Aggregation of modified hexabenzocoronenes as models for early stage asphaltene self-assembly

2018 ◽  
Vol 44 (12) ◽  
pp. 992-1003 ◽  
Author(s):  
Lidiya Gavrilenko ◽  
Jeffery B. Klauda
Keyword(s):  
Self Assembly ◽  
Early Stage

Mesoscale modelling of droplets’ self-assembly in microfluidic channels

Soft Matter ◽  
2021 ◽  
Author(s):  
Andrea Montessori ◽  
Adriano Tiribocchi ◽  
Marco Lauricella ◽  
Fabio Bonaccorso ◽  
Sauro Succi
Keyword(s):  
Self Assembly ◽  
Early Stage ◽  
Microfluidic Channels ◽  
Contact Interactions ◽  
Mesoscale Modelling ◽  
Multicomponent Flows

A recently proposed mesoscale approach for the simulation of multicomponent flows with near-contact interactions is employed to investigate the early stage formation and clustering statistics of soft flowing crystals in microfluidic channels.

scholarly journals The macroscopic shape of assemblies formed from microparticles based on host–guest interaction dependent on the guest content

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takahiro Itami ◽  
Akihito Hashidzume ◽  
Yuri Kamon ◽  
Hiroyasu Yamaguchi ◽  
Akira Harada
Keyword(s):  
Molecular Recognition ◽  
Smart Materials ◽  
Self Assembly ◽  
Early Stage ◽  
Contact Point ◽  
Sodium Acrylate ◽  
Contact Points ◽  
Assembly Behavior ◽  
Small Clusters ◽  
Macroscopic Shape

AbstractBiological macroscopic assemblies have inspired researchers to utilize molecular recognition to develop smart materials in these decades. Recently, macroscopic self-assemblies based on molecular recognition have been realized using millimeter-scale hydrogel pieces possessing molecular recognition moieties. During the study on macroscopic self-assembly based on molecular recognition, we noticed that the shape of assemblies might be dependent on the host–guest pair. In this study, we were thus motivated to study the macroscopic shape of assemblies formed through host–guest interaction. We modified crosslinked poly(sodium acrylate) microparticles, i.e., superabsorbent polymer (SAP) microparticles, with β-cyclodextrin (βCD) and adamantyl (Ad) residues (βCD(x)-SAP and Ad(y)-SAP microparticles, respectively, where x and y denote the mol% contents of βCD and Ad residues). Then, we studied the self-assembly behavior of βCD(x)-SAP and Ad(y)-SAP microparticles through the complexation of βCD with Ad residues. There was a threshold of the βCD content in βCD(x)-SAP microparticles for assembly formation between x = 22.3 and 26.7. On the other hand, the shape of assemblies was dependent on the Ad content, y; More elongated assemblies were formed at a higher y. This may be because, at a higher y, small clusters formed in an early stage can stick together even upon collisions at a single contact point to form elongated aggregates, whereas, at a smaller y, small clusters stick together only upon collisions at multiple contact points to give rather circular assemblies. On the basis of these observations, the shape of assembly formed from microparticles can be controlled by varying y.

Monitoring the Early Stage Self-Assembly of Enzyme-Assisted Peptide Hydrogels

2013 ◽  
Vol 66 (5) ◽  
pp. 572 ◽  
Author(s):  
Richard J. Williams ◽  
James Gardiner ◽  
Anders B. Sorensen ◽  
Silvia Marchesan ◽  
Roger J. Mulder ◽  
...  
Keyword(s):  
1H Nmr ◽  
Self Assembly ◽  
Early Stage ◽  
The Self ◽  
Spectroscopic Techniques ◽  
Subsequent Formation ◽  
Self Assembling ◽  
Hydrogel Formation ◽  
Assembly Kinetics ◽  
Peptide Hydrogels

