Dendrimers as reactive modules for the synthesis of new structure-controlled, higher-complexity megamers

2000 ◽  
Vol 72 (12) ◽  
pp. 2343-2358 ◽  
Author(s):  
Donald A. Tomalia ◽  
Srinivas Uppuluri ◽  
Douglas R. Swanson ◽  
Jing Li
Keyword(s):  
Functional Groups ◽  
Molecular Level ◽  
Covalent Bonding ◽  
Core Shell ◽  
New Class ◽  
Generic Structures ◽  
Sterically Induced

Dendrimers are macromolecular, nanoscale objects that are widely recognized as precise, mathematically defined, covalent core-shell assemblies. As such, they are composed of quantized numbers of atoms, monomers, and terminal functional groups relative to the respective shell levels (generations) surrounding their cores. Dendrimers have been referred to as molecular-level analogs of atoms. This perspective arises from their potential to function as precise macromolecular tectons (modules), suitable for the synthesis of structure-controlled complexity beyond dendrimers. We have termed this major new class of generic structures "megamers". Our group has now synthesized such "megamer complexity" in the form of both covalent and supra-macromolecular dendri-catenanes, dendri-macrocycles, dendri-clefts, and dendri-clusters. The covalent dendri-cluster subset of megamers has been coined "core-shell tecto(dendrimers)". New mathematically defined, covalent bonding rules for tecto(dendrimer) formation are consistent with sterically induced stoichiometry (SIS) predictions and have been verified experimentally.

A three-dimensional hierarchical Fe2O3@NiO core/shell nanorod array on carbon cloth: a new class of anode for high-performance lithium-ion batteries

Nanoscale ◽  
2013 ◽  
Vol 5 (17) ◽  
pp. 7906 ◽  
Author(s):  
Qin-qin Xiong ◽  
Jiang-ping Tu ◽  
Xin-hui Xia ◽  
Xu-yang Zhao ◽  
Chang-dong Gu ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
High Performance ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Nanorod Array ◽  
Core Shell ◽  
Carbon Cloth ◽  
New Class

scholarly journals A Tad-like apparatus is required for contact-dependent prey killing in predatory social bacteria

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Sofiene Seef ◽  
Julien Herrou ◽  
Paul de Boissier ◽  
Laetitia My ◽  
Gael Brasseur ◽  
...  
Keyword(s):  
Molecular Level ◽  
Cell Interaction ◽  
Prey Cell ◽  
Predator Prey ◽  
New Class ◽  
Tight Contact ◽  
Type Iv ◽  
Secreted Factors ◽  
Predatory Bacteria ◽  
Prey Killing

Myxococcus xanthus, a soil bacterium, predates collectively using motility to invade prey colonies. Prey lysis is mostly thought to rely on secreted factors, cocktails of antibiotics and enzymes, and direct contac with Myxococcus cells. In this study, we show that on surfaces the coupling of A-motility and contact-dependent killing is the central predatory mechanism driving effective prey colony invasion and consumption. At the molecular level, contact-dependent killing involves a newly discovered type IV filament-like machinery (Kil) that both promotes motility arrest and prey cell plasmolysis. In this process, Kil proteins assemble at the predator-prey contact site, suggesting that they allow tight contact with prey cells for their intoxication. Kil-like systems form a new class of Tad-like machineries in predatory bacteria, suggesting a conserved function in predator-prey interactions. This study further reveals a novel cell-cell interaction function for bacterial pili-like assemblages.

Polymer films prepared using ionically crosslinked soft core–shell nanoparticles: a new class of nanostructured ionomers

Soft Matter ◽  
2011 ◽  
Vol 7 (1) ◽  
pp. 247-257 ◽  
Author(s):  
Orawan Pinprayoon ◽  
Robert Groves ◽  
Peter A. Lovell ◽  
Somjit Tungchaiwattana ◽  
Brian R. Saunders
Keyword(s):  
Polymer Films ◽  
Soft Core ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
New Class ◽  
Core Shell Nanoparticles

Polyzwitterionic aqueous solutions – a new class of electrorheological fluids

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
George S. Georgiev ◽  
Anna A. Tzoneva ◽  
Velin A. Spassov
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Aqueous Solutions ◽  
Structural Organization ◽  
Cluster Formation ◽  
Electrorheological Fluids ◽  
Core Shell ◽  
New Class ◽  
Polyelectrolyte Solutions ◽  
Direction Opposite

AbstractIt has been established that the electroviscosity effect of polyzwitterionic (PZI) aqueous solutions is more considerable than and acts in a direction opposite to that of aqueous polyelectrolyte solutions. Temperature and electric field strength influence the electroviscosity of PZI aqueous solutions in parallel, though the reasons for these effects are quite different. The unusual electroviscosity behaviour of PZI solutions is explained by a ‘core-shell’ model for the structural organization of PZI macromolecules, suggesting that cluster formation is due to intensive dipoledipole interactions between monomer units of the same or of different macromolecules.

