Preparation and structural characterization of sodium polyphosphate coacervate as a precursor for optical materials

Author(s)

Franco, D. F. ; Barud, H. S. ; Santagneli, S. ; Lamarca, R. S. ; Santos, Bruno F. ; Silva, M. A. P. ; de Oliveira, L. F. C. ; Ribeiro, S. J. L. ; Nalin, M.

• Document type: Journal article
• Source: Materials Chemistry and Physics; v. 180, p. 114-121, SEP 1 2016.
• Web of Science Citations: 2

Abstract

This paper describes the preparation of Sodium Polyphosphates Coacervates (NaPC) through the direct addition of different methanol molar fractions to a sodium polyphosphate solution. The presence of methanol reduces the dielectric constant medium and it promotes the coacervate formation. Rheology measurement shows that the NaPC viscosity is dependent on a methanol molar fraction, which is caused by the dielectric constant reduction of the water-methanol mixture. Raman spectra for the lyophilized NaPC show that the symmetric P-O-t stretching mode is more sensitive than the symmetric P-O-b stretching mode, due to the approach of the adjacent polyphosphate chains. The P-31 NMR spectra also confirm a decrease in the Q(2)/Q(1) ratio because of the methanol content. Besides, we have obtained transparent soft Glass-Materials to melt NaPC at 800 degrees C. (C) 2016 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass
• Grantee: Edgar Dutra Zanotto
• Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC