scispace - formally typeset
Search or ask a question
Topic

Sessile drop technique

About: Sessile drop technique is a research topic. Over the lifetime, 2827 publications have been published within this topic receiving 68943 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: In this paper, a new Langmuir-type pendant-drop penetration film balance has been developed combining a Langmire-style pendant drop film balance with a new rapid-subphase-exchange technique.
Abstract: A new Langmuir-type pendant-drop penetration film balance has been developed combining a Langmuir-type pendant-drop film balance with a new rapid-subphase-exchange technique. In addition to the determination of surface pressure—molecular area isotherms of insoluble monolayers deposited on the surface of a pendant drop, it allows the study of reactions with some surfactant added to the subphase. The monolayer is spread on the surface of a drop suspended from a capillary, which is the outer one of an arrangement of two coaxial capillaries connected to the different branches of a microinjector. Once the film is brought to the desired state of compression by varying the drop volume with the microinjector, the subphase liquid in the drop can be exchanged quantitatively by means of the coaxial capillaries. This exchange is complete for a through-flow of at least three times the drop volume, and the monolayers endure it at all tested film pressures. The determination of surface tension as a function of surface area is performed using axisymmetric drop shape analysis (ADSA). The complete set-up, i.e., the image capturing and microinjector system is fully computer controlled by a user-friendly and fully Windows integrated program, including the ADSA surface tension calculus algorithm. As a penetration film balance, pendant-drop methodologies offer a wide range of advantages such as a more stringent control of the environmental conditions and therefore, more uniform temperature, pressure and concentration along the interface, small amounts of material needed, and a 20 times greater interface/volume ratio than in conventional Langmuir toughs.

96 citations

Journal ArticleDOI
TL;DR: In this article, a theoretical model for evaporation of pure liquid drops that includes Marangoni forces due to the thermal gradients produced by non-uniform evapsoration, and heat conduction effects in both liquid and solid phases is presented.
Abstract: We consider theoretically, computationally and experimentally spontaneous evaporation of water and isopropanol drops on smooth silicon wafers. In contrast to a number of previous works, the solid surface we consider is smooth and therefore the droplets' evolution proceeds without contact line pinning. We develop a theoretical model for evaporation of pure liquid drops that includes Marangoni forces due to the thermal gradients produced by non-uniform evaporation, and heat conduction effects in both liquid and solid phases. The key ingredient in this model is the evaporative flux. We consider two commonly used models: one based on the assumption that the evaporation is limited by the processes originating in the gas (vapour diffusion-limited evaporation), and the other one which assumes that the processes in the liquid are limiting. Our theoretical model allows for implementing evaporative fluxes resulting from both approaches. The required parameters are obtained from physical experiments. We then carry out fully nonlinear time-dependent simulations and compare the results with the experimental ones. Finally, we discuss how the simulation results can be used to predict which of the two theoretical models is appropriate for a particular physical experiment.

96 citations

Journal ArticleDOI
TL;DR: In this article, the authors studied oxygen plasma treatment at different times on vertically aligned multiwalled carbon nanotube (VACNT) surfaces using the pulsed-discharge plasma technique.

96 citations

Journal ArticleDOI
TL;DR: In this article, the application and limitations of sessile drop method and capillary rise test on mineral and metallic surface were discussed, and a new reference liquid for the calibration of capillary rises method was proposed.

95 citations

Journal ArticleDOI
TL;DR: In this paper, the authors present a theoretical study of the evolution of a drop of pure liquid on a solid substrate, which it wets completely, and find that the drop radius goes to zero like R∝(t0−t)α, where α has value close to 1/2.
Abstract: We present a theoretical study of the evolution of a drop of pure liquid on a solid substrate, which it wets completely. In a situation where evaporation is significant, the drop does not spread, but instead the drop radius goes to zero in finite time. Our description couples the viscous flow problem to a self-consistent thermodynamic description of evaporation from the drop and its precursor film. The evaporation rate is limited by the diffusion of vapor into the surrounding atmosphere. For flat drops, we compute the evaporation rate as a nonlocal integral operator of the drop shape. Together with a lubrication description of the flow, this permits an efficient numerical description of the final stages of the evaporation problem. We find that the drop radius goes to zero like R∝(t0−t)α, where α has value close to 1/2, in agreement with experiment.

95 citations


Network Information
Related Topics (5)
Coating
379.8K papers, 3.1M citations
83% related
Oxide
213.4K papers, 3.6M citations
82% related
Nanoparticle
85.9K papers, 2.6M citations
81% related
Carbon nanotube
109K papers, 3.6M citations
81% related
Adsorption
226.4K papers, 5.9M citations
81% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202354
2022106
202189
2020105
2019100
2018116