CN-116380834-B - Solvent water content detection system and method based on terahertz time-domain attenuation total reflection method

CN116380834BCN 116380834 BCN116380834 BCN 116380834BCN-116380834-B

Abstract

The invention discloses a solvent water content detection system and method based on a terahertz time-domain attenuation total reflection method, and relates to the field of online detection of solvent water content by using a terahertz time-domain spectroscopy technology, wherein the system comprises a terahertz time-domain detection device, an ATR sensor module and a data processing terminal, wherein the terahertz time-domain detection device is used for transmitting terahertz signals to the ATR sensor module, receiving terahertz total reflection signals transmitted from the ATR sensor module and transmitting the terahertz total reflection signals to the data processing terminal; the device comprises a first ATR sensor module, a second ATR sensor module, a sample solvent on-line liquid taking device and a data processing terminal, wherein the first ATR sensor module is used for receiving a sample solvent to be detected and carrying out total reflection on terahertz signals by using the sample solvent to be detected, the second ATR sensor module is used for carrying out total reflection on the terahertz signals by using a standard sample solvent, the sample solvent on-line liquid taking device is used for controlling the sample solvent to be detected to flow through the first ATR sensor module, and the data processing terminal is used for calculating the water content of the sample solvent to be detected according to the terahertz total reflection signals. The invention can carry out online nondestructive detection on the water content of the solvent.

Inventors

SHANG LIPING
DUAN YONGWEI
LIU QUANCHENG
DENG HU
QU WEIWEI
WU ZHIXIANG
WEI WENQING

Assignees

西南科技大学

Dates

Publication Date: 20260508
Application Date: 20230113

Claims (6)

