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.

Eco-friendly PVA/Kaolin Clay Coating for Barrier Paper

The resistance of wood-fiber paper to water, grease, and water vapor is usually attained by immersing the base paper in hydrophobic oil, laminating with a plastic or metal film, or the application of a barrier coating. Oil impregnation and the addition of films may make the paper difficult to recycle or persistent in the environment owing to their strong binding force and nondegradability. Environmental concerns have attracted worldwide attention to eco-friendly barrier coatings. In this study, degradable polyvinyl alcohol(PVA) and kaolin clay pigment were used to prepare coatings that were applied to a base paper. By measuring the barrier properties of the coated paper, including the water absorptiveness(Cobb60 value), Hercules sizing degree, oil resistance(Kit rating), and water vapor transmission rate(WVTR), an optimal coating formulation and process were proposed. To examine the barrier mechanism of the PVA/kaolin clay coating, we characterized the coating microstructures using a scanning electron microscopy(SEM) and a mercury porosimeter. The results showed that the Cobb60 value and water vapor transmission rate of the coated paper decreased by 61.4% and 98.6%, respectively, compared with the base paper, for a pre-coating weight of 0.98 g/m^2 and a top-coating weight of about 3.23 g/m^2. Furthermore, the Hercules sizing degree rose by a factor of 337.2, while the oil resistance(Kit rating) increased from 0 to 12. The optimum drying temperature for a wet coating layer was found to be 170℃, and the optimum weight ratio of PVA to kaolin clay in the coating was determined to be 50∶50. It was assumed that the PVA/kaolin clay coating improved the smoothness of the paper considerably and decreased the pore size by filling the pores on the paper surface and forming an even film, thus enhancing the paper barrier performance. The coated paper also exhibited good repulpability.

Plastic-Free Bioactive Paper Coatings, Way to Next-Generation Sustainable Paper Packaging Application: A Review

Hydrocarbon-derived polymers have been utilized in various packaging applications, such as pouches, films, foamed containers, rigid containers, and multiple components for medical, food, and other uses. However, mounting environmental considerations increased knowledge of the harmful consequences of greenhouse gas emissions, landfills, and disposal difficulties. Rising oil prices are forcing researchers and businesses to produce environmentally friendly packaging. These new sustainability requirements are particularly suited to biomass-based products, instead of petroleum sources;sourced from biomass entities. More functional and performance-oriented packaging is necessary despite the widespread usage of bio-based materials like paper. As a result, the transition to eco-friendly packaging will necessitate the improvement of existing bio-derived packaging and the development of new bio-derived materials like biopolymer paper coatings. The goal of this brief study was to give a synopsis of the present status of bio-derived packaging and an insight into ongoing and prospective developments in sustainable next-generation paper coatings for the packaging industry.

Preparation of Ultrafine Starch Particle and its Application in Paper Coating

Despite its biodegradability, adequate cohesive strength and comparatively low cost, the use of cooked starch as a paper coating binder is limited due to its high viscosity and serious negative impact on the gloss. Starch-based bio-latex with size in the nanometer or sub-micrometer range has been developed recently to overcome these shortcomings. In this study, ultrafine starch particle(UFSP) was prepared by mechanical milling using a DYNO mill in combination with light chemical pretreatment. Model coating colors containing different dosages of UFSP were applied to base paper and the properties of the coated papers were evaluated. The results showed that the UFSP was disc-shaped with a median particle diameter of 167 nm. Water retention capacity of the coating colors was improved considerably with the addition of UFSP, i.e., the water retention value decreased by nearly 40% when styrene-butadiene latex was replaced by UFSP at a dosage of 3 pph(per hundred parts of pigment). The high shear rate viscosities of the coating colors containing no more than 2 pph of USFP were similar to that of the control coating color at shear strain rate higher than 2000 s^(-1). The properties and performances of the coated papers were comparable to the control coated paper with single synthesized latex binder. The gloss and the print gloss of paper samples with or without USFP were 59.7% and 58.2%, 79.0% and 78.8%, respectively. Surface strength of paper samples with or without USFP were 0.96 and 0.90 m/s, respectively, while the ink absorptivity values were 34% and 33%. This study demonstrates a promising approach to obtain submicrometer sized starch for paper coating.

