Synthesis and properties of polyelectrolyte microgel particles
Nur, H., Pinkrah, V. T., Mitchell, J.C., Benée, L.S. and Snowden, M. J. (2009) Synthesis and properties of polyelectrolyte microgel particles. Advances in Colloid and Interface Science, 158 (1-2). pp. 15-20. ISSN 0001-8686 (doi:10.1016/j.cis.2009.07.008)Full text not available from this repository.
A series of cationic poly(N-isopropylacrylamide/4-vinylpyridine) [poly(NIPAM/4-VP)] polyelectrolyte co-polymer microgels have been prepared by surfactant free emulsion polymerization (SFEP) with varying compositions of 4-VP and NIPAM. The compositions of 4-VP were 15, 25, 35, 45, 55 wt.% relative to NIPAM. The temperature and pH responsive swelling–deswelling properties of these microgels have been investigated using dynamic light scattering (DLS) and electrophoretic mobility measurements. DLS results have shown that the particle diameter of the poly(NIPAM/4-VP) microgels decreases with increasing concentration (wt.%) of 4-VP over the 20–60 °C temperature range due to the increased amount of hydrophobic group. The particle size of all poly(NIPAM/4-VP) microgel series increases with decreasing pH, as the 4-VP units become more protonated at low pH below the pKa (5.39) of the monomer 4-VP. Electrophoretic mobility results have shown that electrophoretic mobility increases as the temperature/pH increases at a constant background ionic strength (1 × 10− 4 mol dm− 3 NaCl). These results are in good agreement with DLS results. The temperature/pH sensitivity of these microgels depends on the ratio of NIPAM/4-VP concentration in the co-polymer microgel systems. The combined temperature/pH responsiveness of these polyelectrolyte microgels can be used in applications where changes in particle size with small change in pH or temperature is of great consequence.
|Additional Information:|| First available online: 5 August 2009.  First published in print: 12 July 2010.  Published in Advances in Colloid and Interface Science, Volume 158, Issues 1–2, 12 July 2010 - special issue Polyelectrolytes.|
|Uncontrolled Keywords:||polyelectrolyte, microgels, DLS, electrophoretic mobility, pH and temperature responsive swelling|
|Subjects:||Q Science > QD Chemistry|
|Faculty / Department / Research Groups:||Faculty of Engineering & Science > Department of Pharmaceutical, Chemical & Environmental Sciences|
|Last Modified:||08 Dec 2016 15:59|
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