POSITRON LIFETIME STUDY OF THERMALLY INDUCED MICROSTRUCTURAL CHANGES IN NISTARI SILK FIBER

Positron lifetime measurements have been made in natural polymer-Nistari silk fibers as a function of isochronalannealing temperature in the range of 27℃ to 280℃. The variations in the positron results indicate the structural changesoccurring in the Nistari silk fibers and determine the glass transition temperature as 170℃. Activation energies weremeasured separately for the crystalline and amorphous regions indicating the versatility of the technique. These values areclose to the N--H bond dissociation energy, suggesting N--H bond dissociation as the most probable process occurringduring thermal treatment As an extension of the positron results, the molecular weight of the Nistari silk fibers wasdetermined to be 10.7×10~5 based on free volume, which lies within the range suggested for the silk fibers. There seems to bean indication that cross-linking changes the spiral structure of cotton fibers to network type. However, this needs to be validated by other techniques.

Chemical Modification of Silk Fibers with Ethylene Glycol Dimethacrylate

Silk fibers have been grafted with ethylene glycol dimethacrylate (EGDMA) and characteristics of the grafted silk fibers were analyzed in relation to the graft yield on the basis of the tensile properties, dyeing behaviour, durability during laundering and solubility of the specimen in NaOH solution. The amount of the acid dye absorbed by the fibers decreased with increasing graft yield, while the value of rating for washing fastness on silk fibers was almost unchanged by the graft treatment. The breaking loads of the fiber were almost unchanged whereas rigidity of the fibers increased after graft treatment. Graft treatment enhanced silk fiber durability during laundering and in NaOH solution.

Structures of Silk Fibers Grafted with Hexafluorobutyl Methacrylate

The relationship between the graft yield and the effect of hexafluorobutyl methacrylate graft treatment on the structural changes of the silk fibers was studied on the basis of the results of scanning electron micrograph photographs(SEM), infrared spectroscopy (IR), Raman spectrum, wide-angle X-ray diffraction patterns(WAXD), nuclear magnetic resonance(NMR) and amion acid analysis. The results showed that the crystalline regions of grafted fibers were hardly affected and the fiber fission occurred on the cross sections of grafted fibers. The surface of fibers was covered with a high polymer film. The Raman spectrum showed there was little change in the conformation of grafted fibers which mainly remained β-sheet conformation. The IR of the grafted silk fibers showed new absorption of bands occurred which belonged to the stretching-vibration-absorption-peak bands of VCO and VC-F of aliphatic ester species. The CF3-, -CF2- and -CFH- structures of grafted silk macromolecule were verified in the NMR spectrum. The amion acid analysis indicated fluoride monomers were inclined to graft with TYR, ARG and GLU of silk fibers.

Study of Spider Silk Fibers by Raman Microscopy

Spider silk fibers of species of the genera Araneus, Gasteracantha, and Linothele sericata were studied. The fibers are composed of axial threads and lateral villi, allowing adhesion to surfaces. Raman spectroscopy was used to determine the surface and internal composition of the threads forming the structure. In the three species, the characteristic amino acid peaks of the spider web were found between 2871 and 2975 cm-1, which belong to L-glycine, L-alanine, L-glutamine, and L-proline. The threads are composed of a protective layer mainly composed of amides, alanine, and glycine. The fibrils surrounding the axial fibers consist mainly of amide II (1533 cm-1), which allows adhesion between the thread and the surfaces onto which the spider weaves the web. For the genus Linothele sericata, there is a peak on the surface of this spider web located at 2145 cm-1, which is associated with isonitriles with R-N-C bonds.

Research on the Development of Fibroin and Nano-Fiber from Silk Cocoons for Regenerated Tissue Engineering Applications by Electro-Spinning

In this paper, the main goal is to prepare silk fibroin nano-fiber, which is used for regenerated tissue applications. Silk scaffold nano-fibers made by electro-spinning technology can be used in regenerated tissue applications. The purpose of the research is to prepare a silk-fibroin nano-fiber solution for potential applications in tissue engineering. Using a degumming process, pure silk fibroin protein is extracted from silk cocoons. The protein solution for fibroin is purified, and the protein content is determined. The precise chemical composition, exact temperature, time, voltage, distance, ratio, and humidity all have a huge impact on degumming, solubility, and electro-spinning nano-fibers. The SEM investigates the morphology of silk fibroin nano-fibres at different magnifications. It also reveals the surface condition, fiber orientation, and fiber thickness of the silk fibroin nano-fiber. The results show that regenerated silk fibroin and nano-fiber can be used in silk fibroin scaffolds for various tissue engineering applications.