Surfactant-Assisted Poly(lactic acid)/Cellulose Nanocrystal Bionanocomposite for Potential Application in Paper Coating

The current article addresses a new strategy for the preparation of polylactic acid/cellulose nanocrystal(PLA/CNCs)nanobiocomposite films with improved structural morphology,mechanical and barrier properties for food packaging applications.The addition of hexadecyltrimethylammonium bromide(CTAB)and sodium lauryl sulfate(SLS)as cationic and anionic surfactants respectively,was found to play a crucial role in preventing re-aggregation of the CNCs during drying and improving the dispersion of CNCs in the PLA.The coated paper was characterized using mechanical tests,water vapor permeability(WVP),X-ray diffraction(XRD),scanning electron microscopy(SEM)and air permeability.The results showed that the paper coated with PLA containing 7.5%CNCs and 0.15%CTAB based on weight of PLA,gives the highest measured paper properties,where an increase in tensile strength(+133%),Young’s modulus(+309%),tear index(+183%),burst(+60.8)and a decrease in air permeability(−92%)was obtained.

Preparation of Water Based Polymeric Binders for Paper Surface Coating

Binder is an important ingredient in pigment coating as it is used to impart adhesion, gloss and flexibility to the dried film as well as binding the pigment particles together. The aim of this work was to synthesize polymeric binders via radical copolymerization of acrylic acid (AA) with maleic anhydride (MA) and with 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS). The chemical structures of the prepared binders were characterized by FTIR and 1HNMR analysis. The rheology of the prepared binders was also investigated. The prepared binders were applied in paper coating suspensions and their effects on optical, mechanical, and physical properties in addition to printability of the coated paper were studied. The results showed that acrylic maleic anhydride copolymers increased the adhesion, gave good film forming properties and good surface activity which increased print quality of paper coating. It was also found that MA/AA (50:50) and the blend between MA/AA (50:50) with AMPS:AA (30:70) have more suitable coating film properties and have highest pick resistance which is resemble to the commercial binder.

EFFECT OF THICKENERS ON PAPER COATING VISCOELASTIC BEHAVIOR

Paper coating has a viscoelastic character, which affected by dissolved polymer in the aqueous phase. The different thickeners have different effects on Paper Coating viscoelasticity behavior. CMC, PVA and CMS are compared in this article, and CMC have the strongest effect than the others.

STUDY ON VISCOELASTIC BEHAVIOR OF PAPER COATING

The flow behavior of paper coating is critical to the coating operation. In this work, the influence of the added agents on the flow behavior and the viscoelastic behavior is investigated using rheometer in steady and dynamic oscillatory modes.

Extracellular polymeric substances as paper coating biomaterials derived from anaerobic granular sludge

Recovering extracellular polymeric substances(EPS)from waste granular sludge offers a cost-effective and sustainable approach for transforming wastewater resources into industrially valuable products.Yet,the application potential of these EPS in real-world scenarios,particularly in paper manufacturing,remains underexplored.Here we show the feasibility of EPS-based biomaterials,derived from anaerobic granular sludges,as novel coating agents in paper production.We systematically characterised the rheological properties of various EPS-based suspensions.When applied as surface sizing agents,these EPS-based biomaterials formed a distinct,ultra-thin layer on paper,as evidenced by scanning electron microscopy.A comprehensive evaluation of water and oil penetration,along with barrier properties,revealed that EPS-enhanced coatings markedly diminished water absorption while significantly bolstering oil and grease resistance.Optimal performance was observed in EPS variants with elevated protein and hydrophobic contents,correlating with their superior rheological characteristics.The enhanced water-barrier and grease resistance of EPS-coated paper can be attributed to its non-porous,fine surface structure and the functional groups in EPS,particularly the high protein content and hydrophobic humic-like substances.This research marks the first demonstration of utilizing EPS from anaerobic granular sludge as paper-coating biomaterials,bridging a critical knowledge gap in the sustainable use of biopolymers in industrial applications.

