Article
Chemistry, Multidisciplinary
Mitsuhiro Matsumoto, Taka-Aki Asoh, Tatsuya Shoji, Yasuyuki Tsuboi
Summary: This study demonstrates liquid-liquid phase separation of a thermoresponsive polymer through near-infrared laser-induced coacervation and coil-to-globule phase transition. By focusing a laser beam, single polymer microdroplets can be formed and trapped at the focal point, allowing for selective analysis. The results indicate that PDEA undergoes dehydration and coacervation in addition to a coil-to-globule phase transition.
Article
Chemistry, Physical
Biaolan Liu, Xiaoshuang Yan, Zhihui Zhao, Jian Wang, Jiwen Feng
Summary: The solvation behaviors and intermolecular interactions of PDEA gel network in water/DMSO and water/acetone mixtures were investigated. Unlike PNIPAM gel, distinct phase transition behaviors were observed for PDEA gel, which are attributed to the different polymer-cosolvent interactions in water/acetone and water/DMSO systems.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Polymer Science
Niamh Bayliss, Gokhan Yilmaz, Alexander Plucinski, C. Remzi Becer, Bernhard V. K. J. Schmidt
Summary: Aqueous two-phase systems (ATPS) have gained attention in polymer chemistry due to their biocompatibility and applications in biomaterials and biology. This study investigated ATPS formed from poly(N,N-diethylacrylamide) (PDEA) with dextran and poly(ethylene glycol), and observed a significant shift in PDEA's cloud point temperature in the ATPS compared to pure aqueous solutions. This effect on thermoresponsive behavior opens up new possibilities for water-based polymer systems in areas such as multicompartment hydrogels or biotechnology.
Article
Chemistry, Multidisciplinary
Hironori Ishihara, Reika Ikemoto, Misato Yamamoto, Yusuke Sanada, Keisuke Watanabe, Yukiteru Katsumoto
Summary: The relationship between dehydration of polymer chains and the nanodroplet formation through macroscopic liquid-liquid phase separation (LLPS) was investigated. It was found that PNiPAm chains have a narrower temperature range of dehydration compared to PNdEAm. The sharp dehydration of PNiPAm chains leads to its characteristic thermoresponsive behavior in water. For PNiPAm solutions with a high meso content, the dehydration of chains occurs before the macroscopic LLPS.
Article
Polymer Science
Shin-nosuke Nishimura, Kei Nishida, Tomoya Ueda, Shohei Shiomoto, Masaru Tanaka
Summary: Poly(N-isopropylacrylamide) (PNIPAM) is a commonly used thermoresponsive polymer that has been widely applied in biological applications. However, due to the presence of a hydrogen-bond donor, PNIPAM often induces blood clot formation, making alternatives to PNIPAM with aprotic polar functional groups necessary. In this study, acrylate polymers containing the aprotic polar functional group pyrrolidone ring were synthesized, and their lower critical solution temperatures (LCSTs) could be precisely controlled. These polymers demonstrated good blood compatibility and cell affinity, and interestingly, could activate macrophages without cytotoxicity when their hydrophobic/hydrophilic balance was altered.
Article
Chemistry, Physical
Tiantian Fang, Xifan Chen, Changyu Yang, Yaqi Cao, Junshi Zhang, WenChao Peng, Yang Li, Fengbao Zhang, Xiaobin Fan
Summary: In this study, a smart hydrogel was developed by combining poly(N-isopropylacrylamide) (PNIPAM) with two-dimensional (2D) silicene nanosheets. The resulting silicene/PNIPAM composite hydrogel exhibited dual thermal and near-infrared (NIR) responsive properties, with rapid, reversible, and repeatable NIR light-responsive behaviors. This smart hydrogel holds potential for applications in remote light-controlled devices.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Polymer Science
Alexander Plucinski, Marko Pavlovic, Mairi Clarke, David Bhella, Bernhard V. K. J. Schmidt
Summary: The study investigated the aggregation behavior of high molar mass block copolymer in an organic solvent, revealing unprecedented behavior under specific conditions. Potential future applications in photonics and templating of inorganic structures were envisioned for this new thermo-responsive block copolymer.
