Abstract
Temperature- and pH-induce aggregation of graft copolymers comprising poly(acrylic acid ) (PAAc) as the backbone and poly(N-isopropylacrylamide) (PNIPAAm) and monomethoxy poly(ethylene glycol) (mPEG) as the grafts in different pH buffer solutions was investigated. The graft copolymers undergo complex formation via hydrogen bonding at pH < 3.4 and rearrange into spherical particles with core/shell structure with increasing temperature form 8 oC to 60 oC. The graft copolymers existed as unimers at pH 5.0 below the critical aggregation temperature (CAT), whereas the copolymer self-assembled into core-shell-corona micelles with increasing temperature. With signification increase in degree of PAAc dissociation, the copolymer underwent self-assembling into larger and looser polymeric aggregates above CAT at pH 7.0 due to the formation of the multicore structure. The graft copolymers only with PNIPAAm grafts form more hydrophobic complex particles at pH 3. When the copolymer solution was heated above 20 oC, the particles further aggregate and increase in size without distinct core-shell structure.
Sign-in/Register to access full text options 
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 callDisclaimer: 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.
