WATER DROPLET EVAPORATION IN A CHAMBER ISOLATED FROM THE EXTERNAL ENVIRONMENT

2021 ◽  
Vol 7 (1) ◽  
pp. 26-43
Author(s):  
Ksenia A. BATISHCHEVA ◽  
Yuliya N. Vympina ◽  
Evgeniya G. ORLOVA
Keyword(s):  
Magnesium Alloy ◽  
Self Assembly ◽  
Droplet Evaporation ◽  
The Self ◽  
Homogeneous Layer ◽  
Nanosecond Laser ◽  
Alloy Sample ◽  
Textured Surface ◽  
Colloidal Solutions ◽  
Aluminum Magnesium Alloy

Establishing the characteristics of the self-assembly of micron and sub-micron particles when colloidal solution droplets evaporate from solid surfaces is an urgent problem. This is explained by the possibility of using these structures obtained by droplet technologies to create and optimize the production of direct and indirect liquid cooling devices, electronic and sensor working boards, current-conducting coatings, optical crystals, and chemo sensors. The method used in this study for processing of metals and alloys by laser radiation is prospective for controlling the processes at the liquid/gas/solid interface. This article aims to analyze the effect of laser processing of the widely used in the industry aluminum-magnesium alloy on the formation of a layer of particles during the droplet evaporation of colloidal solutions. The samples’ surfaces were processed by two methods: polished by tumbling and nanosecond laser pulses. The geometric parameters of the droplets of colloidal solutions evaporating from the samples’ surfaces were determined by the shadow method. To process the obtained shadow images, the Young — Laplace method was used. Using a scanning electron microscope, the authors have received the images of the particles’ layers formed due to the droplet evaporation of colloidal solutions. The experimental studies reveal the effect of texture formed on aluminum-magnesium alloy sample on the morphology of the layer of polystyrene nanoparticles during the droplet evaporation of colloidal solutions. Due to the self-assembly of particles, solid ring-like sediments are formed, which are elongated under the action of the capillary force parallel to the motion vector of the laser beam (when creating the texture). When the solvent evaporated from the solution droplet on the textured surface, in addition to the rings, a homogeneous layer of polystyrene particles was formed. This refers to the droplet evaporation of the solution. The results show that with an increase in the concentration of particles in the solution, the sizes of radial cracks on the rings formed due to particle deposition increase. There were no cracks on the rings at a relatively low volume concentration of particles.

Influence of substrate wettability and air humidity on self-assembly of nanoparticles in evaporating droplets of colloidal solutions

2019 ◽  
Vol 5 (3) ◽  
pp. 83-96
Author(s):  
Mohammed Ali Y. Ali Al-Muzaiqer ◽  
Tair E. Esenbaev ◽  
Nikolai S. Kubochkin ◽  
Maria D. Goreva ◽  
Natalya A. Ivanova
Keyword(s):  
Aluminum Oxide ◽  
Self Assembly ◽  
Droplet Evaporation ◽  
Air Humidity ◽  
Colloidal Solutions ◽  
Evaporation Time ◽  
Oxide Particles ◽  
Influence Of Substrate ◽  
Evaporation Dynamics

This article discusses the influence of substrate wettability and air humidity on the process of nanoparticle patterns formation in evaporating microdroplets. The process of self-assembly of polystyrene and aluminum oxide particles on the glass covered with titanium, tungsten, carbon, and teflon was investigated.<br> The droplet evaporation time and the obtained packing of particles with increasing hydrophobicity of substrates were evaluated. The influence of air humidity on the evaporation dynamics and on the process of nanoparticles self-assembly is revealed.

