Preparation Of Hydrophobic Indole-based Porous Material And Its Application In Oil-water Separation

The rise of many industries such as the production and life of human society will produce a large amount of oily wastewater,which seriously pollutes the ocean,lakes and other water bodies.Among them,oil extraction,incomplete thermal processing of solid dyes,and continuous occurrence of offshore oil transportation accidents are the main sources of oily wastewater discharge.For example,in the early twentieth century,oil spills occurred during oil extraction in the Gulf of Mexico and Bohai Bay.It has caused a devastating blow to the ocean and brought disasters to life and ecosystems.Therefore,the research on high-efficiency oil-water separation materials has great application value and scientific significance.First of all,the investigation of many materials used for oil-water separation found that,for other materials,porous materials have large pore volume,low skeleton density,and high specific surface area;the required group can be modified according to the application,and the pore structure can be adjusted;synthesis simple,high-yield,green,mild and other characteristics.In addition,many porous materials have encountered bottlenecks in degradation and recycling.Therefore,in order to avoid the secondary pollution of the porous material to the environment,the hemiacetal structure is selected to introduce to the absorbents.The porous material containing the hemiacetal structure can be degraded and recovered by adjusting the p H value,and the absorbent material can be re-used to oil-water separation again.This thesis mainly includes the following two research contents:（1）In the third chapter of this thesis,aerogel porous material（PCINA）,a superhydrophobic indole group was successfully prepared by sol-gel method using cystamine and 4,4’-bis（5-aminoindole）diphenylsulfone（INA）as monomers.The aerogel can be used for oil-water separation and exhibits superhydrophobic property（water contact angle is 150.3°）,a high specific surface area(31.93 m²?g^-1)and good oil adsorption capacity(19.94g?g^-1).Moreover,the efficiency of oil-water emulsion separation is?96%and the adsorption capacity as well as water contact angle is still high after multiple cycles.Through the hemiacetal structure,the goal of degradable recycling of porous materials is achieved.In addition,the desorption method of PCINA is a chemical desorption method which is different from the physical desorption method of other porous materials.（2）In the fourth chapter of this article,the superhydrophobic indole-based supramolecular porous material（TDINA）were successfully synthesized by freeze-drying using tryptamine and 3,3’-（（4-aminophenyl）methylene）bis（1H-indole）（DINA）.The porous material displays good superhydrophobic property（water contact angle is 151.8°）and is used for oil-water separation.It has a high specific surface area of 88.30 m²?g^-1 and perfect oil adsorption capacity(55.03 g?g^-1).Most importantly,the oil-water emulsion separation efficiency could achieve 99%.After many cycles,it still maintains a high adsorption capacity and water contact angle.This chapter realizes the chemical desorption recycling and degradable regeneration of porous adsorbent materials.