多壳中空结构的分级孔微纳米材料的可控合成及其构效关系
发布时间：2019-05-17 05:04
【摘要】：进入21世纪以来,材料工业作为现代工业的支柱性产业之一,已经取得了长足发展并促进社会的高速发展。中空核壳材料,特别是多壳中空结构的微纳米材料,因其具有大的比表面积、丰富的活性位点、低密度、短的传质路径以及广阔的空腔结构等优点,使其在电化学、生物医药及环境保护等领域有着重要发展并广泛引起人们的关注。与此同时,分级孔材料,即一类在微纳米材料表面具有不同分级孔道结构(具有两种或两种以上孔道结构,如小孔-介孔、介孔-大孔等)的材料,也逐渐引起大家的关注。复杂的孔道结构赋予材料不仅更多的活性位点和更大的比表面积,而且也大大提高了传质效率并降低了传质阻力。基于此,既具有多壳中空结构又具有分级孔结构的微纳米材料具有良好的发展应用前景。本论文基于多壳中空结构的分级孔材料的研究现状,运用牺牲模板法成功地可控合成了具有多壳中空结构的分级孔微纳米材料。通过调节反应条件样品壳层数可控。利用X-射线衍射、场发射扫描电子显微镜、透射电子显微镜等手段对样品的化学组分、形貌结构以及应用性能进行分析表征。并对样品的形成机理进行了研究讨论,为指导合成更多的具有多壳中空结构的分级孔微纳米材料提供坚实的理论基础和实验依据。性能研究分析了这种复合结构微纳米材料在电化学及环境保护领域的应用,初步探讨了其构效关系。为进一步优化分级孔材料的多壳中空结构进而提高其性能提供了可靠的实验依据。本论文主要开展以下几项工作:(1)、可控合成具有多壳中空结构的分级孔二氧化硅微纳米材料,并研究其形成机理和电化学性能。利用牺牲模板法合成单层、双层及三层壳中空结构的分级孔二氧化硅微球,样品的壳层数能够通过前驱体的负载量控制。通过对样品的分析表征,研究了样品的形貌结构及化学组成;并对样品的形成机理进一步研究,发现前驱体在模板上的吸附深度对样品形貌起到关键性作用。以样品作为锂离子电池负极材料,研究其电化学性能。结果表明,随着二氧化硅的壳层数的增加,其充放比容量依次增加。尤其是对于具有三层壳中空结构的分级孔二氧化硅微球,它不但具有高的充放比容量又具有良好的循环稳定性。(2)、可控合成具有多壳中空结构的分级孔氧化镧微纳米材料,并研究其形成机理和磷的移除性能。利用牺牲模板法合成具有单层、双层及三层壳中空结构的分级孔氧化镧微球,样品的壳层数能够通过前驱体的负载量及煅烧梯度控制。通过对样品的分析表征,研究了样品的形貌结构及化学组成;又对样品的形成机理进行探究,提出了分段受热原理。通过该机理的研究分析,前驱体的吸附深度及模板的分段受热共同影响最终样品的形貌结构。特别是后者,更为缓慢的核壳受热分离过程使壳层具有更好的机械性能、良好的结构完整性和稳定性。它也使纳米颗粒堆积更为复杂进而导致样品具有更丰富的活性位点。基于此,我们提出的分段受热机理为合成具有相似结构的材料提供理论依据。(3)、具有三层壳中空结构的分级孔氧化镧微纳米材料(记为THLM)作为污水处理中磷的吸附剂,研究其磷的移除性能。结果表明,样品THLM对磷具有大的单分子层吸附能力(最大吸附量达到109.02 mg P/g),并且随着吸附剂用量的增加其吸附性能逐级增加。同时,THLM与磷之间的吸附主要为化学作用及颗粒间的内扩散作用,其次THLM与磷间的吸附机理(即两者间的吸附作用关系)主要为配体转换机制。除此之外,THLM具有良好的酸碱适应性及循环吸附性能。基于以上研究,THLM作为磷的吸附材料用于污水处理具有良好的应用前景。(4)、初步探讨了可控合成具有多壳中空结构的分级孔羟基磷灰石和氧化锆微纳米材料。利用牺牲模板法合成单层、双层及三层壳中空结构的分级孔羟基磷灰石和氧化锆微球,其样品的壳层数能够通过模板用量控制。通过对样品的分析表征,研究了样品的形貌结构及化学组成,并认识到前驱体在吸附于模板前的离子化作用对样品形貌起到关键性作用。特别是羟基磷灰石的合成研究,对于合成类似结构的复杂磷酸盐具有指导意义。
[Abstract]:Since the 21st century, the material industry has made great progress and promoted the high-speed development of the society as one of the important industries of the modern industry. the hollow core-shell material, in particular the micro-nano material of the multi-shell hollow structure, has the advantages of large specific surface area, rich active site, low density, short mass transfer path and wide cavity structure, There are important developments in the fields of biological medicine and environmental protection, and it is of great concern to people. At the same time, the material of graded pore, that is, a class of materials with different hierarchical pore structures (with two or more pore structures, such as small pores, mesopores, meso-pores, etc.) on the surface of the micro-nano material, has also gradually attracted the attention of the people. The complex pore structure gives the material not only more active sites and larger specific surface area, but also greatly improves the mass transfer efficiency and reduces the mass transfer resistance. The micro-nano material with the multi-shell hollow structure and the hierarchical pore structure has good development and application prospect. In this paper, based on the research status of the hierarchical pore material of the multi-shell hollow structure, the hierarchical pore micro-nano-material with the multi-shell hollow structure is successfully controlled by using the sacrificial template method. And the number of the shell layers of the sample shell can be controlled by adjusting the reaction condition. The chemical composition, morphology and application of the sample were characterized by X-ray diffraction, field emission scanning electron microscope and transmission electron microscope. And the formation mechanism of the sample is studied and discussed, and a solid theoretical foundation and experimental basis for guiding the synthesis of the graded pore micro-nano material with the multi-shell hollow structure are provided. The application of the composite structure micro-nano-material in the field of electrochemical and environmental protection was analyzed and the structure-effect relationship was discussed. And provides a reliable experimental basis for further optimizing the multi-shell hollow structure of the graded pore material and further improving the performance. In this paper, the following work is carried out: (1) to control the synthesis of