Thermoresponsiveness Across the Physiologically Accessible Range: Effect of Surfactant, Cross-Linker, and Initiator Content on Size, Structure, and Transition Temperature of Poly( N -isopropylmethacrylamide) Microgels.

Autor:	Winning D; School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland., Wychowaniec JK; School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland.; AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos, Switzerland., Wu B; Dutch-Belgian Beamline (DUBBLE), European Synchrotron Radiation Facility (ESRF), 71 Avenue Des Martyrs, CS 40220, Grenoble 38043, France., Heise A; Department of Chemistry, Royal College of Surgeons in Ireland, Dublin 9, Ireland., Rodriguez BJ; Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland.; School of Physics, University College Dublin, Belfield, Dublin 4, Ireland., Brougham DF; School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland.
Jazyk:	angličtina
Zdroj:	ACS omega [ACS Omega] 2024 Aug 12; Vol. 9 (34), pp. 36185-36197. Date of Electronic Publication: 2024 Aug 12 (Print Publication: 2024).
DOI:	10.1021/acsomega.4c02115
Abstrakt:	The influence of surfactant, cross-linker, and initiator on the final structure and thermoresponse of poly( N -isopropylmethacrylamide) (pNIPMAM) microgels was evaluated. The goals were to control particle size (into the nanorange) and transition temperature (across the physiologically accessible range). The concentration of the reactants used in the synthesis was varied, except for the monomer, which was kept constant. The thermoresponsive suspensions formed were characterized by dynamic light scattering, small-angle X-ray scattering, atomic force microscopy, and rheology. Increasing surfactant, sodium dodecyl sulfate content, produced smaller microgels, as expected, into the nanorange and with greater internal entanglement, but with no change in phase transition temperature (LCST), which is contrary to previous reports. Increasing cross-linker, N , N -methylenebis acrylamide, content had no impact on particle size but reduced particle deformability and, again contrary to previous reports of decreases, progressively increased the LCST from 39 to 46 °C. The unusual LCST trends were confirmed using different rheological techniques. Initiator, potassium persulfate, content was found to weakly influence the outcomes. An optimized content was identified that provides functional nanogels in the 100 nm (swollen) size range with controlled LCST, just above physiological temperature. The study contributes chemistry-derived design rules for thermally responsive colloidal particles with physiologically accessible LCST for a variety of biomedical and soft robotics applications. Competing Interests: The authors declare no competing financial interest. (© 2024 The Authors. Published by American Chemical Society.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu