Migration Characteristics Of Atrazine And Paraquat In The Gold Channel

Nanochannel is the tubles or pores with diameter from 0.1 to 100 nanometers. Because of the unique size effect, it is exhibiting a great potential advantage and a good prospect in physical and chemical properties of materials, biomedical and other applications. Currently, nanochannel technology research mainly deals with the preparation of the membrane, the permeation behaviour of molecules throug the channel and related mechanism. This paper is mainly centered on the preparation process of gold nanochannels, the transport performance of pesticide through channels under external electric field to separate and determine the pesticide molecules.Atrazine(ATR), as a widely used herbicide, has a good effect on against broadleaf weeds. However, because of the poor absorption in sandy soil, it is easy eluted with the rain and irrigation into the ground, resulting in groundwater contamination. Atrazine hazards human health by breathing, ingestion or skin contact, and has proved to be a potential carcinogen and endocrine disruptor. Generally, herbicide is often separated and detected by gas chromatography-mass spectrometry, high performance liquid chromatography, liquid chromatography-mass spectrometry and supercritical fluid chromatography. Contrast to these analysis methods, nanochannel technology is more effective and has better performance. Details are presented in this thesis as follows:(1)An electroless deposition method was used to deposit gold within the pores of the polycarbonate template membrane. Au nanochannels with different diameters were successfully obtained by changing the deposition conditions. Scanning electron microscope, transmission electron microscope were used to characterize the pore size and the surface appearance.(2)The gold nanochannels with negative charge are hydrophobic. Atrazine and paraquat are different in structure. In aqueous solution, paraquat forms cation and atrazine is a hydrophobic molecular. Because of the role of the electrophoresis, paraquat will be directely transport through the nanotubules membrane under a constant voltage, resulting in the separation of atrazine and paraquat. (3)The cationic surfactant cetyltrimethylammonium bromide (CTAB) adsorbed on gold nanochannel surface with a negative charge due to the electrostatic interaction. Hydrophobic groups of the CTAB connect the water phase and the nanochannel surface was "hydrophobic state". At the micelle concentration of CTAB, the pore size would become smaller because micelle formed within the Au channels. The paraquat and atrazine migration characteristics in the gold channels were studied(4)L-cysteine and 3-mercaptopropionic acid were self-assembled on the Au nanochannels of polycarbonate template membrane. There are hydrogen adsorption between atrazine and modifier of the channels. The effects of metal ions on the hydrogen adsorption were studied here and possible reasons of this change were also discussed.In summary, we developed some new approaches to separate and detect pesticide by nanochannels. Some mechanisms in the transport process were proposed. We can expect to provide many theoretical supports for more widely practical application of nanaochannels.