搜索

x

留言板

尊敬的读者、作者、审稿人, 关于本刊的投稿、审稿、编辑和出版的任何问题, 您可以本页添加留言。我们将尽快给您答复。谢谢您的支持!

姓名
邮箱
手机号码
标题
留言内容
验证码

掺杂石墨烯纳米片对硝酸钠相变特性的影响及机理

吕浩翔 冯黛丽 冯妍卉 张欣欣

引用本文:
Citation:

掺杂石墨烯纳米片对硝酸钠相变特性的影响及机理

吕浩翔, 冯黛丽, 冯妍卉, 张欣欣

Effect and mechanism of doped graphene nanosheets on phase transition properties of sodium nitrate

Lü Hao-Xiang, Feng Dai-Li, Feng Yan-Hui, Zhang Xin-Xin
PDF
HTML
导出引用
  • 纳米增强剂通常被用来提升相变材料的导热性能, 但这种方式通常伴随着复合后材料相变焓的降低. 虽然这种降低难以避免, 但其微观机理乃至影响规律却始终未能明晰. 为深入探究纳米复合相变材料相变焓降低的机理, 本文以熔融硝酸钠(太阳盐的重要组成成分)为相变材料, 制备了石墨烯纳米片质量分数为0%, 0.5%, 1%, 1.5%, 2%的复合相变材料. 通过实验测量与分子动力学模拟的方法深入分析了石墨烯纳米片的掺杂导致熔融硝酸钠产生团簇以及复合材料熔点和相变焓非依数性降低的影响机理. 结果表明, 石墨烯纳米片质量分数为1.5%时, 硝酸钠致密层和石墨烯纳米片间的质心等效距离最接近他们相互作用势的势阱位置, 此时二者之间相互吸引作用最强, 熔盐分子的运动受限最为严重, 难以发生熔化, 从而导致相变焓降低最为显著. 为了最大限度地避免纳米复合相变材料相变焓的损失, 应根据相变材料与纳米增强剂的类型及其相互作用类型, 合理选择纳米增强剂的质量分数. 在实际应用中, 恰当的质量分数还将在一定程度上降低复合相变材料的制备成本.
    Molten salt is regarded as one of most promising candidates for solar energy storage due to possessing stable properties and large energy storage densities. However, the intrinsically low thermal conductivity of molten salt has become a bottleneck for rapid heat storage and transport. The addition of nanoparticles is generally considered to be a most effective way to improve the thermal conductivity of molten salt phase change materials (PCMs), while the phase change enthalpies of the nanocomposite phase change materials usually show two opposite trends of enhancement or decrement. Furthermore, the reason for the abnormal change of phase change enthalpy has not been clear in the literature so far, so the mechanism of change needs to be further explored. In this work, graphene nanosheets (GNS)@NaNO3 (sodium nitrate) nanocomposite phase change materials are prepared by the hydration ultrasonic method. The materials are characterized by scanning electron microscope, and the phase change characteristics are measured using differential scanning calorimeter. Molecular dynamics simulation is carried out to explain the mechanism for the formation of the NaNO3 dense layer and the non-collateral decrease of the enthalpy from the microscopic level. With the increase of GNS mass fraction, the melting point of the GNS@NaNO3 composite phase change material decreases slightly while the phase change enthalpy decreases significantly with a non-colligative trend. A 13.81% decrease of the theoretical phase change enthalpy is observed with a GNS doping ratio of 1.5%. The NaNO3 clusters observed on the surface of GNS are considered to have not melted, thereby resulting in a reduction in the phase change enthalpy. The mechanism is further investigated by molecular dynamics simulation, showing that the strong van der Waals attraction between GNS and NaNO3 leads the 2–4 Å-thick NaNO3 dense layer to form in the vicinity of GNS. With the increase of GNS mass fraction, the centroid equivalent distance between the dense layer and GNS gradually increases, which leads their mutual attraction to first increase and then weaken. When GNS mass fraction is 1.5%, the centroid equivalent distance reaches the position closest to the potential well, leading to a strongest mutual attraction. In other words, the phase change enthalpy decreases most obviously at this mass fraction. Thus, some conclusions can be drawn as follows. The type of interaction between molten salt and nano-enhancers and the position of the potential well are the fundamental reasons for the thickness of molten salt dense layer and the reduction of phase change enthalpy. The calculation of the interaction energy can be used to guide the selection of the mass fraction of the nano-enhancers, so as to avoid the loss of core material cluster and phase change enthalpy caused by the introduction of the nano-enhancers to a greatest extent. The preparation cost of the composite phase change material can also be reduced to a certain extent.
      通信作者: 冯黛丽, dlfeng@ustb.edu.cn ; 冯妍卉, yhfeng@me.ustb.edu.cn
    • 基金项目: 国家重点研发计划(批准号: 2018YFA0702300)和国家自然科学基金(批准号: 52176054, 51876007)资助的课题.
      Corresponding author: Feng Dai-Li, dlfeng@ustb.edu.cn ; Feng Yan-Hui, yhfeng@me.ustb.edu.cn
    • Funds: Project supported by the National Key R & D Program of China (Grant No. 2018YFA0702300) and the National Natural Science Foundation of China (Grant Nos. 52176054, 51876007).
    [1]