Wet-spinning of Regenerated Silk Fiber from Aqueous Silk Fibroin Solutions: Influence of Calcium Ion Addition in Spinning Dope on the Performance of Regenerated Silk Fiber

Ca（II） ions are added in the spinning dope to adjust the solidification rate of regenerated silk fibroin （RSF） solution during the wet-spinning process since Ca（II） ions are proved to be favorable to maintain the stable silk fibroin network in our previous work. The results show that when Ca（II）/RSF ratios are 1/50 and 1/20, the resulted RSF fibers exhibit good performance with the breaking energy more than 70 kJ/kg. However, higher Ca（II）/RSF ratio （for example, 1/10） hinders the solidification of spinning dope and results in poor RSF fibers. These observations together with earlier papers from this laboratory confirm that to produce tough silk fibers the spinning conditions must allow sufficient time for the adjustment of silk fibroin molecular chains.

A host-guest approach to fabricate metallic cobalt nanoparticles embedded in silk-derived N-doped carbon fibers for efficient hydrogen evolution

Hydrogen evolution reaction(HER) plays a key role in generating clean and renewable energy. As the most effective HER electrocatalysts, Pt group catalysts suffer from severe problems such as high price and scarcity. It is highly desirable to design and synthesize sustainable HER electrocatalysts to replace the Pt group catalysts. Due to their low cost, high abundance and high activities, cobalt-incorporated N-doped nanocarbon hybrids are promising candidate electrocatalysts for HER. In this report, we demonstrated a robust and eco-friendly host-guest approach to fabricate metallic cobalt nanoparticles embedded in N-doped carbon fibers derived from natural silk fibers. Benefiting from the onedimensional nanostructure, the well-dispersed metallic cobalt nanoparticles and the N-doped thin graphitized carbon layer coating, the best Cobased electrocatalyst manifests low overpotential(61 mV@10 mA/cm^2) HER activity that is comparable with commercial 20% Pt/C, and good stability in acid. Our findings provide a novel and unique route to explore high-performance noble-metal-free HER electrocatalysts.

Blended Yarns of Modacrylic Fibers with Silk Protein

The fiber properties of modacrylic fibers with silk protein and spinning technology for blended knitting yarns are studied. By testing the fiber properties, fiber spinnability is analysed. Modacrylic fibers with silk protein are brittle and have poor cohesion, so the key to process modacrylic fibers with silk protein lies in forming lap and sliver. During opening and carding, low speed is used to decrease fiber damage and the proper static resistant oil is applied to eliminate lapping fibers. Besides, the temperature and relative humidity have to be strictly controlled. The applications of modacrylic fibers with silk protein are also put forward.

玉米须不溶性膳食纤维分析及其对面包品质和消化特性的影响研究

首先分析玉米须不溶性膳食纤维(corn silk insoluble dietary fiber,CSIDF)的组分和物理特性,再研究其添加量及粒径对面包比容、色泽、质构、孔隙度、感官等品质和消化特性的影响。结果表明,其主要含80.64%膳食纤维和10.15%蛋白质,以及少量的灰分和脂肪,主要由50.41%纤维素和28.80%半纤维素组成,具有良好的持水、持油和膨胀特性,且粒径越大,3种特性越好;添加玉米须不溶性膳食纤维后面包比容减小,色泽加深,硬度增大,孔隙度降低,不同CSIDF添加量及粒径间存在差异,面包品质与CSIDF添加量及粒径基本呈现负相关,综合分析确定粒径最小的D_(1)(平均粒径为24.91μm)最适宜添加,其添加量为3%时较合适;体外消化试验表明,CSIDF可以通过降低面包中RDS含量、提高SDS和RS含量来延缓淀粉的消化吸收,维持血糖稳定。

