Coalescence driven self-organization of growing nanodroplets around a microcap.

Soft Matter

Department of Chemical & Materials Engineering, Faculty of Engineering, University of Alberta, Edmonton, Alberta T6G1H9, Canada. and Soft Matter & Interfaces Group, School of Engineering, RMIT University, Melbourne, VIC 3001, Australia and Physics of Fluids Group, Department of Science and Engineering, Mesa+ Institute, J. M. Burgers Centre for Fluid Dynamics and the Max Planck Center Twente for Complex Fluid Dynamics, University of Twente, P. O. Box 217, 7500 AE Enschede, The Netherlands.

Published: April 2018

The coalescence between growing droplets is important for the surface coverage and spatial arrangements of droplets on surfaces. In this work, total internal reflection fluorescence (TIRF) microscopy is utilized to in situ investigate the formation of nanodroplets around the rim of a polymer microcap, with sub-micron spatial and millisecond temporal resolution. We observe that the coalescence among droplets occurs frequently during their growth by solvent exchange. Our experimental results show that the position of the droplet from two merged droplets is related to the size of the parent droplets. The position of the coalesced droplet and the ratio of parent droplet sizes obey a scaling law, reflecting a coalescence preference based on the size inequality. As a result of droplet coalescence, the angles between the centroids of two neighbouring droplets increase with time, obeying a nearly symmetrical arrangement of droplets at various time intervals. The evolution of the position and number from coalescence of growing droplets is modelled. The mechanism for coalescence driven self-organization of growing droplets is general, applicable to microcaps of different sizes and droplets of different liquids. The understanding from this work may be valuable for positioning nanodroplets by nucleation and growth without using templates.

Download full-text PDF

Source
http://dx.doi.org/10.1039/C7SM02490HDOI Listing

Publication Analysis

Top Keywords

growing droplets
12
droplets
10
coalescence driven
8
driven self-organization
8
self-organization growing
8
coalescence growing
8
coalescence
7
growing
4
growing nanodroplets
4
nanodroplets microcap
4

Similar Publications

α-Synuclein (αS) is a 140 amino-acid neuronal protein highly enriched in presynaptic nerve terminals. Its progressive accumulation in Lewy bodies and neurites is the hallmark of Parkinson's disease (PD). A growing number of studies highlights a critical interplay between lipid metabolism and αS biology.

View Article and Find Full Text PDF

Synchronized acoustic emission and high-speed imaging of cavitation-induced atomization: The role of shock waves.

Ultrason Sonochem

January 2025

School of Engineering Computing and Mathematics, Oxford Brookes University, Oxford, UK; Department of Materials, University of Oxford, Oxford, UK.

This study experimentally investigates the role of cavitation-induced shock waves in initiating and destabilizing capillary (surface) waves on a droplet surface, preceding atomization. Acoustic emissions and interfacial wave dynamics were simultaneously monitored in droplets of different liquids (water, isopropyl alcohol and glycerol), using a calibrated fiber-optic hydrophone and high-speed imaging. Spectral analysis of the hydrophone data revealed distinct subharmonic frequency peaks in the acoustic spectrum correlated with the wavelength of capillary waves, which were optically captured during the onset of atomization from the repetitive imploding bubbles.

View Article and Find Full Text PDF

Airborne Escherichia coli bacteria biosynthesize lipids in response to aerosolization stress.

Sci Rep

January 2025

Aerosol Technology Laboratory, Biological and Agricultural Engineering Department, Texas A&M University, College Station, TX, 77843, USA.

Gram-negative bacteria pose an increased threat to public health because of their ability to evade the effects of many antimicrobials with growing antibiotic resistance globally. One key component of gram-negative bacteria resistance is the functionality and the cells' ability to repair the outer membrane (OM) which acts as a barrier for the cell to the external environment. The biosynthesis of lipids, particularly lipopolysaccharides, or lipooligosaccharides (LPS/LOS) is essential for OM repair.

View Article and Find Full Text PDF

Electroactive organisms contribute to metal cycling, pollutant removal, and other redox-driven environmental processes via extracellular electron transfer (EET). Unfortunately, developing genotype-phenotype relationships for electroactive organisms is challenging because EET is necessarily removed from the cell of origin. Microdroplet emulsions, which encapsulate individual cells in aqueous droplets, have been used to study a variety of extracellular phenotypes but have not been applied to investigate EET.

View Article and Find Full Text PDF

Prospects of cowpea protein as an alternative and natural emulsifier for food applications: Effect of pH and oil concentration.

Int J Biol Macromol

January 2025

Department of Food Engineering and Technology, Institute of Biosciences, Humanities and Exact Sciences, São Paulo State University (UNESP), Street Cristóvão Colombo, 2265, São José do Rio Preto 15054-000, Brazil. Electronic address:

In response to the growing need to expand the knowledge base on novel, more sustainable protein sources, this study investigated the effectiveness of cowpea protein concentrate (CPC) as a natural emulsifying agent, examining the relationships between pH (3-11), oil concentration (2-10 %), and emulsion stability. pH and oil concentration significantly impacted droplet size distribution, with uniformity decreasing in the order of pH 9 > pH 11 > pH 7, which was attributed to droplet coalescence and flocculation. As evidenced by circular dichroism, alkalinity induced a slight increase in the beta-sheet content of CPC, while simultaneously reducing the alpha-helix content.

View Article and Find Full Text PDF

Want 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!