新型负载型除湿材料性能的研究

发布时间：2019-04-04 14:00

【摘要】：除湿是工业生产和人们日常生活中经常遇到的问题。湿度的合理控制对于保护人体健康、改善生活环境、提升生活品质等都具非常重要的意义。在吸附除湿领域中，固体多孔吸附材料的吸湿性能是关键。针对传统除湿材料存在吸湿容量低、再生难的问题，本文主要研制了适用低湿度范围的钙改性分子筛和适用中等湿度范围的镁改性硅胶材料，考察了制备条件对其除湿性能性能的影响，探究了水蒸气在除湿材料上的吸附动力学，并与几种商用的分子筛、硅胶材料进行性能比较，此外，还对MOFs材料在除湿领域的潜在应用进行探索。本文研究了改性分子筛除湿材料在低湿度范围内的除湿性能。结果表明：同条件下Ca-5A的吸湿性能较好；且当纸片浸渍负载时间为10min，CaCl2为2.0M时，所制备的改性分子筛的除湿稳定性较好，其除湿性能为日本及瑞典分子筛的2倍以上；吸湿动力学的实验结果显示：水蒸气在2.0M-Ca-5A-0.5H~+上的扩散属活化扩散，，扩散系数在10-10cm2/s范围内，吸附活化能为45.41kJ/mol。本文研究了改性硅胶除湿材料在中等湿度范围内的除湿性能。研究表明：同条件下Mg-B的吸湿性能最好；其最佳的制备条件为：负载时间10min，MgCl2浓度2.0M；在该条件下所制备的改性硅胶除湿材料具有较好的除湿稳定性，其除湿效果优于广东某公司和瑞典硅胶40%以上；估算得到水蒸气在材料中的扩散系数介于3.07-14.68×10-10cm2/s之间，吸附活化能为38.15kJ/mol，亦表明其扩散过程属于活化扩散。本文对几种水热稳定性较好的MOFs材料进行负载制备，并对其除湿性能进行研究。研究表明：MOF-SCUT2#和MOF-SCUT3#在低湿度范围内的除湿量为传统4A、5A分子筛的2-3倍以上，而脱附温度相对较高，这是由于这两种材料具有较密集的微孔以及骨架结构中不饱和金属吸附位点的强吸附作用；MOF-SCUT1#及其与氧化石墨复合材料则在中高湿度条件下，对水汽显示出很高的吸附容量，其除湿量为传统硅胶材料的2.8-5.1倍，由于水分子是通过氢键的“搭桥效应”形成水簇的，这种较弱的相互作用力使得这两种材料在脱附性能也有较强的竞争优势。
[Abstract]:Dehumidification is a common problem in industrial production and people's daily life. The reasonable control of humidity is very important to protect human health, improve the living environment and improve the quality of life. In the field of adsorption and dehumidification, the moisture absorption performance of solid porous adsorption materials is the key. In order to solve the problems of low moisture absorption capacity and difficult regeneration of traditional dehumidifying materials, calcium modified molecular sieves suitable for low humidity range and magnesium modified silica gel materials suitable for medium humidity range were mainly developed in this paper. The influence of preparation conditions on its dehumidification performance was investigated, and the adsorption kinetics of water vapor on dehumidifying materials was investigated. In addition, the adsorption kinetics of water vapor on dehumidifying materials was compared with that of several commercial molecular sieves and silica gel materials. The potential application of MOFs in the field of dehumidification is also explored. In this paper, the dehumidification performance of modified molecular sieve dehumidification material in low humidity range has been studied. The results showed that the hygroscopicity of Ca-5A was better under the same conditions. When the impregnation time was 10 min and CaCl _ 2 was 2.0 M, the dehumidification stability of the modified zeolites was better, and the dehumidification performance of the modified zeolites was more than 2 times as high as that of Japanese and Swedish zeolites. The experimental results of hygroscopic kinetics show that the diffusion of water vapor on 2.0m Ca ~ (5 +) _ (5) A ~ (0.5) H ~ (2 +) belongs to activation diffusion. The diffusion coefficient is in the range of 10-10cm2/s, and the adsorption activation energy is 45.41 kJ 路mol ~ (- 1). The dehumidification performance of modified silica gel dehumidification material in medium humidity range was studied in this paper. The results showed that Mg-B had the best hygroscopicity under the same conditions, and the optimum preparation conditions were as follows: loading time 10 min, MgCl _ 2 concentration 2.0M; The modified silica gel dehumidification material prepared under this condition has good dehumidification stability, and its dehumidification effect is better than that of some Guangdong company and Sweden silica gel more than 40%. It is estimated that the diffusion coefficient of water vapor in the material ranges from 3.07 to 14.68 脳 10-10cm2/s, and the adsorption activation energy is 38.15 kJ / mol, which also indicates that the diffusion process belongs to activation diffusion. In this paper, several MOFs materials with good hydrothermal stability were prepared by loading and their dehumidification properties were studied. The results show that the amount of dehumidification of MOF-SCUT2# and MOF-SCUT3# in low humidity range is higher than that of traditional 4A, and the desorption temperature of 5A molecular sieves is higher than that of 5A molecular sieves. This is due to the dense micropores and the strong adsorption of unsaturated metal sites in the framework structure of the two materials. MOF-SCUT1# and its composites with graphite oxide exhibit a high adsorption capacity for water vapor under medium and high humidity conditions, and the dehumidification amount is 2.8 脳 5. 1 times as much as that of traditional silica gel materials, and the dehumidification capacity of the composites is higher than that of conventional silica gel materials. Because water molecules form water clusters through the "bridging effect" of hydrogen bonds, this weak interaction makes the two materials have a strong competitive advantage in desorption performance.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TQ424;TU834.9

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