title: Co-intercalation of Acid Red 337 and a UV absorbent into layered double hydroxides: enhancement of photostability.
abstract: Organic-inorganic hybrid pigments with enhanced thermo- and photostability have been prepared by co-intercalating C.I. Acid Red 337 (AR337) and a UV absorbent (BP-4) into the interlayer of ZnAl layered double hydroxides through a coprecipitation method. The obtained compounds were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric-differential thermogravimetric-differential thermal analysis, UV-visible spectroscopy, and the International Commission on Illumination (CIE) 1976 L*a*b* color scales. The results show the successful co-intercalation of AR337 and BP-4 into the interlayer region of layered double hydroxides (LDHs) and reveal the presence of host-guest interactions between LDH host layers and guest anions of AR337 and BP-4 and guest-guest interactions between AR337 and BP-4. The intercalation can improve the thermostability of AR337 due to the protection of LDH layers. Moreover, the co-intercalation of AR337 and BP-4 not only markedly enhances the photostability of AR337 but also significantly influences the color of the hybrid pigment.
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology , Beijing 100029, People's Republic of China.
authors.forename: Dianqing
authors.initials: D
authors.lastname: Li
authors.forename: Leilei
authors.initials: L
authors.lastname: Qian
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Feng
authors.forename: Junting
authors.initials: J
authors.lastname: Feng
authors.forename: Pinggui
authors.initials: P
authors.lastname: Tang
authors.forename: Lan
authors.initials: L
authors.lastname: Yang
keywords: hybrid pigment; intercalation; layered double hydroxides; photostability; thermostability