Microstructural Features Of Poly(N-Vinylpyrrolidone)-La(No3)(3) Center Dot 6h(2)O Hydrogel

The structural features of the poly(N-vinylpyrrolidone)-La(NO3)(3) center dot 6H(2)O composite hydrogel were studied by scanning and transmission electron microscopy. The La(NO3)(3) center dot 6H(2)O powder, which was used for the preparation of the composite, was shown to contain also hexagonal prismatic crystals with an edge of similar to 1.8 mu m and needle-like crystals with a width of 1 mu m and a length of up to 50 mu m. During the composite formation, the La(NO3)(3) center dot 6H(2)O powder is hydrolyzed in the bulk of the hydrogel, and lanthanum is uniformly distributed in the matrix. However, flower-like structures up to 20 mu m in diameter are formed on the surface of the composite. These structures are composed of lanthanum- and oxygen-rich nanorods. Transmission electron microscopy studies of dried hydrogels showed that the composite hydrogel and flower-like inclusions have an amorphous structure.