Polymer-encapsulated hydrophilic carbon black nanoparticles free from aggregation

Poly(vinyl alcohol) (PVA) with high hydrolysis degree and poly(acrylamide) (PAM) was selected to encapsulate carbon black (CB) nanoparticles via a simple method of coacervation. Transmission electron microscopy (TEM) images clearly demonstrated that the successful encapsulation of the two polymers happened at the surfaces of CB nanoparticles. The particle size distribution measurements indicated that the majority of the obtained polymer-encapsulated CB (CB@polymer) nanoparticles has the nanoscale dimension, and that PVA is more suitable to prepare hydrophilic CB@polymer nanoparticles than PAM. The effect of the nonsolvent of PVA and the shear force during the encapsulation on the size of CB nanoparticles was discussed in detail.