500 Hz. Besides, 200 nm TiO₂ was more conductive to the increase of sound absorption properties at lower frequency region compared to 10 nm TiO₂. Sound absorption properties of composites with air back cavity shifted to a lower frequency region, too. SEM showed that there was nano particle aggregation when loaded TiO₂ nano particles. XRD showed that ZrC nano particles loaded in PVA nano fiber retained their crystalline structure while TiO₂ didn’t. It appeared from the results that nano particles had an effect on sound absorption materials, with different kinds and different sizes, sound absorption properties will improve in different ranges of frequency     

Preparation and characterization of cellulose nanofiber reinforced thermoplastic starch composites

In the present study, cellulose nanofibers composite films were manufactured based on thermoplastic starch. Nanofibers were extracted from rice straw employing a developed chemo-mechanical method. In the chemical step, almost all of non-cellulosic components were removed and a white pulp of cellulose microfibers was obtained. Then, a diluted suspension of fibers was ultrasonicated to destruct intermolecular hydrogen bonds achieving nanofibers networks. Afterward, bio-nanocomposites were prepared by film casting. In order to study the effect of nanofibers content on the composite properties, the mechanical and dynamic mechanical properties, morphology, humidity absorption, and transparency of films were investigated. The yield strength and Young modulus of nanocomposites were satisfactorily enhanced compared to the pure thermoplastic starch film. The glass transition temperature of films was shifted to higher temperatures by increasing nanofibers contents. The uniform dispersion of the nanofibers was investigated using SEM images. The humidity absorption resistance of films was significantly enhanced by using 10 wt% cellulose nanofibers. The transparency of the nanocomposites was reduced compared to the pure starch films.     

Preparation and blood compatibility of electrospun PLA/curcumin composite membranes

In this article, curcumin-loaded electrospun Polylactic acid (PLA) composite membranes were prepared. Curcumin with different concentrations (1, 3 and 5 wt%) was loaded to the PLA membranes to study its anticoagulant property as a drug-eluting stent. X-ray diffraction (XRD) characterization of the prepared membranes indicates that PLA and curcumin mix together well through the method of electrospinning and the composite membrane has larger crystallinity than that of PLA membrane. The in vitro blood compatibility of curcumin-eluting stents was investigated by static platelet adhesion and blood coagulation time (APTT and PT) tests, revealing that the blood compatibility of composite membranes is superior to the pure PLA membrane, and the blood compatibility significantly improves with curcumin concentration increasing by dint of observing SEM images and calculating the inhibition rate of platelet aggregation. Moreover, PLA/curcumin membrane can effectively prolong the blood coagulation time compared with the plasma, and the blood coagulation time of composite membranes improves significantly as curcumin concentration increasing.     

Effects of visible light irradiation on the oxidative stability in rice bran

Raw rice bran was treated with or without visible light exposure at room temperature or stored at 40 °C in the dark for 10 days and rice bran oil (RBO) was recovered from each rice bran. Headspace oxygen content from rice bran and conjugated dienoic acid (CDA) value, acid value, content of γ-oryzanol, and fluorescence intensity in RBO were analyzed to determine the effects of visible light on the oxidative stability in rice bran. Headspace oxygen content in visible light irradiated rice bran (RBL) decreased by 12.8% for 10 days while those in the dark (RBD) and stored at 40 °C (RBT) decreased by 5.87 and 5.35%, respectively, implying visible light irradiation accelerates the consumption of oxygen. CDA values in RBO from RBL were significantly higher than those in RBO from RBD and RBT (p < 0.05). However, acid values in RBO were not significantly different among samples (p > 0.05). Both γ-oryzanol content and fluorescence intensity in RBO from RBL were significantly lower than those in RBO from RBD and RBT (p < 0.05). Fluorescence intensity, which is related to the content of chlorophylls, decreased in samples under light only, implying that chlorophyll photosensitization may play important roles in the acceleration of lipid oxidation in rice bran.     

