Comparative Study on Dispersion of Carbon Nanofibers and Enhancement on Mechanical Property and Microstructure in Cement Composites.

Carbon nanofibers (CNFs) could not be distributed evenly in cement composites due to their high specific surface area and van der Waals force, and the poor dispersion of CNFs significantly influenced the performance of cement composites. Therefore, uniform dispersion of CNFs plays a significant role in the properties of cement composites. This study mainly investigated the cement composite samples with CNFs treated respectively by methyl cellulose (MC), sodium dodecyl sulfate (SDS) and MC+SDS. The UV-vis spectroscopy and optical microscopy results showed that the dispersion of CNFs in the MC+SDS solution was much better than that in MC and SDS solution. MC, SDS and MC+SDS solution improved the mechanical properties of CNFs reinforced cement composites, but the MC+SDS solution exhibited the greatest effect. Furthermore, the microstructure and morphology analysis indicated that uniform dispersed CNFs could accelerate the hydration process and phase formation, and improved the compactness and interfacial connection, so as to enhance the mechanical properties and microstructure of cement composites.