Identification of 13th-14th Century Chinese Handmade Paper Fibers Collected in Yuan Dynasty Paper Currencies

The earliest paper currencies in existence in China were handcrafted during the Yuan dynasty.These currencies were scientifically excavated from different ruins or tombs,whereas scientific analyses of the papers are rare.This study used optical and scanning electron microscopy to examine the fibers collected in Yuan dynasty paper currencies in conjunction with the Herzberg staining method.Despite differences in circulation period,paper fibers in both Zhi Yuan Tong Xing Bao Chao(two Guan)and Zhong Tong Yuan Bao Jiao Chao(one Guan and 500 Wen,issued in Zhi Zheng period)were identified as similar papermaking materials,bast fibers of mulberry bark.The results indicate that mulberry bark,a durable papermaking material used since ancient times,was mainly utilized as a raw material in these Yuan dynasty paper currency.This fiber identification work solved the critical problem of papermaking material in the Yuan dynasty paper currency and provided important information for conserving these precious cultural relics.

Preparation and Characterization of Activated Carbon Fiber from Paper

Activated carbon fibers （ACFS） with surface area of 1388 m2/g prepared from paper by chemical activation with KOH has been utilized as the adsorbent for the removal of methylene blue from aqueous solution. The experimental data were analyzed by Langmuir and Freundlich models of adsorption. The effects of pH value on the adsorption capacity of ACFS were also investigated. The rates of adsorption were found to conform to the kinetic model of Pseudo-second-order equation with high values of the correlation coefficients （R〉0.998）. The Langmuir isotherm was found to fit the experimental data better than the Feundlich isotherm over the whole concentration range. Maximum adsorption capacity of 520 mg/g at equilibrium was achieved. It was found that pH played a major role in the adsorption process, higher pH value favored the adsorption of MB.

Integrated Co3O4/carbon fiber paper for high-performance anode of dual-ion battery

In dual-ion batteries (DIBs), energy storage is achieved by intercalation/de-intercalation of both cations and anions. Due to the mismatch between ion diameter and layer space of active materials, however, volume expansion and exfoliation always occur for electrode materials. Herein, an integrated electrode Co3O4/carbon fiber paper (CFP) is prepared as the anode of DIB. As the Co3O4 nanosheets grow on CFP substrate vertically, it promotes the immersion of electrolyte and shortens the pathway for ionic transport. Besides, the strong interaction between Co3O4 and CFP substrate reduces the possibility of sheet exfoliation. An integrated-electrode-based DIB is therefore packaged using Co3O4/CFP as anode and graphite as cathode. As a result, a high energy density of 72 Wh/kg is achieved at a power density of 150 W/kg. The design of integrated electrode provides a new route for the development of high-performance DIBs.

Improved properties of carbon fiber paper as electrode for fuel cell by coating pyrocarbon via CVD method

The fabrication of a pyrocarbon coated carbon paper and its application to the gas diffusion lay(GDL) of proton exchange membrane(PEM) fuel cell were described.This carbon paper was fabricated by using conventional carbon paper as the precursor,and coating it with pyrocarbon by pyrolyzing propylene via the chemical vapor deposition(CVD) method.For comparison,conventional carbon paper composites were also prepared by using PAN-based carbon fiber felt as the precursor followed by impregnation with resin,molding and heat-treatment.SEM characterization indicates that pyrocarbon is uniformly deposited on the surface of the fiber in the pyrocarbon coated carbon paper and made the fibers of carbon felt bind more tightly.In contrast,there are cracks in matrix and debonding of fibers due to carbonization shrinkage in the conventional carbon paper.Property measurements show that the former has much better conductivity and gas permeability than the latter.In addition,current density-voltage performance tests also reveal that the pyrocarbon coating can improve the properties of carbon paper used for electrode materials of fuel cell.

