Secondary micro- and nanostructures on the surface of microwave carbonized cotton fibers

E. V. Matveev, A. Gaidar, B. Lapshinov, V. V. Berestov
{"title":"Secondary micro- and nanostructures on the surface of microwave carbonized cotton fibers","authors":"E. V. Matveev, A. Gaidar, B. Lapshinov, V. V. Berestov","doi":"10.30791/0015-3214-2023-6-57-74","DOIUrl":null,"url":null,"abstract":"The method of scanning electron microscopy and X-ray microanalysis was used to study the morphology and surface composition of cotton lint fibers carbonized by microwave radiation and secondary micro- and nanostructures formed on the surface of the fibers in the process of carbonization. The mass of 3 g of cotton lint treated with 5 at. % H3PO4 solution and having a cylindrical form with transverse notches was used as samples for microwave carbonization. It was shown that impurity elements contained in the initial fibers move during microwave carbonization from the central region of the sample to the marginal zones, where they are deposited on the fibers both as continuous phosphorus-containing coatings and as micro- and nanostructures with different morphology and composition. It was found that the most difficult to remove impurities are P and Ca. On the surfaces of notches of microwave carbonized samples, mainly in the central part, there are areas of deep black color characteristic of activated carbon. It is shown that the carbonized fibers of these areas do not contain impurity elements. Significant differences in the morphology of the fiber surface in this area were found. Four characteristic types of fiber surface structure were revealed. In similar areas of samples without notches, carbonized earlier, the fiber surface always contained a small amount of impurity elements (phosphorus ~ 3 – 6 at. %, calcium ~ 1 – 3 at. %), and the fiber structure was fairly uniform. Secondary carbon structures of various morphologies were found on the surfaces of the cuts: monolithic carbon deposits with a hummocky and platelet structure, thin transparent films (presumably, graphene-like structures), carbon nanofibers and nanotubes (straight and curved, diameter 70 – 150 nm and several microns long). A large variety of structures of carbon products and the absence of impurities in them is due to the high heterogeneity of the process conditions in the slit gap, within which microplasma spots, spark and arc discharges arise.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"36 21","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physics and Chemistry of Materials Treatment","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.30791/0015-3214-2023-6-57-74","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0

Abstract

The method of scanning electron microscopy and X-ray microanalysis was used to study the morphology and surface composition of cotton lint fibers carbonized by microwave radiation and secondary micro- and nanostructures formed on the surface of the fibers in the process of carbonization. The mass of 3 g of cotton lint treated with 5 at. % H3PO4 solution and having a cylindrical form with transverse notches was used as samples for microwave carbonization. It was shown that impurity elements contained in the initial fibers move during microwave carbonization from the central region of the sample to the marginal zones, where they are deposited on the fibers both as continuous phosphorus-containing coatings and as micro- and nanostructures with different morphology and composition. It was found that the most difficult to remove impurities are P and Ca. On the surfaces of notches of microwave carbonized samples, mainly in the central part, there are areas of deep black color characteristic of activated carbon. It is shown that the carbonized fibers of these areas do not contain impurity elements. Significant differences in the morphology of the fiber surface in this area were found. Four characteristic types of fiber surface structure were revealed. In similar areas of samples without notches, carbonized earlier, the fiber surface always contained a small amount of impurity elements (phosphorus ~ 3 – 6 at. %, calcium ~ 1 – 3 at. %), and the fiber structure was fairly uniform. Secondary carbon structures of various morphologies were found on the surfaces of the cuts: monolithic carbon deposits with a hummocky and platelet structure, thin transparent films (presumably, graphene-like structures), carbon nanofibers and nanotubes (straight and curved, diameter 70 – 150 nm and several microns long). A large variety of structures of carbon products and the absence of impurities in them is due to the high heterogeneity of the process conditions in the slit gap, within which microplasma spots, spark and arc discharges arise.
微波碳化棉纤维表面的二次微结构和纳米结构
采用扫描电子显微镜和 X 射线显微分析方法研究了经微波辐射碳化的棉绒纤维的形态和表面成分,以及碳化过程中在纤维表面形成的次生微结构和纳米结构。微波碳化的样品是用 5 % H3PO4 溶液处理过的棉绒,质量为 3 克,呈带横向缺口的圆柱形。结果表明,在微波碳化过程中,初始纤维中所含的杂质元素会从样品的中心区域移动到边缘区域,并以连续含磷涂层和具有不同形态和成分的微纳米结构的形式沉积在纤维上。研究发现,最难去除的杂质是 P 和 Ca。在微波碳化样品的凹口表面,主要是中央部分,有活性炭特有的深黑色区域。结果表明,这些区域的碳化纤维不含杂质元素。该区域的纤维表面形态存在显著差异。纤维表面结构有四种特征类型。在没有缺口、碳化较早的类似样品区域,纤维表面总是含有少量杂质元素(磷 ~ 3 - 6 at.在切口表面发现了形态各异的次生碳结构:具有驼峰状和板状结构的整体碳沉积、透明薄膜(推测为类似石墨烯的结构)、纳米碳纤维和纳米管(直的和弯的,直径 70 - 150 纳米,长几微米)。碳产品的结构种类繁多且不含杂质,这是因为狭缝间隙中的工艺条件具有高度异质性,在狭缝间隙中会产生微等离子点、火花放电和电弧放电。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
自引率
0.00%
发文量
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信