    Lee D, Jo B 2021 Int. J. Energy Res. 45 3231Google Scholar

    [2]

    Xiong Y X, Wang Z Y, Sun M Y, Wu Y T, Xu P, Qian X, Li C, Ding Y L, Ma C F 2021 Int. J. Energy Res. 45 5248Google Scholar

    [3]

    Kumar N, Hirschey J, LaClair T J, Gluesenkamp K R, Graham S 2019 J. Energy Storage 24 100794Google Scholar

    [4]

    Choi D H, Lee J, Hong H, Kang Y T 2014 Int J. Refrig. 42 112Google Scholar

    [5]

    Wang M R, Kang Q J, Pan N 2009 Appl. Therm. Eng. 29 418Google Scholar

    [6]

    Kim Y S, Kim D, Martin K J, Yu C, Grunlan J C 2010 Macromol. Mater. Eng. 295 431Google Scholar

    [7]

    Shin D, Banerjee D 2010 J. Heat Transfer 133 024501Google Scholar

    [8]

    Shin D, Banerjee D 2011 Int. J. Heat Mass Transfer 54 1064Google Scholar

    [9]

    Jo B, Banerjee D 2014 Acta Mater. 75 80Google Scholar

    [10]

    Qiao G, Alexiadis A, Ding Y L 2017 Powder Technol. 314 660Google Scholar

    [11]

    Xiong Y X, Wang Z Y, Xu P, Chen H B, Wu Y T 2019 Energy Procedia 158 5551Google Scholar

    [12]

    Li Z, Li B R, Du X Z, Wu H W 2020 Renewable Energy 146 816Google Scholar

    [13]

    Engelmann S, Hentschke R 2019 Sci. Rep. 9 1Google Scholar

    [14]

    Li J F, Lu W, Zeng Y B, Luo Z P 2014 Sol. Energy Mater. Sol. Cells 128 48Google Scholar

    [15]

    Liu Y S, Yang Y Z 2017 Appl. Therm. Eng. 124 533Google Scholar

    [16]

    Yu Q, Lu Y W, Zhang C C, Wu Y T, Sunden B 2019 Sol. Energy Mater. Sol. Cells 201 110055Google Scholar

    [17]

    Park S, Ruoff R S 2009 Nat. Nanotechnol. 4 217Google Scholar

    [18]

    Morelos-Gomez A, Terashima S, Yamanaka A, Cruz-Silva R, Ortiz-Medina J, Sánchez-Salas R, Fajardo-Díaz J L, Muñoz-Sandoval E, López-Urías F, Takeuchi K 2021 Carbon 181 118Google Scholar

    [19]

    Yan X X, Zhao H B, Feng Y H, Qiu L, Lin L, Zhang X X, Ohara T 2022 Compos. B Eng. 228 109435Google Scholar

    [20]

    D’Aguanno B, Karthik M, Grace A, Floris A 2018 Sci. Rep. 8 10485Google Scholar

    [21]

    Jayaraman S, Thompson A P, von Lilienfeld O A, Maginn E J 2010 Ind. Eng. Chem. Res. 49 559Google Scholar

    [22]

    Plimpton S 1995 J. Comput. Phys. 117 1Google Scholar

    [23]

    Stuart S J, Tutein A B, Harrison J A 2000 J. Chem. Phys. 112 6472Google Scholar

    [24]

    Jones J E 1924 Proc. R. Soc. Lond. A 106 463Google Scholar

    [25]

    Xiong Y H, Wu H, Gao J S, Chen W, Zhang J C, Yue Y N 2019 Acta Phys. Chim. Sin. 35 1150Google Scholar

    [26]

    Li Z, Cui L, Li B R, Du X Z 2020 Int. J. Heat Mass Transfer 153 119578Google Scholar

    [27]

    Yang M J, Stipp S S, Harding J 2008 Cryst. Growth Des. 8 4066Google Scholar

  • 图 1  石墨烯纳米片@硝酸钠复合相变材料的制备流程

    Fig. 1.  Preparation process of GNS@NaNO3.

