Stimuli-responsive electrospun nanofibers from poly(N-isopropylacrylamide)-co-poly(acrylic acid) copolymer and polyurethane

Lin, Xiuling; Tang, Dewei; Yu, Zaiqian; Qian, Feng

doi:10.1039/c3tb21519a

Cited by 64 publications

(64 citation statements)

References 40 publications

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“…As shown in Figure 13, the disappearance of the characteristic strong peak at ~1.44 ppm corresponding to the methyl protons of the t-butyl group demonstrates the successful hydrolysis of PtBA block of the side chains [39][40][41][42]. In this spectrum the chemical shift, 11.33-12.87 ppm is attributed to the -OH (c′) group indicating the presence of PAA arms [47]. While, in the 1 H NMR spectrum (Figure 14) of Cell-g-(PAA 294 -b-POEGA 115 ) brush-shaped block copolymer (Table 1, entry 5), the chemical shifts, 1.28-2.00, 2.10-2.40, 3.18-3.26, 3.26-3.35, 3.45-3.72, and 3.90-4.25 ppm, are attributed to the -CH 2 -(β″), -CH-(α″), -OCH 3 (e), -O-CH 2 -CH 2 -OCO-(f), -CH 2 -from poly(ethylene glycol) backbone (g), and -O-CH 2 -CH 2 -OCO-(h) groups of POEGA arms, clearly indicating the presence of POEGA chains [48][49][50].…”

Section: 3mentioning

confidence: 84%

Cellulose-based graft copolymers prepared by simplified electrochemically mediated ATRP

Chmielarz¹

2017

Express Polym. Lett.

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Abstract. Brush-shaped block copolymer with a dual hydrophilic poly(acrylic acid)-block-poly(oligo(ethylene glycol) acrylate) (PAA-b-POEGA) arms was synthesized for the first time via a simplified electrochemically mediated ATRP (seATRP) under both constant potential electrolysis and constant current electrolysis conditions, utilizing only 30 ppm of catalyst complex. The polymerization conditions were optimized to provide fast reactions while employing low catalyst concentrations and preparation of cellulose-based brush-like copolymers with narrow molecular weight distributions. The results from proton nuclear magnetic resonance ( 1 H NMR) spectral studies support the formation of cellulose-based graft (co)polymers. It is expected that these new polymer brushes may find application as pH-and thermo-sensitive drug delivery systems.

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Section: 3mentioning

confidence: 84%

Cellulose-based graft copolymers prepared by simplified electrochemically mediated ATRP

Chmielarz¹

2017

Express Polym. Lett.

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“…Such a comparison with comonomers investigated in the literature is difficult to make due to often different comonomer contents as well as different experimental conditions used to measure the cloud point (polymer concentration, heating rate, etc.). Nevertheless, the 32 o C cloud point shift obtained at CBA content of 4.3 mol% and polymer concentration of 2 mg/mL is among the largest variation, [8][9][10][11][12][13][14] indicating the high efficiency of CBA for the targeted comonomer effect. (Table 3).…”

Section: Ph-induced Lcst Shiftmentioning

confidence: 94%

“…For instance, with acrylic acid (pKa 5) units in PNIPAM, pH variation around 4--6 shifts reversibly the LCST over a temperature range generally above the initial LCST of PNIPAM, because acrylic acid in both the protonated neutral (COOH) and the deprotonated ionic form (COO --) is more hydrophilic than NIPAM, [8][9][10][11][12] with few exceptions. 13 By contrast, with propylacrylic acid, the protonated acid form is more hydrophobic than NIPAM due to the propyl group in the comonomer structure, while the deprotonated form is more hydrophilic than NIPAM; consequently, the pH--triggered LCST shift extends from below to above 32 o C. 9,14 Similar effect was observed with pH-sensitive homopolymers containing side groups of different hydrophobicity.…”

Section: Introductionmentioning

confidence: 99%

A new comonomer design for enhancing the pH-triggered LCST shift of thermosensitive polymers

et al. 2015

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A Thermosensitive polymers exhibiting a lower critical solution temperature (LCST) can be made responsive to pH change by introducing acid or base comonomer units, and the LCST can be switched between higher and lower temperatures as a result of the polarity change of the comonomer units upon their pH--induced protonation or deprotonation. In the present study, we describe a new comonomer design that aims at increasing the magnitude of the pH--triggered LCST shift.Random copolymers of N--isopropylacrylamide and 4--((2--carboxyallyl)oxy)benzoic acid, denoted as P(NIPAM--co--CBA), were synthesized, in which each CBA comonomer unit bears an acrylic acid and a benzoic acid group of similar pKa. With respect to comonomers containing a single acid group, this particular comonomer structure makes it more hydrophobic in the protonated state (pHpKa) due to the doubled charge, which results in larger pH--triggered LCST shift based on the comonomer effect. The demonstrated comonomer design principle, which is general and can also be applied to base comonomers, represents a useful strategy for enhancing the efficiency and sensitivity of the pH--responsiveness of LCST polymers. 15 A rational comonomer design leads to large pH-induced LCST shift.

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“…Localized surface plasmon resonances in noble metallic nanogaps can significantly elevate and localize the incident electromagnetic field, known as ‘hotspots’ . Two main approaches have been developed for the fabrication of SERS substrate with ‘hotspots’: top‐down methods such as lithography‐based fabrication and bottom‐up methods such as wet chemistry‐based plasmonic metal nanoparticle assembly . Lithography‐made SERS substrates show large enhancement and well reproducibility but are time‐consuming and need the auxiliary of expensive instruments.…”

Section: Introductionmentioning

confidence: 99%

Laser-induced plasmonic heating on silver nanoparticles/poly(N-isopropylacrylamide) mats for optimizing SERS detection

Wang

Zhang

et al. 2016

J. Raman Spectrosc.

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Silver nanoparticle (AgNP)/poly(N‐isopropylacrylamide) (PNIPAAm) composite solution was electrospun followed by crosslinking to fabricate AgNP/PNIPAAm composite nanofiber mats. Embedded AgNPs were found to align along the PNIPAAm nanofibers, which generate more hotspots upon laser‐induced plasmonic heating. This kind of AgNP/PNIPAAm mats show enhanced surface‐enhanced Raman scattering (SERS) effect upon continuous pulsed laser irradiation, showing a ‘laser heating sensitive’ SERS effect. Laser‐induced plasmonic heating can also tune the temperature‐responsive interaction between PNIPAAm and analytes and has been applied in the on‐site ‘laser heating sensitive’ separation and SERS detection of analytes. The composite nanofiber mats also showed good reproducibility and stability. What is more, this ‘laser heating sensitivity’ has also been applied in the direct SERS detection of adenosine in urea solution without urea interference. Together with the advantages of ease of large‐scale fabrication, stable and ‘laser heating sensitivity’, AgNP/PNIPAAm mats might find application in sensitive multicomponent biosensing. Copyright © 2016 John Wiley & Sons, Ltd.

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Stimuli-responsive electrospun nanofibers from poly(N-isopropylacrylamide)-co-poly(acrylic acid) copolymer and polyurethane

Cited by 64 publications

References 40 publications

Cellulose-based graft copolymers prepared by simplified electrochemically mediated ATRP

Cellulose-based graft copolymers prepared by simplified electrochemically mediated ATRP

A new comonomer design for enhancing the pH-triggered LCST shift of thermosensitive polymers

Laser-induced plasmonic heating on silver nanoparticles/poly(N-isopropylacrylamide) mats for optimizing SERS detection

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