首页|基于可视化热重分析技术的宣纸热分解特性研究及动力学分析

基于可视化热重分析技术的宣纸热分解特性研究及动力学分析

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为了解宣纸的劣化机理,本文利用可视化热重分析技术对宣纸在氮气与空气中的热分解过程进行了实验和分析,结果表明其过程主要阶段为发挥性成分的析出过程,宣纸样品经历快速失重、面积收缩且颜色加深,其中空气气氛可促进热分解反应并在反应后期氧化前期生成的炭化物;然后以高斯分布函数对微商热重(DTG)曲线进行拟合得到三组分,并且三组分的反应区间符合生物质的热分解特性且受气氛影响;此外,本文还基于 Lab色彩空间对实时观察热分解图像进行了分析,其结果相比热失重数据在反应起始和中止阶段灵敏度更高,并可对热失重数据进行补充;同时,本文以 Friedman法、FWO 法计算宣纸在氮气与空气中的表观活化能E,得到氮气与空气气氛中的结果分别为 195。4 kJ/mol、162。98 kJ/mol;最后通过 Malek 法对宣纸样品的热分解数据进行最概然机理函数的选择,并得到氮气中的热分解活化能E 为 245。60 kJ/mol,指前因子的自然对数 ln A为 37。39 s-1;空气中活化能E 在 150。18~305。41 kJ/mol,ln A在 49。13~20。18 s-1。
Thermal Decomposition Characteristic and Kinetic Analysis of Xuan Paper Based on Visual Thermogravimetric Analysis
As a world intangible cultural heritage,Xuan paper has been used in the protection of artworks and cultural relics for centuries.A large number of rare ancient books and famous artists'paintings and calligraphy are stored on Xuan paper,which are suffering from aging erosion.The thermochemical kinetic parameters of the materials can be used to reflect the aging process of the materials.The research on the thermal decomposition characteristics will help to reveal the internal mechanism of Xuan paper aging,which has important theoretical significance and application value.Experimentally,the thermal decomposition of samples in nitrogen(N2)and air was experimentally investigated.The thermal decomposition of Xuan paper has three stages:dehydration,organic material,and residue decomposition.The main stage is the organic material.At this stage,the sample undergoes rapid weightlessness,shrinks in area,and darkens in color.The new technology of visual thermogravimetric analysis was used to observe the morphology of samples in the process of thermal decomposition through the sample observation system in real time,and the resulting images were analyzed by Lab color space.The chromaticity analysis has high sensitivity in the detection of the production and disappearance of colored substances.In order to analyze the complex chemical composition of the paper and accurately reveal the reaction mechanism of the thermal decomposition process,the Gaussian distribution model was used to fit the DTG curve,and three virtual components in accordance with the thermal decomposition law of biomass were obtained.As a parameter characterizing the overcoming of an energy barrier by chemical reaction,activation energy can characterize the essential properties of the paper thermal aging process.The results obtained by the integral method and the differential method are basically the same.The activation energies of nitrogen and air are 195.4 kJ/mol and 162.98 kJ/mol,respectively.The Valensi equation is the most likely function of the Xuan paper pyrolysis reaction in nitrogen.The reaction mechanism is two-dimensional diffusion,D2-decelerated,G(α)=α+(1-α)ln(1-α),and the activation energy and ln A are 245.60 kJ/mol and 37.39 s-1,respectively.Biomass converted to carbon in the latter stage of the thermal decomposition process in air,making it more difficult to determine the function.The possible mechanism functions were the Valensi equation,Ginstling-Brounshtein equation,and Power Lawer equation,and the activation energy ranged from 150.18 to 305.41 kJ/mol.The ln A ranged from 49.13 to 20.18 s-1.

chromaticity analysiskineticactivation energyreaction mechanism function

陈彪、付小航、谭静、卢郁静、丁延伟

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中国科学技术大学 科技史与科技考古系, 安徽 合肥 230026

中国科学技术大学 合肥微尺度物质科学国家研究中心, 安徽 合肥 230026

色度分析 动力学 活化能 反应机理函数

国家重点研发计划国家自然科学基金中国科学技术大学2022-2023学年度创新创业教育研究课题安徽省高等学校省级质量工程项目安徽省高等学校省级质量工程项目安徽省高等学校省级质量工程项目安徽省新时代育人质量工程项目安徽省新时代育人质量工程项目安徽省新时代育人质量工程项目中国科学技术大学校级教学研究项目中国科学技术大学校级教学研究项目中国科学技术大学校级教学研究项目中国科学技术大学校级教学研究项目中国科学技术大学校级教学研究项目中国科学技术大学校级教学研究项目中国科学技术大学校级教学研究项目中国科学技术大学校级教学研究项目

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2024

复旦学报(自然科学版)
复旦大学

复旦学报(自然科学版)

CSTPCD北大核心
影响因子:0.388
ISSN:0427-7104
年,卷(期):2024.63(1)
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