一步法氧化改性纳米碳增强芒硝基复合相变材料热性能  

One⁃step Oxidation of Nano Carbon Materials to Enhance the Thermal Properties of Glauber's Salt PCMs

作　　者：蒋自鹏 张雨 铁健 铁生年[1] JIANG Zipeng;ZHANG Yu;TIE Jian;TIE Shengnian(Qinghai Provincial Key Laboratory of Advanced Materials and Applied Technology,Qinghai University,Xining 810016,China;College of Physics and Electronic Information Engineering,Qinghai Normal University,Xining 810016,China)

机构地区：[1]青海大学青海省先进材料与应用技术重点实验室,西宁810016 [2]青海师范大学物电学院,西宁810016

出　　处：《材料导报》2022年第12期22-27,共6页Materials Reports

基　　金：青海省自然基金项目(2020⁃ZJ⁃909;2021⁃ZJ⁃906);材料复合新技术国家重点实验室(武汉理工大学)开放基金项目(2020⁃KF⁃1)。

摘　　要：以Na_(2)SO_(4)·10H_(2)O和Na_(2)CO_(3)·10H_(2)O复合物为相变材料,通过浓H_(2) SO_(4)和浓HNO_(3)一步法氧化改性得到多壁碳纳米管和纳米碳粉表层亲水基团结构,以改性亲水纳米碳为添加剂制备改性纳米炭材料/Na_(2) SO_(4)·10H_(2) O复合相变材料。实验结果表明:两种强酸能够有效地在纳米炭材料表面氧化得到亲水性的羧基基团,氧化后碳纳米管和纳米碳粉表面的O元素含量分别增加至7.93%和10.53%(原子分数,下同),富含羧基的纳米炭材料能与芒硝基复合相变材料均匀分散且不发生相分层,添加0.05%、0.1%和0.25%的不同含量氧化后的改性碳纳米材料,相变潜热均大于200 J·g^(-1),导热系数和热扩散系数大幅度提升,制备的相变材料表现出优异的热性能。相变材料经过200次吸放热循环实验后仍能保持较高的相变潜热和较低的相变过冷度,本工作通过一步氧化法成功地制备出热性能优异且稳定的改性纳米炭材料/Na_(2)SO_(4)·10H_(2) O复合相变材料。Na_(2) SO_(4)·10H_(2) O and Na_(2) CO_(3)·10H_(2) O composites were used as the basic phase change materials(PCMs),and multi⁃walled carbon nanotubes and carbon nano powder were modified to form hydrophilic groups on the surface of materials by one⁃step oxidation with concentrated H_(2) SO_(4) and concentrated HNO_(3).The modified carbon nanomaterials were used as the additives to prepare modified carbon nano powders/Na_(2) SO_(4)·10H_(2) O composites PCMs.The experimental result shows that the two kinds of mixed acids can effectively oxidize to form abundant hydrophilic carboxyl groups on the surface of the nano carbon materials,and the O element content of two kinds of modified carbon nanomaterials increases to 7.93at%and 10.53at%,respectively;the surface carboxyl groups of the nano carbon can effectively affinity and uniformly distribute with the glauber's salt⁃based composite PCMs;the latent heat of phase change after adding 0.05at%,0.1at%and 0.25at%of different kinds of modified carbon nano materials of them are greater than 200 J·g^(-1),while the thermal conductivity and thermal diffusion coefficients are greatly improved,and the prepared PCMs exhibit excellent thermal properties.After 200 cycles,the PCMs can still maintain a high phase transition latent heat and a low phase transition supercooling degree.In this work,the modified carbon nano materials/Na_(2) SO_(4)·10H_(2) O composite PCMs with excellent and stable thermal properties were successfully prepared by one⁃step oxidation method.

关 键 词：改性纳米炭材料 一步氧化 Na_(2)SO_(4)·10H_(2)O 相变材料 相变热性能 

分 类 号：TQ12[化学工程—无机化工] TB34[一般工业技术—材料科学与工程]