Preparation And Properties Of Ordered LB Films Based On Carbon Spheres And Amino Modified Multi-Walled Carbon Nanotubes Assembly Units

Carbon microspheres（CS）are zero dimensional carbon materials with a fullerene structure.Due to their many excellent properties,they are used as thin film materials,high performance liquid chromatography fillers,adsorbent carriers,catalyst carriers,stealth materials,and anode materials for lithium batteries.Carbon nanotubes are tubular fullerenes,which have many excellent properties due to their unique structure.After the amination modification,the surface of carbon nanotubes not only added amino active groups,but also their tubular fullerene structure was not damaged.Moreover,the solubility and dispersity of the modified aminoated carbon nanotubes are improved,making them suitable for LB technology.Molecular self-assembly is a technology that utilizes non covalent bond forces between molecules,enabling molecules to aggregate from disordered and disordered states into ordered nanoscale aggregates.The molecular self-assembly technology at the gas-liquid interface is called Langmuir Blodgett（LB）technology.This technology uses special LB instruments to prepare functional composites by physically force at the air-liquid interface.In this experiment,we first synthesized self-assembled Langmuir composite films of CS with methylene blue（MB）,neutral red（NR）,congo red（CR）,and safranine T（ST）by using LB technology,and studied their applications in acid alkaline gas sensing,Raman enhancement,and photoelectric conversion.It was found that CS/CR composite films have good acid/alkaline gas sensitivity,and their characteristic absorption peaks have significant shifts in the ultraviolet visible spectral region.In addition,through surface enhanced Raman scattering（SERS）experiments,and calculating its enhancement factor（EF）and relative standard deviation values,it was proved that the prepared composite LB film has good Raman enhancement performance,excellent reproducibility and uniformity,and is suitable for the detection of trace molecules.Through the study of photoelectric conversion,experiments have proved that the CS/NR composite film has a high carrier mobility,providing a reference for the further development of CS based optoelectronic devices.Secondly,using the same method,a composite LB film of aminated carbon nanotubes（MWCNTs-NH₂）with methylene blue（MB）,neutral red（NR）,and safranine T（ST）was prepared.Its acid alkaline gas sensing performance,Raman enhancement performance,and photoelectric conversion performance were also studied.The prepared MWCNTs-NH₂/MB-40 composite film has good Raman enhancement performance,repeatability and uniformity.In order to further explore the interaction mechanism between MWCNTs-NH₂ and dyes,MWCNTs-NH₂/dye composite LB films were obtained by using LB technology,and their photoelectric conversion properties were studied.The experimental results show that MWCNTs-NH₂/MB composite film has good photocurrent enhancement performance and stable usage performance.