porous silica micro-nano-materials with multi-shell hollow structure, and to study its formation mechanism and electrochemical performance. And the shell number of the sample can be controlled by the loading amount of the precursor by using the sacrificial template method to synthesize the graded-hole silicon dioxide microsphere with the hollow structure of the single layer, the double layer and the three-layer shell. The morphology and chemical composition of the samples were studied by the analysis and characterization of the samples, and the formation mechanism of the samples was further studied. The adsorption depth of the precursor on the template was found to play a key role in the morphology of the samples. The electrochemical performance of the sample was studied as the negative electrode of Li-ion battery. The results show that with the increase of the shell number of the silica, the charge-and-discharge ratio increases in turn. In particular to a hierarchical pore silica microsphere with a three-layer shell hollow structure, which not only has high charge and discharge ratio capacity but also has good cycle stability. (2) the micro-nano-material with the hierarchical pores of the multi-shell hollow structure can be controlled and synthesized, and the forming mechanism and the removal performance of the phosphorus are studied. By using the sacrificial template method to synthesize the graded-hole oxidized polystyrene microsphere with the hollow structure of the single layer, the double layer and the three-layer shell, the shell number of the sample can be controlled by the loading of the precursor and the sintering gradient. The morphology and chemical composition of the samples were studied by the analysis and characterization of the samples, and the formation mechanism of the samples was investigated. Through the research and analysis of the mechanism, the adsorption depth of the precursor and the sectional heat of the template influence the appearance structure of the final sample. In particular the latter, the more slow core-shell heat separation process enables the shell to have better mechanical properties, good structural integrity and stability. It also makes the nanoparticle build-up more complex and results in a more abundant active site for the sample. Based on this, the proposed segmented heating mechanism provides a theoretical basis for the synthesis of materials with similar structure. And (3) a graded-hole-oxidized micro-nano-material (called THLM) with a three-layer shell hollow structure is used as an adsorbent for phosphorus in the sewage treatment, and the removal performance of the phosphorus is studied. The results show that the sample THLM has a large adsorption capacity (maximum adsorption amount of 109.02 mg P/ g) for phosphorus, and the adsorption performance of the sample is increased gradually with the increase of the amount of the adsorbent. At the same time, the adsorption between THLM and phosphorus is mainly the chemical action and the internal diffusion of the particles, and then the adsorption mechanism between the THLM and the phosphorus (that is, the relationship between the adsorption of the two) is mainly the ligand conversion mechanism. In addition, the THLM has good acid-base adaptability and cyclic adsorption performance. Based on the above research, THLM has a good application prospect as a phosphorus adsorption material for sewage treatment. (4) A preliminary study on the controllable synthesis of graded-pore hydroxyapatite and oxide micro-nano-materials with a multi-shell hollow structure. By using the sacrificial template method to synthesize the graded-hole hydroxyapatite and the oxygen-oxide microsphere of the hollow structure of the single-layer, the double-layer and the three-layer shell, the shell number of the sample can be controlled by the amount of the template. The morphology and chemical composition of the samples were studied by the analysis and characterization of the samples. In particular, the synthesis of hydroxyapatite is of great significance in the synthesis of complex phosphate with similar structure.