THE SCROOPING TREATMENT OF POLYESTER SILKLIKE FIBERS

In this paper the mechanism producing scrooping sound has been discussedtheoretically.It has been recognized that the continuous stick-slip vibrationhaving a certain period and the bigger △E(△E——enery released by stick-slipvibration at one time)are the requisite and surfficient conditions producingscrooping sound.For fiber sample,its surface properties and internal structureare two principal factors influencing scrooping sound. Considering the surface properties of polyester fiber after scrooping treatmentare the synthetic reflection of the properties used treatment reagents and thesurface properties of the fiber,how selecting proper reagents for scroopingtreatment would be the key factor influencing the scrooping effect.Sometreatment solutions having better scrooping effect have been obtained in the paper. In order to cause better scrooping effect,not only the treatment reagent andsurface properties of the fiber,but also the internal structure of the fiber must beconsidered,It has been shown in

功能性蚕丝纤维研究新进展

蚕丝纤维因其优异的穿着舒适性,出色的力学性能、生物相容性、生物可降解性及其对人体无毒无炎症的特点,逐渐在多学科交叉融合应用方面表现出巨大的潜力,但同时也因其存在光致发黄、老化、细菌引起的变形甚至降解、不能机洗、难打理等缺陷,急需实现技术创新,开发具有更广阔应用场景的高性能/多功能蚕丝纤维。本文系统总结了高性能/多功能蚕丝纤维制备新技术,包括基因编辑法、添食法、物理改性法、化学改性法,并指出其所存在的问题和面临的挑战。在此基础上,进一步探讨了高性能/多功能蚕丝纤维的未来发展方向,以期为我国桑蚕产业的转型升级提供理论支撑。

茶梗儿茶素的制备及其对蚕丝织物的染色和功能改性

为提高茶梗废弃物的利用率,从中提取天然色素用于蚕丝织物的染色和功能改性。采用LC-MS、FTIR以及UV对茶梗提取物进行结构鉴定及表征;探究染色时间、染色温度、染色pH值等工艺参数对染色蚕丝颜色性能的影响,比较铁观音茶梗、铁观音茶叶、高山绿茶的提取物对蚕丝织物的染色性能以及抗紫外、抗氧化性能差异。结果表明:该茶梗提取物主要成份为儿茶素,对蚕丝染色的最佳工艺条件为染色时间70 min、染色温度80℃、染色pH值为7.5;3种不同来源儿茶素染色性能相比,铁观音茶梗儿茶素染色蚕丝的表面得色量稍高,色牢度三者相当;3种儿茶素染色蚕丝的抗氧化和抗紫外性能较未处理蚕丝有大幅度提高,直接染色蚕丝的紫外防护系数UPF值均大于150,抗氧化活性均大于60%;采用铝离子前媒染后染色蚕丝的UPF值均大于230,抗氧化活性均大于70%,铁观音茶梗儿茶素染色蚕丝的抗紫外性能优于另外两种茶叶,抗氧化性能比绿茶低、与铁观音绿茶相当。

力学增强且降解延缓的编织型丝素纤维人工韧带材料研究

针对人工韧带产品在临床应用中存在的问题,如不可降解、应力遮挡、中远期疲劳松弛、慢性炎症等,研究力学性能优良的可降解人工韧带材料是新的发展方向。以丝素纤维为原材料,设计并制备了一种“壳芯”结构的人工韧带原型材料(artificial ligament, AL),并以负载纳米羟基磷灰石(hydroxyapatite, Hap)的聚氨酯(polyurethane, PU)溶液对AL进行涂层得到人工韧带材料(coated artificial ligament, CAL),并对CAL的形态结构、显微结构、力学性能、降解性能、细胞和组织相容性等进行了系统表征。研究结果表明:“壳芯”结构的CAL结构规整、表面平整、孔隙均匀。相较于AL,CAL的力学性能得到了显著提高(P<0.05),且体外降解速率明显延缓。此外,CAL的细胞及组织相容性良好,炎症反应低。该项研究可为开发新型高强可降解人工韧带产品提供理论依据及实践参考。

后道拉伸对聚丁二酸丁二醇酯/丝胶蛋白共混纤维结构与性能的影响

为提高纤维的力学性能,采用后道拉伸处理聚丁二酸丁二醇酯(poly(butylene succinate),PBS)/丝胶蛋白(silk sericin,SS)共混纤维,研究拉伸倍数和拉伸温度对纤维形态结构、化学结构、热性能、力学性能与降解性能的影响。结果表明,随着拉伸倍数增加,PBS与丝胶蛋白发生相对位移,纤维表面沿拉伸方向出现明显条纹;随着拉伸温度增加,纤维表面的条纹减少,表明温度的增加提高了PBS分子链的运动能力,使纤维保持致密结构。随着拉伸倍数和拉伸温度的提高,共混纤维的力学性能和结晶度呈现先增加后减小的趋势,在后道拉伸倍数为4倍,拉伸温度为75℃时,纤维的结晶度可达61.30%,此条件下的纤维断裂强度最大为2.0 cN/dtex,接近粘胶纤维的力学强度,可满足纺纱、非织造等纺织加工工艺的要求。