Study of the efficacy of a Wheaton coated bottle with permethrin and deltamethrin in laboratory conditions and a WHO impregnated paper with bendiocarb in field conditions

Objective:To determine the efficacy of WHO impregnated paper and CDC coated bottle based on number of storage days and number of limes of consecutive use,in the assessment of insecticide vector susceptibility tests in laboratory and field conditions.Methods:Larvae and pupae of Anopheles gambiae s.l.mosquitoes were collected from the breeding sites in Seme-Kpodji and Cotonou districts in Southern Benin in April 2013 during the first rainy season.Anopheles gambiae s.l.mosquitoes were also collected from the breeding sites in Parakou district in Northern Benin in May 2013 at the beginning of the rainy season.Susceptibility tests were done using impregnated paper with bendiocarb(0.1%)following WHO protocol and stock solutions of permethrin(21.5 ug per bottle)and deltamethrin(12.5 ug per bottle)following CDC protocol on unfed female mosquitoes aged 2-5 days old.These bioassays were repeated a certain number of times.The temperature and relative humidity were monitored and recorded during the susceptibility tests.Results:This study showed that a WHO impregnated paper with bendiocarb could be used four times during four consecutive days in field conditions.Regarding a Wheaton coated bottle with permethrin or deltamethrin,they could be used at least three limes during four consecutive days in laboratory conditions.Conclusions:The day storage and the number of times that a WHO impregnated paper and a CDC coated bottle maintained their efficacy are useful in the assessment of insecticide vectors susceptibility tests.

Development of temperature indicator prototype: Cardpaper coated with chitosan intelligent films

An intelligent and biodegradable material pack- aging was developed based on a natural and thermal-sensitive pigment. Anthocyanin (ATH, 0.50 g/100g) was incorporated into chitosan matrix films (2 g/100g) forming a chitosan intelligent film (C-ATH). The system is able to indicate the variation of temperature during distribution and storage chain of industrial products. The novelty of this work was an alternative packaging material that it is biodegradable and could inform any temperature variations on the range of 40?C - 70?C, by irreversible visual colour changes. The effects of temperature (10?C, 30?C and 50?C) and luminosity (0, 500 and 1000 l×) were analyzed on C-ATH using an experimental design of 2 variables, measuring the colour parameters (L*, a*, b*) and mechanical properties (tensile strength, elongation break and Young’s modulus) as responses. C-ATH suspensions were applied as a coating on cardpaper surface forming a temperature indicator prototype (TIP). C-ATH darkened after being exposed to temper- atures above 50?C and luminosity of 1000 lx for 72 hours. TIP was obtained, without bubbles or defects, with reduced water absorption capacity. Irreversible visual colour change was verified on TIP exposed at 40?C independently of luminosity, turned gradually yellow. Chitosan suspensions containing ATH and applied as a coated on card paper sheets could be an alternative of biode-gradable material for packaging system that indicates efficiently temperature changes. This indicator system has potential application temperature range of 40?C to 70?C, such as food, pharmaceuticals, biological, agricultural and others products, that are highly dependent of storage temperature conditions.

PRELIMINARY STUDY ON RETRO-REFLECTIVE COATED PAPER BASED ON MICROGLASS BEADS

High-reflectivity micro-glass bead, as a kind of retro-reflective material, is widely used in reflective fabric or film and other reflective coatings. But it is rarely used in coated paper. The retro-reflective theory of micro-bead is described. Also the effect of size of micro-bead, dosage of binder and different color layers on reflective properties of coated paper are discussed in this article. The results show that its retro-reflective efficiency is good, equally to reflective fabric or film when the micro-glass bead is used in coated paper.

绘画手绘创作在纸质与颜料相互作用分析

纸质与颜料的相互作用在美术领域扮演着重要角色。在远古时期,人们对美就有了追求,将天然的染料涂在自己服装上,以此表达追求美的欲望,从而有了最初的手绘服装。随着科技的发展,人们运用绘画的颜料及技巧也有较大进步。绘画颜料中,氧化铁颜料具有合成度高、色相广泛、粒径均匀的优势特征,逐渐代替传统天然类产品。因此,为提高氧化铁颜料质量,其在不同纸张上表现出来的特性也截然不同,影响艺术家在创作过程中的选材。从超细与耐高温氧化铁颜料出发,详细阐述此类颜料的组成、选择、要求及开发,并提出氧化铁颜料不同配比、不同介质及相关绘画颜料的对比分析,然后结合绘画工艺的图案、色彩与中国传统文化,针对纸张与颜料的相互作用对绘画效果的影响展开分析,以期能为美术领域提供参考。