Properties of paper mill sludge–wood fiber–HDPE composites after exposure to xenon-arc weathering

We used paper mill sludge（PMS） to substitute for part of the wood fibers（WF） used to reinforce high density polyethylene（HDPE）.The resulting composites were subjected to xenon-arc weathering.The composite filled with limited PMS（under 10 %） had mechanical properties and aging resistance similar to those without PMS.The composites containing more PMS faded and cracked more readily than those without PMS.Based on the carbonyl index,crystallinity,and wood index,PMS appeared to accelerate the degradation of composites during weathering.Adding PMS to WF–HDPE composites reduced the weathering resistance,and this reduction was not significant if the PMS content did not exceed 20 % of the wood fibers.Therefore,PMS could be used as a reinforcement in wood-plastic composites at levels less than20 % of the wood fiber content.

Manufacturing of High-efficiency Air Filter Paper Using Ultra-fine Fibers

In this paper,the manufacturing of high-efficiency air filter paper is reported.The air filter paper was produced using ultra-fine fibers and wateroat fibers mercerized by alkali,using an electrospinning apparatus with multiple rings.The high efficiency air filter paper has an antibacterial effect after adding a chitosan-copper complex which is harmless to humans.As a result of the measurement,the filtering efficiency of the air filter paper is approximately 99.998%and its antibacterial efficiency is approximately 99.5%.

Effect of Waste Paper Fiber on Properties of Cementbased Mortar and Relative Mechanism

The aim of this work was to investigate the effect of waste paper fiber on the properties of cement-based mortar and the relative mechanism. The cement-based mortars with various contents and mixing way of waste paper fibers were prepared and the slump flow, setting time and strength developments of all mortars were tested. Besides, Ca（OH）_2 content in hardened pastes at different ages and the microstructures of all mortar at 90 d were observed by scanning electron microscopy. The experimental results showed that in the process of mixing, more superplastizier was consumed to maintain the workability because of the absorption of water and superplastizer on waste paper fiber. With more waste paper fiber being added, longer setting time is available for the pastes with it because of the carbohydrate dissolving and its retarding to the cement hydration. Waste paper fiber is adverse to the early and later strength of cement-based mortar, but it increases the mortar strengths at 7 and 28 d. The strength, Ca（OH）_2 content and microstructure are related to the content and mixing way of waste paper fiber. Waste paper fiber helps produce the Ca（OH）_2 at 7 and 28 d, but this case is reverse at ages of 1 and 3 d. Overall, waste paper fiber leads to the appearance of more pores in the hardened paste. However, it increases the toughness of cement-based mortar.

Electromagnetic Interference Shielding Properties of Electroless Nickel-coated Carbon Fiber Paper Reinforced Epoxy Composites

Carbon fibers（CFs） were coated with a nickel-phosphorus（Ni-P） film using an electroless plating process. The morphology, elemental composition and phases in the coating layer of the CFs were investigated by scanning electron microscopy（SEM）, energy dispersive spectroscopy（EDS） and X-ray diffraction（XRD）, respectively. Wet paper-making method was used to prepare nickle coated carbon fiber paper（NCFP）. Vacuum assisted infusion molding process（VAIMP） was employed to manufacture the NCFP reinforced epoxy composites, and carbon fiber paper（CFP） reinforced epoxy composites were also produced as a comparison. Electromagnetic interference（EMI） shielding properties of the composites were measured in the 3.22-4.9 GHz frequency range using waveguide method. Both NCFP and CFP reinforced epoxy composites of 0.5 mm thickness exhibited high EMI shielding effectiveness（SE） at 8wt% fiber content, 35 d B and 30 d B, respectively, and reflection was the dominant shielding mechanism.