绢丝/毛/棉色纺纱的组成调控与性能分析

绢丝质地柔软光滑、手感舒适,在服装与家居纺织品等领域中得到了广泛应用,是中国绢纺产业的重要产品之一;然而,目前绢丝织物生产仍存在高能耗、高排污问题,且产品竞争力不足。为此,采用低污染的色纺技术对绢丝进行精确配色,并引入羊绒、羊毛、棉等纤维组分,制备色泽独特且性能优异的色纺纱,以满足市场多样化的需求。通过调控纱线中纤维组成与配比,探究其对混纺色纱条干、机械性能及色牢度的影响规律。通过引入不同颜色与配比的各类纤维后,纤维间的优势互补提升了绢丝系列产品的机械性能、色牢度,完善了绢丝产品性能的不足,实现了绢丝系列产品的多样化,减少了绢纺业的生产能耗与排污。

PREPARATION AND CATALYTIC ACTIVITY OF BIOACTIVE FIBERS

Two kinds of water-soluble metallophthalocyanines, binuclear cobalt phthalocyanine （Co2Pc2） and binuclear ferric phthalocyanine （Fe2Pc2）, were synthesized through phenylanhydride-urea route and characterized by elemental analysis and FT-IR spectra. Binuclear metallophthalocyanine derivatives （Mt2Pc2） were immobilized on silk fibers and modified viscose fibers to construct bioactive fibers of mimic enzyme. Mt2Pc2 was used as the active center of bioactive fibers, viscose and silk fibers as the microenvironments. The catalytic oxidation ability of bioactive fibers on the malodors of methanthiol and hydrogen sulfide was investigated at room temperature. The experimental results indicated that the catalytic activity of such bioactive fibers was closely correlative to the types ofbioactive fibers and substrates.

利用棕榈丝纤维和棕榈仁粕栽培茶树菇配方试验

[目的]研究能提高茶树菇产量的配方,丰富栽培茶树菇的原辅材料。[方法]利用棕榈丝纤维和棕榈仁粕混合配方栽培茶树菇,设3个不同配比,并以杂木屑配方作为对照,对比4个配方间产量的差异。[结果]棕榈丝纤维和棕榈仁粕可以显著提高茶树菇的产量,其中添加棕榈配方的茶树菇平均单袋产量可达277.7 g,比杂木屑配方的产量(178.9 g)提高了55.2%左右。但是菌丝的生长速度随着加入棕榈原材料量的增加而减缓,特别是棕榈仁粕,当其量达一定值时,茶树菇菌丝生长缓慢甚至无法满袋,且无法正常出菇。[结论]在实际生产中,可在杂木屑配方中适当添加棕榈丝纤维或者棕榈仁粕,以提高茶树菇产量。

蜘蛛丝蛋白纤维的研究进展

蜘蛛丝是一种具有卓越力学性能和生物相容性的天然材料,近年来在医学、纺织、航空、军事等领域得到了广泛的应用。本文首先介绍了蜘蛛丝蛋白的基本结构与性质,然后梳理了目前合成蜘蛛丝纤维的主要方法,包括遗传工程、溶剂纺丝和湿法纺丝等。在此基础上,分析了现有研究中存在的问题及挑战,并展望了未来研究方向。

Preparation of Silk-Like PET Microfilament and Its Properties

The polyester microfilament was prepared by means ofnormal fully drawn yarn(FDY)equipment.The effectof water content in chips,the molecular weight of thechips,the jet stretch ratio and the lateral blow on thespinnability and the finest titre of filament that could bereach were discussed.Under convenient conditions,thefiber with linear density of about 1.4 dtex could be ob-tained.By means of wide angle X-ray diffractometer(WAXD),differential scanning calorimeter(DSC)andInstrontester,the structure and properties of the mi-crofilament were discussed.