MACROMOLECULAR RAPID COMMUNICATIONS
(2022)
Article
Polymer Science
Chi Wang, Takeji Hashimoto, Ya-Chen Chuang, Keiji Tanaka, Yen-Pin Chang, Ting-Wei Yang, Meng-Tse Huang
Summary: This study investigates the phase transitions and gelation properties of aqueous solutions of atactic poly(N-isopropylacrylamide). The gel point and critical gel temperature were determined, and a phase diagram was constructed to describe the different phases of the solution. The structure and formation mechanism of gel junctions were also explored.
Article
Biochemistry & Molecular Biology
David Joram Mendoza, Meri Ayurini, Christine Browne, Vikram Singh Raghuwanshi, George P. Simon, Joel F. Hooper, Gil Garnier
Summary: A family of thermoresponsive poly(N-isopropyla-crylamide)-grafted cellulose nanofibers was synthesized via a silver-promoted decarboxylative polymerization approach. The method allows for control over functionalization and grafting amount, and the resulting grafted nanofibers exhibit remarkable thermoresponsive properties and can be used as thermosensitive biomaterials. This study validates a novel approach for the synthesis of new thermoresponsive and transparent hydrogels.
Article
Polymer Science
Shafia Lateef, Nadeem Bashir Ganaie, Ghulam Mustafa Peerzada
Summary: This study investigated the ferroin-catalyzed Belousov-Zhabotinsky oscillatory chemical reaction with catechol as the organic substrate in aqueous acid media. The system exhibited oscillations within a narrow range of initial reagent concentrations and showed a long induction time and numerous oscillations at 30±0.1 degrees C. The thermosensitive polymer PNIPAA influenced the induction time and number of oscillations in the system.
Article
Polymer Science
Julie Stastna, Vladislav Ivaniuzhenkov, Lenka Hanykova
Summary: The combination of swelling experiments and NMR spectroscopy was used to investigate the sensitivity of hydrogels with a single- and double-network structure to various stimuli. The behavior of the double network was found to be significantly affected by the introduction of the second component and the formation of the interpenetrating structure.
Article
Chemistry, Physical
Di Zhou, Ling-Shu Wan, Zhi-Kang Xu, Kenji Mochizuki
Summary: Raman-MCR was used to study the changes in the hydration shell around poly(N,N-diethylacrylamide) (PDEAM) upon heating, compared to poly(N-isopropylacrylamide) (PNIPAM). It was found that PDEAM has a less-ordered and smaller hydration shell than PNIPAM, and that the hydration-shell structure of PDEAM is not affected by the clouding transition, allowing for coil-globule transition and aggregation of multiple chains without structural transformation of the hydration shell.
JOURNAL OF PHYSICAL CHEMISTRY B
(2021)
Review
Materials Science, Multidisciplinary
Lin Tang, Ling Wang, Xiao Yang, Yiyu Fen, Yu Li, Wei Feng
Summary: PNIPAM-based smart hydrogels are important smart materials with unique thermo-responsive properties and promising applications. This review summarizes the development, fundamental design, synthetic strategies, and potential applications of these materials in various fields.
PROGRESS IN MATERIALS SCIENCE
(2021)
Article
Polymer Science
Migle Babelyte, Laura Peciulyte, Vesta Navikaite-Snipaitiene, Joana Bendoraitiene, Volodymyr Samaryk, Ramune Rutkaite
Summary: Thermoresponsive chitosan-graft-poly(N-isopropylacrylamide) copolymers with different compositions were synthesized. The chemical structure of the copolymers was confirmed and their lower critical solution temperature (LCST) behavior was assessed. Copolymers with a certain content of poly(N-isopropylacrylamide) side chains demonstrated LCST behavior and could potentially be used in drug delivery systems or tissue engineering.
Article
Polymer Science
Isaac J. Gresham, Ben A. Humphreys, Joshua D. Willott, Edwin C. Johnson, Timothy J. Murdoch, Grant B. Webber, Erica J. Wanless, Andrew R. J. Nelson, Stuart W. Prescott
Summary: The structure of grafted-from poly(N-isopropylacrylamide) brushes under confinement shows a uniform internal structure and specific volume fraction distribution, eliminating the critical transition point in their thermal response. Different experimental methods find qualitative agreement, but variations exist due to path-dependent behavior.