Abstract

Surface chemical characterization of a set of activated composite membranes containing different concentrations of di-(2-ethylhexyl)dithiophosphoric acid (DTPA) as carrier was performed by x-ray photoelectron spectroscopy (XPS). As a result of the addition of DTPA to the membrane samples, the N 1s signal intensities decrease, whereas the P 2p signal intensities increase with increasing carrier concentration. Upon acid addition, the polyamide component of the membrane was protonated and a new peak at higher binding energies was observed in the N 1s XPS signal, due to the increase of the positive charge of these protonated nitrogen atoms. The S 2p signals indicate the coexistence of two contributions assigned to the presence of the acid carrier ionically bonded to the protonated amide and to free acid molecules.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.