Anomalous rheological behavior of poly(1‐vinyl‐2‐pyrrolidone) and CuCl2 in solution and their interactions in solid composites

BACKGROUND: The aggregation structure of polymers in solution is an important aspect of their behavior. The interactions between metal ions and water-soluble polymers have a significant influence on the conformation behavior of biological macromolecules, and on the ionic selectivity of cells, etc. RESULTS: The rheological behavior of poly(1-vinyl-2-pyrrolidone) (PVP) and CuCl2 dispersed in N,N-dimethylformamide was investigated using rheological techniques. Concentrated solutions containing CuCl2 exhibited a rheological behavior different from those containing other metal chlorides (LiCl, CaCl2 and CoCl2). This indicated that the variation in the aggregation state of the PVP chains with concentration of CuCl2 was different from those of PVP solutions containing Li+, Ca2+ or Co2+ ions. CONCLUSION: The interactions between PVP and CuCl2 inhibit the crystallization of CuCl2 and induce the formation of microphase separation in the system. Copyright © 2009 Society of Chemical Industry