PMMA colloid particles stabilized by layered silicate with PMMA-b-PDMAEMA block copolymer brushes

The amphiphilic poly(methyl methacrylate-block-2-(dimethylamino)ethyl methacrylate) (PMMA-b-PDMAEMA) block copolymer brushes on the surface of clay layers were synthesized by in situ atom transfer radical polymerization. X-ray diffraction results indicate that both exfoliated and intercalated structure can be found in the nanocomposites. The block copolymer brushes can make different nanopatterns on the surface of clay layers after treatment in different solvents. After treatment in tetrahydrofuran block copolymer brushes form lamella structure on the surface, and after treatment in water surface micelles and wormlike structure can be observed. PMMA colloid particles armored by clay nanocomposites were prepared by suspension polymerization. Transmission electron microscopy and scanning electron microscopy were used to characterize the structure and morphology of the colloid particles. Colloid particles with clay layers around the surface can be observed. X-ray photoelectron spectroscopy (XPS) was used to analyze the surface of the colloid particles. N-1s binding energy of PDMAEMA blocks on the surface of clay layers was detected by XPS. The two peaks of the N-1s binding energy indicate two different nitrogen environments on the surface of clay layers. The peak with a lower binding energy is characteristic of neutral nitrogen on PDMAEMA blocks, and the peak with a higher binding energy is attributed to protonated nitrogen on PDMAEMA blocks.