Poly(4-vinylpyridine)-dodecylbenzenesulfonic acid [P4VPy(DBSA)(x)] complexes form interpolymer complexes with poly(acrylic acid) (PAA) in ethanol. The layer structures with nearly unchanged long periods are retained in the interpolymer complexes even when the PAA content is as high as 50 wt %. P4VPy(DBSA)(x) complexes form miscible blends with poly(p-vinylphenol) (PVPh). The miscible blends also possess well-defined layer structures. PAA and PVPh are confined and dispersed in the polar layer of the P4VPy(DBSA)(x) complex.