Enhanced electrical properties of electrospun nylon66 nanofibers containing carbon nanotube fillers and Ag nanoparticles

In this study, we describe the preparation and characterization of electrospun Nylon66 composite nanofibers incorporated with carbon nanotubes (CNT) fillers and silver nanoparticles. We have incorporated the composites in to Nylon66 nanofibers to enhance the characteristics of the resultant composite nanofibers. The resultant composite nanofibers were characterized by using field-emission scanning electron microscopy, energy dispersive X-ray analysis, high-resolution transmission electron microscopy, X-ray diffraction, and current-voltage (I–V) measurement analysis. The morphology of the composite nanofibers exhibited densely arranged mesh-like ultrafine nanofibers which were strongly bound in between the main fibers. From I–V characteristics, it was observed that the incorporation of CNT fillers and Ag nanoparticles in to electrospun Nylon66 composite nanofibers can be significantly enhanced the electrical properties.     

Preparation of fluorescent polyacrylonitrile nanofiber membrane based on polymerizable 1,8-naphthalimide fluorescent disperse dye

One new polymerizable fluorescent disperse dye (PEANI) based on 1,8-naphthalimide was synthesized via reaction of 2-(2-hydroxyethyl)-6-(1-pyrrolidinyl)-1H-benzo [de]isoquinoline-1,3(2H)-dione (PAENI) with acryloyl chloride firstly. Dye’s structure and fluorescent properties were carefully investigated using nuclear magnetic resonance (¹H-NMR), UV-Vis and fluorescent spectra. Then the yellow copolymer (F-PAN) of PEANI and acrylonitrile was obtained through radical polymerization. Fluorescent nanofiber membrane could be prepared by electrospinning of the F-PAN solution in N,N-dimethylformamide solvent and strong green fluorescent emission located around 510 nm could be found (λ_ex=450 nm). The electrospun F-PAN membrane showed obvious fluorescent effect even the mass ratio of PEANI to acrylonitrile was only 0.1 %, which has broken through the traditional limitation of using the cationic dye involved in the dyeing procedure to obtain fluorescent acrylic fabrics.     

Preparation of inorganic silica nanofibers containing silver nanoparticles

Silica nanofibers containing silver nanoparticles were successfully prepared using sol-gel chemistry and electro-spinning technique. Solution of tetraethly orthosilicate in ethanol containing silver nitrate was aged to have sufficient viscosity and electrospun to form nanofibers. Upon thermal treatment, the gelation reaction between silanols was completed in the prepared silica nanofibers, and at the same time, silver ions in the nanofiber changed to metallic silver or silver oxides. The reduction of silver ions could be also achieved by UV irradiation, and the generated silver nanoparticles were present preferentially on the surface of the silica nanofibers. On testing release behavior of silver ions, it was found that most of silver remained in the silica nanofiber. The silica nanofibers containing silver nanoparticles exhibited excellent antibacterial and deodorant properties.     

Preparation and application of polyurethane-urea microcapsules containing phase change materials

For thermal adaptable fabrics, the polyurethane-urea microcapsules containing phase-change materials (PCMs: hexadecane, octadecane and eicosane) were successfully synthesized by interfacial polycondensation using 2,4-toluene diisocyanate (TDI)/poly(ethylene glycol) (PEG400)/ethylene diamine (EDA) as shell monomers and nonionic surfactant NP-12 in an emulsion system under stirring rates of 3,000～13,000 rpm. The mean particle size of microcapsule decreased significantly with increasing the stirring rate up to 11,000 rpm, and then leveled off. The mean particle size increased with increasing the content and molecular weight (eicosane > octadecane > hexadecane) of PCMs at the same stirring rate. The mean particle sizes of microcapsules were found to decrease with increasing the NP-12 content up to 1.5 wt%, and thereafter increased a little. It was found that the melting temperature (T_m) and crystallization temperature (T_c) of three kinds of encapsulated PCMs and their enthalpy changes (ΔH_m, ΔH_c) increased with increasing PCM contents. The encapsulation efficiencies (Ee) of hexadecane microcapsule linearly increased with increasing the content of hexadecane. It was found that the stable microcapsule containing 50 wt% of hexadecane could be obtained in this study. However, Ee of octadecane and eicosane microcapsules increased with increasing PCM’s contents up to 40 wt%, and then decreased a little. By considering the encapsulation efficiency, it was found that the maximum/optimum contents of octadecane and eicosane microcapsules were about 40 wt%. By the dynamic thermal performance test, it was found that the maximum buffering levels of Nylon fabrics coated with hexadecane, octadecane, and eicosane microcapsules were about ?2.4/+2.9°C, ?3.6/+3.6°C and ?4.0/+4.7°C, respectively.     

