Application Of Drop-based Microfluidic Devices And Absorbing Materials In The Treatments For Aqueous Samples

The treatments of aqueous samples are important issues in the fields of health caring, environment protecting and biological analysis. As these fields attract more and more interests, the need for the treatments of aqueous samples has increased dramatically and the requirements for these treatments have become much higher, which promotes the development and application of new methods, new technologies or new materials in the field of liquid treatments.Under these situations, we are focusing on the new technologies and new materials in the field of liquid treatments, and carry out some researches in these fields. Specifically, we choose microfluidic device as an example of the new technologies that are applied in liquid treatments, and we also choose modified functional substrates as well as carbon materials to represent the new materials in the field of liquid treatments. Using these technologies or materials, we demonstrate their applications in liquid treatments from different angles.In order to achieve faster, more automatic treatments of aqueous samples and make them more suitable for long-term monitoring, we studied the application of microfluidic devices in liquid treatments, and liquid-liquid extraction using monodispersed droplets was introduced. With the design of guiding tracks and absorbing channel in microfluidic chips, we overcame the problems for online collecting and absorbing of monodispersed droplets, and achieved effective separation and recycling of the droplets of extracting reagent from a continuously flowing sample. Using these monodispersed droplets of extracting reagent, detectable extraction of sample molecules was achieved in 30 sec, which indicated the great potentials of these microfluidic devices.To achieve liquid treatments with better control and promote the design or application of some relative devices or equipment, we fabricated the electrochemical responsive substrates and discussed their application in the treatments of protein solutions. During the fabrication of substrates, surface initiated atom transfer radical polymerization was used to get a plenty of reaction sites, and then host-guest interactions between β-cyclodextrin and ferrocene were introduced onto the surface to achieve the electrochemical responsive substrates. With these substrates, electrochemistry controlled transformation between the adsorption and anti-adsorption of protein was demonstrated, which indicated that this work was a valuable reference for the surface modification of some relative devices or equipment with electrochemical responsive molecules and promoted their electrochemistry controlled applications in the treatments of liquid samples.From the angle for more convenient usage in liquid treatments, we studied the direct usage of graphene oxide in the adsorption of β-estradiol from aqueous solutions. Comparing to other carbon materials such as carbon nanotubes or reduced graphene oxides, the preparation of graphene oxide avoided complex procedures or equipment and graphene oxide could stably disperse in aqueous solutions without further modifications, which was more suitable for the usage in aqueous solutions. Herein we found that the adsorption ability of graphene oxide for β-estradiol was similar with some other carbon materials, and they had potentials for direct usage to achieve more convenient and consumption saving treatments of aqueous samples.Through three different researching angles, we demonstrate that new technologies or new materials in the field of liquid treatments have a great diversity and many kinds of methods could be involved. In summary, our work have expanded the application of relative technologies or materials in the field of liquid treatments.