Bacteria in Indian Food Packaging Papers and Paperboards with Various Contents of Pulp Fiber

The food packaging industry generally uses papers and paperboards (PPBs) especially for disposable products. According to the Framework Regulation (EC) No. 1935/2004 of the European Union, no transfer of contamination should occur from food packaging material to the food items. The aim of this study was to determine the presence, numbers, source and different kinds of bacteria present in food packaging PPBs with various contents of pulp fiber. The samples were randomly collected from popular confectioners and fast food restaurants in Saharanpur, India. The results indicated the presence of bacteria in all the samples, ranging from 1.3 × 102 to 6.1 × 103 cfu/g. Most of the samples contained bacteria in more than the permitted concentration of 2.5 × 102 cfu/g as set by Food and Drug Administration (FDA). The detected bacteria were from genera Bacillacea, Staphylococcus and Pseudomonas. According to the FDA declaration, pathogenic bacteria such as B. cereus and S. aureus have been associated with food borne diseases (FBD). Some contaminants in food packaging PPBs were found to be B. subtilis and P. aeroginosa, which produce enzymes like peroxidases and lipoxygenases that are odor generating enzymes.

Raw Materials of Chinese Traditional Handmade paper

Chinese traditional handmade papers,due to their numerous names,have been misunderstood by the public about raw materials for a long time.This manuscript aims to introduce the raw materials of traditional Chinese handmade paper in a botanical aspect in chronological order.Chinese handmade paper’s raw materials are divided into two groups,bast fiber and grass fiber.Bast fiber paper includes ramie-made rag paper,mulberry and paper mulberry paper,Thymelaeaceae paper,and vine paper.Stalk and grass fiber paper includes bamboo paper,grass paper,and stalk paper.

Mode-Locked Thulium Ytterbium Co-Doped Fiber Laser with Graphene Oxide Paper Saturable Absorber

A mode-locked thulium ytterbium co-doped fiber laser （TYDFL） is proposed and demonstrated by using a commercial graphene oxide （GO） paper as saturable absorber （SA）. The GO paper is sandwiched between two fiber ferrules and incorporates a ring laser cavity to generate soliton pulse train operating at 1942.0nm at a threshold multimode pump power as low as 1.8 W. The mode-locked TYDFL has a repetition rate of 22.32 MHz and the calculated pulse width of 1.1 ns. Even though the SA has a low damage threshold, the easy fabrication of GO paper should promote its potentiM application in ultrafast photonics.

FIBER ORIENTATION DISTRIBUTION OF PAPER SURFACE CALCULATED BY IMAGE ANALYSIS

Anisotropy of paper is an important parameter of paper structure. Image analysis technique was improved for accurate fiber orientation in paper surfaces. Image analysis using Fast Fourier Transform was demonstrated to be an effective means to determine fiber orientation angle and its intensity. Binarization process of micrograph images of paper surface and precise calculation for average Fourier coefficients as an angular distribution by interpolation developed were found to improve the accuracy. This analysis method was applied to digital optical micrographs and scanning electron micrographs of paper. A laboratory handsheet showed a large deviation in the average value of fiber orientation angle, but some kinds of machine-made paper showed about 90 degrees in the orientation angle with very small deviations as expected. Korea and Japanese paper made in the traditional ways showed its own characteristic depending on its hand making processes.

Chemicals Used in Polymeric Material Coated Waste Paper Composites

In this research, at different quantities as fillers, Boric Acid, Calcite (CaCO3), SPT (Sodium Perborate Tetrahydrate) and as coupling matters, 3%, MAPE (Maleic Anhydride Grafted Polyethylene), Titanate and Silanyl (Vinyltriethoxysilane) were added waste paper. Composite boards were pressed and cut in 1 × 30 × 30 cm. In order to identify some properties of the produced boards, experimental works were applied according to the standards. In conclusion, bending stress reduced with filler materials and chemicals was reduced even more than the bending stress except for some experimental groups. In addition, it was observed that the coupling chemicals increased the bending strength and modulus of elasticity compared to the fillers.

