Cooperative assembly of Janus particles and amphiphilic oligomers: the role of Janus balance

Nanoscale ◽  
2019 ◽  
Vol 11 (15) ◽  
pp. 7221-7228 ◽  
Author(s):  
Jiawei Li ◽  
Junfeng Wang ◽  
Qiang Yao ◽  
Kai Yu ◽  
Youguo Yan ◽  
...  
Keyword(s):  
Spatial Localization ◽  
Janus Particles ◽  
Janus Nanoparticles ◽  
Hybrid Assemblies ◽  
Cooperative Assembly

The spatial localization of Janus nanoparticles within hybrid assemblies can be controlled by regulating the Janus balance of nanoparticles.

scholarly journals Substrate wettability guided oriented self assembly of Janus particles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Meneka Banik ◽  
Shaili Sett ◽  
Chirodeep Bakli ◽  
Arup Kumar Raychaudhuri ◽  
Suman Chakraborty ◽  
...  
Keyword(s):  
Self Assembly ◽  
Janus Particles ◽  
Water Molecules ◽  
Functional Coatings ◽  
Hexagonal Close Packed ◽  
Local Densities ◽  
Inhomogeneous Properties ◽  
Metal Polymer ◽  
Specific Orientation

AbstractSelf-assembly of Janus particles with spatial inhomogeneous properties is of fundamental importance in diverse areas of sciences and has been extensively observed as a favorably functionalized fluidic interface or in a dilute solution. Interestingly, the unique and non-trivial role of surface wettability on oriented self-assembly of Janus particles has remained largely unexplored. Here, the exclusive role of substrate wettability in directing the orientation of amphiphilic metal-polymer Bifacial spherical Janus particles, obtained by topo-selective metal deposition on colloidal Polymestyere (PS) particles, is explored by drop casting a dilute dispersion of the Janus colloids. While all particles orient with their polymeric (hydrophobic) and metallic (hydrophilic) sides facing upwards on hydrophilic and hydrophobic substrates respectively, they exhibit random orientation on a neutral substrate. The substrate wettability guided orientation of the Janus particles is captured using molecular dynamic simulation, which highlights that the arrangement of water molecules and their local densities near the substrate guide the specific orientation. Finally, it is shown that by spin coating it becomes possible to create a hexagonal close-packed array of the Janus colloids with specific orientation on differential wettability substrates. The results reported here open up new possibilities of substrate-wettability driven functional coatings of Janus particles, which has hitherto remained unexplored.

scholarly journals Anti-cooperative assembly of the SRP19 and SRP68/72 components of the signal recognition particle

2008 ◽  
Vol 415 (3) ◽  
pp. 429-437 ◽  
Author(s):  
Tuhin Subhra Maity ◽  
Howard M. Fried ◽  
Kevin M. Weeks
Keyword(s):  
Electrostatic Interactions ◽  
Signal Recognition Particle ◽  
Cooperative Binding ◽  
Signal Recognition ◽  
Parallel Orientation ◽  
Domain Interactions ◽  
Cooperative Assembly ◽  
Srp Rna ◽  
Antagonistic Interactions

The mammalian SRP (signal recognition particle) represents an important model for the assembly and role of inter-domain interactions in complex RNPs (ribonucleoproteins). In the present study we analysed the interdependent interactions between the SRP19, SRP68 and SRP72 proteins and the SRP RNA. SRP72 binds the SRP RNA largely via non-specific electrostatic interactions and enhances the affinity of SRP68 for the RNA. SRP19 and SRP68 both bind directly and specifically to the same two RNA helices, but on opposite faces and at opposite ends. SRP19 binds at the apices of helices 6 and 8, whereas the SRP68/72 heterodimer binds at the three-way junction involving RNA helices 5, 6 and 8. Even though both SRP19 and SRP68/72 stabilize a similar parallel orientation for RNA helices 6 and 8, these two proteins bind to the RNA with moderate anti-cooperativity. Long-range anti-cooperative binding by SRP19 and SRP68/72 appears to arise from stabilization of distinct conformations in the stiff intervening RNA scaffold. Assembly of large RNPs is generally thought to involve either co-operative or energetically neutral interactions among components. By contrast, our findings emphasize that antagonistic interactions can play significant roles in assembly of multi-subunit RNPs.

