Competitive molecular-/ion-recognition responsive characteristics of poly(N-isopropylacrylamide-co-benzo-12-crown-4-acrylamide) copolymers with benzo-12-crown-4 as both guest and host units.
Novel dual molecular- and ion-recognition responsive poly(N-isopropylacrylamide-co-benzo-12-crown-4-acrylamide) (PNB12 C4 ) linear copolymers with benzo-12-crown-4 (B12C4) as both guest and host units are prepared. The copolymers exhibit highly selective sensitivities toward γ-cyclodextrin (γ-CD) and Na(+) . The presence of γ-CD induces the lower critical solution temperature (LCST) of PNB12 C4 copolymer to shift to a higher value due to the formation of 1:1 γ-CD/B12C4 host-guest inclusion complexes, while Na(+) causes a negative shift in LCST due to the formation of 2:1 "sandwich" B12C4/Na(+) host-guest complexes. Regardless of the complexation order, when γ-CD and Na(+) coexist with PNB12 C4 , competitive complexation actions of B12C4 as both guest and host units toward γ-CD and Na(+) finally form equilibrium 2:2:1 γ-CD/B12C4/Na(+) composite complexes, and the final LCST values of PNB12 C4 copolymer reach almost the same level. The results provide valuable guidance for designing and applying PNB12 C4 -based smart materials in various applications.
School of Chemical Engineering, Sichuan University, Chengdu, Sichuan, 610065, China.
Yin-Mei
YM
Wang
Xiao-Jie
XJ
Ju
Zhuang
Z
Liu
Rui
R
Xie
Wei
W
Wang
Jiang-Feng
JF
Wu
Yan-Qiong
YQ
Zhang
Liang-Yin
LY
Chu
D020106:Acrylamide / Q000737:chemistry*; D000178:Acrylamides / Q000737:chemistry*; D043844:Crown Ethers / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D044367:Phase Transition; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry; D047408:gamma-Cyclodextrins / Q000737:chemistry
D000178:Acrylamides; D043844:Crown Ethers; D007477:Ions; D011108:Polymers; D047408:gamma-Cyclodextrins; D020106:Acrylamide; D012964:Sodium; C067295:N-isopropylacrylamide; C557123:12-crown-4; C023792:gamma-cyclodextrin
competitive complexation; host-guest systems; molecular-/ion-recognition; phase transitions; stimuli-sensitive polymers