纳米限域下聚乙二醇的储热性能和十七醇的相行为研究

发布时间：2018-06-15 13:03

本文选题：聚乙二醇 + 十七醇　；参考：《山东农业大学》2017年硕士论文

【摘要】：相变材料(PCM-Phase Change Material)具有在一定温度范围内改变其物理状态的能力,物理性质转变的过程为相变过程,在该过程中相变材料吸收或释放大量的潜热。根据相变材料的这种性能,通过恰当的设计,可以有效提高能源的利用率,有利于满足人们对能源日益增长的需求。聚乙二醇(PEG)是一系列分子量不同的聚合物,相变温度范围为3.2°C~68.7°C。由于聚乙二醇具有合适的相变温度、较高的相变焓、化学稳定性好、价格低廉等特点,而成为了具有广泛应用前景的相变储能材料。十七醇(C17OH)是一种无支链的饱和脂肪醇,晶体结构丰富,纳米限域下可能会有新相产生。本研究利用溶液浸渍法将相变材料填充到了多孔材料孔内,制备了相应的复合相变材料,并对其相关性能进行了研究。本研究主要工作内容如下:利用溶液浸渍法,通过多孔材料的吸附作用,制备了PEG10k/SG、PEG2k/SG复合材料和C17OH/SG、C17OH/CPG和C17OH/SBA-15复合相变材料。使用差示扫描量热仪(DSC)对制备的复合材料的相变温度、相变焓等性能参数进行相关研究及分析。实验结果表明,随着硅胶孔径的减小,复合材料的相变温度和相变焓都随之减小,且PEG10k/SG复合材料的下降幅度比PEG2k/SG复合材料的大。使用DSC对复合材料进行十次及以上的热循环性能测试,并研究其过冷度等相关热性能。实验结果表明复合材料的热循环性能稳定,且其过冷度随着孔径的减小而增大。利用傅立叶变换红外光谱(FT-IR)、扫描电子显微镜(SEM)、X射线衍射(XRD)等手段对复合材料进行相关性研究。实验结果表明,受限于纳米级硅胶孔内的聚乙二醇的结构没有发生改变,即介孔材料与填充材料之间只存在简单的物理吸附作用,并没有发生化学变化。
[Abstract]:PCM-Phase change material (PCM-Phase change material) has the ability to change its physical state within a certain temperature range. The process of physical property transformation is a phase transition process, in which the PCM-Phase change material absorbs or releases a large amount of latent heat. According to the properties of phase change materials, the energy efficiency can be improved effectively by proper design, which is beneficial to meet the increasing demand for energy. Polyethylene glycol (PEG) is a series of polymers with different molecular weights. The transition temperature ranges from 3.2 掳C to 68.7 掳C. Polyethylene glycol (PEG) has become a widely used phase change energy storage material due to its suitable phase transition temperature, high enthalpy of phase transition, good chemical stability and low price. Octadecanol C _ (17) O _ (H) is a branchless saturated fatty alcohol with abundant crystal structure. In this study, phase change materials were filled in porous materials by solution impregnation method, and the corresponding composite phase change materials were prepared, and their related properties were studied. The main work of this study is as follows: by solution impregnation, PEG10k / SGG2k / SG composites and C17OH- / SG-C17OH- / CPG and C17OH- / SBA-15 composite phase change materials were prepared by adsorption of porous materials. The phase transition temperature and enthalpy of the composites were studied and analyzed by differential scanning calorimeter (DSC). The experimental results show that the phase transition temperature and enthalpy of the composites decrease with the decrease of the pore size of silica gel, and the decrease of PEG 10 k / SG composite is larger than that of PEG 2 k / SG composite. The thermal cycling properties of composites were tested by DSC for 10 times or more, and the relative thermal properties such as undercooling degree were studied. The experimental results show that the thermal cycling performance of the composites is stable and the undercooling degree increases with the decrease of pore size. The correlation of the composites was studied by means of Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The experimental results show that the structure of polyethylene glycol confined to nano-silica gel does not change, that is, there is only a simple physical adsorption between mesoporous material and filling material, but no chemical change.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB34

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