SYNTHESIS OF POLYELECTROLYTE PAni MEMBRANE BY PHASE INVERSION AND ITS CHARACTERIZATIONS NURUL IZZATI IZNI BT MAT YUSOFF During the last few decades, the application of membrane b.
Fast water transport channels are crucial for water-related membrane separation processes. However, overcoming the trade-off between flux and selectivity is still a major challenge. To address this, we constructed spherical polyelectrolyte brush (SPB) structures with a highly hydrophilic polyelectrolyte brush layer, and introduced them into GO laminates, which increased both the flux and the separation factor. At 70 °C, the flux reached 5.23 kg m -2 h -1 , and the separation factor of butanol/water increased to ~8000, which places it among the most selective separation membranes reported to date. Interestingly, further studies demonstrated that the enhancement of water transport was not only dependent on the hydrophilicity of the polyelectrolyte chains, but also influenced by their flexibility in the solvent. Quartz crystal microbalance with dissipation and molecular dynamics simulations revealed the structure–performance correlations between water molecule migration and the flexibility of the ordered polymer chains in the 2D confined space.
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A multicomponent polymerization for the efficient synthesis of heteroaromatic hyperbranched polyelectrolytes was developed. These hyperbranched polymers showed excellent solubility, high quantum yields, tunable emission, and strong ROS generation ability, allowing for their widespread applications in highly ordered fluorescent photopatterning, efficient bacterial killing, and customizable photodynamic patterning of living organisms.
Abstract
We reported an efficient multicomponent polyannulation for in situ generation of heteroaromatic hyperbranched polyelectrolytes by using readily accessible internal diynes and low-cost, commercially available arylnitriles, NaSbF6, and H2O/AcOH. The polymers were obtained in excellent yields (up to 99 %) with extraordinary high molecular weights (Mw up to 1.011×106) and low polydispersity indices. The resulting polymers showed good processibility and high quantum yields with tunable emission in the solid state, making them ideal materials for highly ordered fluorescent photopatterning. These hyperbranched polyelectrolytes also possessed strong ability to generate reactive oxygen species, which allowed their applications in efficient bacterial killing and customizable photodynamic patterning of living organisms in a simple and cost-effective way.
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A novel multicomponent polymerization has been developed for the facile synthesis of heteroaromatic hyperbranched polyelectrolytes. As Chunlei Zhu, Jacky W. Y. Lam, Ben Zhong Tang et al. demonstrate in their Research Article (DOI: 10.1002/anie.202104709), the resulting hyperbranched polyelectrolytes show strong capability to facilitate the generation of reactive oxygen species, allowing for their applications in efficient bacterial killing and customizable photodynamic patterning of living organisms.
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Journal of the American Chemical SocietyDOI: 10.1021/jacs.1c01148
Fabian Späth, Carsten Donau, Alexander M. Bergmann, Moritz Kränzlein, Christopher V. Synatschke, Bernhard Rieger, and Job Boekhoven
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Polyelectrolytes such as DNA or heparin are long linear or branched macromolecules onto which charges are appended. The counterions neutralizing these charges can dissociate in water and this will largely determine the interaction of such polyelectrolytes with biomolecules, particularly with proteins. This Review discusses studies on the interaction of proteins with polyelectrolytes and how this knowledge can be used for medical applications.
Abstract
The counterions neutralizing the charges on polyelectrolytes such as DNA or heparin may dissociate in water and greatly influence the interaction of such polyelectrolytes with biomolecules, particularly proteins. In this Review we give an overview of studies on the interaction of proteins with polyelectrolytes and how this knowledge can be used for medical applications. Counterion release was identified as the main driving force for the binding of proteins to polyelectrolytes: Patches of positive charge become multivalent counterions of the polyelectrolyte and lead to the release of counterions from the polyelectrolyte and a concomitant increase in entropy. This is shown from investigations on the interaction of proteins with natural and synthetic polyelectrolytes. Special emphasis is paid to sulfated dendritic polyglycerols (dPGS). The Review demonstrates that we are moving to a better understanding of charge–charge interactions in systems of biological relevance. Research along these lines will aid and promote the design of synthetic polyelectrolytes for medical applications.