Experimental investigation of nanoparticles distribution mechanisms and deposition patterns during nanofluid droplet evaporation

2020 ◽  
Vol 92 (1) ◽  
pp. 11101 ◽  
Author(s):  
Bin Liu ◽  
ShengWei Wang ◽  
Lin Chai ◽  
Georges El Achkar ◽  
Aiqiang Chen ◽  
...  
Keyword(s):  
Self Assembly ◽  
Mass Fraction ◽  
Drug Testing ◽  
Wide Spectrum ◽  
Droplet Evaporation ◽  
The Self ◽  
Deposition Patterns ◽  
Process Characteristics ◽  
Biomedical Diagnosis ◽  
20 Nm

Droplet evaporation is fascinating, ubiquitous, and relevant for a wide spectrum of applications, such as printing, drug testing, coating, and biomedical diagnosis. In this paper, the effects of substrate temperature (30 °C, 47 °C, 64 °C, 81 °C) and 20 nm Al2O3 nanoparticles mass fraction (0.05%, 0.1%, 0.2%) on the nanoparticles distribution mechanisms and deposition patterns during the evaporation of Al2O3-H2O nanofluid droplet were experimentally investigated. An experimental device was designed and realized. The self-assembly and Marangoni forces were first highlighted and compared. Two coffee-ring and inner-ring patterns were then identified and analyzed. The evaporation process characteristics were finally determined and discussed.

The Nature of Rapidly Extracted Phycocyanin from the Blue-Green Alga Plectonema Boryanum

1971 ◽  
Vol 29 ◽  
pp. 366-367
Author(s):  
M. Kessel ◽  
R. MacColl
Keyword(s):  
Self Assembly ◽  
Analytical Ultracentrifugation ◽  
Uranyl Acetate ◽  
The Self ◽  
Major Protein ◽  
Subunit Structure ◽  
Blue Green Alga ◽  
Thin Sections ◽  
Blue Green Algae ◽  
Cacodylate Buffer

The major protein of the blue-green algae is the biliprotein, C-phycocyanin (Amax = 620 nm), which is presumed to exist in the cell in the form of distinct aggregates called phycobilisomes. The self-assembly of C-phycocyanin from monomer to hexamer has been extensively studied, but the proposed next step in the assembly of a phycobilisome, the formation of 19s subunits, is completely unknown. We have used electron microscopy and analytical ultracentrifugation in combination with a method for rapid and gentle extraction of phycocyanin to study its subunit structure and assembly.To establish the existence of phycobilisomes, cells of P. boryanum in the log phase of growth, growing at a light intensity of 200 foot candles, were fixed in 2% glutaraldehyde in 0.1M cacodylate buffer, pH 7.0, for 3 hours at 4°C. The cells were post-fixed in 1% OsO4 in the same buffer overnight. Material was stained for 1 hour in uranyl acetate (1%), dehydrated and embedded in araldite and examined in thin sections.

Interrelationship of the cellular distribution and secretion of regular structure (RS) protein in Bacillus licheniformis nm 105

1992 ◽  
Vol 50 (1) ◽  
pp. 712-713
Author(s):  
Xiaorong Zhu ◽  
Richard McVeigh ◽  
Bijan K. Ghosh
Keyword(s):  
Alkaline Phosphatase ◽  
Bacillus Licheniformis ◽  
Self Assembly ◽  
Gel Electrophoresis ◽  
Culture Supernatant ◽  
Regular Structure ◽  
The Self ◽  
Cellular Distribution ◽  
Structural Protein ◽  
Laboratory Cultures

A mutant of Bacillus licheniformis 749/C, NM 105 exhibits some notable properties, e.g., arrest of alkaline phosphatase secretion and overexpression and hypersecretion of RS protein. Although RS is known to be widely distributed in many microbes, it is rarely found, with a few exceptions, in laboratory cultures of microorganisms. RS protein is a structural protein and has the unusual properties to form aggregate. This characteristic may have been responsible for the self assembly of RS into regular tetragonal structures. Another uncommon characteristic of RS is that enhanced synthesis and secretion which occurs when the cells cease to grow. Assembled RS protein with a tetragonal structure is not seen inside cells at any stage of cell growth including cells in the stationary phase of growth. Gel electrophoresis of the culture supernatant shows a very large amount of RS protein in the stationary culture of the B. licheniformis. It seems, Therefore, that the RS protein is cotranslationally secreted and self assembled on the envelope surface.

