Self‐assembly of Atomically Dispersed Ag Catalysts on Polyhedral Co 3 O 4 at Elevated Temperatures: A Top‐Down Nanofabrication of High‐Loading Atomically Dispersed Catalysts

ChemCatChem ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 561-568 ◽  
Author(s):  
Zhiwei Huang ◽  
Jie Zhang ◽  
Yuyao Du ◽  
Ying Zhang ◽  
Xiaomin Wu ◽  
...  
Keyword(s):  
Self Assembly ◽  
Elevated Temperatures ◽  
High Loading ◽  
Top Down ◽  
Dispersed Catalysts ◽  
Ag Catalysts

scholarly journals Kinked Bisamides as Efficient Supramolecular Foam Cell Nucleating Agents for Low-Density Polystyrene Foams with Homogeneous Microcellular Morphology

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1094
Author(s):  
Bastian Klose ◽  
Daniel Kremer ◽  
Merve Aksit ◽  
Kasper P. van der Zwan ◽  
Klaus Kreger ◽  
...  
Keyword(s):  
Cell Size ◽  
Self Assembly ◽  
Large Scale ◽  
Elevated Temperatures ◽  
Foam Cell ◽  
Cell Structure ◽  
Expansion Ratio ◽  
Low Density ◽  
Nucleating Agents ◽  
Foam Density

Polystyrene foams have become more and more important owing to their lightweight potential and their insulation properties. Progress in this field is expected to be realized by foams featuring a microcellular morphology. However, large-scale processing of low-density foams with a closed-cell structure and volume expansion ratio of larger than 10, exhibiting a homogenous morphology with a mean cell size of approximately 10 µm, remains challenging. Here, we report on a series of 4,4′-diphenylmethane substituted bisamides, which we refer to as kinked bisamides, acting as efficient supramolecular foam cell nucleating agents for polystyrene. Self-assembly experiments from solution showed that these bisamides form supramolecular fibrillary or ribbon-like nanoobjects. These kinked bisamides can be dissolved at elevated temperatures in a large concentration range, forming dispersed nano-objects upon cooling. Batch foaming experiments using 1.0 wt.% of a selected kinked bisamide revealed that the mean cell size can be as low as 3.5 µm. To demonstrate the applicability of kinked bisamides in a high-throughput continuous foam process, we performed foam extrusion. Using 0.5 wt.% of a kinked bisamide yielded polymer foams with a foam density of 71 kg/m3 and a homogeneous microcellular morphology with cell sizes of ≈10 µm, which is two orders of magnitude lower compared to the neat polystyrene reference foam with a comparable foam density.

scholarly journals Multiscale additive manufacturing of polymers using 3D photo-printable self-assembling ionic liquid monomers

2019 ◽  
Vol 4 (3) ◽  
pp. 580-585 ◽  
Author(s):  
Bineh G. Ndefru ◽  
Bryan S. Ringstrand ◽  
Sokhna I.-Y. Diouf ◽  
Sönke Seifert ◽  
Juan H. Leal ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Additive Manufacturing ◽  
Self Assembly ◽  
Low Cost ◽  
Low Resolution ◽  
Top Down ◽  
Bottom Up ◽  
Cost Approach ◽  
Self Assembling ◽  
Nanoscale Features

Combining bottom-up self-assembly with top-down 3D photoprinting affords a low cost approach for the introduction of nanoscale features into a build with low resolution features.

ChemInform Abstract: Integrating Top-Down and Self-Assembly in the Fabrication of Peptide and Protein-Based Biomedical Materials

ChemInform ◽  
2011 ◽  
Vol 42 (49) ◽  
pp. no-no
Author(s):  
Katherine H. Smith ◽  
Esther Tejeda-Montes ◽  
Marta Poch ◽  
Alvaro Mata
Keyword(s):  
Self Assembly ◽  
Top Down ◽  
Biomedical Materials

Block Copolymer Films Hierarchical Assembly in Confinement

2007 ◽  
Vol 364-366 ◽  
pp. 437-441
Author(s):  
Yong Zhi Cao ◽  
Shen Dong ◽  
Ying Chun Liang ◽  
Tao Sun ◽  
Yong Da Yan
Keyword(s):  
Block Copolymer ◽  
Self Assembly ◽  
Structural Control ◽  
Computer Control ◽  
The Self ◽  
Top Down ◽  
Bottom Up ◽  
Dimensional Precision ◽  
Periodic Arrays ◽  
Copolymer Films

Ultrathin block copolymer films are promising candidates for bottom-up nanotemplates in hybrid organic-inorganic electronic, optical, and magnetic devices. Key to many future applications is the long range ordering and precise placement of the phase-separated nanoscale domains. In this paper, a combined top-down/bottom-up hierarchical approach is presented on how to fabricate massive arrays of aligned nanoscale domains by means of the self-assembly of asymmetric poly (styrene-block-ethylene/butylenes-block-styrene) (SEBS) tirblock copolymers in confinement. The periodic arrays of the poly domains were orientated via the introduction of AFM micromachining technique as a tool for locally controlling the self-assembly process of triblock copolymers by the topography of the silicon nitride substrate. Using the controlled movement of 2- dimensional precision stage and the micro pressure force between the tip and the surface by computer control system, an artificial topographic pattern on the substrate can be fabricated precisely. Coupled with solvent annealing technique to direct the assembly of block copolymer, this method provides new routes for fabricating ordered nanostructure. This graphoepitaxial methodology can be exploited in hybrid hard/soft condensed matter systems for a variety of applications. Moreover, Pairing top-down and bottom-up techniques is a promising, and perhaps necessary, bridge between the parallel self-assembly of molecules and the structural control of current technology.