1. The solvent water content detection system based on the terahertz time-domain attenuation total reflection method is characterized by comprising a terahertz time-domain detection device, an ATR sensor module, a sample solvent on-line liquid taking device and a data processing terminal; The terahertz time-domain detection device is used for transmitting terahertz signals to the ATR sensor module, receiving terahertz total reflection signals transmitted from the ATR sensor module and transmitting the terahertz total reflection signals to the data processing terminal; the ATR sensor module comprises a first ATR sensor module and a second ATR sensor module; The ATR sensor module comprises a sample chamber, a sample inflow port, a sample outflow port, a sample containing chamber and a silicon prism; The reflecting surface of the silicon prism is the bottom surface of the sample chamber; the bottom surface of the sample containing cavity is in contact connection with the reflecting surface of the silicon prism, the sample containing cavity is provided with the sample inflow port and the sample outflow port, the sample solvent flows into the sample containing cavity through the sample inflow port, and the sample solvent flows out of the sample Rong Qiangshi through the sample outflow port; The terahertz signal is reflected by the reflecting surface of the silicon prism after entering from the incident surface of the silicon prism, so as to obtain the terahertz total reflection signal; the optical parameters of the ATR sensor module satisfy: ; Wherein, the For the incidence angle of terahertz waves at the reflective surface of the ATR sensor, The refractive index of the ATR sensor medium, The maximum refractive index of the solvent of the sample to be detected; the angle of the apex angle of the silicon prism is 51.6 DEG The first ATR sensor module is used for receiving the sample solvent to be detected conveyed by the sample solvent on-line liquid taking device and carrying out total reflection on the terahertz signal by utilizing the sample solvent to be detected; the second ATR sensor module is used for carrying out total reflection on the terahertz signal by using a standard sample solvent; The sample solvent online liquid taking device is used for controlling the sample solvent to be detected to flow through the first ATR sensor module; And the data processing terminal is used for calculating the water content of the sample solvent to be detected according to the terahertz total reflection signal.
2. The solvent water content detection system based on the terahertz time-domain attenuation total reflection method according to claim 1, wherein the sample solvent online liquid taking device comprises a peristaltic pump, an input pipeline and an output pipeline; The peristaltic pump is arranged on the input pipeline or the output pipeline and is used for controlling the solvent of the sample to be detected to flow through the first ATR sensor module; One end of the input pipeline is connected with a sample solvent to be detected; the other end of the input pipeline is connected with a sample inflow port of the first ATR sensor module, and the sample solvent to be detected flows into the first ATR sensor module through the input pipeline; One end of the output pipeline is connected with a sample solvent to be detected, the other end of the output pipeline is connected with a sample outflow port of the first ATR sensor module, and the sample solvent to be detected flows out of the first ATR sensor module through the output pipeline.
3. The terahertz time-domain-attenuated total reflectance-based solvent water content detection system according to claim 1, wherein the refractive index of the silicon prism is 3.42.
4. The method for detecting the water content of the solvent based on the terahertz time-domain total reflection method is applied to the solvent water content detection system based on the terahertz time-domain total reflection method, which is disclosed in any one of claims 1 to 3, and is characterized by comprising the following steps: The method comprises the steps of obtaining a first terahertz total reflection signal of an ATR sensor module in a solvent-free state to obtain a terahertz time domain reference signal, obtaining a second terahertz total reflection signal of different concentration sample solvents for total reflection of the terahertz signal to obtain terahertz time domain signals of different concentration sample solvents, obtaining a transfer function of the ATR sensor module corresponding to the different concentration sample solvents according to the terahertz time domain signals and the terahertz time domain reference signal of the different concentration sample solvents, calculating the total reflection coefficient and the dielectric constant of the different concentration sample solvents according to the transfer function of the ATR sensor module corresponding to the different concentration sample solvents by applying a Fresnel equation, determining the refractive index variation and the absorption coefficient variation according to the total reflection coefficient and the dielectric constant of the different concentration sample solvents, analyzing main components of the refractive index variation and the absorption coefficient variation, and determining the refractive index variation and the absorption coefficient variation with accumulation contribution higher than a set threshold value to obtain a final refractive index variation and a final regression coefficient variation; Acquiring a third terahertz total reflection signal of a sample solvent to be detected for carrying out total reflection on the terahertz signal, and obtaining a first terahertz time-domain sample signal; Obtaining a fourth terahertz total reflection signal of the standard sample solvent for carrying out total reflection on the terahertz signal, and obtaining a second terahertz time-domain sample signal; determining a transfer function of a first ATR sensor module according to the terahertz time-domain reference signal and the first terahertz time-domain sample signal; determining a transfer function of a second ATR sensor module according to the terahertz time-domain reference signal and the second terahertz time-domain sample signal; Applying a Fresnel equation according to the transfer function of the first ATR sensor module to obtain the total reflection coefficient and the dielectric constant of the sample solvent to be detected; Applying a Fresnel equation according to the transfer function of the second ATR sensor module to obtain the total reflection coefficient and the dielectric constant of the standard sample solvent; Determining the refractive index and the absorption coefficient of the sample solvent to be detected according to the total reflection coefficient and the dielectric constant of the sample solvent to be detected; Determining the refractive index and the absorption coefficient of the standard sample solvent according to the total reflection coefficient and the dielectric constant of the standard sample solvent; determining the refractive index variation and the absorption coefficient variation according to the refractive index and the absorption coefficient of the standard sample solvent and the refractive index and the absorption coefficient of the sample solvent to be detected; And according to the refractive index variation and the absorption coefficient variation, determining the water content of the sample solvent to be detected by applying the multiple linear regression model.
5. The method for detecting water content of a solvent based on terahertz time-domain reflectometry according to claim 4, wherein the main component analysis is performed on the refractive index variation and the absorption coefficient variation to determine a refractive index variation and an absorption coefficient variation with accumulated contributions higher than a set threshold, and obtain a final refractive index variation and a final absorption coefficient variation, specifically comprising: Performing principal component analysis on the refractive index variation and the absorption coefficient variation, and determining a covariance matrix of the refractive index variation and a covariance matrix of the absorption coefficient variation; determining a refractive index characteristic value of a covariance matrix of the refractive index variation and an absorption coefficient characteristic value of the covariance matrix of the absorption coefficient variation; arranging the refractive index characteristic values from large to small to obtain a refractive index characteristic value matrix; arranging the characteristic values of the absorption coefficient from large to small to obtain a characteristic value matrix of the absorption coefficient; according to the refractive index characteristic value matrix, determining the refractive index variation corresponding to the characteristic value with the accumulated contribution rate larger than a first set threshold value as a final refractive index variation; and determining the change amount of the absorption coefficient corresponding to the characteristic value with the accumulated contribution rate larger than the second set threshold value as the final change amount of the absorption coefficient according to the characteristic value matrix of the absorption coefficient.
6. The method for detecting the water content of the solvent based on the terahertz time-domain attenuated total reflection method of claim 4, wherein the multiple linear regression model is: ; Wherein B is the output of the multiple linear regression model, Is a constant of the linear regression of the data, As a linear regression coefficient of the amount of change in the absorption coefficient, As a linear regression coefficient of the amount of change in refractive index, Is a random variable.