Nanoscale Self-Assembly Using Ion and Electron Beam Techniques: A Rapid Review

MRS Advances ◽  
2020 ◽  
Vol 5 (64) ◽  
pp. 3507-3520
Author(s):  
Chunhui Dai ◽  
Kriti Agarwal ◽  
Jeong-Hyun Cho
Keyword(s):  
Electron Beam ◽  
Self Assembly ◽  
Ion Beam ◽  
Three Dimensional ◽  
The Self ◽  
Stress Generation ◽  
Rapid Review ◽  
High Yield ◽  
3D Nanostructures ◽  
Self Assembled

AbstractNanoscale self-assembly, as a technique to transform two-dimensional (2D) planar patterns into three-dimensional (3D) nanoscale architectures, has achieved tremendous success in the past decade. However, an assembly process at nanoscale is easily affected by small unavoidable variations in sample conditions and reaction environment, resulting in a low yield. Recently, in-situ monitored self-assembly based on ion and electron irradiation has stood out as a promising candidate to overcome this limitation. The usage of ion and electron beam allows stress generation and real-time observation simultaneously, which significantly enhances the controllability of self-assembly. This enables the realization of various complex 3D nanostructures with a high yield. The additional dimension of the self-assembled 3D nanostructures opens the possibility to explore novel properties that cannot be demonstrated in 2D planar patterns. Here, we present a rapid review on the recent achievements and challenges in nanoscale self-assembly using electron and ion beam techniques, followed by a discussion of the novel optical properties achieved in the self-assembled 3D nanostructures.

Bottom-up Evolution from Disks to High-Genus Polymersomes

2018 ◽  
Author(s):  
Claudia Contini ◽  
Russell Pearson ◽  
Linge Wang ◽  
Lea Messager ◽  
Jens Gaitzsch ◽  
...  
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Amphiphilic Copolymers ◽  
Chain Entanglement ◽  
Bottom Up ◽  
New Approach ◽  
High Genus ◽  
Transmission Electron ◽  
Minimal Radius ◽  
Stop Flow

<div><div><div><p>We report the design of polymersomes using a bottom-up approach where the self-assembly of amphiphilic copolymers poly(2-(methacryloyloxy) ethyl phosphorylcholine)–poly(2-(diisopropylamino) ethyl methacrylate) (PMPC-PDPA) into membranes is tuned using pH and temperature. We study this process in detail using transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) spectroscopy, dynamic light scattering (DLS), and stop-flow ab- sorbance disclosing the molecular and supramolecular anatomy of each structure observed. We report a clear evolution from disk micelles to vesicle to high-genus vesicles where each passage is controlled by pH switch or temperature. We show that the process can be rationalised adapting membrane physics theories disclosing important scaling principles that allow the estimation of the vesiculation minimal radius as well as chain entanglement and coupling. This allows us to propose a new approach to generate nanoscale vesicles with genus from 0 to 70 which have been very elusive and difficult to control so far.</p></div></div></div>

Bottom-up Evolution from Disks to High-Genus Polymersomes

2018 ◽  
Author(s):  
Claudia Contini ◽  
Russell Pearson ◽  
Linge Wang ◽  
Lea Messager ◽  
Jens Gaitzsch ◽  
...  
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Amphiphilic Copolymers ◽  
Chain Entanglement ◽  
Bottom Up ◽  
New Approach ◽  
High Genus ◽  
Transmission Electron ◽  
Minimal Radius ◽  
Stop Flow

