Related Experiment Video
Updated: Jan 26, 2026
10:08
Phase Behavior of Charged Vesicles Under Symmetric and Asymmetric Solution Conditions Monitored with Fluorescence Microscopy
Published on: October 24, 2017
9.6K
Polyamine Colloids Cross-Linked with Phosphate Ions: Towards Understanding the Solution Phase Behavior.
Santiago E Herrera1, Maximiliano L Agazzi1, M Lorena Cortez1
1Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CONICET, La Plata, 1900, Argentina.
Summary
Poly(allylamine)/phosphate (PAH/Pi) colloids form via electrostatic interactions. Their stability and pH responsiveness are tunable by ionic strength, making them promising for drug delivery.
Area of Science:
- Materials Science
- Supramolecular Chemistry
- Nanotechnology
Background:
- Ionically crosslinked poly(allylamine)/phosphate (PAH/Pi) colloids are self-assembled nanostructures.
- These colloids are stabilized by supramolecular interactions.
- Effective drug delivery requires these interactions under physiological conditions (high ionic strength, narrow pH window).
Purpose of the Study:
- To investigate the effect of pH and ionic strength on the chemical behavior of poly(allylamine hydrochloride) (PAH) and inorganic phosphate (Pi).
- To understand the driving forces behind PAH-Pi colloid formation.
- To assess the suitability of PAH-Pi colloids as pH-responsive nanocarriers.
Main Methods:
- Combination of experimental measurements and theoretical modeling.
- Analysis of aqueous solutions containing PAH and Pi.
- Investigation of systems with varying pH and ionic strength (KCl addition).
Main Results:
- Colloid formation is driven by electrostatic pairing between positively charged amino groups in PAH and negatively charged HPO4^2- ions.
- Increased ionic strength weakens PAH-Pi interactions and narrows the pH stability window from 4 to 1.8 pH units.
- A reversible assembly/disassembly system was achieved by adjusting pH between 6.8 and 7.1 at high ionic strength.
Conclusions:
- Electrostatic interactions are key to PAH-Pi colloid formation.
- Ionic strength modulates colloid stability and pH responsiveness.
- The tunable nature of these colloids makes them suitable for pH-responsive nanocarrier applications in drug delivery.
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