Recently, the steady-state process of convective assembly has emerged as a viable production route for colloidal monolayers. The present study models the regions of particle assembly: Region I comprises convective concentration of a particle suspension in a liquid below a meniscus, Region II comprises permeation of fluid through the dense particle monolayer, and Region III comprises capillary densification. For each region, the dominant physics and nondimensional groups are identified, and quantitative models are derived to describe the evolution of microstructure in terms of the main process parameters. The concentration profile within the assembly zone of Region I is predicted, including the role of a concentration-dependent diffusion constant and the shape of the meniscus. The fluid flow through the assembled monolayer is treated in Region II, along with a stability calculation to reveal that isolated particle clusters do not survive on top of the monolayer. The physics of capillary crystallization is addressed in Region III, with an emphasis on the density of cracks that emerge. The Peclet number and Capillary number both play important roles but in different regions of the assembly process.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.langmuir.5b03635 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Cooperative Multiscale-Assembly for Directional and Hierarchical Growth of Highly Oriented Porous Organic Cage Single-Crystal Microtubes and Arrays.
Angew Chem Int Ed Engl
December 2024
MOE Key Laboratory of Cluster Science, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 102488, P. R. China.
The directional assembly of porous organic molecules into long-range ordered architectures, featuring controlled hierarchical porosity and oriented pore channels with defined spatial arrangements, is a fundamental challenge in chemistry and materials science. Herein, using porous organic cages as starting units, we present a cooperative multiscale-assembly strategy enabling the simultaneous alignment of pore channels and directional hierarchical growth in a single step. At the microscopic level, we employed double solvents to manipulate the intermolecular packing of microporous tetrahedral [4+6] imine cages (CC1 and CC3), resulting in pore channel orientation.
View Article and Find Full Text PDFGuided assembly of mixed-metal oxide arrays from a liquid metal.
Mater Horiz
December 2024
North Carolina State University, Department of Materials Science & Engineering, Raleigh, NC 27695, USA.
Article Synopsis
- Bottom-up nano- to micro-fabrication is essential for advancing electronics and optics, but traditional methods struggle with balancing performance and cost.
- The study presents a new mixed-metal array fabrication technique that uses guided self-assembly of organometallic compounds to create high-quality metal wire arrays through natural processes like capillary action.
- This innovative approach allows for the creation of hierarchical and complex geometries, resulting in high-performance materials suitable for opto-electronics applications like diodes and gates.
Model predictive control of non-interacting active Brownian particles.
Soft Matter
November 2024
Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
Active matter systems are strongly driven to assume non-equilibrium distributions owing to their self-propulsion, , flocking and clustering. Controlling the active matter systems' spatiotemporal distributions offers exciting applications such as directed assembly, programmable materials, and microfluidic actuation. However, these applications involve environments with coupled dynamics and complex tasks, making intuitive control strategies insufficient.
View Article and Find Full Text PDFConvective assembly of silica colloidal particles inside photonic integrated chip-based microfluidic systems for gas sensing applications.
Nanoscale
September 2024
Center for Photonic Science and Engineering, Skolkovo Institute of Science and Technology, 30 Bld. 1 Bolshoy Boulevard, 121205, Russia.
Article Synopsis
- Optofluidics combines microfluidics and photonics, presenting exciting opportunities for gas sensing technologies.
- This study explores the creation of monolayer structures on a silicon nitride substrate, achieving a surface coverage of 59% through a microfluidic process.
- The research highlights how linking these monolayers with a photonic integrated chip can enhance gas detection capabilities.
Thermo-optical tweezers based on photothermal waveguides.
Microsyst Nanoeng
September 2024
Photonics Research Center, School of Optoelectronic Engineering, Guilin University of Electronic Technology, Guilin, 541004, China.
Field-controlled micromanipulation represents a pivotal technique for handling microparticles, yet conventional methods often risk physical damage to targets. Here, we discovered a completely new mechanism for true noncontact manipulation through photothermal effects, called thermal-optical tweezers. We employ a laser self-assembly photothermal waveguide (PTW) for dynamic microparticle manipulation.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!