Mineralogy of halloysites and their interaction with porphyrine

0421827 - ÚACH 2014 RIV CZ eng J - Journal Article
Vašutová, V. - Bezdička, Petr - Lang, Kamil - Hradil, David
Mineralogy of halloysites and their interaction with porphyrine.
Ceramics - Silikáty. Roč. 57, č. 3 (2013), s. 243-250. ISSN 0862-5468. E-ISSN 1804-5847
Institutional support: RVO:61388980
Keywords : organoclays * mineralogy * porphyrine * CEC
Subject RIV: CA - Inorganic Chemistry
Impact factor: 0.434, year: 2013

Samples representing two modifications of halloysites, dehydrated (7 angstrom) and hydrated (10 angstrom) forms, respectively, were examined with the aim to select suitable candidates for to be used as carriers of porphyrine photoactive molecules. The samples were analysed by powder X-ray diffraction (pXRD), infrared spectroscopy (FT-IR), and high resolution transmission electron microscopy (HRTEM). Chemical composition was also determined. For the determination of cationic exchange capacity (CEC) the silver thiourea method (AgTU) was used. Silver cations concentrations in the solution before and after the interaction were determined by atomic absorption spectrometry (AAS). By the interaction of two pure hydrated halloysites with porphyrine it was found that porphyrine does not intercalate the interlayer space, but it is adsorbed on the outer surface of halloysite. This interaction changed the colour of clay sample from white to green. The changes were also clearly visible on diffuse reflectance spectra (DRS).
Permanent Link: http://hdl.handle.net/11104/0229935