scholarly journals Using Evaporation-Induced Self-Assembly for the Direct Drug Templating of Therapeutic Vectors with High Loading Fractions, Tunable Drug Release, and Controlled Degradation

2013 ◽  
Vol 25 (23) ◽  
pp. 4671-4678 ◽  
Author(s):  
Thomas Fontecave ◽  
Cedric Boissiere ◽  
Niki Baccile ◽  
Francisco J. Plou ◽  
Clement Sanchez
Keyword(s):  
Drug Release ◽  
Self Assembly ◽  
High Loading ◽  
Evaporation Induced Self Assembly

Polymersomes with high loading capacity prepared by direct self-assembly of block copolymers in drugs

Polymer ◽  
2018 ◽  
Vol 134 ◽  
pp. 117-124 ◽  
Author(s):  
Fang-Yu Lin ◽  
Chih-Yang Cheng ◽  
Yu-Hao Chuang ◽  
Shih-Huang Tung
Keyword(s):  
Block Copolymers ◽  
Self Assembly ◽  
High Loading ◽  
Loading Capacity

Preparing a highly dispersed catalyst supported on mesoporous microspheres via the self-assembly of amphiphilic ligands for the recovery of ultrahigh concentration wastewater

2016 ◽  
Vol 4 (17) ◽  
pp. 6304-6312 ◽  
Author(s):  
Shengyang Tao ◽  
Yandong Chen ◽  
Huan Wang ◽  
Jieshan Qiu ◽  
Xinkui Wang
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Significant Recovery ◽  
Dispersed Catalysts ◽  
Mesoporous Microspheres ◽  
Highly Dispersed

Highly dispersed catalysts supported on mesoporous microspheres were prepared and displayed significant recovery properties for ultrahigh concentration wastewater.

scholarly journals β-Cyclodextrin-Poly (β-Amino Ester) Nanoparticles Are a Generalizable Strategy for High Loading and Sustained Release of HDAC Inhibitors

2020 ◽  
Author(s):  
Sauradip Chaudhuri ◽  
Martha Fowler ◽  
Afroz S. Mohammad ◽  
Wenqui Zhang ◽  
Cassandra Baker ◽  
...  
Keyword(s):  
Self Assembly ◽  
Network Architecture ◽  
Hydrophobic Interactions ◽  
Drug Loading ◽  
Aqueous Media ◽  
Nile Red ◽  
High Loading ◽  
Hydrophobic Core ◽  
Amino Ester ◽  
Critical Determinant

<p> Here, we describe a simple, efficient formulation of a novel library of β-cyclodextrin-poly (β-amino ester) networks (CDN) to achieve this goal. We observed that network architecture was a critical determinant of CDN encapsulation of candidate molecules, with a more hydrophobic core enabling effective self-assembly and a PEGylated surface enabling high loading (up to ~30% w/w), effective self assembly of the nanoparticle, and slow release of drug into aqueous media (24 days) for the model <i>HDACi</i> panobinostat. Optimized CDN nanoparticles were taken up by GL261 cells in culture, and released panobinostat was confirmed to be bioactive. Pharmacokinetic analyses demonstrated that panobinostat was delivered to the brainstem, cerebellum, and upper spinal cord following intrathecal administration via cisterna magna injection in healthy mice. We next constructed a library of CDNs to encapsulate various small, hydrophobic, ionizable molecules (panobinostat, quisinostat, dacinostat, givinostat, and bortezomib, camptothecin, nile red, and cytarabine), which yielded important insights into the structural requirements for effective drug loading and CDN self-assembly. Taken in sum, these studies present a novel nanocarrier platform for encapsulation of <i>HDACi</i> via both ionic and hydrophobic interactions, which is an important step toward better treatment of disease via <i>HDACi</i> therapy.</p>

scholarly journals In-Depth Analysis of the Effect of Fragmentation on the Crystallization-Driven Self-Assembly Growth Kinetics of 1D Micelles Studied by Seed Trapping

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3122
Author(s):  
Gerald Guerin ◽  
Paul A. Rupar ◽  
Mitchell A. Winnik
Keyword(s):  
Growth Kinetics ◽  
Self Assembly ◽  
Growth Process ◽  
Elevated Temperatures ◽  
Polymer Chains ◽  
Exponential Law ◽  
Depth Analysis ◽  
Protein Fibrils ◽  
Polymer Fractionation ◽  
Kinetics Of

Studying the growth of 1D structures formed by the self-assembly of crystalline-coil block copolymers in solution at elevated temperatures is a challenging task. Like most 1D fibril structures, they fragment and dissolve when the solution is heated, creating a mixture of surviving crystallites and free polymer chains. However, unlike protein fibrils, no new nuclei are formed upon cooling and only the surviving crystallites regrow. Here, we report how trapping these crystallites at elevated temperatures allowed us to study their growth kinetics at different annealing times and for different amounts of unimer added. We developed a model describing the growth kinetics of these crystallites that accounts for fragmentation accompanying the 1D growth process. We show that the growth kinetics follow a stretched exponential law that may be due to polymer fractionation. In addition, by evaluating the micelle growth rate as a function of the concentration of unimer present in solution, we could conclude that the micelle growth occurred in the mononucleation regime.

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