Cation hydration in hydrogelic polyacrylamide-phosphoric acid network: A study by Raman spectroscopy

• Published in: Solid state ionics Vol. 145; no. 1; pp. 79 - 84
• Main Authors: Amorim da Costa, A.M, Amado, A.M
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.2001; Elsevier Science
• Subjects: Applied sciences; Cation hydration; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Polyacrylamide-phosphoric acid network; Properties and characterization; Raman spectra; Solution and gel properties; Raman spectra; Polyacrylamide-phosphoric acid network; Cation hydration; Colloidal gel; Phosphoric acid; Local structure; Salt effect; Lithium chloride; Concentration effect; Acrylamide polymer; Magnesium chloride; Experimental study; Calcium chloride
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/S0167-2738(01)00916-X

The effects upon the structure and morphology of adding lithium, calcium and magnesium chlorides to a phosphoric acid/polyacrylamide 2:1 molar ratio proton conducting hydrogel are examined by observing the changes in the vibrational features of the polyacrylamide chain, in the phosphate group and in the interstitial water molecules as a function of the concentration and the cationic nature of the additive, at 295 K. On adding H 3PO 4 to the polyacrylamide hydrogel matrix, the amide groups become more accessible and the polyacrylamide-phosphoric acid network behaves like structure-makers promoting a larger association in the ‘bulk’ liquid water molecules.