【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1
本文编号：2478823
[Abstract]:Since the 21st century, the material industry has made great progress and promoted the high-speed development of the society as one of the important industries of the modern industry. the hollow core-shell material, in particular the micro-nano material of the multi-shell hollow structure, has the advantages of large specific surface area, rich active site, low density, short mass transfer path and wide cavity structure, There are important developments in the fields of biological medicine and environmental protection, and it is of great concern to people. At the same time, the material of graded pore, that is, a class of materials with different hierarchical pore structures (with two or more pore structures, such as small pores, mesopores, meso-pores, etc.) on the surface of the micro-nano material, has also gradually attracted the attention of the people. The complex pore structure gives the material not only more active sites and larger specific surface area, but also greatly improves the mass transfer efficiency and reduces the mass transfer resistance. The micro-nano material with the multi-shell hollow structure and the hierarchical pore structure has good development and application prospect. In this paper, based on the research status of the hierarchical pore material of the multi-shell hollow structure, the hierarchical pore micro-nano-material with the multi-shell hollow structure is successfully controlled by using the sacrificial template method. And the number of the shell layers of the sample shell can be controlled by adjusting the reaction condition. The chemical composition, morphology and application of the sample were characterized by X-ray diffraction, field emission scanning electron microscope and transmission electron microscope. And the formation mechanism of the sample is studied and discussed, and a solid theoretical foundation and experimental basis for guiding the synthesis of the graded pore micro-nano material with the multi-shell hollow structure are provided. The application of the composite structure micro-nano-material in the field of electrochemical and environmental protection was analyzed and the structure-effect relationship was discussed. And provides a reliable experimental basis for further optimizing the multi-shell hollow structure of the graded pore material and further improving the performance. In this paper, the following work is carried out: (1) to control the synthesis of porous silica micro-nano-materials with multi-shell hollow structure, and to study its formation mechanism and electrochemical performance. And the shell number of the sample can be controlled by the loading amount of the precursor by using the sacrificial template method to synthesize the graded-hole silicon dioxide microsphere with the hollow structure of the single layer, the double layer and the three-layer shell. The morphology and chemical composition of the samples were studied by the analysis and characterization of the samples, and the formation mechanism of the samples was further studied. The adsorption depth of the precursor on the template was found to play a key role in the morphology of the samples. The electrochemical performance of the sample was studied as the negative electrode of Li-ion battery. The results show that with the increase of the shell number of the silica, the charge-and-discharge ratio increases in turn. In particular to a hierarchical pore silica microsphere with a three-layer shell hollow structure, which not only has high charge and discharge ratio capacity but also has good cycle stability. (2) the micro-nano-material with the hierarchical pores of the multi-shell hollow structure can be controlled and synthesized, and the forming mechanism and the removal performance of the phosphorus are studied. By using the sacrificial template method to synthesize the graded-hole oxidized polystyrene microsphere with the hollow structure of the single layer, the double layer and the three-layer shell, the shell number of the sample can be controlled by the loading of the precursor and the sintering gradient. The morphology and chemical composition of the samples were studied by the analysis and characterization of the samples, and the formation mechanism of the samples was investigated. Through the research and analysis of the mechanism, the adsorption depth of the precursor and the sectional heat of the template influence the appearance structure of the final sample. In particular the latter, the more slow core-shell heat separation process enables the shell to have better mechanical properties, good structural integrity and stability. It also makes the nanoparticle build-up more complex and results in a more abundant active site for the sample. Based on this, the proposed segmented heating mechanism provides a theoretical basis for the synthesis of materials with similar structure. And (3) a graded-hole-oxidized micro-nano-material (called THLM) with a three-layer shell hollow structure is used as an adsorbent for phosphorus in the sewage treatment, and the removal performance of the phosphorus is studied. The results show that the sample THLM has a large adsorption capacity (maximum adsorption amount of 109.02 mg P/ g) for phosphorus, and the adsorption performance of the sample is increased gradually with the increase of the amount of the adsorbent. At the same time, the adsorption between THLM and phosphorus is mainly the chemical action and the internal diffusion of the particles, and then the adsorption mechanism between the THLM and the phosphorus (that is, the relationship between the adsorption of the two) is mainly the ligand conversion mechanism. In addition, the THLM has good acid-base adaptability and cyclic adsorption performance. Based on the above research, THLM has a good application prospect as a phosphorus adsorption material for sewage treatment. (4) A preliminary study on the controllable synthesis of graded-pore hydroxyapatite and oxide micro-nano-materials with a multi-shell hollow structure. By using the sacrificial template method to synthesize the graded-hole hydroxyapatite and the oxygen-oxide microsphere of the hollow structure of the single-layer, the double-layer and the three-layer shell, the shell number of the sample can be controlled by the amount of the template. The morphology and chemical composition of the samples were studied by the analysis and characterization of the samples. In particular, the synthesis of hydroxyapatite is of great significance in the synthesis of complex phosphate with similar structure.
【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1
【参考文献】
相关期刊论文 前1条
1 高家诚,张亚平;羟基磷灰石生物陶瓷材料的现状和发展[J];材料导报;1991年06期
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