Polyacrylamide “revisited”: UCST-type reversible thermoresponsive properties in aqueous alcoholic solutions

Asadujjaman, Asad; Oliveira, Tiago E. de; Mukherji, Debashish; Bertin, Annabelle

doi:10.1039/c7sm02424j

Cited by 21 publications

(18 citation statements)

References 54 publications

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“…AAm on the other hand is an example for a non-TSP in watery solution. 39 NMAAm has been conjectured to exhibit an LCST above 373 K, in aqueous solution. 4 , 22 To our knowledge, this assertion has hitherto not been confirmed experimentally.…”

Section: Introductionmentioning

confidence: 99%

Thermosensitive Hydration of Four Acrylamide-Based Polymers in Coil and Globule Conformations

et al. 2020

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To characterize the thermosensitive coil–globule transition in atomistic detail, the conformational dynamics of linear polymer chains of acrylamide-based polymers have been investigated at multiple temperatures. Therefore, molecular dynamic simulations of 30mers of polyacrylamide (AAm), poly- N -methylacrylamide (NMAAm), poly- N -ethylacrylamide (NEAAm), and poly- N -isopropylacrylamide (NIPAAm) have been performed at temperatures ranging from 250 to 360 K for 2 μs. While two of the polymers are known to exhibit thermosensitivity (NEAAm, NIPAAm), no thermosensitivity is observed for AAm and NMAAm in aqueous solution. Our computer simulations consistently reproduce these properties. To understand the thermosensitivity of the respective polymers, the conformational ensembles at different temperatures have been separated according to the coil–globule transition. The coil and globule conformational ensembles were exhaustively analyzed in terms of hydrogen bonding with the solvent, the change of the solvent accessible surface, and enthalpic contributions. Surprisingly, independent of different thermosensitive properties of the four polymers, the surface affinity to water of coil conformations is higher than for globule conformations. Therefore, polymer–solvent interactions stabilize coil conformations at all temperatures. Nevertheless, the enthalpic contributions alone cannot explain the differences in thermosensitivity. This clearly implies that entropy is the distinctive factor for thermosensitivity. With increasing side chain length, the lifetime of the hydrogen bonds between the polymer surface and water is extended. Thus, we surmise that a longer side chain induces a larger entropic penalty due to immobilization of water molecules.

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Section: Introductionmentioning

confidence: 99%

Thermosensitive Hydration of Four Acrylamide-Based Polymers in Coil and Globule Conformations

et al. 2020

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“…In contrast to LCST-type VPTT, studies on the polymers with UCST or UCST-type VPTT have been reported at a much lessened extent [ 38 ]. Polysulfobetaine [ 39 ] and poly( N -acrylolyglyciamide) [ 40 – 42 ] are the polymers reportedly with UCST in water, while polyacryamide [ 43 ] and poly(acetoacetoxyethyl methacrylate) [ 44 ] are reported to exhibit UCST in binary ethanol/water solvent mixture. Roth et al demonstrated that poly[oligo(ethylene glycol) methyl ether methacrylate], (POEGMA), exhibited UCST in a large variety of aliphatic alcohols and that the UCST phase transition temperature was dependent on the structure, molecular weight, and the concentration of POEGMA, as well as the solvent, co-solvents [ 45 ].…”

Section: Resultsmentioning

confidence: 99%

“…In fact, hydrogel particles with their R h around 10 nm, determined by DLS, were often reported. Diverse examples are available, such as polyacrylamide above its UCST in aqueous alcohol solutions [ 43 ] and 4-propoxyazobenzene-terminated PNIPAM in aqueous solution below its LCST [ 47 ]. And R h as small as 2 to 3 nm was reported for an OEG-based responsive polymer below its LCST [ 48 ].…”

Section: Resultsmentioning

confidence: 99%

Preparation of Thermoresponsive Polymer Nanogels of Oligo(Ethylene Glycol) Diacrylate-Methacrylic Acid and Their Property Characterization

et al. 2018

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Stimuli-responsive polymers have received growing attention in recent years owing to their wide applications in diverse fields. A novel stimuli-responsive polymer, based on oligo(ethylene glycol) diacrylate (OEGDA) and methacrylic acid (MAA), P(OEGDA-MAA), is prepared by precipitation polymerization and is shown to have a LCST-type VPTT (volume phase transition temperature) at 33 °C in water and a UCST-type VPTT at 43 °C in ethanol, all at concentration of 1 mg/mL. Both VPTTs are strongly concentration and pH dependent, providing an easy way to tune the phase transition temperature. The polymer is characterized with regard to its composition and its morphology in water and in ethanol at different concentration. The two transitions are studied and interpreted based on the results. This work provides a novel way for the preparation of a new type of stimuli-responsive polymer with great potential for different applications, particularly those in biomedical areas because PEG-based stimuli-responsive polymers are known to be nontoxic and non-immunogenic.Electronic supplementary materialThe online version of this article (10.1186/s11671-018-2610-6) contains supplementary material, which is available to authorized users.

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“…The syntheses of poly[ N‐ (6‐acetamidopyridin‐2‐yl)acrylamide] PNAcAPAM and polyacrylamide (PAM) were performed according to previous works.…”

Section: Methodsmentioning

confidence: 99%

2,6‐Diaminopyridine and Acrylamide‐Based Copolymers with Upper Critical Solution Temperature‐type Behavior in Aqueous Solution

Asadujjaman

Ahmadi

Franc

et al. 2019

J. Polym. Sci. Part A: Polym. Chem.

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A novel copolymer based on supramolecular motif 2,6-diaminopyridine and water-soluble acrylamide, poly[N-(6-acetamidopyridin-2-yl) acrylamide-co-acrylamide], was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization with various monomer compositions. The thermoresponsive behavior of the copolymers was studied by turbidimetry and dynamic light scattering (DLS). The obtained copolymers showed an upper critical solution temperature (UCST)-type phase transition behavior in water and electrolyte solution. The phase transition temperature was found to increase with decreasing amount of acrylamide in the copolymer and increasing concentration of the solution. Furthermore, the phase transition temperature varied in aqueous solutions of electrolytes according to the nature and concentration of the electrolyte in accordance with the Hoffmeister series. A dramatic solvent isotope effect on the transition temperature was observed in this study, as the transition temperature was almost 10-12 C higher in D 2 O than in H 2 O at the same concentration and acrylamide composition. The size of the aggregates below the transition temperature was larger in D 2 O compared to that in H 2 O that can be explained by deuterium isotope effect. The thermoresponsive behavior of the copolymers was also investigated in different cell medium and found to be exhibited UCST-type phase transition behavior in different cell medium. Such behavior of the copolymers can be useful in many applications including biomedical, microfluidics, optical materials, and in drug delivery.

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Polyacrylamide “revisited”: UCST-type reversible thermoresponsive properties in aqueous alcoholic solutions

Cited by 21 publications

References 54 publications

Thermosensitive Hydration of Four Acrylamide-Based Polymers in Coil and Globule Conformations

Thermosensitive Hydration of Four Acrylamide-Based Polymers in Coil and Globule Conformations

Preparation of Thermoresponsive Polymer Nanogels of Oligo(Ethylene Glycol) Diacrylate-Methacrylic Acid and Their Property Characterization

2,6‐Diaminopyridine and Acrylamide‐Based Copolymers with Upper Critical Solution Temperature‐type Behavior in Aqueous Solution

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