The early stages of the self-assembly of peptide hydrogels largely determine their final material properties. Here we discuss experimental methodologies for monitoring the self-assembly kinetics which underpin peptide hydrogel formation. The early stage assembly of an enzyme-catalysed Fmoc-trileucine based self-assembled hydrogel was examined using spectroscopic techniques (circular dichroism, CD, and solution NMR) as well as chromatographic (HPLC) and mechanical (rheology) techniques. Optimal conditions for enzyme-assisted hydrogel formation were identified and the kinetics examined. A lag time associated with the formation and accumulation of the self-assembling peptide monomer was observed and a minimum hydrogelator concentration required for gelation was identified. Subsequent formation of well defined nano- and microscale structures lead to self-supporting hydrogels at a range of substrate and enzyme concentrations. 1H NMR monitoring of the early self-assembly process revealed trends that were well in agreement with those identified using traditional methods (i.e. HPLC, CD, rheology) demonstrating 1H NMR spectroscopy can be used to non-invasively monitor the self-assembly of peptide hydrogels without damaging or perturbing the system.

Monitoring pattern formation in drying and wetting dispersions of gold nanoparticles by ESEM

2015 ◽  
Vol 181 ◽  
pp. 281-298 ◽  
Author(s):  
Casper Kunstmann-Olsen ◽  
Domagoj Belić ◽  
Mathias Brust
Keyword(s):  
Gold Nanoparticles ◽  
Self Assembly ◽  
Early Stage ◽  
Environmental Scanning Electron Microscopy ◽  
Water Soluble ◽  
Environmental Scanning ◽  
Evaporation And Condensation ◽  
Lift Off ◽  
Poly Ethylene

We report an investigation of the self-assembly of patterns from functionalized gold nanoparticles (GNPs) by monitoring the process in situ by environmental scanning electron microscopy (ESEM) during both evaporation and condensation of the dispersant. As this method limits the choice of dispersants to water, GNPs functionalized with hydrophilic thiol ligands, containing poly(ethylene)glycol (PEG) groups, were used on a variety of substrates including pre-patterned ones. Particular emphasis was given to early stage deposition of GNPs, as well as redispersion and lift-off upon condensation of water droplets. ESEM presents a unique opportunity of directly imaging such events in situ. It was found that attractive interactions between the substrate and the GNPs are often stronger than expected once the particles have been deposited. The role of nickel perchlorate as a highly water-soluble additive was studied. It was found that entropically driven deposition of particles and decoration of surface features was enhanced in its presence, as expected.

scholarly journals Bifurcation of self-assembly pathways to sheet or cage controlled by kinetic template effect

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Leonardo Hayato Foianesi-Takeshige ◽  
Satoshi Takahashi ◽  
Tomoki Tateishi ◽  
Ryosuke Sekine ◽  
Atsushi Okazawa ◽  
...  
Keyword(s):  
Self Assembly ◽  
Early Stage ◽  
Building Blocks ◽  
The Self ◽  
Numerical Analyses ◽  
Template Effect ◽  
Self Assembled ◽  
Assembly Pathways ◽  
Formation Step

Abstract The template effect is a key feature to control the arrangement of building blocks in assemblies, but its kinetic nature remains elusive compared to the thermodynamic aspects, with the exception of very simple reactions. Here we report a kinetic template effect in a self-assembled cage composed of flexible ditopic ligands and Pd(II) ions. Without template anion, a micrometer-sized sheet is kinetically trapped (off-pathway), which is converted into the thermodynamically most stable cage by the template anion. When the template anion is present from the start, the cage is selectively produced by the preferential cyclization of a dinuclear intermediate (on-pathway). Quantitative and numerical analyses of the self-assembly of the cage on the on-pathway revealed that the accelerating effect of the template is stronger for the early stage reactions of the self-assembly than for the final cage formation step itself, indicating the kinetic template effect.

