Self-switchable polymer reactor with PNIPAM-PAm smart switch capable of tandem/simple catalysis

Wei, Wenjing; Thakur, Vijay Kumar; Li, Songjun; Chianella, Iva

doi:10.1016/j.polymer.2021.124265

Cited by 10 publications

(3 citation statements)

References 35 publications

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“…The temperature- and pressure-induced coil-to-globule transition of poly( N -isopropylacrylamide) (PNIPAM) in water has attracted much interest in the scientific community, initially because of its possible analogies with folding processes of natural polypeptides , and later for its potential as a mechanism of sophisticated molecular actions, including the mechanical transduction of thermal pulses , or the selection of reactants in stimuli-responsive nanodevices. − Experimental characterizations focused on mechanistic aspects of the transition, such as the presence of intermediates and hysteresis, − highlighting the role of the polymer–water interactions. − In particular, the abrupt conformational change from an extended, highly hydrated coil state to a collapsed, partially dehydrated one, triggered by a temperature increase above the coil-to-globule transition temperature ( T C ), inspired the idea of a cooperative hydration pattern. ,,− Consequently, access to the molecular details of the PNIPAM chain and of its aqueous surrounding as a function of temperature and pressure, which can be difficult using experimental methods, has gained growing interest. Atomistic molecular dynamics (MD) simulation owes much of its fortune to the successful investigation of biopolymers, as recognized by the Nobel Prize in Chemistry assigned to M. Karplus, M. Levitt, and A. Warshel in 2013 .…”

Section: Introductionmentioning

confidence: 99%

Modeling Solution Behavior of Poly(N-isopropylacrylamide): A Comparison between Water Models

2022

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Water is known to play a fundamental role in determining the structure and functionality of macromolecules. The same crucial contribution is also found in the in silico description of polymer aqueous solutions. In this work, we exploit the widely investigated synthetic polymer poly( N -isopropylacrylamide) (PNIPAM) to understand the effect of the adopted water model on its solution behavior and to refine the computational setup. By means of atomistic molecular dynamics simulations, we perform a comparative study of PNIPAM aqueous solution using two advanced water models: TIP4P/2005 and TIP4P/Ice. The conformation and hydration features of an atactic 30-mer at infinite dilution are probed at a range of temperature and pressure suitable to detect the coil-to-globule transition and to map the P–T phase diagram. Although both water models can reproduce the temperature-induced coil-to-globule transition at atmospheric pressure and the polymer hydration enhancement that occurs with increasing pressure, the PNIPAM–TIP4P/Ice solution shows better agreement with experimental findings. This result can be attributed to a stronger interaction of TIP4P/Ice water with both hydrophilic and hydrophobic groups of PNIPAM, as well as to a less favorable contribution of the solvent entropy to the coil-to-globule transition.

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Section: Introductionmentioning

confidence: 99%

Modeling Solution Behavior of Poly(N-isopropylacrylamide): A Comparison between Water Models

2022

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“…[1,2] Many biopolymers like proteins also demonstrated LCST behaviors. [3][4][5][6][7] The unique phase transition behavior of LCST molecules has allowed the corresponding material systems to be widely applied in the fields of sensing, [8,9] catalysis, [10,11] drug delivery, [12,13] tissue engineering, [14,15] and separation, [16,17] to name a few. Despite the rapid research progress on LCST polymers regarding the fine-tuning of the key parameters such as the cloud point (T cp ) through chemical strategies (copolymerization or end group modification) [18][19][20] or physical strategies (alternation of concentration and ionic strength or mixing different building blocks), fabricating the LCST polymers with tailored properties such as high accessibility, appropriate T cp , prompt temperature responsiveness, excellent reversibility towards specific application scenario remains challenging due to the structural complexity of the polymer skeleton.…”

Section: Introductionmentioning

confidence: 99%

A Coordinating Small Organic Molecule with Tunable Lower Critical Solution Temperature for Efficient Management of Solar Radiation

Zhou,

Yuan,

Qing

et al. 2024

Macromol. Rapid Commun.

