Abstract

Large transitions in viscosity are demonstrated for suspensions of environmentally sensitive gel microspheres upon application of external stimuli. Depending on the number concentration of microspheres, these suspensions may thicken to become semisolid, essentially undergoing a sol-gel transition. These reversible viscosity transitions are directly related to the volume transitions observed previously in the literature for individual environmentally sensitive gels. Temperature-sensitive poly-N-isopropyl-acrylamide microspheres were synthesized, and the effects of microsphere concentration on the temperature-induced viscosity transitions were measured. The viscosity of poly-N-isopropylacrylamide microsphere suspensions could also be increased by addition of sodium dodecyl sulfate. Non-temperature-sensitive, commercially available poly-acrylamide microspheres were used to demonstrate viscosity transitions as a function of solvent composition in acetone/water mixtures. Potential applications for these systems were suggested. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1369–1372, 1997

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.