    图 2  石墨烯纳米片@硝酸钠复合相变材料的扫描电子显微照片 (a)石墨烯纳米片; (b) 纯硝酸钠; (c) 纳米片质量分数为0.5%的石墨烯纳米片@硝酸钠; (d) 纳米片质量分数为1.0%的石墨烯纳米片@硝酸钠; (e) 纳米片质量分数为1.5%的石墨烯纳米片@硝酸钠; (f) 纳米片质量分数为2.0%的石墨烯纳米片@硝酸钠

    Fig. 2.  Scanning electron micrograph of GNS@NaNO3: (a) GNS; (b) pure NaNO3; (c) GNS@NaNO3 when GNS weight concentration is 0.5%; (d) GNS@NaNO3 when GNS weight concentration is 1.0%; (e) GNS@NaNO3 when GNS weight concentration is 1.5%; (f) GNS@NaNO3 when GNS weight concentration is 2.0%.

    图 3  硝酸钠和石墨烯纳米片@硝酸钠复合相变材料的热流曲线

    Fig. 3.  Heat flow curves of pure NaNO3 and GNS@NaNO3.

    图 4  石墨烯纳米片质量分数为1.0%的石墨烯纳米片@硝酸钠复合相变材料结构模型

    Fig. 4.  Structural model of GNS@NaNO3 when GNS weight concentration is 1.0%.

    图 5  石墨烯纳米片@硝酸钠复合相变材料300 K下的均方位移

    Fig. 5.  MSD of GNS@NaNO3 composites at 300 K.

    图 6  石墨烯纳米片附近的原子分布(纳米片质量分数为1.5%的石墨烯纳米片@硝酸钠)

    Fig. 6.  NaNO3 atomic distribution close to GNS (GNS@NaNO3 when GNS weight concentration is 1.5%).

    图 7  石墨烯纳米片@硝酸钠原子间L-J相互作用示意 (a) 石墨烯纳米片质量分数为1.0% 的石墨烯纳米片@硝酸钠; (b) 石墨烯纳米片质量分数为1.5%的石墨烯纳米片@硝酸钠

    Fig. 7.  L-J interaction between atoms in GNS@NaNO3: (a) GNS@NaNO3 when GNS weight concentration is 1.0%; (b) GNS@NaNO3 GNS weight concentration is 1.5%.

    图 8  石墨烯纳米片与硝酸钠之间的相互作用能

    Fig. 8.  Interaction energy between GNS and NaNO3.

    表 1  硝酸钠和石墨烯纳米片@硝酸钠复合相变材料的相变热性能

    Table 1.  Phase change characteristics of pure NaNO3 and GNS@NaNO3.

    样品Tm/℃HS,comp/(J·g–1)Theoretical HS,comp/(J·g–1)θ/%
    Pure NaNO3308.00±0.57174.00±1.62174100
    0.5%GNS@NaNO3306.87±0.40153.12±1.48173.1388.44
    1.0%GNS@NaNO3307.91±0.55165.24±1.68172.2695.92
    1.5%GNS@NaNO3307.33±0.42147.72±1.15171.3986.19
    2.0%GNS@NaNO3307.46±0.60160.08±1.53170.5293.88
    下载: 导出CSV

    表 2  各原子到石墨烯纳米片的质心等效距离

    Table 2.  Centroid equivalent distance of atoms in NaNO3 dense layer to GNS.

