类丁二炔凝胶复合材料的辐射效应研究

发布时间：2018-05-08 19:35

本文选题：类丁二炔 + 吸收剂量　；参考：《中国工程物理研究院》2015年硕士论文

【摘要】：剂量控制是核技术应用中辐照质量控制的一个关键因素,需要通过精确的方法进行测量,以保证受辐照物质的吸收剂量满足要求。在辐射加工过程、核电机组内、肿瘤的放射治疗和一些特殊狭小异形环境的科学实验中需要进行三维空间的剂量标定,这就要求剂量计具有三维、高精度、灵敏和可塑的特性。目前常用的辐射剂量计主要包括量热计、电离室剂量计、硫酸亚铁(Fricke)剂量计、自由基剂量计和薄膜剂量计等。相比之下,凝胶剂量计具有体积小、制备简单、测试方便等优点,并且能够在特殊的狭小异形环境中进行三维空间的剂量测定。类丁二炔受到电离辐照后会发生辐射聚合反应,产生明显的颜色变化。由于其吸光度响应与吸收剂量相关,因此可以利用类丁二炔受辐照前后的吸光度变化来表征吸收剂量。根据这一特性,可以将类丁二炔与凝胶载体相结合制备出含类丁二炔的凝胶复合材料,用于三维空间剂量分布的测定。本文中使用的类丁二炔为10,12-二十五碳二炔酸,通过旋转蒸发仪蒸干成膜,加入去离子水后超声,自组装形成囊泡溶液。将其固载于选取的凝胶载体之中,制备成具有辐射变色响应特性的凝胶复合材料。利用60Co-γγ辐射源对类丁二炔和凝胶复合材料进行辐照实验,详细研究了类丁二炔辐射反应机理和类丁二炔复合材料的剂量响应、剂量率效应、辐射后效应和温度效应。为避免高剂量率γ辐照源的准直性较差带来的误差影响,利用电子加速器考察了类丁二炔囊泡在凝胶体系中的扩散效应。最终本论文得出以下结论：1.琼脂糖和丙烯酰胺两种凝胶体系经γ辐照后的力学性能和化学性质均有所改变。琼脂糖凝胶在辐照过程中出现一定程度的降解,力学性能随吸收剂量的增加而降低,体系经辐照后出现羰基,并生成少量的无害气体。丙烯酰胺凝胶在辐照过程中发生二次交联,随着吸收剂量的继续增加,5 k Gy之后发生降解,其化学结构稳定,经辐照后没有新的官能团产生,辐照后产生极少量的无害气体。2.通过对类丁二炔囊泡的辐射变色机理研究发现,类丁二炔囊泡体系经γ射线辐照后,体系中水辐解产生的·H或·OH等自由基引发类丁二炔单体聚合,分子结构由C≡C-C≡C的π-π共轭逐渐转变为[C≡C-C=C]n的大π键共轭结构从而显色。类丁二炔囊泡体系经γ辐照后主吸收峰位于660 nm左右,吸光度随吸收剂量增大而增大；拉曼光谱的特征吸收峰向低波数移动同样可归因于随吸收剂量的增大,共轭体系变大,导致分子振动能级降低。3.以琼脂糖凝胶为载体和丙烯酰胺凝胶为载体的类丁二炔凝胶复合材料分别在500～2000 Gy和50～2000 Gy的吸收剂量范围内具有良好的线性响应；两种复合材料总吸收剂量相同的情况下吸收剂量响应与所研究的剂量率范围(0.1～40 Gy/min)无关；样品辐射后效应不明显,辐照后24 h体系吸光度基本不变；同时两种凝胶复合材料的剂量响应不受分次辐照的影响,随温度变化有一定程度波动。4.经准直的电子束辐照,复合材料的变色范围随时间的推移无明显变化。由于类丁二炔囊泡被固载于凝胶体系之中没有出现扩散现象,因此类丁二炔凝胶复合材料可以精确记载三维空间的剂量分布信息。5.本论文首次成功制备了以类丁二炔囊泡作为显色剂的凝胶复合材料。在三维空间对γ射线具有良好的线性响应,为凝胶剂量计的进一步发展提供了可参考的新方向。
[Abstract]:Dose control is a key factor in the radiation quality control of nuclear technology applications. It needs to be measured by a precise method to ensure that the absorbed dose of the irradiated material meets the requirements. In the radiation processing process, the three dimensional space needs to be carried out in the scientific experiments of the nuclear motor group, tumor radiation therapy and some special narrow and heteromorphic environments. Dose calibration, which requires the dosimeter to have three dimensional, high precision, sensitive and plastic characteristics. The current radiation dosimeters mainly include calorimeter, ionization chamber dosimeter, Fricke dosimeter, free radical dosimeter and thin film dosimeter. In contrast, the gel dosimeter is small in volume, simple in preparation and convenient in testing. It can be used to measure the dose of three-dimensional space in a special narrow and special-shaped environment. The radiation polymerization of the two alkyne can occur after ionizing radiation, which produces obvious color changes. As the absorbance response is related to the absorbed dose, the absorption of the butyrate two acetylene can be used to characterize the absorption of the absorbance before and after irradiation. According to this characteristic, the two alkynes of butyl two can be combined with gelatin carrier to prepare the gel composite containing two alkyne, which is used for the determination of the dose distribution in three-dimensional space. The dicyne two acetylene is used in this paper, which is twenty-five carbon and two alkynic acid, and is steamed by a rotary evaporator to form a film, adding deionized water after ultrasonic and self assembling to form a capsule. A gel composite was prepared in a selected gel carrier and prepared into a selected gel