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Hi Reddit,
We are Hadi Fares, chemistry PhD candidate, and Joseph B. Schlenoff, Leo Mandelkern Professor of Polymer Science at Florida State University and Senior Editor of the ACS Langmuir journal. We will answer questions about our research focused on polymer materials as well as the ChemChamps competition organized by the American Chemical Society.
Joseph Schlenoff (JBS): I am a chemist interested in polyelectrolyte and zwitterated interfaces and their bioapplicability. Polyelectrolytes were thought to be un-processable until a couple of decades ago. We have discovered ways to process biocompatible synthetic polyelectrolytes using salt instead of heat. Salt helps in exposing the charged sites in these macromolecules, making it easier to extrude them to form different shapes such as tapes, tubes and rods, or to deposit them using the layer-by-layer (Lbl) technique or spin-coating.
Hadi Fares (HF): I am interested in charge compensation and diffusion inside polyelectrolyte films and complexes. We found a way to eliminate salt trapped in polyelectrolyte multilayers during buildup to obtain stoichiometric uniform thin films (few hundreds of nanometers). Using this new platform, I’m currently studying polyelectrolyte diffusion in these films in an attempt to make better materials and understand the way polyelectrolytes behave in complexes. These films have been proposed for uses as coatings and reservoirs in fields ranging from electronics to medicine. I’m also the winner of last year’s “Chemistry Champions”, a science communication competition organized by the American Chemical Society. Besides the many lessons I learned about communicating science, the competition has allowed me to travel to attend a public briefing on science education policy on Capitol Hill in Washington, DC. I also shot an upcoming “ACS Reactions” (https://www.youtube.com/user/ACSReactions) video about why we salivate when we see food (my favorite topic). You can read more about my ChemChamps experience in this blog post (https://speakingaboutscience.wordpress.com/). I will also be answering questions about this year’s edition of the competition starting soon. Every chemist 35 or under should apply!!
Feel free to ask us anything about polyelectrolyte materials, life in graduate school or ChemChamps!
We will be online at 11:00 am ET (8 am PST, 4 pm UTC) to begin answering your questions.
[EDIT] 11:00am ET, I am online to answer your questions. Thanks for the parti
... keep reading on reddit ➡Journal of the American Chemical SocietyDOI: 10.1021/jacs.9b12051
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Polyelectrolytes such as e.g. DNA or heparin are long linear or branched macromolecules onto which charges are appended. The counterions neutralizing these charges may dissociate in water and will largely determine the interaction of such polyelectrolytes with biomolecules and in particular with proteins. Here we review studies on the interaction of proteins with polyelectrolytes and how this knowledge can be used for medical applications. Counterion release was identified as the main driving force for the binding of proteins to polyelectrolytes: Patches of positive charge become multivalent counterions of the polyelectrolyte which leads to the release of counterions of the polyelectrolyte and a concomitant increase of entropy. We show this by surveying investigations done on the interaction of proteins with natural and synthetic polyelectrolytes. Special emphasis is laid on sulfated dendritic polyglycerols (dPGS). The entire overview demonstrates that we are moving on to a better understanding of charge‐charge interaction in system of biological relevance. Hence, research along these lines will aid and promote the design of synthetic polyelectrolytes for medical applications.
https://ift.tt/3i5lDwb
The development of facile methods for the synthesis of functional hyperbranched polyelectrolytes plays a pivotal role for biomimicry and the creation of new materials. In this study, we reported an efficient multicomponent polyannulation for in situ generation of heteroaromatic hyperbranched polyelectrolytes by using readily accessible internal diynes and low‐cost, commercially available arylnitriles, NaSbF 6 , and H 2 O/AcOH. The polymers were obtained in excellent yields (up to 99%) with extraordinary high molecular weights (Mw up to 1.011 × 10^6 ) and low polydispersity indices. The resulting polymers showed good processibility and high quantum yields with tunable emission in the solid state, making them as ideal materials for highly ordered fluorescent photopatterning. These hyperbranched polyelectrolytes also possessed strong ability to generate reactive oxygen species, which allowed their applications in efficient bacterial killing and customizable photodynamic patterning of living organisms in a simple and cost‐effective way. In view of the unique properties and functionalities, these hyperbranched polyelectrolytes hold great promise to be used in a plethora of follow‐up studies, such as photoelectronic materials, disease theranostics, biochips, and tissue engineering.
https://ift.tt/2RjnW64