Manufacturing and Product Analysis of Non-Woven and Paper Based Epoxy Composites

Fiber-reinforced polymer composites are used in a wide variety of applications due to their many advantages, such as relatively low production costs, ease of fabrication, and superior strength compared to pure polymer resins. Polymer reinforcement can be either synthetic or natural. Synthetic fibers such as carbon have high specific strength, but their application fields are limited due to their high manufacturing cost. Recently, interest in recycled fiber-based composites has increased due to their many advantages. In this context, research has been carried out to better utilize non-woven and paper-based materials to make value-added products. The aim of the current research work is to compare the mechanical performance of non-woven and paper-based reinforced epoxy composites manufactured by the VARTM process. Mechanical properties such as tensile strength, flexural strength (using three-point bending), impact strength, hardness strength, and water absorption were measured. A multi-criteria decision approach called TOPSIS (The Technique for Order of Preference by Similarity to Ideal Solution) was used to select the best alternative from the investigated materials.

碳纤维纸张电热及温敏性效应研究

碳纤维纸张可作为优良的面状发热材料,若将其作为采暖地板中的电热元件,可实现地板、采暖一体化,具有广阔的市场前景,为避免碳纤维纸张在使用过程中出现安全隐患,需对碳纤维在碳纤维纸张中的电热和负温度系数(NTC)效应的作用机制进行研究。为了探究碳纤维纸张在通电加热条件下电热及电阻随温度变化的规律,采用红外热成像仪、体式显微镜等仪器分析了碳纤维单丝、搭接单丝、平行单丝及碳纤维纸张4种发热单元的电热和温敏效应,结果表明:碳纤维单丝、搭接单丝及碳纤维纸张表面温度变化趋势均随着输入功率的增加呈现线性增加,在单丝平行方向和垂直方向温度均呈GaussAmp方程曲线分布,碳纤维单丝相互距离等于或者小于0.8 cm,即可将两单丝间温度不均匀度控制在1℃以内;通电加热初期,发热单元电阻随温升的增加而急剧下降,当碳纤维单丝加载80 mW功率(即单丝温度接近35℃),纸张加载2000 mW功率(即纸张表面温度接近97℃)时,电阻值变化趋势趋于稳定,表明碳纤维单丝及碳纤维纸张均具有明显的NTC效应,并且发热单元中搭接单丝的NTC效应和电热效应在碳纤维纸张中起着主导作用,这对于创制适宜的采暖地板发热元件具有积极的指导意义。

沉析纤维尺寸和含量对间位芳纶纸性能的影响

使用不同目数的筛网对自制的Z沉析纤维进行筛分,将得到的不同尺寸的沉析纤维与间位芳纶短切纤维按一定质量比配抄成纸,制备间位芳纶纸;通过红外光谱、X射线衍射、扫描电镜及热失重、动态滤水分析对自制的Z沉析纤维的化学结构、热性能、动态滤水性能进行表征,并与进口的J沉析纤维对比;研究了沉析纤维的尺寸和含量对间位芳纶纸性能的影响。结果表明:Z沉析纤维与J沉析纤维均为膜状结构,化学结构基本一致,动态滤水性能及热性能相当;经30目或50目的筛网筛分后的沉析纤维可以与短切纤维更好地抱合,间位芳纶纸的抗张强度、断裂伸长率、撕裂度、击穿强度均达到较大值;间位芳纶纸的撕裂度随沉析纤维含量的增加逐渐降低,间位芳纶纸的抗张强度、断裂伸长率、击穿强度随沉析纤维含量的增加呈现先增后降的变化趋势,当沉析纤维质量分数为55%时,间位芳纶纸的抗张强度、断裂伸长率、击穿强度均达到最大值,分别为3.0 kN/m、5.50%、18.7 kV/mm。

