| Essentail oil is an important chemical component of traditional Chinese medicine.It has many pharmacological effects such as anti-tumor,hypolipidemic,anti-atherosclerotic,anti-oxidation,antibacterial,antipyretic,anti-inflammatory,analgesic and anticonvulsant.Large-scale industrial production usually uses steam distillation to extract essentail oil.However,due to the high temperature and high pressure and short separation time of oil and water,the extraction process has low oil recovery rate and difficult oil collection.Oil-water separation has always been a problem that plagues the world.So,whether the new separation technology can be used to efficiently separate and obtain essentail oil is also a problem faced by the Chinese medicine industry.As a new technology,vapor permeate membrane technology is widely used in organic solvent dehydration,organic/organic mixture separation and in juice beverages,with low operating temperature,no phase change in separation process,no introduction of organic solvents,low energy consumption,no The advantages of pollution,etc.,have been widely used in the field of petrochemicals and the recovery of flavor substances in juices.However,the research on the separation of essentail oilfrom traditional Chinese medicine by steam infiltration technology is still in its infancy.In the early stage,the research team introduced steam permeable membrane technology into the oil-containing water body of traditional Chinese medicine.Based on the previous research,this paper further combined macroscopic experimental detection and micro-molecular dynamics simulation to analyze the separation process of common Chinese medicine essential oil in vapor permeable membrane.Through the law,the interaction between the compounds of the main structural types of essential oils of traditional Chinese medicines and membrane materials is clarified,aiming at the experimental and theoretical basis for the efficient separation of essential oils from traditional Chinese medicines.The research content of this thesis is divided into the following three parts:(1)Study on the suitability of steam infiltration technology for the separation of essentail oilfrom traditional Chinese medicine18 kinds of common Chinese medicine essentail oilwere used to prepare Chinese oil-containing water body.The 18 kinds of oil-containing water bodies were filtered by steam permeable membrane using PDMS/PVDF membrane.Membrane fouling is one of the main factors affecting the normal operation of the membrane separation process.Scanning electron microscopy showed that the surface and section of the membrane before and after the membrane were free from contaminants and no obvious damage to the structure,indicating the resistance of the membrane material.The ability to pollute and the suitability for the separation of essentail oils from traditional Chinese medicines.The permeability test of membrane filtration essentail oilshowed that 18 essentail oils could obtain clear and transparent essentail oilby steam infiltration,but the permeability of different kinds of essentail oils was greatly different;further detection of contact angle measurement between essentail oiland membrane material surface The results show that the higher the contact angle between the essentail oiland the surface of the membrane,the lower the transmittance.The above results show that the interaction between the main chemical components in the essentail oiland the membrane material is the key link in the separation of essentail oilfrom traditional Chinese medicine.(2)Consistency evaluation of essentail oilvapor permeable membrane filtration of traditional Chinese medicineQualitative analysis by GC-MS compared the changes in the chemical constituents in the essentail oilbefore and after the membrane.The collected PDMS/PVDF membrane permeate and the stock solution were qualitatively analyzed by GC-MS technique,and the relative percentage of the components was calculated by the area normalization method.It was found that the chemical constituents in the essentail oilbefore and after the membrane did not appear obvious.The change,that is,the type of the essentail oilin the essentail oilbefore and after membrane separation,has no obvious loss.At the same time,cluster analysis of the large components in the essentail oilshows that the olefins,alcohols and ketones can be grouped into one kind,which are expressed in the membrane separation process.Similar transmission rates,ethers and esters are also grouped into the same class,showing similarities through the law during the separation process.This finding provides theoretical basis and data support for the design of special separation membranes for the separation of special components.The content of main medicinal components in essentail oilbefore and after membrane was quantitatively analyzed by GC-MS.The content of the main medicinal components in the essentail oilbefore and after the membrane was quantitatively analyzed by GC-MS.It was found that the content of most components in the permeate was significantly higher than that of the original solution.The content of some components was not as high as that of the original solution,and it was still as high as 80%of the original solution.Further proves the feasibility of using steam infiltration technology to separate and concentrate the oily water body of essentail oil.Pharmacodynamic evaluation was carried out to study the difference in the efficacy of essentail oilstocks and permeates.Taking the essentail oilof Shichangpu as an example,the pharmacodynamics of the essentail oilbefore and after membrane separation were investigated.The previous study found that the species of essentail oilin the essentail oilbefore and after the membrane did not change,and the quantitative results showed that the main medicinal component β was detected by GC-MS.-The content of asarone was slightly decreased,but it was not significantly decreased compared with the original solution.The results of pharmacodynamic experiments showed that the permeate collected after membrane separation was not as effective as the original solution,but still had good curative effect on inhibiting inflammatory factors.The release can be achieved by increasing the dose to achieve the same effect as the stock solution,demonstrating the feasibility and safety effectiveness of using vapor permeable membrane technology for the separation of essentail oilfrom Acorus calamus.(3)Study on the mechanism of essentail oilvapor permeable membrane process of traditional Chinese medicine.The mechanism of vapor osmosis membrane separation experiments was carried out by simulating solutions of five different concentrations of monomer components in essentail oil.Because the chemical components in the essentail oilof traditional Chinese medicine are complex and diverse,the same component also shows different transmittance in the essentail oilsystem of different traditional Chinese medicines.Therefore,in order to study the permeation mechanism of different components in essentail oil,this study selected five kinds of common ones in the essentail oilof traditional Chinese medicine.The body composition(α-pinene,β-pinene,limonene,linalool and cinnamaldehyde)was studied by membrane mechanism.It was found that there is a common rule with the five components-as the concentration of the component increases,it passes through The rate of increase and then decrease is presumed to be related to the mechanism of "dissolution-diffusion" of the separation mechanism.As the concentration increases,the components dissolved in the membrane reach saturation,so that the excess components cannot continue to enter the membrane.This results in a decrease in transmittance.Molecular dynamics simulation techniques were used to study the adsorption between the five monomer components and the membrane and the state of motion within the membrane.The molecular dynamics simulation technique was used to study the separation mechanism at the molecular level.The results showed that the adsorption energy between the five components and the membrane was significantly higher than that between the water and the membrane.It is the van der Waals force,the electrostatic force does not work,and the intermolecular interaction is weak.Comparing the permeation rules of different components at the same concentration,it is found that the permeation of components is affected by the adsorption energy,adsorption coefficient,interaction energy and diffusion coefficient.That is to say,the dissolution and diffusion process play a decisive role in the membrane separation process—the dissolution-diffusion mechanism of vapor permeation membrane separation. |
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