Preparation and properties of flame-retardant viscose fiber containing phosphazene derivative

The object of this work is to develop a flame-retardant viscose fiber containing phosphazene derivative. Hexaphenoxycyclotriphosphazene (HPTP) was synthesized and applied to viscose fiber through wet spinning method, with alkyl polysaccharide glycoside as dispersant. Properties of the fiber were tested and discussed. All flame-retardant samples survived 3 ignitions, according to 45 degree slope burning method. Limiting oxygen index value of the flame-retardant fiber containing 16% flame retardant was 28.6 %. The number decreased to 27.5 % after 30 washing cycles. After burning, inflated carbonized coat was found on the fiber surface in scanning electron microscopy image. Thermal gravimetric analysis and differential scanning calorimetry results indicated that the primary decomposition of fiber was moved up by about 20°C, while secondary decomposition was delayed by around 46°C. Damage on mechanical properties of fibers was insignificant. The introduction of HPTP was compatible and the flame retardancy of viscose fiber was greatly improved with limited negative impact.     

Preparation of electrospun affinity membrane and cross flow system for dynamic removal of anionic dye from colored wastewater

In this research, poly(vinyl alcohol) (PVA)/chitosan electrospun nanofibrous membrane (ENM) was prepared by electrospinning method in order to investigate its dye removal ability from colored wastewater. The morphology and average fiber diameter of the membranes were investigated by scanning electron microscopy (SEM), image analysis and atomic force microscopy (AFM). The chemical characterization was studied by Fourier transform infrared spectroscopy (FTIR). The permeability of the membranes was evaluated by measuring pure water flux (PWF). In order to investigate the performance of the prepared membranes they were used in the batch adsorption and membrane separation for dye removal from colored wastewater. The effect of pH, number of membranes and dye concentration on the dye removal ability of the ENM was investigated. Response surface methodology (RSM) was used to achieve multi-objective optimization and equations of adsorption capacity and breakthrough time regarding operating conditions. The results demonstrated the potential of using PVA/chitosan nanofiber membrane as a microfiltration (MF) membrane for dye removal. Moreover, the recoverability property of prepared membranes was noticeable.     

Development of UV protective sheath for high performance fibers for high altitude applications

High performance fibers have distinguished properties such as high tensile strength, good thermal and chemical resistance, dimensional stability, lightweight, and high electrical conductivity. Due to these superior properties, high performance fibers made it to the scene of broad range of applications such as aerospace, automotive, windmill, fiber reinforced composites, high strength tethers, tendons for scientific balloon, tension structures, protective clothing, and marine. Examples of such fibers are Zylon®, Kevlar®, and Vectran®. However, the fibers lose their strength significantly upon exposure to Ultraviolet (UV) and visible light. In this research, UV protective films from extruded low density polyethylene (LDPE) loaded with different content of UV stabilizers (TiO₂ nanoparticles and White PE CC®) were investigated. To assess the degree of UV blockage of each extruded protective film, their transmittance to UV and visible (UV-VIS) light was measured. Additionally, Zylon® braids were sheathed with the protective films and the strength of the braids and yarns raveled from braids was measured before and after UV exposure for different number of days. LDPE loaded with White PE CC® and 10 % TiO₂ showed the least transmittance to UV-VIS and their yarns and braids exhibited highest strength retention after exposure to artificial UV. Strength retention of braids was higher than that of individual yarns due to weak link effect and braid structure assistant.     

