Two dimensional size controlled confinement of poly(vinyl pyrrolidone) in the interlayer space of swelling clay mineral

A water soluble polymer, poly(vinyl pyrrolidone) (PVP), was intercalated into the two dimensional interlayer space of a layered silicate, synthetic saponite (Sumecton SA; Kunimine Ind. Co.), which adsorbed rhodamine 6G (R6G) by ion exchange. The basal spacing was systematically controlled up to ca. 5 nm by the change of PVP to SA weight ratio. Depending on the expansion of the interlayer space, the luminescence self-quenching efficiency varied, possibly because of the distance between R6G, which directly correlated with the possibility of self- quenching. In addition, R6G degradation upon artificial sunlight irradiation was suppressed in the PVP-saponite system.