Importance of Nanosensors: Feynman's Vision and the Birth of Nanotechnology

MRS Bulletin ◽  
2007 ◽  
Vol 32 (9) ◽  
pp. 718-725 ◽  
Author(s):  
Jozef T. Devreese
Keyword(s):  
Molecular Level ◽  
State Of The Art ◽  
Fast Response ◽  
Atomic Scale ◽  
Advanced Materials ◽  
New Class ◽  
Intelligent Sensors ◽  
Integrated Devices ◽  
Further Development ◽  
Better Than

In his visionary 1959 lecture at Caltech, Richard P. Feynman foresaw the potential of the ability to manipulate matter at the atomic scale. In this article, adapted from Integrated Nanosensors, MRS Symposium Proceedings Volume 952E, edited by I.K. Schuller, Y. Bruynseraede, L.M. Lechuga, and E. Johnson (2007), Jozef T. Devreese (University of Antwerp) discusses implementations of Feynman's vision in the field of nanosensors and perspectives of its further development and applications.Nanoparticles are unique tools as sensors. Particles with sizes at the nanoscale reveal physical properties that do not exist in bulk materials; these properties can operate well inside living cells. Nanosensors possess unique physical characteristics. Their sensitivity can be orders of magnitude better than that of conventional devices. Nanosensors possess such performance advantages as fast response and portability. State-of-the-art nanosensors are based on various advanced materials (quantum dots, nanoshells, nanopores, carbon nanotubes, etc.). Nanosensors furthermore allow for building an entirely new class of integrated devices that provide the elemental base for “intelligent sensors” capable of data processing, storage, and analysis. Advances can open unprecedented perspectives for the application of nanosensors in various fields, for example, as molecular-level diagnostic and treatment instruments in medicine and as networks of nanorobots for real-time monitoring of physiological parameters of a human body.

Hierarchical core/shell Janus-type α-Fe2O3/PEDOT nanoparticles for high performance flexible energy storage devices

2016 ◽  
Vol 4 (21) ◽  
pp. 8263-8271 ◽  
Author(s):  
Jin Wook Park ◽  
Wonjoo Na ◽  
Jyongsik Jang
Keyword(s):  
Energy Storage ◽  
Vapor Deposition ◽  
High Performance ◽  
Hybrid Nanoparticles ◽  
Core Shell ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Liquid Diffusion ◽  
New Class

A new class of hierarchical α-Fe2O3/poly(3,4-ethylenedioxythiophene) (PEDOT) core/shell Janus-type hybrid nanoparticles (HNPs) was successfully synthesized using sonochemical, liquid–liquid diffusion-assisted crystallization, and vapor deposition polymerization methods.

scholarly journals Construction of multi-layered white emitting organic nanoparticles by clicking polymers

2015 ◽  
Vol 3 (39) ◽  
pp. 10277-10284 ◽  
Author(s):  
H. Keita ◽  
B. Guzelturk ◽  
J. Pennakalathil ◽  
T. Erdem ◽  
H. V. Demir ◽  
...  
Keyword(s):  
Functional Groups ◽  
Core Shell ◽  
Organic Nanoparticles ◽  
Shell Type

A series of blue, green and red emitting polymers that are appropriately functionalized with alkyne and azide functional groups have been prepared and clicked together to construct bi-layered and tri-layered white emitting core–shell type nanoparticles.

Formation of a new class of 7π radicals via sterically induced P–P bond cleavage of the dimers [(CH)2(NR)2P]2

2009 ◽  
pp. 1691 ◽  
Author(s):  
Ruth Edge ◽  
Robert J. Less ◽  
Eric J. L. McInnes ◽  
Kristine Müther ◽  
Vesal Naseri ◽  
...  
Keyword(s):  
Bond Cleavage ◽  
New Class ◽  
Sterically Induced

scholarly journals Deciphering nanoconfinement effects on molecular orientation and reaction intermediate by single molecule imaging

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Bin Dong ◽  
Yuchen Pei ◽  
Nourhan Mansour ◽  
Xuemei Lu ◽  
Kai Yang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Single Molecule ◽  
Molecular Orientation ◽  
Rational Design ◽  
Molecular Level ◽  
Catalyst Activity ◽  
Molecular Transport ◽  
Nanoporous Structure ◽  
Core Shell ◽  
Single Molecule Studies

Abstract Nanoconfinement could dramatically change molecular transport and reaction kinetics in heterogeneous catalysis. Here we specifically design a core-shell nanocatalyst with aligned linear nanopores for single-molecule studies of the nanoconfinement effects. The quantitative single-molecule measurements reveal unusual lower adsorption strength and higher catalytic activity on the confined metal reaction centres within the nanoporous structure. More surprisingly, the nanoconfinement effects on enhanced catalytic activity are larger for catalysts with longer and narrower nanopores. Experimental evidences, including molecular orientation, activation energy, and intermediate reactive species, have been gathered to provide a molecular level explanation on how the nanoconfinement effects enhance the catalyst activity, which is essential for the rational design of highly-efficient catalysts.

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