Preparation And Property Manipulation Of Novel Composites Of Carbon Materials/organized Molecular Assemblies Of Surfactants

Carbon nanomaterials include zero dimensional fullerenes, one dimensional (1D) carbon nanotubes (CNTs), two dimensional (2D) graphene and three dimensional (3D) diamond, etc. Most of them have excellent properties of mechanical, electrical, thermal, biocompatible and other characteristics, which is the brightest star in the field of nanotechnology. Carbon became the only element to get this prize twice, thus it set off a wave of the research of carbon materials. The organic/inorganic composite material was built by doping carbon nanomaterial into surfactant molecular organized assembly. Due to the interaction between the two material, the composite material exhibits various components in addition to its nature. Surfactant organized assembly (also known as amphiphilic molecular organized assembly) is formed when the surfactant molecules reached a certain concentration in solution, including micelle, vesicle, liquid crystal, gel, etc. Among them, lyotropic liquid and gel are more special. They have good biological compatibility and with a wide range of applications in nature, daily life, production and living body.In recent years, the template function of surfactant organized assembly was used to prepare nano-functional material, which received widespread attention. By changing the type, specie, concentration and other factors of surfactant, we can control the combination of surfactant organized assembly effectively which finally obtained to meet people’s needs of organic/inorganic composite materials. In this thesis, we selected three kinds of carbon materials: CNTs, graphene and graphene oxide(GO), and they were doped into lyotropic liquid crystals or biological supramolecular hydrogel to prepare composites with different characteristics, as follows:Firstly, we incorporated CNTs into a lyotropic liquid crystal (LLC) matrix formed by a nonionic surfactant (n-dodecyl tetraethylene monoether, C12E4) at room temperature, and this process were implement by spontaneous phase separation which were induced by different high molecular weight polymer of PEG Effect of molecular weight and concentration of PEG and the concentration of carbon material were study. Polarized optical microscopy images, small-angle X-ray scattering, Raman spectra and rheological property were measured. The result indicated molecular weight and concentration of PEG had a significant impact on the phase separation process and the property of the CNTS/C12E4 composites. Moreover, Raman spectra, POM image and SAXS results indicated that CNTs were incorporated into LLC matrix without damage the structure of the matrix.Secondly, we compared the difference between graphene and graphene oxide doped into LLC matrix formed by C12E4. The graphene/C12E4 composites and graphene oxide/C12E composites were characterized by transmission electron microscopy (TEM), POM, small-angle X-ray scattering (SAXS) and rheological measurements. The results of SAXS indicated that both of graphene and GO are dispersed well in the LLC matrix formed by C12E4, the interaction between LLC matrix and carbon materials were occurred. Due to the different properties between graphene and GO, graphene oxide interacted with the hydrophilic part of LLC matrix while graphene interacted with the hydrophobic part. Finally, phase separation method was used to confirm the mechanism of graphene/C12E4/PEG system and GO/C12E4/PEG system.Thirdly, we incorporated graphene oxide into a composite LLC matrix formed by C12E4 and C12mimBr (ionic liquids, ILs). The study of composite LLC matrix with GO materials and it’s the temperature resistance were investigated. The composite materials were characterized by POM image, rheological measurement and SAXS, the results indicated that the addition of carbon materials were helpful for mechanical properties of the system. Because ionic liquids are resistance to temperature, the composite liquid crystals have a better property of temperature resistance than liquid crystals formed by single non-ionic surfactant. Moreover, the addition of GO material enhanced temperature resistance of the composite liquid crystals. So the composite liquid crystal formed by ionic liquids and the traditional surfactant enriched the variety of liquid crystal template, and explored a new way for the application of liquid crystal material.Lastly, we explored the effects of GO concentrations and salt concentrations on the gelation of NaDC hydrogels, and the gel’s application on dye absorption. NaDC/GO/PBS hydrogels were characterized by phase behavior observation, TEM, SEM, XRD, Fourier transform infrared (FT-IR) spectra, X-ray powder diffraction (XRD) and rheological measurements. Results showed that graphene oxide were well dispersed in NaDC hydrogel and the addition of graphene oxide enhanced the mechanical strength of the hydrogel. Furthermore, the concentration of PBS could enhance the mechanical properties as well. In the dye adsorption tests, NaDC/GO composite hydrogels were swelling without dissolving and had an ability to absorb the dye, while the NaDC hydrogels without GO were dissolved in MB aqueous solution finally.