论文总字数：26774字

摘 要

建筑节能在环保领域有重要意义，相变纳米胶囊在新型建筑材料领域的应用越来越得到人们的关注。为探究相变纳米胶囊在建筑节能领域的应用，本文采用微乳液聚合法，以十八烷为芯材，制备了有机硅包覆的十八烷相变材料纳米胶囊。采用红外光谱、扫描电镜、差示扫描量热法和热重分析对十八烷相变纳米胶囊的热力学特性、表面形貌、化学结构和结晶结构、分解温度以及热循环稳定性进行探究。采用FT-IR分析对正十八烷、二氧化硅和十八烷相变纳米胶囊的各衍射峰，发现正十八烷成功地被包裹且芯材正十八烷与二氧化硅壁材之间未发生化学反应。采用扫描电镜(SEM)发现纳米胶囊样品的粒径在0.5~2 μm之间，纳米胶囊的形貌主要是规则的球形形状。采用DSC结果表明，相变纳米胶囊的芯材包覆率为52.13%，能量储存效率为48.87%，相变温度是26.3 ℃。经过50次DSC高低温循环后，十八烷相变纳米胶囊的50次熔化/凝固过程绘制出的曲线重合度较高，相变温度和相变焓变化较小，表明十八烷相变纳米胶囊在热循环过程中仍能够保持良好的热稳定性。TAG实验结果表明，纳米胶囊的壳材有效地减缓了加热过程中挥发性产物的逸出，纳米胶囊的分解温度得到提升，纳米胶囊具有比较好的热稳定性。经过经济性分析，十八烷相变纳米胶囊能够在新型建筑材料等领域产生良好的经济效益。综上，以十八烷为芯材，有机硅包覆的十八烷相变纳米胶囊由于其相变温度适宜，是一种理想的储能材料，可在新型绿色建筑材料中广泛应用。

关键词：相变材料 纳米胶囊 正十八烷 微乳液聚合 性能表征

Preparation and characterization of octadecane phase change nanocapsules

Abstract

Building energy saving is of great significance in the field of environmental protection, and the application of phase change nanocapsules in the field of new building materials has attracted more and more attention. In order to explore the application of phase change nanocapsules in the field of building energy conservation, microemulsion polymerization method and eighteen alkane core materials were used to prepare silicone encapsulated eighteen phase phase change materials nanocapsules. The thermal properties, surface morphology, chemical structure, crystal structure, decomposition temperature and thermal cycle stability of octadecane phase-change nanocapsules were studied by IR, SEM, DSC and TGA. The diffraction peaks of n-octadecane, silica and octadecane phase change nanocapsules were analyzed by FT-IR. It was found that n-octadecane was successfully coated and no chemical reaction occurred between n-octadecane core material and silica wall material. Scanning electron microscopy (SEM) showed that the size of the nanocapsules was between 0.5 μ m and 2 μ m, and the shape of the nanocapsules was mainly regular spherical. The results of DSC show that the core material coverage rate is 52.13%, the energy storage efficiency is 48.87%, and the transformation temperature is 26.3 ℃. After 50 cycles of DSC at high and low temperature, the curves of octadecane phase-change nanocapsules during 50 cycles of melting / solidification showed a high degree of coincidence, and the changes of phase-change temperature and enthalpy were small, indicating that octadecane phase-change nanocapsules could still maintain good thermal stability during the thermal cycle. The results of tag experiment show that the shell material of the nanocapsule effectively slows down the escape of volatile products during the heating process, the decomposition temperature of the nanocapsule is improved, and the nanocapsule has better thermal stability. Through economic analysis, octadecane phase-change nanocapsules can produce good economic benefits in new building materials and other fields. To sum up, octadecane phase-change nanocapsules with octadecane as the core material and silicone as the coating are ideal energy storage materials due to their suitable phase-change temperature, which can be widely used in new green building materials.

Keywords: phase change materials; nanocapsules; n-Octadecane; microemulsion polymerization; performance characterization

目 录

摘 要 I

Abstract i

第一章 绪论 1

1.1 研究背景 1

1.2 相变纳米胶囊的制备方法 2

1.2.1 原位聚合法 3

1.2.2 溶胶-凝胶法 3

1.2.3 界面聚合法 3

1.2.4 微乳液聚合法 4

1.2.5 悬浮聚合法 4

1.2.6 自组装法 4

1.3 相变纳米胶囊的研究进展 5

1.4 本文工作 6

第二章 十八烷相变纳米胶囊的制备 8

2.1 制备工艺及反应原理 8

2.2 材料 9

2.3 实验设备 10

2.4 实验过程 12

2.4.1 亲水亲油平衡值（HLB）选择 12

2.4.2 称量 12

2.4.3 微乳液的制备 13

2.4.4 纳米胶囊的制备 13

2.5 本章小结 14

第三章 十八烷相变纳米胶囊的性能表征 15

3.1 傅里叶红外光谱分析仪（FT-IR） 15

3.2 扫描电镜（SEM） 17

3.3 差式扫描量热仪（DSC） 19

3.3.1 纳米胶囊的相变温度和相变焓 20

3.3.2 相变纳米胶囊的包覆率 20

3.3.3 相变纳米胶囊的能量储存效率 20

3.3.4 纳米胶囊的过冷度 21

3.4 热重分析仪（TGA） 21

3.5 热循环稳定性 22

3.6 经济性分析 24

3.7 本章小结 25

第四章 结论与展望 27

4.1 结论 27

4.2 展望 27

参考文献 29

致谢 33

第一章 绪论

1.1 研究背景

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