Preparation And Properties Of Graphene Composites / Sodium Alginate

Taking sodium alginate(SA) as raw material preparation for marine biomass fibers exhibit flame retardant, high moisture absorption, anti-bacterial and biological compatibility and other outstanding features attracted widespread attention, easy degradation and poor physical performance as problems to be solved. Graphene as a new two-dimensional carbon material has a large specific surface area, is expected to be efficient free radical scavenger, effectively inhibit polymer degradation. In this thesis, graphene oxide (GO) filled SA composite material for the study, the research investigated the rheological behavior of suspensions of nanoparticles dispersed state in the polymer matrix, delve into GO significant impact on the degradation performance of the SA solution; prepared GO/SA nanocomposite fibers and systematic study of its physical properties.1. Different contents of GO prepared by solution blending method SA spinning solution, then use stress-type rotational rheometer to study its rheological properties. The results show that GO/SA composite spinning solution showed a typical shear thinning behavior, belong to pseudoplastic fluids. The addition of GO does not change the fluid types of the SA solution. With the increase of GO content, the viscosity of the complex solution increased gradually, newton platform area become shorter, shear thinned phenomenon is obvious. Dynamic rheological test results show that adding small GO can significantly increase the storage modulus and loss modulus of SA spinning solution, reflecting good dispersibility of GO nanosheets in SA solution, Cole-Cole curves also proved. The viscosity of the composite system is reduced with increasing temperature, through theoretical calculations found that the addition of GO reduces the viscous flow activation energy of the SA solution, the solution is less sensitive to temperature.2. System characterized the viscosity of GO/SA composite spinning solution change over time under different degradation conditions, the results showed GO at lower contents can be effectively suppressed SA degradation at room temperature and with the increase of temperature inhibition is gradually reduced. SA solution can easily occur degradation in the presence of small amounts of H2O2, degradation rate can reach89.8%after10hours, while after adding3wt%GO the degradation rate was only21.7%, the effect is significant, due to the GO excellent oxidation resistance. 3. Using wet spinning preparation GO/SA composite fibers, and characterize their structure and performance by XRD、TGA, etc. The results show that the GO uniformly dispersed in SA and did not cause changes in the SA fiber structure. Through the fiber tensile test showed that the addition of a small amount of GO make SA fiber mechanical strength increased by20%, thermal gravimetric analysis indicates that adding GO improve the thermal stability of the SA fiber, and the thermal stability increased with the increase of GO content. In addition, the salt tolerance and hydrogen peroxide resistance of GO/SA composite fiber have also been significantly improved.