【作者】 房文杰；

【导师】 屠天民；

【作者基本信息】 东华大学 ， 纺织化学与染整工程， 2011， 硕士

【摘要】 分光光度法具有灵敏度高、选择性较好、测定快速,仪器价格较低、使用面广等特点,是染色工作者测定染料浓度所用的基本方法,也是目前最具可行性的在线染料浓度检测手段。在线监测染色过程的染料浓度变化应该是染色技术进步的一个重要方向。应用分光光度法对染色过程中的染料浓度进行在线监测,具有方便、快速、成本低等优点。但国际上染液浓度在线监测技术目前还处于起步阶段,在生产中的应用基本上是空白,还有很多技术问题需要解决。其主要问题在于大范围内准确、快速地测得染浴中的染料浓度,尤其是混合染液的各个染料浓度测定。常用的分光光度法测定最大吸收波长相距较大的染料的混合染液浓度,误差较小。当两种染料颜色接近时,吸收光谱重叠严重,或者其中一个染料的浓度相对于其他组分很小的时候,测定误差较大。本课题期望通过分光光度法对染料浓度测试的深入探索,寻找适用于染色时染料浓度的测定方法及设备条件,为染色过程中的染料浓度在线监测技术的发展提供参考。课题首先通过染色和色差测定,获得实际生产中可能需要测定的染料浓度范围及拼染时的染料浓度比例范围。在现有的仪器和测定误差要求条件下,通过试差法和插值法得到可以测定的染料浓度范围和混合浓度比例范围。然后通过使用多种分析处理过程比较,探索突破现有装置检测限度的途径。最后,通过对染色实验过程的实际监测,探索有关方法和装置的应用效果。实验表明,实际染色需要测定的染料浓度范围约为0.0015-5g/L。常规分光光度计以固定光径的比色皿无法覆盖实际染色需要浓度范围,必须采用不同光径才可能将可测定的浓度范围扩大。通过两种染料拼染及采用常用的最大吸收波长-联立方程法测定双组分染液浓度,部分双组份浓度比例范围可以准确测定,但大多数情况下各种染料的实际染色拼混比例范围也远远超出了常规分光光度计可准确测定的范围。分别采用吸收光谱峰面积法、一阶导数法和一阶比值导数法对扩大双组份染液可准确测定的拼混比例范围进行了一定的探索。吸收光谱峰面积法相对最大吸收波长-联立方程法可测定的比例范围有一定扩大,但也无法涵盖实际染色时的所有比例范围。对于颜色相近的两种染料的混合染液浓度,采用吸收光谱峰面积法和一阶比值导数法有较小的测定误差。对于三组分染料混合染液的浓度测定,采用最大吸收波长-联立方程法和吸收光谱峰面积法得到的误差较一阶比值导数法小。通过活性染料染色的各种添加剂和染色条件对吸光度影响的试验,考察了中性盐、碱剂、温度的影响,并对此类影响作了修正及效果试验,获得了误差较小、适用于实际染色过程中浓度测定的数据修正处理方法。采用光纤光谱仪对染色时的染料浓度变化进行了实时测定。实验结果证实,采用光纤光谱仪测定染浴的染料浓度变化是较为理想的在线监测方法。但是采用此类光谱仪也存在着缺陷,即在染色初期,染浴的染料浓度过高,在最小光径下染浴的吸光度偏高,出现光谱数据不稳定的现象,需要更小光径的光谱仪进行测定。本课题的研究结果为染色过程中染料浓度的在线监测技术的可行性及发展提供了一定支持。但在现阶段染料浓度的在线监测要实现工业化应用还有不少困难,许多测定条件还有待深入研究,仪器设备性能还有待改良。更多还原

【Abstract】 With such merits as high sensitivity, good selectivity, rapid determination, a wide range of usage and lower price of the instruments, the spectrophotometry is the basic method for determination of dye concentration, which is also the most feasible means for online detection of dye concentration at present. Online monitoring of dye concentration in the dyeing process should be an important direction of dyeing technological progress. Online monitoring of dye concentration by spectrophotometry has many advantages, such as convenience, high-speed and low cost and so on. But the Online monitoring technique of dye concentration is still in the initial stage around the world, and essentially blank in the dyeing process now. There are many technical problems to be solved. The main problem is how to measure the dyestuff concentration of dye bath in a wide range rapidly and accurately, especially for the solution of mixed dyes.Normally,λmax of the dyes more different each other, the errors of determined by spectrophotometry will be smaller. When the dye’s color is close to the other, their absorption spectra overlap seriously, or the concentration of one component is relatively lower than others’, the measurement errors will be larger. In this paper, through in-depth exploration for the dye concentration determination by spectrophotometry, it is expected to obtain the determination methods of dye concentration and equipment conditions, in order to provide a reference for the development of online monitoring technology of dye concentration in the dyeing process.At first, through dyeing and color difference measurement, the dye concentration and its ratio range in combination dyeing possibly needed to determine in the practical production was obtained.Under the status quo of the instruments’conditions and measurement error’s requirements, the dye concentration and its ratio range of mixed dyes which can be measured by trial and error method and interpolation were also obtained. Then, a variety of analysis and treatment processes were compared to explore the approach to break through the limits of current testing device. Finally, through monitoring of the dyeing experiment process, the relevant methods and application result of the device were explored.Results showed that the concentration range of dye need to be measured in practical dyeing is about 0.0015-5g/L.For conventional spectrophotometer, the cuvette with fixed optical pathlength can not reach the practical concentration range of dye, so the application of different optical pathlengths to expand the range of concentration which can be determined is possible.Through combination dyeing of two dyes and their concentration determination by the maximum absorption wavelength-simultaneous equations method which is commonly used, parts of the concentration ratio range of two dyes can be accurately measured, but mostly, the concentration ratio range of blending dyes in practical dyeing exceeded what can be accurately measured by conventional spectrophotometer a lot. Absorption spectrum-peak area method, first order derivative and first derivative-ratio spectrophotometric method were applied to expand the ratio range of bi-component dyes which can be measured accurately was explored. Compared to the maximum absorption wavelength-simultaneous equations method, the absorption spectrum-peak area method has a larger ratio range of blending dyes, but it still can not reach all the proportion range in practical dyeing.For the mixed concentration of two dyes with similar color, a small measurement error was acquired by absorption spectra-peak area and first derivative-ratio spectrophotometric method. Maximum absorption wavelength-simultaneous equations and absorption spectra-peak area method were more accurate than first derivative-ratio spectrophotometric method for concentration determination of ternary mixture of dyes.Through influence test of additives and conditions in the dyeing process of reactive dyes on absorption, the influences of neutral salt, alkali and temperature were investigated, which were modified and which effect tests were carried out, and a data correctional solution with small error and applicability on concentration determination of dye in the dyeing process was acquired.The change of dye concentration in dyeing process was real-time determined by fiber optical spectrometer. Experimental results showed that, measuring the dye concentration in the dye bath using fiber optical spectrometry is a relatively ideal method for online monitoring. But its defect exists, that is, the absorption of the dye bath is extremely high even if the optical pathlength is minimum, which is due to high dye concentration in the early stage of dyeing process, thus the spectrometer with a smaller optical pathlength is required for online monitoring.The results of the project provide some supports for the feasibility and development of online monitoring technology of dye concentration in dyeing process. However, to achieve the industrial application of online monitoring of dye concentration, there are many difficulties to be solved currently, and many determination conditions remain to be further studied and the equipment performance has yet to be improved.更多还原