<div><div><div><p>We report the design of polymersomes using a bottom-up approach where the self-assembly of amphiphilic copolymers poly(2-(methacryloyloxy) ethyl phosphorylcholine)–poly(2-(diisopropylamino) ethyl methacrylate) (PMPC-PDPA) into membranes is tuned using pH and temperature. We study this process in detail using transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) spectroscopy, dynamic light scattering (DLS), and stop-flow ab- sorbance disclosing the molecular and supramolecular anatomy of each structure observed. We report a clear evolution from disk micelles to vesicle to high-genus vesicles where each passage is controlled by pH switch or temperature. We show that the process can be rationalised adapting membrane physics theories disclosing important scaling principles that allow the estimation of the vesiculation minimal radius as well as chain entanglement and coupling. This allows us to propose a new approach to generate nanoscale vesicles with genus from 0 to 70 which have been very elusive and difficult to control so far.</p></div></div></div>

Clathrin-Inspired Coating and Stabilization of Liposomes by DNA Self-Assembly

2019 ◽  
Author(s):  
Kevin N. Baumann ◽  
Luca Piantanida ◽  
Javier García-Nafría ◽  
Diana Sobota ◽  
Kislon Voïtchovsky ◽  
...  
Keyword(s):  
Self Assembly ◽  
Mechanical Stability ◽  
Lipid Vesicles ◽  
The Self ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cryo Electron Microscopy ◽  
Further Development ◽  
Liposome Surface ◽  
Dna Coating

The self-assembly of the protein clathrin on biological membranes facilitates essential processes of endocytosis in biological systems and has provided a source of inspiration for materials design by the highly ordered structural appearance. By mimicking the architecture of clathrin self-assemblies to coat liposomes with biomaterials, new classes of hybrid carriers can be derived. Here we present a method for fabricating DNA-coated liposomes by hydrophobically anchoring and subsequently growing a DNA network on the liposome surface which structurally mimics clathrin assemblies. Dynamic light scattering (DLS), ζ-potential and cryo-electron microscopy (cryo-EM) measurements independently demonstrate successful DNA coating. Nanomechanical measurements conducted with atomic force microscopy (AFM) show that the DNA coating enhances the mechanical stability of the liposomes relative to uncoated ones. Furthermore, we provide the possibility to reverse the coating process by triggering the disassembly of the DNA coating through a toehold-mediated displacement reaction. Our results describe a straightforward, versatile, and reversible approach for coating and stabilizing lipid vesicles by an interlaced DNA network. This method has potential for further development towards the ordered arrangement of tailored functionalities on the surfaces of liposomes and for applications as hybrid nanocarrier.

The Self-Assembly of an Amphiphilic Block Copolymer: A Dissipative Particle Dynamics Study

2005 ◽  
Vol 42 (3) ◽  
pp. 180-183 ◽  
Author(s):  
S. G. Schulz ◽  
U. Frieske ◽  
H. Kuhn ◽  
G. Schmid ◽  
F. Müller ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Self Assembly ◽  
Dissipative Particle Dynamics ◽  
Particle Dynamics ◽  
The Self ◽  
Amphiphilic Block Copolymer

Multifactor mathematical model of criticality of welding process of products from aluminum- magnesium alloys

2020 ◽  
pp. 12-18
Author(s):  
F.A. Urazbahtin ◽  
A.YU. Urazbahtina
Keyword(s):  
Mathematical Model ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Welding Process ◽  
Welding Equipment ◽  
Equipment Operation ◽  
Aluminum Magnesium Alloys ◽  
Aluminum Magnesium Alloy ◽  
Welding Materials

A multifactor mathematical model of the welding process of products from aluminum-magnesium alloys, consisting of 71 indicators that assess the quality of the weld, the welding process, costs, equipment operation and quality of the welded material. The model can be used to control and optimize the welding process of products from aluminum-magnesium alloys. Keywords welding, products, aluminum-magnesium alloy, indicators, process parameters, welding equipment, welding materials, electrode sharpening, lining [email protected]

Sign in / Sign up

Export Citation Format

Share Document