Synchrotron X-ray scattering reveals early-stage crystallinity during the self-assembly of polyaniline nanotubes with rectangular cross-sections

2012 ◽  
Vol 161 (23-24) ◽  
pp. 2739-2742 ◽  
Author(s):  
Cosmin Laslau ◽  
Bridget Ingham ◽  
Zoran D. Zujovic ◽  
Pavla Čapková ◽  
Jaroslav Stejskal ◽  
...  
Keyword(s):  
Cross Sections ◽  
Self Assembly ◽  
Early Stage ◽  
The Self ◽  
X Ray ◽  
X Ray Scattering ◽  
Polyaniline Nanotubes ◽  
Ray Scattering

scholarly journals Gliadin proteolytical resistant peptides: the interplay between structure and self-assembly in gluten-related disorders

2021 ◽  
Author(s):  
Maria Georgina Herrera ◽  
Veronica Isabel Dodero
Keyword(s):  
Self Assembly ◽  
Early Stage ◽  
Wheat Gluten ◽  
In Vivo Models ◽  
Biophysical Characterization ◽  
Gut Mucosa ◽  
Gliadin Peptides ◽  
Wheat Sensitivity

Abstract In recent years, the evaluation of the structural properties of food has become of crucial importance in the understanding of food-related disorders. One of the most exciting systems is gliadin, a protein in wheat gluten, that plays a protagonist role in gluten-related disorders with a worldwide prevalence of 5%, including autoimmune celiac disease (CeD) (1%) and non-celiac wheat sensitivity (0.5–13%). It is accepted that gliadin is not fully digested by humans, producing large peptides that reach the gut mucosa. The gliadin peptides cross the lamina propria eliciting different immune responses in susceptible patients. Many clinical and biomedical efforts aim to diagnose and understand gluten-related disorders; meanwhile, the early stages of the inflammatory events remain elusive. Interestingly, although the primary sequence of many gliadin peptides is well known, it was only recently revealed the self-assembly capability of two pathogenic gliadin fragments and their connection to the early stage of diseases. This review is dedicated to the most relevant biophysical characterization of the complex gliadin digest and the two most studied gliadin fragments, the immunodominant 33-mer peptide and the toxic p31-43 in connection with inflammation and innate immune response. Here, we want to emphasize that combining different biophysical methods with cellular and in vivo models is of key importance to get an integrative understanding of a complex biological problem, as discussed here.

scholarly journals Phospholipid membranes promote the early stage assembly of α-synuclein aggregates

2018 ◽  
Author(s):  
Zhengjian Lv ◽  
Mohtadin Hashemi ◽  
Siddhartha Banerjee ◽  
Karen Zagorski ◽  
Jean-Christophe Rochet ◽  
...  
Keyword(s):  
Lipid Bilayers ◽  
Self Assembly ◽  
Early Stage ◽  
Time Lapse ◽  
Supported Lipid Bilayers ◽  
Membrane Composition ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nanomolar Concentration ◽  
Surface Changes

AbstractDevelopment of Parkinson’s disease is associated with spontaneous self-assembly of α-synuclein (α-syn). Efforts aimed at understanding this process have produced little clarity and the mechanism remains elusive. We report a novel effect of phospholipid bilayers on the catalysis of α-syn aggregation from monomers. We directly visualized α-syn aggregation on supported lipid bilayers using time-lapse atomic force microscopy. We discovered that α-syn assemble in aggregates on bilayer surfaces even at the nanomolar concentration of monomers in solution. The efficiency of the aggregation process depends on the membrane composition, being highest for a negatively charged bilayer. Furthermore, assembled aggregates can dissociate from the surface, suggesting that on-surface aggregation can be a mechanism by which pathological aggregates are produced. Computational modeling revealed that interaction of α-syn with bilayer surface changes the protein conformation and its affinity to assemble into dimers, and these properties depend on the bilayer composition. A model of the membrane-mediated aggregation triggering the assembly of neurotoxic aggregates is proposed.

Sign in / Sign up

Export Citation Format

Share Document