Experimental (X-Ray Photoelectron Spectroscopy) and theoretical studies of benzene based organics intercalated into layered double hydroxide

The present paper deals with a fine physico-chemical analysis of some hybrid materials combining an inorganic layered double hydroxide phase (LDH) with an organic benzene derivative entity R'-C6H4-R with R = -eSO(3)(-), eCO(2)(-) and R' eH, -eOH. The main topic of this work is, in a nanoscale, to propose a way to approach the understanding of the interactions between inorganic and organic sub-systems. The role of the anionic headgroup R is discussed in term of reactivity with the mineral support. The classical expertise of materials via the PXRD technique puts into light an effective LDH interlayer space enlargement with the organics incorporation and a minimum angle of inclination for every organics within the LDH matrix. The originality of this study is to use the X-Ray Photoelectron spectroscopy (XPS) as a local probe of the chemical environments of the headgroup of the organic entities. In a parallel way, some quantum calculations (by using molecular and periodical codes) are carried out to best appreciate the electronic and structural evolutions before and after the intercalation step. A specific reactivity of the -eSO(3)(-) group compared with the eCO(2)(-) one is evidenced. Moreover, a correlation at the first order is then set up between the net charges of atoms and the XPS binding energies of their core levels. (C) 2011 Published by Elsevier Masson SAS.