carrier. The 60Co- gamma ray radiation source was used to irradiate the two alkyne and gel composite materials. The radiation reaction mechanism of the butylene two acetylene and the dose response and dose rate effect of the butylene two alkyne composite were studied in detail. Post radiation effect and temperature effect. In order to avoid the error caused by the poor collimation of high dose rate gamma radiation source, the diffusion effect of two alkyne vesicles in the gel system was investigated by electron accelerator. Finally, the following conclusion was drawn: 1. the mechanical properties of two kinds of agarose and acrylamide gel systems after gamma irradiation. The chemical properties of the agarose gel were degraded to a certain extent. The mechanical properties of the gel decreased with the increase of the absorption dose. The carbonyl group appeared after irradiation and produced a small amount of harmless gas. The acrylamide gel occurred two times in the irradiation process, followed by the continued increase of the absorbed dose, after 5 K Gy. The chemical structure is stable, and the chemical structure is stable. After irradiation, no new functional group is produced. After irradiation, a very small amount of harmless gas.2. is produced through the study of the mechanism of radiation discoloration of the two alkyne vesicles. After gamma ray irradiation, the two alkyne vesicles in the system are irradiated by radiolysis. The free radical initiating two alkyne monomers, such as H or. The molecular structure is transformed from the pi - pi conjugation of C C-C C to the large pi bond structure of [C C-C=C]n. The absorption peak of the two alkyne vesicle system is about 660 nm, and the absorbance increases with the absorption dose, and the absorption peak of the Raman spectrum is also attributable to the absorption dose. With the increase of the conjugated system, the molecular vibration energy level is reduced by.3., and the two alkyne gel composites with agarose gel as the carrier and the acrylamide gel as carrier have good linear response in the range of 500~2000 Gy and 50~2000 Gy, respectively. The two composite materials have the same total absorption dose. The dose response has nothing to do with the dose rate range (0.1 ~ 40 Gy/min). The effect of the sample after radiation is not obvious. The absorbance of the 24 h system after irradiation is basically unchanged. At the same time, the dose response of the two gel composites is not affected by the fractional irradiation, and the.4. is irradiated by the collimated electron beam with a certain range of temperature variation. The color change range has no obvious change with time. As the two alkyne vesicles are immobilized in the gel system, there is no diffusion in the gel system. Therefore, the dosing two alkyne gel composites can accurately record the dose distribution information of the three-dimensional space.5. in this paper, the gel composite of the two alkyne vesicles is prepared for the first time in this paper. The material has good linear response to gamma rays in three dimensional space. It provides a new direction for further development of gel dosimeter.

【学位授予单位】：中国工程物理研究院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ427.26;TB33

【共引文献】