Silage and milk production: a comparison between concentrates containing different amounts of protected protein as supplements for silage of high digestibility

Grass silage made in late May from S24 perennial ryegrass was offered ad libitum to eight Ayshire cows in a 16-week feeding experiment. The silage had a DM concentration of 244 g kg⁻¹, contained 163 g crude protein (kg DM)⁻¹ with a ruminal degradability of 0.77 and had an in vitro DOMD concentration of 678 g kg⁻¹. In addition, four concentrates each containing 167 g soya-bean meal kg⁻¹ were consumed at a mean daily rate of 6.43 kg DM per cow. The soya-bean meal was either untreated, or 'protected' by formalin and mixed in the following proportions, 100:0; 66:34; 34:66; and 0:100 respectively, in the four concentrates. The daily intakes of silage DM were not significantly different on the four treatments and averaged 90 kg DM per cow, giving a mean total daily DM intake of 32.4 g kg⁻¹ live weight. The milk yields were not significantly different on the four treatments and averaged 23.9 kg ⁻¹ The treatments had small and non-significant effects on milk composition and live weight. It is concluded that with a high-digestibility, well-preserved grass silage of satisfactory protein content the inclusion of 'protected' protein in the supplementary concentrate had no beneficial effects on milk production.     

Preparation, structure, and in vitro degradation behavior of the electrospun poly(lactide-co-glycolide) ultrafine fibrous vascular scaffold

The PLGA ultrafine fibrous scaffold was successfully fabricated by electrospinning. The morphology and properties of the PLGA vascular scaffolds were examined. In particular, the in vitro degradation behavior of the electrospun PLGA vascular scaffolds was investigated by means of morphology, microstructure, mass loss, M_w, and breaking strength characterization. The results showed that electrospun scaffold possessed ultrafine fibrous and porous structure, and had adequate mechanical properties to be developed as a substitute for native blood vessels. In vitro degradation study showed that the PLGA ultrafine fibrous scaffold could biodegrade in the PBS solution, and the mass loss, M_w, and breaking strength studies indicated that degradation rate of the electrospun PLGA nanofibers was greater in the first 2 weeks. After the degradation of 2 weeks, the degradation slowed down. Furthermore, with the extension of the degradation time, the thermal decomposition temperature of the PLGA scaffold decreased gradually. The results indicated that the electrospun PLGA vascular scaffold could be considered as an ideal candidate for tissue-engineered blood vessel.     

Synthesis and application of novel high light fastness red dyes for ultra high molecular weight polyethylene fibers

A new series of anthraquinoid red dyes were synthesized with 1-amino-2-bromo-4-hydroxyanthraquinone and nalkylphenols to dye UHMWPE fibers with high light fastness. Their dyeability was examined depending on the length of alkyl chains. As the length of alkyl substituents increases, the dyeability toward UHMWPE fibers improves rapidly from methyl to ethyl substituents and maintains almost same level of color strength, and then decreases from heptyl to octyl groups. The color strength of dyeings increased dramatically with the increase of dyeing temperature from 100 °C to 130 °C. The maximum build-up was shown at around 5 % owf dye amount. From the dyeing rate, equilibrium dyeing was achieved at around 5 h at 130 °C. All kinds of fastnesses were good enough showing higher than ratings 4-5 to washing and rubbing for the longer alkyl substituents. Especially, much improvement was achieved in light fastness showing ratings 4, which was higher than ratings 2 of the previous study.     

Preparation and flammability properties of hybrid materials containing phosphorous compounds via sol-gel process

Organic-inorganic hybrid coatings containing phosphoric acid (PA) bonded to the organic-inorganic network were prepared from tetraethoxysilane (TEOS) using a sol-gel process. The effect of sol-gel phosphate-based flame retardant coating on polyacrylonitrile fabric properties (flammability, stiffness, and strength) was investigated. Sample characterization of the coated samples were investigated using differential thermal/thermogravimetric analysis (DTA/TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), and scanning electron microscopy (SEM). The results showed that hybrid coating on the polyacrylonitrile fabrics influenced fabric stiffness, strength, and flammability. And also, flammability of the coated samples after washing cycles was investigated, and the flame retardancy properties of the samples after 10 repeated washings were not completely lost.     

高蛋白大豆中黄42产量表现及栽培技术

中黄42是中国农科院作物所以诱处4号为母本、锦豆33号为父本杂交选育出的大豆新品种,2007年通过国家农作物品种审定委员会审定。2010年通