Cooperative Assembly of Metal Nitrate and Citric Acid with Block Copolymers: Role of Carbonate Conversion Temperature on the Mesostructure of Ordered Porous Oxides

2015 ◽  
Vol 119 (22) ◽  
pp. 12138-12148 ◽  
Author(s):  
Michael C. Burroughs ◽  
Sarang M. Bhaway ◽  
Pattarasai Tangvijitsakul ◽  
Kevin A. Cavicchi ◽  
Mark D. Soucek ◽  
...  
Keyword(s):  
Citric Acid ◽  
Block Copolymers ◽  
Metal Nitrate ◽  
Porous Oxides ◽  
Cooperative Assembly ◽  
Ordered Porous ◽  
Conversion Temperature

Behavior of Janus Particles at Liquid Interfaces

2014 ◽  
Author(s):  
Hossein Rezvantalab ◽  
Shahab Shojaei-Zadeh
Keyword(s):  
Small Difference ◽  
Separation Distance ◽  
Janus Particles ◽  
Interface Plane ◽  
Fluid Interfaces ◽  
Liquid Interfaces ◽  
Ellipsoidal Particles ◽  
Particle Force ◽  
Energetic Interactions

We study the capillary-induced interactions and configuration of spherical and non-spherical Janus particles adsorbed at flat liquid-fluid interfaces. For Janus spheres, the equilibrium orientation results in each hemisphere being exposed to its more favored fluid. However, experimental observations suggest that some of these particles may take a tilted orientation at the interface, giving rise to a deformed interface. On the other hand, Janus ellipsoids with a large aspect ratio or a small difference in the wettability of the two regions tend to tilt even at equilibrium. The overlap of deformed menisci results in energetic interactions between neighboring particles. We numerically calculate the interface shape around the particles by minimizing the total surface energy of the system comprising of the interface and particle-fluid regions. We quantify these interactions through evaluation of capillary energy variation as a function of the orientation and separation distance between the particles. We find that Janus spheres with similar orientations undergo a relative realignment in the interface plane in order to minimize the capillary energy. In case of ellipsoidal particles, the particles assemble in a preferred side-by-side configuration. We evaluate the role of anisotropy and degree of amphiphilicity on the inter-particle force and the capillary torque. The results can be used to predict the migration and oriented assembly of Janus particles with various geometrical and surface properties at liquid-fluid interfaces.

The role of chemical dynamics in plant morphogenesis1

2010 ◽  
Vol 38 (2) ◽  
pp. 645-650 ◽  
Author(s):  
David M. Holloway
Keyword(s):  
De Novo ◽  
Spatial Localization ◽  
Break Symmetry ◽  
Chemical Patterning ◽  
Plant Morphogenesis ◽  
Formation Pattern ◽  
History Of ◽  
Biological Development ◽  
Concentration Patterns

In biological development, the generation of shape is preceded by the spatial localization of growth factors. Localization, and how it is maintained or changed during the process of growth, determines the shapes produced. Mathematical models have been developed to investigate the chemical, mechanical and transport properties involved in plant morphogenesis. These synthesize biochemical and biophysical data, revealing underlying principles, especially the importance of dynamics in generating form. Chemical kinetics has been used to understand the constraints on reaction and transport rates to produce localized concentration patterns. This approach is well developed for understanding de novo pattern formation, pattern spacing and transitions from one pattern to another. For plants, growth is continual, and a key use of the theory is in understanding the feedback between patterning and growth, especially for morphogenetic events which break symmetry, such as tip branching. Within the context of morphogenetic modelling in general, the present review gives a brief history of chemical patterning research and its particular application to shape generation in plant development.

Role of Geometry and Amphiphilicity on Capillary-Induced Interactions between Anisotropic Janus Particles

Langmuir ◽  
2013 ◽  
Vol 29 (48) ◽  
pp. 14962-14970 ◽  
Author(s):  
Hossein Rezvantalab ◽  
Shahab Shojaei-Zadeh
Keyword(s):  
Janus Particles

Controlled fabrication of polymeric Janus nanoparticles and their solution behaviors

RSC Advances ◽  
2016 ◽  
Vol 6 (107) ◽  
pp. 105070-105075 ◽  
Author(s):  
Wei Zhang ◽  
Jinxin He ◽  
Xia Dong
Keyword(s):  
Janus Particles ◽  
Janus Nanoparticles

Well-defined Janus particles with tunable Janus balances are achieved, and the influences of Janus balance have been discussed in detail.

Role of Protein−Protein Bridging Interactions on Cooperative Assembly of DNA-Bound CRP−CytR−CRP Complex and Regulation of theEscherichia ColiCytR Regulon†

Biochemistry ◽  
2003 ◽  
Vol 42 (13) ◽  
pp. 3812-3825 ◽  
Author(s):  
Mayy Chahla ◽  
John Wooll ◽  
Thomas M. Laue ◽  
Nghia Nguyen ◽  
Donald F. Senear
Keyword(s):  
Cooperative Assembly
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