Dispersing Graphene in Hydroxypropyl Cellulose by Utilizing its LCST Behavior

A novel method for producing graphene/hydroxypropyl cellulose (HPC) composite with a fine dispersion of graphene is established. The thermoresponsive HPC, with low a critical solution temperature (LCST) behavior, becomes self-associated into nanospheres when its homogeneous solution is heated to a temperature higher than the LCST. The formed nanospheres of HPC can then clamp graphene layers and get them finely dispersed in solution and in the polymer matrix. Incorporating graphene via this method can largely prevent graphene from agglomeration. Compared with the conventional casting method, the proposed LCST method can further enhance the electrical conductivity of HPC/graphene composites by 23 orders of magnitude. The percolation threshold value of RGO loading is as low as 0.11 vol%.