Impact of molecular size on the protonation/deprotonation equilibria of acrylic and polyacrylic acids in aqueous electrolyte solutions
View Full Paper
Ask AI
Bookmark
Share
Key Points
This work aims to investigate how molecular size influences the protonation and deprotonation equilibria of polyacrylic acids in aqueous solutions.
Conducted potentiometric acid-base titration experiments for polyacrylic acids of various molecular weights (1.8, 5, 90, and 700 kDa) and poly(acrylic acid-co-maleic acid) 3 kDa.
Developed an adsorption model to evaluate titration data and fitted using surface complexation models.
Calculated the degree of dissociation of polyelectrolytes based on pH and ionic strength.
pKa values exhibited a nearly linear dependence on ionic strength, varying significantly with molecular size.
Larger polyacrylic acids show weaker acidity of the same acidic group at low ionic strengths.
At approximately 0.5 M concentration, the differences in acidity between varying molecular sizes diminish.
Discussion
No takes yet. Share an insight, caveat, or question.
Implication
Randomized trial reveals how molecular size impacts protonation in aqueous polyelectrolytes, indicating important insights for applications.