高光泽喷墨打印纸的涂层结构及其性能比较研究

以三种市售喷墨打印纸为研究对象,分别以样品A、样品B、样品C表示,其中样品A和样品C为国内产品阿博特和佳艺,样品B为国外产品古楼.研究确定了三种样品涂层的结构组成,并分析三种样品涂层的表面性能,这有助于了解市场上喷墨打印纸的产品性能现状,对影响喷墨打印纸涂层性能的各因素的研究具有指导意义.采用AFM和SEM观察三种样品涂层表面形貌,发现样品A和样品B的涂层颜料颗粒分散均匀性良好,样品C涂层颜料颗粒聚集,分散均匀性较差;截面SEM和EDS分析结果表明:只有样品B涂层具有双层结构,其中,底层为铝基颜料和硅基颜料,面层只有铝基颜料,样品A和样品C的涂层均为单层铝基材料.对三种样品涂层表面的性能进行分析,结果表明:三种样品的基础性能都符合产品质量标准,其中,样品B的涂层具有最高的光泽度(74.30%),硬度(3H)和耐水性,在吸墨性上样品B涂层的吸墨性(64.7%)高于样品C(57.9%),略低于样品A(69.2%),样品B在三种样品中综合性能最优异.最后,提出一种提高喷墨打印纸性能的双层涂布工艺方案,这为提高喷墨打印纸性能提供了方向,对高级喷墨打印纸的研究具有实际意义.

基于纸包装生物基涂层的研究进展

随着人们环保意识的逐渐提高,环保友好、节能减排已成为全球人们关注的重点,在限塑令、禁塑令背景下,以纸代塑是实现环境保护和可持续发展的主要方式。但由于纸基材料表面疏松多孔的结构,小分子的水和气体很容易通过孔隙渗透和润湿纤维,不能满足包装材料的阻隔功能要求,同时纸张没有热封性能,无法通过加热自粘制袋的方式达到工业化生产的要求,且其在机械强度方面难以与塑料相媲美。本文主要从防潮性、阻气性、热封性和机械强度四个角度综述了生物基涂层改性纸基包装材料的研究。

基于正交试验的PE淋膜纸冲裁工艺参数优化

为了提高冲裁加工PE淋膜纸的断面质量,该文以冲裁速度、冲裁间隙、斜刃倾角三种工艺参数为影响因素,选择纸张毛刺高度作为评价指标,利用正交试验对工艺参数进行分析。结果表明:冲裁工艺参数对纸张毛刺高度的影响程度分别为:加工间隙>冲裁速度>斜刃倾角。冲裁速度的变化与纸张毛刺高度的变化呈负相关,斜刃倾角、加工间隙的变化与纸张毛刺高度的变化呈正相关。研究得出最优冲裁工艺参数组合为:冲裁速度为220 n·min^(-1),斜刃倾角为0.35°,加工间隙为20μm。该项实验研究结果对提高冲裁加工PE淋膜纸的断面质量和生产效率以及降低产品的加工成本具有重要参考价值,在实际生产中具有一定的实用性、经济性价值。