    原子种类Centroid equivalent distance/Å
    0.5%1.0%1.5%2.0%
    Na3.313.113.423.92
    N3.233.634.174.53
    O3.233.554.235.10
    下载: 导出CSV
  • [1]

    Lee D, Jo B 2021 Int. J. Energy Res. 45 3231Google Scholar

    [2]

    Xiong Y X, Wang Z Y, Sun M Y, Wu Y T, Xu P, Qian X, Li C, Ding Y L, Ma C F 2021 Int. J. Energy Res. 45 5248Google Scholar

    [3]

    Kumar N, Hirschey J, LaClair T J, Gluesenkamp K R, Graham S 2019 J. Energy Storage 24 100794Google Scholar

    [4]

    Choi D H, Lee J, Hong H, Kang Y T 2014 Int J. Refrig. 42 112Google Scholar

    [5]

    Wang M R, Kang Q J, Pan N 2009 Appl. Therm. Eng. 29 418Google Scholar

    [6]

    Kim Y S, Kim D, Martin K J, Yu C, Grunlan J C 2010 Macromol. Mater. Eng. 295 431Google Scholar

    [7]

    Shin D, Banerjee D 2010 J. Heat Transfer 133 024501Google Scholar

    [8]

    Shin D, Banerjee D 2011 Int. J. Heat Mass Transfer 54 1064Google Scholar

    [9]

    Jo B, Banerjee D 2014 Acta Mater. 75 80Google Scholar

    [10]

    Qiao G, Alexiadis A, Ding Y L 2017 Powder Technol. 314 660Google Scholar

    [11]

    Xiong Y X, Wang Z Y, Xu P, Chen H B, Wu Y T 2019 Energy Procedia 158 5551Google Scholar

    [12]

    Li Z, Li B R, Du X Z, Wu H W 2020 Renewable Energy 146 816Google Scholar

    [13]

    Engelmann S, Hentschke R 2019 Sci. Rep. 9 1Google Scholar

    [14]

    Li J F, Lu W, Zeng Y B, Luo Z P 2014 Sol. Energy Mater. Sol. Cells 128 48Google Scholar

    [15]

    Liu Y S, Yang Y Z 2017 Appl. Therm. Eng. 124 533Google Scholar

    [16]

    Yu Q, Lu Y W, Zhang C C, Wu Y T, Sunden B 2019 Sol. Energy Mater. Sol. Cells 201 110055Google Scholar

    [17]

    Park S, Ruoff R S 2009 Nat. Nanotechnol. 4 217Google Scholar

    [18]

    Morelos-Gomez A, Terashima S, Yamanaka A, Cruz-Silva R, Ortiz-Medina J, Sánchez-Salas R, Fajardo-Díaz J L, Muñoz-Sandoval E, López-Urías F, Takeuchi K 2021 Carbon 181 118Google Scholar

    [19]

    Yan X X, Zhao H B, Feng Y H, Qiu L, Lin L, Zhang X X, Ohara T 2022 Compos. B Eng. 228 109435Google Scholar

    [20]

    D’Aguanno B, Karthik M, Grace A, Floris A 2018 Sci. Rep. 8 10485Google Scholar

    [21]

    Jayaraman S, Thompson A P, von Lilienfeld O A, Maginn E J 2010 Ind. Eng. Chem. Res. 49 559Google Scholar

    [22]

    Plimpton S 1995 J. Comput. Phys. 117 1Google Scholar

    [23]

    Stuart S J, Tutein A B, Harrison J A 2000 J. Chem. Phys. 112 6472Google Scholar

    [24]

    Jones J E 1924 Proc. R. Soc. Lond. A 106 463Google Scholar

    [25]

    Xiong Y H, Wu H, Gao J S, Chen W, Zhang J C, Yue Y N 2019 Acta Phys. Chim. Sin. 35 1150Google Scholar

    [26]

    Li Z, Cui L, Li B R, Du X Z 2020 Int. J. Heat Mass Transfer 153 119578Google Scholar

    [27]

