Warren, Nicholas J.; Derry, Matthew J.; Mykhaylyk, Oleksandr O.; Lovett, Joseph R.; Ratcliffe, Liam P. D.; Ladmiral, Vincent; Blanazs, Adam; Fielding, Lee A.; Armes, Steven P.
Critical Dependence of Molecular Weight on Thermoresponsive Behavior of Diblock Copolymer Worm Gels in Aqueous Solution
Reversible addition–fragmentation chain transfer (RAFT) aqueous dispersion polymerization of 2-hydroxypropyl methacrylate was used to prepare three poly(glycerol monomethacrylate)x–poly(2-hydroxypropyl methacrylate)y (denoted Gx-Hy or PGMA-PHPMA) diblock copolymers, namely G37-H80, G54-H140, and G71-H200. A master phase diagram was used to select each copolymer composition to ensure that a pure…
Smart release of antimicrobial ZnO nanoplates from a pH-responsive keratin hydrogel
Villanueva, María E.; Cuestas, María L.; Pérez, Claudio J.; Campo Dall′ Orto, Viviana; Copello, Guillermo J.
A smart antibacterial biomaterial based on a keratin hydrogel with pH-dependent behavior and Zinc Oxide nanoplates as biocide agent has been developed. The pH of a chronic wound is basic due to bacterial metabolism. Originally shrank at acid pH, keratin hydrogels swell upon contact with a bacterial contaminated media leading…
Robust poly(aryl piperidinium)/N-spirocyclic poly(2,6-dimethyl-1,4-phenyl) for hydroxide-exchange membranes
Chen, Nanjun; Lu, Chuanrui; Li, Yunxi; Long, Chuan; Zhu, Hong
Herein, for realizing the high efficiency and long lifetime of hydroxide exchange membranes (HEMs) for alkaline membrane fuel cell (AMFC) applications, a series of robust poly(biphenyl piperidinium) (PBP)/6-azaspiro undecane (ASU)-functionalized polyphenyl ether (ASU-PPO) membranes were prepared by a crosslinked strategy. Crosslinked PBP-ASU-PPO membrane combines the advantage of PBP and…
Photopolymerization-assisted self-assembly as a strategy to obtain a dispersion of very high aspect ratio nanostructures in a polystyrene matrix
Montoya Rojo, Ú. M.; Riccardi, C. C.; Ninago, M. D.; Ciolino, A. E.; Villar, M. A.; Ceolín, M.; Zucchi, I. A.; Schroeder, W. F.
Very high aspect ratio nano-objects dispersed in a polymer matrix impart a number of desired characteristics to the material, such as barrier properties to the diffusion of small molecules. Commonly, these dispersions are obtained via top-down procedures that require several time-consuming steps of purification, surface modification, and processing. In this…
Influence of amide-containing side chains on the mechanical properties of diketopyrrolopyrrole-based polymers
Ocheje, Michael U.; Selivanova, Mariia; Zhang, Song; Nguyen, Thi Hai Van; Charron, Brynn P.; Chuang, Ching-Heng; Cheng, Yu-Hsuan; Billet, Blandine; Noori, Suendues; Chiu, Yu-Cheng; Gu, Xiaodan; Rondeau-Gagné, Simon
An efficient strategy to modulate the mechanical properties of conjugated polymers has been developed through the incorporation of amide-containing alkyl chains in diketopyrrolopyrrole-based conjugated polymers. The side-chain engineering performed with hydrogen bonding moieties (up to 20 mol% of amide-containing side-chains) was found to reduce the crystallinity of the conjugated polymers…
Crystal Structure of a Tetrameric DNA Fold-Back Quadruplex
Chu, Betty; Zhang, Daoning; Hwang, Wonseok; Paukstelis, Paul J.
DNA can adopt many structures beyond the Watson–Crick duplex. However, the bounds of DNA structural diversity and how these structures might regulate biological processes is only beginning to be understood. Here, we describe the 1.05 Å resolution crystal structure of a DNA oligonucleotide that self-associates to form a non-G-quadruplex fold-back…
Effects of Interconnected Polymer Nanopores Leading to Different Degrees of Confined Polymerization
Wang, Kui; Lei, Jinhua; Nie, Heran; Shen, Lu; Chen, Peng; Zhou, Guangyuan
In this study, different degrees of ethylene-confined polymerization (non-confined, slightly confined, and highly confined) are presented in porous polymer microspheres (PPMs) with an interconnected tri-modal pore structure. First, three catalysts, Cp2ZrCl2, Cp2TiCl2, and TiCl4, are attached to the interface of PPMs to form a nano-confined space for ethylene polymerization. Then…
Phase Transition and Side-Chain Crystallization of Poly(methyl vinyl ether-alt-maleic anhydride)-g-Alkyl Alcohol Comb-like Polymers
Li, Jing; Wang, Haixia; Kong, Lei; Zhou, Yong; Li, Shuqin; Shi, Haifeng
A series of poly(methyl vinyl ether-alt-maleic anhydride)-g-alkyl alcohol (PVEM -Cn) comb-like polymers were synthesized by a simple esterification reaction between poly(methyl vinyl ether-alt-maleic anhydride) and n-alkyl alcohol with n = 14–26. Thermal property, side-chain crystallization, and phase transition behavior of PVEM-Cn comb-like polymers were investigated by 1H NMR,DSC,…
Tailoring the stability and photo-Fenton activity of Fe-modified nanostructured silicates by tuning the metal speciation from different synthesis conditions
Elías, Verónica R.; Ochoa Rodriguez, Pablo A.; Vaschetto, Eliana G.; Pecchi, Gina A.; Huck-Iriart, Cristián; Casuscelli, Sandra G.; Eimer, Griselda A.
The stability and photo Fenton activity of nanoarchitectured silicates modified with Fe by the wet impregnation method were studied as a function of the used solvent, calcination temperature and iron loading. The physicochemical properties were characterized by SAXS, XRD, N2 physisorption, SEM, AA, UV–Vis DR, XPS and TPR. All solids…
Design and application of volatilizable solid additives in non-fullerene organic solar cells
Yu, Runnan; Yao, Huifeng; Hong, Ling; Qin, Yunpeng; Zhu, Jie; Cui, Yong; Li, Sunsun; Hou, Jianhui
High-boiling-point solvent additives are commonly used to optimize the device performance of organic solar cells but they make problems for device stability and reproducibility. Here Yu et al. design volatilizable solid additives that can improve the device performance without causing above…