高性能碳纤维纸研究

研究了用于燃料电池气体扩散层的高性能碳纤维纸,把针叶木浆纤维和碳纤维进行复合制备;对工序及其参数,如碳纤维的表面预处理和分散、针叶木浆打浆工艺、碳纤维配比、不同定量等开展了综合研究,分析了工艺参数对碳纤维纸物性指标和纤维形态的影响。结果表明,对碳纤维表面进行去胶处理时,使用乙醇加热回流萃取的方法效果较佳;针叶木浆较佳的打浆工艺为:疏解10min+2.1kg压力打浆10min+3.1kg压力打浆10min(打浆度24°SR);普通碳纤维导电纸较佳的碳纤维配比为15%,高性能碳纤维纸较佳的碳纤维配比为40%,所制备的高性能碳纤维纸电阻率低、强度较好、透气度较高。

炭黑/废纸导电纤维的制备及其在聚丙烯中的应用

利用多巴胺氧化自聚合将炭黑粘附到废纸纤维表面,制备了炭黑/废纸柔性导电纤维,分析了炭黑含量对纤维导电性能的影响,然后,将该导电纤维与聚丙烯熔融共混制备复合材料,分析了导电纤维添加量对复合材料导电和力学性能的影响。结果表明,聚多巴胺将炭黑均匀粘附在废纸纤维表面,纤维的电阻率随着炭黑含量增加而逐渐降低,当炭黑含量为15%时,废纸纤维的电阻率logρ下降至2.16Ω·cm。柔性导电纤维能更好地控制聚丙烯复合材料电导率降低幅度,当纤维添加量为15%(炭黑含量为2.27%)时,复合材料的表面电阻率为3.71×10^(10)Ω,体积电阻率为2.45×10^(11)Ω·cm,能达到抗静电级别。此时,复合材料的弹性模量和拉伸强度分别为565.65和17.01 MPa,模量提高了1.07%,但强度降低了32.82%。

基于纸张纤维特征的纸页抗张强度智能模拟及预测研究

对纸页抗张强度进行智能模拟,有助于更好地对某种纸页的性能进行分析甚至预测。基于此,针对现有纸页抗张强度模拟方法的缺陷进行总结,认为现有典型Page分析模型存在客观性分析不足等问题,结合偏最小二乘法、支持向量机等构建了一种基于造纸纤维特性的纸页抗张强度智能模拟模型,借助该模型对某种典型纸页的性能进行模拟分析。测试结果表明:该模型能够高效、准确地对纸页抗张强度进行预测,与传统模型相比具有更强的实用性。

应用衰减全反射红外光谱无损鉴别中国传统手工纸的方法研究

纤维种类鉴别是古代纸张保护的重要基础工作。探究中国传统手工纸的无损纤维鉴别的方法对中国古籍、档案及纸质文物的研究和保护具有重要意义。该研究应用衰减全反射傅里叶变换红外光谱(ATRFTIR)对已知纤维成分的17类64种中国传统手工纸标准样品进行了无损分析,参考纤维素和木质素的红外峰位及部分纸样的X射线衍射(XRD)分析结果确认纸样中的所有红外谱峰归属;并采用分波段比较分析的方法对相似度极高的谱图进行比对分析,分别总结各类纸张在4000~1800、1800~1500、1500~1200和1200~600cm^(-1)四个波段的谱图特征;同时对4cm^(-1)精度的谱图进行二阶导数处理,分别总结各类纸张在1500~1200和1200~900cm^(-1)两个波段的二阶导数谱图特征;最后通过红外结晶指数及其他峰高和峰面积比值计算结果实现对纸类更细致的区分。应用上述方法对16个盲测样品进行了有效性测试,红外分析结果与显微纤维鉴别结果一致,初步证明了该方法在中国传统手工纸无损纤维鉴别上的可行性和有效性。实验结果表明,应用ATR-FTIR无损分析法可对麻、桑构皮、檀皮、瑞香皮和竹几大类原料的传统手工纸纤维类型作出快速而准确的鉴别,对于混料的宣纸也同样适用;但对于显微分析也难以鉴别的亲缘关系较近的植物原料如桑、构皮之间的精细鉴别仍有一定局限性。