ELECTROCHEMICAL AND CONFORMATIONAL PROPERTIES OF POLYACRYLIC ACID AND POLY-2-METHYL-5-VINYLPYRIDINE HYDROGELS DURING THEIR REMOTE INTERACTION IN AQUEOUS ENVIRONMENT

Abstract

Abstract. Introduction. Previous research on the intergel system of polyacrylicacid(PAA) and
polyethyleneimine (PEI) revealed that at a hydrogel ratio of 3:3, significant activation occurs at 24 hours.
This indicates substantial changes in electrochemical and conformational properties at this ratio. The
purpose of this research is to investigate the remote interaction between the weak polyelectrolyte
polyacrylic acid (PAA) and the weak polybase poly-2-methyl-5-vinylpyridine (P2M5VP) over time and at
various molar ratios in an aqueous environment. The study seeks to explore the activation potential of
these hydrogels by analyzing their electrochemical properties using conductometry and pH-metry, and to
determine the effect of molar ratios on the specific conductivity and swelling degree of the hydrogels.The
obtained results.The maximum conductivity of 14.4 µS/cm was achieved at a ratio of 2:4 at 2.5 hours,
coinciding with the minimum pH value of 4.4. In the 6:0 ratio, where only the PAA hydrogel is present,
the conductivity changes remained minimal within the range of 1-2 µS/cm, indicating the stability of this
hydrogel in the absence of P2M5VP. The swelling coefficient also exhibited interesting dynamic changes
depending on the time and component ratios. The swelling coefficient of PAA remained stable at 11-14
for the individual hydrogel but showed a maximum value of 41 at a ratio of 1:5 after 24 hours, indicating
significant interaction between the hydrogels. The maximum swelling coefficient of P2M5VP, 7.5 and
7.6, was observed at ratios of 5:1 and 2:4, respectively, 2.5 hours into the study, suggesting optimal
interaction of the hydrogels during these time intervals. Conclusion. The studies showed that initial
differences in conductivity are minimal; however, significant changes occur over time due to
intermolecular interactions between the components. The obtained results can be useful for optimizing the
sorption properties of hydrogels in metal extraction processes.