Description

Solvent water content detection system and method based on terahertz time-domain attenuation total reflection method Technical Field The invention relates to the field of online detection of solvent water content by using a terahertz time-domain spectroscopy technology, in particular to a solvent water content detection system and method based on a terahertz time-domain attenuation total reflection method. Background Along with the development of the related field of modern fine chemical industry, higher requirements are put forward on the accurate detection and control of the solvent water content, an online rapid detection method of the solvent water content is researched, the optical parameter characteristics and inversion rules of the solvent water content under the terahertz attenuated total reflection time domain spectrum are searched, and the method has important industrial application value on the real-time detection of the solvent water content and the accurate measurement and control of the solvent water content. The detection method of the water content of the solvent is always a hot research problem in the field of domestic and foreign industrial detection. Disclosure of Invention The invention aims to provide a solvent water content detection system and method based on a terahertz time-domain attenuation total reflection method, by detecting the corresponding relation between the water content of a sample solvent with a preset concentration gradient and the optical parameters thereof, the solvent to be detected is sampled on line by utilizing the sample solvent on-line liquid taking device, and the water content of the solvent can be detected on line in a nondestructive mode. In order to achieve the above object, the present invention provides the following solutions: The system comprises a terahertz time-domain detection device, an ATR sensor module, a sample solvent on-line liquid taking device and a data processing terminal; The terahertz time-domain detection device is used for transmitting terahertz signals to the ATR sensor module, receiving terahertz total reflection signals transmitted from the ATR sensor module and transmitting the terahertz total reflection signals to the data processing terminal; the ATR sensor module comprises a first ATR sensor module and a second ATR sensor module; The first ATR sensor module is used for receiving the sample solvent to be detected conveyed by the sample solvent on-line liquid taking device and carrying out total reflection on the terahertz signal by utilizing the sample solvent to be detected; the second ATR sensor module is used for carrying out total reflection on the terahertz signal by using a standard sample solvent; The sample solvent online liquid taking device is used for controlling the sample solvent to be detected to flow through the first ATR sensor module; And the data processing terminal is used for calculating the water content of the sample solvent to be detected according to the terahertz total reflection signal. Optionally, the sample solvent online liquid taking device comprises a peristaltic pump, an input pipeline and an output pipeline; The peristaltic pump is arranged on the input pipeline or the output pipeline and is used for controlling the solvent of the sample to be detected to flow through the first ATR sensor module; One end of the input pipeline is connected with a sample solvent to be detected; the other end of the input pipeline is connected with a sample inflow port of the first ATR sensor module, and the sample solvent to be detected flows into the first ATR sensor module through the input pipeline; One end of the output pipeline is connected with the sample solvent to be detected; the other end of the output pipeline is connected with a sample outflow port of the first ATR sensor module, and the sample solvent to be detected flows out of the first ATR sensor module through the output pipeline; Optionally, the ATR sensor module comprises a sample chamber, a sample flow inlet, a sample flow outlet, a sample containment chamber, and a silicon prism; The reflecting surface of the silicon prism is the bottom surface of the sample chamber; the bottom surface of the sample containing cavity is in contact connection with the reflecting surface of the silicon prism, the sample containing cavity is provided with the sample inflow port and the sample outflow port, the sample solvent flows into the sample containing cavity through the sample inflow port, and the sample solvent flows out of the sample Rong Qiangshi through the sample outflow port; the terahertz signal is reflected by the reflecting surface of the silicon prism after entering from the incident surface of the silicon prism, so as to obtain the terahertz total reflection signal, and the terahertz total reflection signal is emitted from the emergent surface of the silicon prism. Optionally, the optical parameters of the ATR sensor module satisfy: Wherein, θ 1 is