Boronic Acid Terminated Thermo-Responsive and Fluorogenic Polymer: Controlling Polymer Architecture for Chemical Sensing and Affinity Separation
摘要:
Thermo-responsive poly(N-isopropylacrylamide) (polyNIPAm) containing terminal boronic acid was synthesized using atom transfer radical polymerization (ATRP) in combination with Cu(I)-catalyzed alkyne-azide 1,3-dipolar cycloaddition (CuAAC) reaction. Alkyne-terminated polyNIPAm was first synthesized by ATRP using an alkyne-containing initiator. A fluorogenic boronic acid, 3-(2-azido-acetylamino)phenylboronic acid (APBA) was then linked to the polyNIPArn through CuAAC. The synthesized polymers were characterized by H-1 NMR, FT-IR, UV-vis, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, and turbidity measurements. The intensity of fluorescence emission of the boronic acid-terminated polyNIPAm (BA-polyNIPAm) was found to increase when increasing amount of a cis-diol compound (i.e., fructose) was added. At physiological pH value, the BA-polyNIPAm effectively bound fructose and could be easily separated from aqueous solution by raising the temperature above its lower critical solution temperature (LCST).
Tetraphenylthiophene-Functionalized Poly(<i>N</i>-isopropylacrylamide): Probing LCST with Aggregation-Induced Emission
作者:Chung-Tin Lai、Rong-Hong Chien、Shiao-Wei Kuo、Jin-Long Hong
DOI:10.1021/ma201089j
日期:2011.8.23
A hydrophobic tetraphenylthiophene (TP) center with novel aggregation-induced emission (AIR) property was chemically linked to two poly(N-isoprppylacrylamide) (PNIPAM) chains to obtain thermoresponsive polymers to study the relationships between the lower critical solution transitions (LCSTs) and the ALE-operative fluorenscence (FL) emission. Three ethynyl-terminated PNIPAMs with different molecular weights were synthesized via controlled atom transfer radical polymerization (ATRP) using ethynyl-functionalized initiator. The PNIPAMs were then coupled with diazide-funtionalized TP (TPN3) via click reaction to obtain the desired TP-embedded polymers of Px (x = 1, 2, and 3). All three polymers show AIE-property from their solution fluorescence behavior in THF/hexane mixtures. In the aqueous solution, the TP-center served as a fluorogenic probe that reveals the LCSTs of polymers and its relation to the degree of TP labeling in terms of polymer concentration. The thermoresponsiveness of Px was demonstrated by the complete emission quench when heated at temperatures above LCST. Dissociation of the TP aggregates above LCST is responsible for the emission quench, which was evaluated through the uses of transmittance measurement, dynamic light scattering, and H-1 NMR spectra.
Clicked (AB)<sub>2</sub>
C-type miktoarm terpolymers: Synthesis, thermal and self-assembly properties, and preparation of nanoporous materials
作者:Jie Song、Eunji Lee、Byoung-Ki Cho
DOI:10.1002/pola.26403
日期:2013.1.15
(PEO‐PS)2‐PLA miktoarmterpolymer (1) was synthesized by stepwise click reactions of individually prepared poly(ethylene oxide) (PEO), polystyrene (PS, polymerized by atom transfer radical polymerization), and polylactide (PLA, polymerized by ring‐opening polymerization) blocks. As characterized by differential scanning calorimetry and small‐angle X‐ray scattering techniques, the terpolymer self‐assembled
Boronic Acid Terminated Thermo-Responsive and Fluorogenic Polymer: Controlling Polymer Architecture for Chemical Sensing and Affinity Separation
作者:Zhifeng Xu、Khan Mohammad Ahsan Uddin、Lei Ye
DOI:10.1021/ma301213f
日期:2012.8.28
Thermo-responsive poly(N-isopropylacrylamide) (polyNIPAm) containing terminal boronic acid was synthesized using atom transfer radical polymerization (ATRP) in combination with Cu(I)-catalyzed alkyne-azide 1,3-dipolar cycloaddition (CuAAC) reaction. Alkyne-terminated polyNIPAm was first synthesized by ATRP using an alkyne-containing initiator. A fluorogenic boronic acid, 3-(2-azido-acetylamino)phenylboronic acid (APBA) was then linked to the polyNIPArn through CuAAC. The synthesized polymers were characterized by H-1 NMR, FT-IR, UV-vis, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, and turbidity measurements. The intensity of fluorescence emission of the boronic acid-terminated polyNIPAm (BA-polyNIPAm) was found to increase when increasing amount of a cis-diol compound (i.e., fructose) was added. At physiological pH value, the BA-polyNIPAm effectively bound fructose and could be easily separated from aqueous solution by raising the temperature above its lower critical solution temperature (LCST).