Temperature and pH dual-responsive behavior of polyhedral oligomeric silsesquioxane-based star-block copolymer with poly(acrylic acid-block-N-isopropylacrylamide) as arms
Poly(acrylic acid-block-N-isopropylacrylamide) (PAAc-b-PNIPAm)-tethered octafunctional polyhedral oligomeric silsesquioxane (POSS) were synthesized via POSSinitialized atom transfer radical polymerization. When very short PAAc blocks are placed between the POSS core and PNIPAm short chains, the...
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Main Authors: | , , , , |
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Other Authors: | |
Format: | Article |
Language: | English |
Published: |
2013
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Online Access: | https://hdl.handle.net/10356/96699 http://hdl.handle.net/10220/13089 |
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Institution: | Nanyang Technological University |
Language: | English |
Summary: | Poly(acrylic acid-block-N-isopropylacrylamide)
(PAAc-b-PNIPAm)-tethered octafunctional polyhedral oligomeric
silsesquioxane (POSS) were synthesized via POSSinitialized
atom transfer radical polymerization. When very
short PAAc blocks are placed between the POSS core and
PNIPAm short chains, the critical temperature (Tc) of POSSPAAc-
b-PNIPAm determined by cloud point measurements
varies in a wide temperature range with pH, and its Tc is
even lower than that of POSS-PNIPAm with similar chain
length at pH05.0, indicating a synergic effect between
high local chain density and intramolecular interaction
between PAAc and PNIPAm. When the PAAc blocks
are relatively long, the pH response of POSS-PAAc-b-
PNIPAm diminishes owing to the reduced local PNIPAm
chain density. |
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