溶液分散体系中纳米颗粒形态与表面状态的原位测量

发布时间：2018-05-30 17:17

本文选题：低场核磁共振(LF-NMR) + 表面官能团　；参考：《西华大学》2017年硕士论文

【摘要】：本文主要使用核磁共振技术(NMR)和紫外可见光光谱技术(UV-Vis)研究了溶液分散体系中纳米颗粒表面状态和形态的原位测量。研究主要分为两个部分:本文研究的一方面是第一次尝试采用低场核磁共振技术(LF-NMR)原位测量二氧化硅纳米颗粒的湿比表面积,根据不同二氧化硅纳米颗粒表面官能团的类别不同,确定二氧化硅纳米颗粒表面束缚水分子的数量以及相应表面官能团的数量。本文用该方法以修饰改性的二氧化硅纳米颗粒为例进行了实验分析对比,氨基修饰的二氧化硅纳米颗粒单位面积所含氨基个数为3.7个/nm~2;羧基修饰的二氧化硅纳米颗粒单位面积所含羧基个数为2.3个/nm~2;羟基修饰的二氧化硅纳米颗粒单位面积所含羟基个数为4个/nm~2。结果与文献相关报道一致,该技术证明可用于原位定性、定量分析纳米颗粒表面的物理化学性质。本文研究的另一方面是使用紫外可见光谱技术(UV-Vis)对溶液中的纳米颗粒吸光度进行实时检测、记录,经计算得到相应的浊度。基于瑞利散射近似理论(RGDA),该浊度可用于计算纳米颗粒粒径分布,对异相材料包覆的颗粒来说,可确定其包覆层厚度。基于光散射原理,该方法只适用于在紫外及可见光谱范围内存在零吸收的物质体系,在这种情况下,颗粒对光的散射作用是造成浊度(吸光度)的唯一原因。该技术成功实现了根据浊度确定纳米颗粒粒径及其包覆层厚度的研究,并且表现出可与动态光散射测量结果相媲美的准确性、灵敏性及方便性。以两个尺寸不同的聚苯乙烯微球包覆牛血清蛋白(BSA)为例进行了实验分析对比,浊度法计算测量的包覆层厚度分别为4.5nm和3.8nm,该结果与动态光散射(DLS)测量结果一致。并且以二氧化硅纳米颗粒为例,根据不同的分散时间进行测量,随着分散时间的增大,二氧化硅纳米颗粒的分散程度越好,当分散时间在15min以后,吸光度基本不再有明显变化,表明二氧化硅纳米颗粒分散程度基本稳定。上述实验结果与用其他传统方法得到的数据是一致的,所以该方法是可靠的。
[Abstract]:In this paper, the in-situ measurement of the surface state and morphology of nanoparticles in solution dispersion system was studied by means of NMR and UV-Vis-UV spectroscopy. The research is divided into two parts: on the one hand, the first attempt was made to measure the wet specific surface area of silica nanoparticles by using low field nuclear magnetic resonance (LF-NMRs) for the first time. According to the different types of functional groups on the surface of silica nanoparticles, the number of bound water molecules on the surface of silica nanoparticles and the number of corresponding surface functional groups are determined. In this paper, the modified silica nanoparticles were used as an example for experimental analysis and comparison. The number of amino groups per unit area of amino modified silica nanoparticles is 3.7 / nmm2; that of carboxyl modified silica nanoparticles is 2.3 / nmm2; and that of hydroxyl modified silica nanoparticles is 2.3 / nm-2. The number of hydroxyl groups in the product is 4 / nmm-2. The results are consistent with those reported in the literature. This technique can be used for in situ qualitative and quantitative analysis of the physicochemical properties of nanoparticles. On the other hand, the UV-Vis-UV spectroscopy is used to detect the absorbance of nanoparticles in solution in real time, record and get the corresponding turbidity by calculation. Based on the Rayleigh scattering approximation theory, the turbidity can be used to calculate the particle size distribution, and the thickness of the coating layer can be determined for the particles coated with heterogeneous materials. Based on the principle of light scattering, this method can only be applied to matter systems with zero absorption in the ultraviolet and visible spectrum. In this case, the scattering effect of particles on light is the only cause of turbidity (absorbance). This technique has successfully realized the study of determining the particle size and the coating thickness according to the turbidity, and has shown that the accuracy, sensitivity and convenience are comparable to those of the dynamic light scattering measurements. Taking two polystyrene microspheres coated with bovine serum protein (BSA) as an example, the thickness of the coating measured by turbidimetric method was calculated to be 4.5nm and 3.8 nm, respectively. The results are in agreement with those measured by dynamic light scattering (DLS). With the increase of dispersion time, the dispersion degree of silica nanoparticles is better. When the dispersion time is at 15min, the absorbance of silica nanoparticles does not change obviously. The results show that the dispersion degree of silica nanoparticles is basically stable. The experimental results are consistent with the data obtained by other traditional methods, so the method is reliable.
【学位授予单位】：西华大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1

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