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Structurally well‐defined small molecules with lower critical solution temperature (LCST) behavior offer enormous prospects for fine‐tuning their phase transition properties to be “on‐demand” applied in the specific scene but are still underexplored. Herein, a novel amphiphilic small LCST molecule is rationally designed and synthesized. The molecule, namely TG, features a conjugation of multiple short ethylene glycol (EG) chains with the functional coordinating terpyridine (Tpy) moiety. The molecule TG demonstrates excellent LCST behavior down to 0.05 × 10−3 m in a water solution. And a cloud point Tcp = 30.9 °C with a very short thermal hysteresis ΔT = 0.2 °C and good reversibility can be achieved when c = 0.1 × 10−3 m. The excellent LCST properties of TG have enabled its successful performance as the smart window for solar radiation management with the ∆Tlum, ∆TIR, and ∆Tsol being 83.6%, 49.1%, and 67.2%, respectively. Moreover, the presence of Tpy moiety in TG enables its coordination with Ru3+ and the resulting complex also exhibits modulated LCST behavior with different concentration‐dependent Tcp. These studies would provide novel small‐molecule‐based scaffolds for constructing better solar radiation management systems as well as other thermal‐responsive smart materials.

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“…According to the charge properties of side groups, copolymerized PAMs can be further divided into cationic, anionic, and amphoteric forms (CPAM, APAM, and AmPAM). , The homopolymerized PAMs contain only the neutral amide side groups. Although the neutral PAM (NPAM) shows electronic difference with CPAM, APAM, and AmPAM, their usages are quite similar indeed. − The most interesting property of PAMs that is distinct from other polymers is that PAMs can be dissolved in water with any ratio, and their water solubility can be hardly affected by molecular weight. Owing to this unique nature, PAMs have extensive applications.…”

Section: Introductionmentioning

confidence: 99%

Surprising Nanomechanical and Conformational Transition of Neutral Polyacrylamide in Monovalent Saline Solutions

Zhang,

Zheng,

Miao

et al. 2023

J. Phys. Chem. B

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Polyacrylamide (PAM) is one of the most important water-soluble polymers that has been extensively applied in water treatment, drug delivery, and flexible electronic devices. The basic properties, e.g., microstructure, nanomechanics, and solubility, are deeply involved in the performance of PAM materials. Current research has paid more attention to the development and expansion of the macroscopic properties of PAM materials, and the study of the mechanism involved with the roles of water and ions on the properties of PAM is insufficient, especially for the behaviors of neutral amide side groups. In this study, single molecule force spectroscopy was combined with molecular dynamic (MD) simulations, atomic force microscope imaging, and dynamic light scattering to investigate the effects of monovalent ions on the nanomechanics and molecular conformations of neutral PAM (NPAM). These results show that the single-molecule elasticity and conformation of NPAM exhibit huge variation in different monovalent salt solutions. NPAM adopts an extended conformation in aqueous solutions of strong hydrated ion (acetate), while transforms into a collapse globule in the existence of weakly hydrated ion (SCN–). It is believed that the competition between intramolecular and intermolecular weak interactions plays a key role to adjust the molecular conformation and elasticity of NPAM. The competition can be largely influenced by the type of monovalent ions through hydration or a chaotropic effect. Methods utilized in this study provide a means to better understand the Hofmeister effect of ions on other macromolecules containing amide groups at the single-molecule level.

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Self-switchable polymer reactor with PNIPAM-PAm smart switch capable of tandem/simple catalysis

Cited by 10 publications

References 35 publications

Modeling Solution Behavior of Poly(N-isopropylacrylamide): A Comparison between Water Models

Modeling Solution Behavior of Poly(N-isopropylacrylamide): A Comparison between Water Models

A Coordinating Small Organic Molecule with Tunable Lower Critical Solution Temperature for Efficient Management of Solar Radiation

Surprising Nanomechanical and Conformational Transition of Neutral Polyacrylamide in Monovalent Saline Solutions

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