无甲醛浸渍胶膜纸用涂布型装饰原纸的制备及性能

【目的】针对现有无醛胶黏剂在纸张内部渗透性较差以及一定程度上遮盖原纸色泽和纹理的问题,从装饰原纸性能着手,采用浆内填料加填结合表面颜料化涂布对装饰原纸进行处理,在保证纸张对胶液的渗透性、吸收性前提下,提高纸张的印刷适性和遮盖力,降低无醛胶黏剂对装饰纸饰面效果的影响,为制备适用的无醛装饰纸提供方法。【方法】选用优质阔叶木浆和针叶木浆进行原纸抄造,浆内填料(TiO_(2))含量设为20%、30%和40%,利用二氧化硅(SiO_(2))和聚乙烯醇(PVA)混合液对3种不同加填量的原纸进行涂布、压光整饰得涂布型装饰原纸。采用聚氨酯类无醛胶黏剂对涂布型装饰原纸进行浸渍处理,继而固化和热压贴面。使用扫描电子显微镜(SEM)和动态渗透性测定仪对装饰原纸的表面状态和动态渗透性进行表征测试,应用喷墨打印机对装饰原纸进行印刷打样,通过分光密度计结合相对反差的计算分析装饰原纸的印刷性能,测试分析装饰原纸的抗张强度、平滑度、透气度、吸水性、白度等物理性能以及装饰纸贴面板的表面耐磨性、表面硬度和表面胶合强度等性能。【结果】浆内填料加填量增加会使填料更多填充到原纸结构空隙中,影响胶液在纸张内部的渗透性,致密的表面涂层也会一定程度上降低胶液在纸张内部的渗透性。未涂布原纸的色密度随浆内填料加填量增加而下降,涂布原纸的青、品红、黄、黑色实地密度较未涂布原纸分别提高69.0%、96.2%、45.6%、86.5%,品红、黄、黑3种色别的相对反差均达到标准要求。涂布对装饰原纸的印刷适性起积极作用,填料加填量变化对涂布后装饰原纸印刷适性的影响并不显著;填料加填量增加致使装饰原纸的抗张强度、吸水性下降,平滑度、紧度、白度提高,涂布后装饰原纸较未涂布原纸抗张强度提高52.8%,平滑度提高97.56%,白度变化不明显,不透明度稍有提高;热压后涂布型无醛浸渍胶膜纸的表面耐磨性、硬度和表面胶合强度均达到标准要求。【结论】减少装饰原纸浆内填料加填量,辅以表面涂布方式,能够提高装饰原纸的物理性能以及印刷适性,该方式生产的装饰原纸适用于无醛胶黏剂浸渍,有利于装饰纸无醛化发展。

纸代塑涂层技术在环保食品包装领域的应用研究

在环保理念指引下,纸质包装因其可循环再利用特性,正逐步成为首选。其独特的材料特性为包装设计提供了丰富的创新空间,不仅增强了包装的视觉吸引力,还实现了实用性与审美性的融合。面对传统纸质包装的局限性,可采用先进的纸代塑涂层技术,研发出新型环保包装材料。这种材料不但符合物理和食品安全标准,而且省去了多层复合工艺,实现了无氟、无塑的环保目标,具备易回收和可降解的特点,标志着包装材料领域的一大进步。

生物质基涂料增强食品包装纸防水防油性研究进展

目的归纳总结目前可增强食品包装纸防水防油性的生物基涂料的最新研究进展,为后续相关领域的研究与应用提供理论参考。方法分类介绍2类生物基涂料(蛋白质和多糖),对不同材料在食品包装领域防水防油改性研究进行详细综述,随后将生物基涂料与传统包装材料性能做对比,并且提出相应的解决办法,最后对目前存在的困难和应用前景进行总结和展望。结论通过与其他生物聚合物复合或添加增塑剂等方式对纤维素、壳聚糖、淀粉和海藻酸盐等疏水性或者疏油性不足的生物聚合物涂料进行改性,可以解决多孔纤维素纸基材料防水防油性不足的问题,并且可以有效避免使用含氟类涂料对人体和周围环境带来的危害,生物涂料在食品包装纸防水防油改性领域具有良好的发展前景。

蜡笺纸的发展历程与研究现状

蜡笺纸是我国古代涂布纸中一种在原纸上施以蜡涂层的加工纸,出现于隋唐,明清时期最为鼎盛,在清末民初失传。我国古代不同时期的蜡笺纸在制作上的差异主要体现在纸张厚度、层数及施蜡手法,根据技法与涂层的材料不同,可分为蜡笺纸、粉蜡笺纸、洒金蜡笺纸等。蜡笺纸类文物的保护修复开始于21世纪初;蜡笺纸的科技分析近几年开始出现,主要是使用无损或微损的方法对蜡笺纸的原料成分和结构进行分析。目前有关蜡笺纸的研究较少,蜡笺纸复原、保护修复还有进一步完善的空间。本文综述了蜡笺纸的发展历程以及蜡笺纸原料、制作工艺、科技分析和保护修复方面的研究成果,以期为后续蜡笺纸的研究提供参考。