    Yang M J, Stipp S S, Harding J 2008 Cryst. Growth Des. 8 4066Google Scholar

  • [1] 刘旺旺, 张克学, 王军, 夏国栋. 过渡区内纳米颗粒的曳力特性模拟研究. 物理学报, 2024, 73(7): 075101. doi: 10.7498/aps.73.20231861
    [2] 刘秀成, 杨智, 郭浩, 陈颖, 罗向龙, 陈健勇. 金刚石/环氧树脂复合物热导率的分子动力学模拟. 物理学报, 2023, 72(16): 168102. doi: 10.7498/aps.72.20222270
    [3] 明知非, 宋海洋, 安敏荣. 基于分子动力学模拟的石墨烯镁基复合材料力学行为. 物理学报, 2022, 71(8): 086201. doi: 10.7498/aps.71.20211753
    [4] 杨亚帆, 王建州, 商翔宇, 王涛, 孙树瑜. 高温下钙蒙脱石膨胀特性的分子动力学模拟. 物理学报, 2022, 71(4): 043102. doi: 10.7498/aps.71.20211565
    [5] 刘青阳, 徐青松, 李瑞. 氮掺杂对石墨烯摩擦学特性影响的分子动力学模拟. 物理学报, 2022, 71(14): 146801. doi: 10.7498/aps.71.20212309
    [6] 潘伶, 张昊, 林国斌. 纳米液滴撞击柱状固体表面动态行为的分子动力学模拟. 物理学报, 2021, 70(13): 134704. doi: 10.7498/aps.70.20210094
    [7] 史超, 林晨森, 陈硕, 朱军. 石墨烯表面的特征水分子排布及其湿润透明特性的分子动力学模拟. 物理学报, 2019, 68(8): 086801. doi: 10.7498/aps.68.20182307
    [8] 何昱辰, 刘向军. 基于基液连续假设的大体系Cu-H2O纳米流体输运特性的模拟研究. 物理学报, 2015, 64(19): 196601. doi: 10.7498/aps.64.196601
    [9] 袁思伟, 冯妍卉, 王鑫, 张欣欣. α-Al2O3介孔材料导热特性的模拟. 物理学报, 2014, 63(1): 014402. doi: 10.7498/aps.63.014402
    [10] 司丽娜, 王晓力. 纳米沟槽表面黏着接触过程的分子动力学模拟研究. 物理学报, 2014, 63(23): 234601. doi: 10.7498/aps.63.234601
    [11] 齐玉, 曲昌荣, 王丽, 方腾. Fe50Cu50合金熔体相分离过程的分子动力学模拟. 物理学报, 2014, 63(4): 046401. doi: 10.7498/aps.63.46401
    [12] 陈青, 孙民华. 分子动力学模拟尺寸对纳米Cu颗粒等温晶化过程的影响. 物理学报, 2013, 62(3): 036101. doi: 10.7498/aps.62.036101
    [13] 孙伟峰, 王暄. 聚酰亚胺/铜纳米颗粒复合物的分子动力学模拟研究. 物理学报, 2013, 62(18): 186202. doi: 10.7498/aps.62.186202
    [14] 李明林, 林凡, 陈越. 碳纳米锥力学特性的分子动力学研究. 物理学报, 2013, 62(1): 016102. doi: 10.7498/aps.62.016102
    [15] 夏冬, 王新强. 超细Pt纳米线结构和熔化行为的分子动力学模拟研究. 物理学报, 2012, 61(13): 130510. doi: 10.7498/aps.61.130510
    [16] 权伟龙, 李红轩, 吉利, 赵飞, 杜雯, 周惠娣, 陈建敏. 类金刚石薄膜力学特性的分子动力学模拟. 物理学报, 2010, 59(8): 5687-5691. doi: 10.7498/aps.59.5687
    [17] 曹莉霞, 尚家香, 张跃. 应力诱发NiAl单晶马氏体相变的分子动力学模拟. 物理学报, 2009, 58(10): 7307-7312. doi: 10.7498/aps.58.7307
    [18] 谢 芳, 朱亚波, 张兆慧, 张 林. 碳纳米管振荡的分子动力学模拟. 物理学报, 2008, 57(9): 5833-5837. doi: 10.7498/aps.57.5833
    [19] 孟利军, 张凯旺, 钟建新. 硅纳米颗粒在碳纳米管表面生长的分子动力学模拟. 物理学报, 2007, 56(2): 1009-1013. doi: 10.7498/aps.56.1009
    [20] 李 瑞, 胡元中, 王 慧, 张宇军. 单壁碳纳米管在石墨基底上运动的分子动力学模拟. 物理学报, 2006, 55(10): 5455-5459. doi: 10.7498/aps.55.5455
计量
  • 文章访问数:  3941
  • PDF下载量:  85
  • 被引次数: 0
出版历程
  • 收稿日期:  2022-02-28
  • 修回日期:  2022-04-04
  • 上网日期:  2022-07-21
  • 刊出日期:  2022-08-05

/

返回文章
返回