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《Carbon》2014
Spherical carbons have been prepared through hydrothermal treatment of three carbohydrates (glucose, saccharose and cellulose). Preparation variables such as treatment time, treatment temperature and concentration of carbohydrate have been analyzed to obtain spherical carbons. These spherical carbons can be prepared with particle sizes larger than 10 μm, especially from saccharose, and have subsequently been activated using different activation processes (H3PO4, NaOH, KOH or physical activation with CO2) to develop their textural properties. All these spherical carbons maintained their spherical morphology after the activation process, except when KOH/carbon ratios higher than 4/1 were used, which caused partial destruction of the spheres. The spherical activated carbons develop interesting textural properties with the four activating agents employed, reaching surface areas up to 3100 m2/g. Comparison of spherical activated carbons obtained with the different activating agents, taking into account the yields obtained after the activation process, shows that phosphoric acid activation produces spherical activated carbons with higher developed surface areas. Also, the spherical activated carbons present different oxygen groups’ content depending on the activating agent employed (higher surface oxygen groups content for chemical activation than for physical activation). 相似文献
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将玉米淀粉按比例混合,制备成玉米淀粉乳液,作为造纸湿部添加剂加入纸浆中,可增强纤维之间的连接,具有稳定纸张纹路作用,能够显著提高原纸的物理性能.该文就玉米淀粉乳液在B级生活用纸中的工艺实践与应用作了介绍. 相似文献
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The continuous production of disposable plastic straw places a high demand on global petrochemical resources and a significant environmental burden. Biodegradable and eco-friendly straws have therefore been studied and produced worldwide. This article briefly introduces the characteristics of paper straws and polylactic acid (PLA) straws, and focuses on edible straws made using, e.g., hydrophilic colloids, zein, and starch. Raw-material selection, preparation methods, advantages, and defects of straws are summarized, to provide a reference for the development and research of eco-friendly straws. 相似文献
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根据隔膜性能要求,采用低浓轻刀打浆和高浓磨浆两种方式制备微纤化纤维,对制备的隔膜进行了物理性能检验,并针对不同孔隙率隔膜制备的超级电容器进行了电化学性能分析。结果表明,与低浓轻刀打浆方式相比,高浓磨浆可以有效地保留纤维长度,提高纤维长径比,在打浆度为85°SR时,隔膜抗张强度达到0.55kN/m,孔隙率为67%,葛尔莱透气度为41.7μm/(Pa·s)。随着隔膜孔隙率的提高,超级电容器的比电容在0.5 A/g电流密度下逐渐增大;孔隙率为68%的隔膜制备的超级电容器循环伏安特性曲线呈明显的矩形,表现出良好的电容性能。 相似文献
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多酚与金属离子形成的金属-多酚网络(metal-polyphenol network,MPN)能发挥金属与多酚的协同效应,既具有金属离子赋予的特定功能,又具有多酚结构对各种表面的高亲和力,能吸附在纳米材料和生物界面等多种表面上,且结构更加稳定。近年来MPN发展迅猛,在很多领域都得到了广泛的应用。本文首先概述了MPN的组装机制和组装原材料(主要是单宁酸和铁离子),简要介绍了一步共混沉积法和层层组装法两种组装方法及常见的表征方法,详细论述了MPN的抗菌性、抗氧化性、吸附性和pH值响应性等功能特性及其在食品领域的应用等,并对MPN的未来发展趋势进行了展望。 相似文献
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Octadecylamine Graft-modified Cellulose Nanofiber and Its Reinforcement to Poly(butylene adipate-co-terephthalate) Composites 下载免费PDF全文
Biodegradable polymers such as poly(butylene adipate-co-terephthalate) (PBAT) have attracted great interest as alternatives to traditional petroleum-based polymers. Nonetheless, it is necessary to improve some properties of PBAT, such as mechanical strength. Cellulose nanofiber (CNF) can improve PBAT mechanical strength, but its dispersion and compatibility in the PBAT matrix require further improvement. In this study, octadecylamine (ODA) was utilized to graft-modify CNF to change the fiber-to-fiber interaction and improve its compatibility with the PBAT matrix. PBAT composites with 1 wt% CNF were prepared using a masterbatch premixing method to avoid CNF aggregation during extrusion. The effects of ODA graft modification on CNF properties were studied; varying degrees of CNF modification were investigated for their effect on PBAT properties. ODA-modified CNF (OCNF)/PBAT melt-extruded composites possessing 17.2% higher tensile strength than pure PBAT polymer were obtained without affecting the thermal stability of PBAT. As a result, surface modification of CNF with ODA is an effective strategy for improving CNF-PBAT compatibility. 相似文献
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滑石颜料高剪切流变性能的研究 总被引:1,自引:1,他引:0
使用毛细管高剪切黏度仪研究了滑石颜料分散体系的高剪切黏度性能,以及pH值、固含量、不同分散剂和润湿剂、不同粒径分布对滑石分散体系高剪切黏度的影响。同时还研究了滑石与GCC及高岭土混合浆料的高剪切黏度性能。结果表明,滑石含量越高、粒度越细,其分散浆料的高剪切黏度值越大。同时发现,滑石高剪切黏度受分散剂和润湿剂的影响不大。提高pH值有利于降低滑石分散体系的高剪切黏度。滑石与GCC混合浆料的高剪切黏度随着GCC粒度的变细而降低。当滑石与GCC的体系中加入高岭土后,混合浆料的高剪切黏度大幅增大,且随着GCC粒度的变细而增大。 相似文献
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