Preparation Of Graphene Oxide Modified Polyamide 6 Film And Its Application In Photothermal Conversion

In recent years,solar energy has attracted people's attention because of its green,renewable and high economic benefits.All the light radiation in the solar light range can be converted into heat energy through the photothermal conversion process.Therefore,the solar-powered water treatment process is considered as an ideal water resource regeneration strategy.In the process of exploration,scientists gradually developed the idea of hot plasma,which uses photothermal conversion materials to directly absorb sunlight and generate nanoscale hot spots,ultimately improving photothermal conversion efficiency.Based on the above theoretical basis,this paper successfully obtained two kinds of photothermal conversion materials through modified polyamide 6(PA6)for application in solar evaporation experiment.The specific contents are as follows:(1)The modified PA6 composite material was synthesized through a simple and efficient one-pot method to realize the simultaneous progress of polymerization,high-temperature reduction and grafting of graphene oxide,and then the non-solvent induced phase separation process by adjusting the ratio of the pore-forming agent Li Cl,a modified PA6 membrane with fast self-stretching performance was obtained as a photothermal conversion material.With its rough honeycomb surface structure,good hydrophilicity and the construction of multiple water supply channels,the entire system exhibits stronger light absorption and evaporation efficiency,with an optical absorption rate as high as 99.8%in the wavelength range of 200-2500 nm.In addition,the modified PA6 membrane evaporation system has the characteristics of long-term stability,low cost,strong acid and alkali corrosion resistance,and it has good practical value in seawater desalination,sewage treatment and other applications.(2)Au nanoparticles(Au NPs)were synthesized by the traditional sodium citrate method,and linearly assembled Au NPs were obtained after modification.Using the modified PA6 membrane as the base membrane,the Au NPs/PA6 composite membrane(AU/PA6)were obtained by vacuum filtration.The effects of different conditions such as light-to-heat conversion performance,thermal insulation performance and light power on the evaporation performance of AU/PA6 composite membranes were explored.When the illumination power is 1 k W m^-2,the steam generation rate of the AU/PA6 composite membrane reached 1.12 kg m^-2h^-1;after optimizing the evaporation conditions,the steam generation rate reached 2.08 kg m^-2h^-1,the evaporation efficiency reached 72.3%.In addition,the AU/PA6 composite membrane evaporation system also shows good stability and high efficiency in long-term use and sewage treatment applications.In summary,through a series of modification of PA6 composite material,this project successfully applied it to the solar energy evaporation experiment,which not only obtained excellent evaporation performance,but more importantly,based on the performance characteristics of the material,expanded the application range of PA6.It lays a foundation for the application of PA6 composite materials in photothermal transformation,and also points out the direction and emphasis for the follow-up research work.