#marangoni drying

[botanyone]

Do orchid seeds fare better in freezers than we thought?

Do orchid seeds fare better in freezers than we thought? https://ift.tt/VHPvKSr Conventional wisdom holds that orchid seeds do not fare well in conventional cool, dry storage conditions used by seed banks. But a new study published in Annals of Botany challenges this long-held assumption, finding that seeds from some orchid species maintain viability for decades under such conditions.  Researchers at the Universidad del Oeste Paulista in Brazil explored how physiological, biochemical and structural traits influence seed longevity in eight species of Cattleya orchids. They collected seeds from these orchids and carefully desiccated them to around 3% moisture content before placing them in cold storage at -18°C for over 10 years.  Cattleya orchids. Image: Canva. Periodically over this time, the researchers conducted germination tests, viability staining and metabolic profiling on the stored seeds to evaluate their storage lifespan. Surprisingly, after more than a decade of dry, cold storage, seeds from all species remained able to germinate, contradicting the idea that orchid seeds are inherently short-lived under these conditions.  Using statistical models, the team projected typical storage lifespans, or “P50y”, of approximately 30 years for seeds of six of the Cattleya species. Even more unexpectedly, the predicted lifespans for seeds of two other Cattleya species were much longer – possibly even centuries of cold storage viability.  The seed longevity parameters determined here for eight species of Cattleya indicate that the seeds are not short-lived and these species are not likely to be exceptional… Such longevity achieved here for Cattleya seeds may reflect the optimisation of steps in post-harvest handling. Francisqueti et al. 2024 Looking deeper, the research team found clues to explain the variation in storage longevity between species. Analyzing seed morphology, they discovered the three species with seeds exhibiting the longest storage lifespan had significantly smaller airspaces surrounding the embryos – only 9-11% of total seed volume, compared to larger airspaces in others.  This structural trait likely allows for more even desiccation and better protection of the embryo during storage, the researchers suggested. Additional post-storage rehydration techniques, such as brief room temperature exposure or treatment with 10% sucrose solution, significantly boosted germination rates – especially in seeds with the smallest embryos.  Metabolite profiling via gas chromatography showed that seeds from all eight species contained high levels of linoleic acid, an unsaturated fatty acid associated with desiccation tolerance. Thermal analysis identified a peak in differential scanning calorimetry readings that correlated with storage longevity potential.  Taken together, these results challenge conventional beliefs about orchid seed storage. When properly desiccated, even orchid seeds demonstrate a tolerance to desiccation that enables long-term survival under conventional gene bank storage conditions.  Morphological and compositional traits provide clues to identify species with seeds best suited for long-term preservation. With nearly 900,000 known orchid species globally, many endangered, the findings offer hope that exhaustive orchid seed banking could help safeguard genetic resources for decades to come.  READ THE ARTICLE  Francisqueti A.M., Rubio Marin R., Marangoni Hengling M., Hosomi S.T., Pritchard H.W., Castilho Custódio C. and Barbosa Machado-Neto N. (2024) ‘Orchid seeds are not always short lived in a conventional seed bank!‘, Annals of Botany.  Available at: https://doi.org/10.1093/aob/mcae021 The post Do orchid seeds fare better in freezers than we thought? appeared first on Botany One. via Botany One https://botany.one/ June 03, 2024 at 10:28AM

[thegallivantersart]

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[yasbxxgie]

Wine tears were understood for several centuries—at least qualitatively. And about 30 years ago, people started doing experiments to actually measure those effects. But they never really looked at the full dynamics. They hadn’t developed a theory of what happened when gravity pulled wine tears back down. They were also looking at just dry surfaces, which doesn’t account for the swirling of wine when you drink it. [Wine tears emerge from an unusual circular shockwave in the liquid, created by a balance of three physical effects: a Marangoni stress effect, gravity, and bulk surface tension (aka, the surface tension of the large pool of wine in the base of a glass).] If you remove any of those three effects, wine tears don’t happen. It needs to be that balance. If you get rid of the Marangoni stress, they won’t happen. They won’t work on the Space Station, with no gravity. And if you use chilled wine, you’re much less likely to see this. [(Chilling alcohol suppresses its evaporation, she explained.)]

Andrea Bertozzi, UCLA Professor of Mathematics; Saveur: Wine Legs: What Causes Those Little Streaks of Wine That Form On The Side of The Glass?

[modutek]

Advantages of HF-Last Etching and IPA Drying in One Chamber

After cleaning, a silicon wafer needs to be effectively cleaned and dried with no particle contamination. Clean wafers are important to avoid errors in the next processing steps to produce devices that are of superior quality and free from defects. Using the single chamber HF-last and IPA vapor dryer show a considerable reduction in wafer substrate particle counts.

By the final stage of silicon wafer cleaning, the silicon oxide layer has to be removed and the cleaned wafer dried free from contaminants. However, transferring the wafers from the HF etching process to a separate drying chamber will likely cause the wafers to pick up particles.

Modutek now has a solution to this problem: the single-chamber HF-last and IPA vapor dryer, which can help to significantly reduce the particle count on wafer substrates.

In the single chamber process, Modutek uses IPA vapor drying in a free-standing unit with one DI water rinsing and drying. This method, also called the Marangoni drying technique, results in clean wafer substrates -- having no contamination or watermarks.

Modutek has modified the IPA vapor dryer to include HF (hydrofluoric) acid injection before the start of the standard IPA vapor drying process. The HF acid injection ratio is controlled and provides an etch to bare silicon. When the silicon is etched, it is then rinsed to a controlled pH level. Once the appropriate pH levels are reached, it is then followed by the IPA drying process without moving the silicon wafers. This results in the low particle count on the wafer.

Initial field results from the single chamber HF-Last IPA dyer that Modutek has supplied to customers are showing outstanding results. Within the 0.3 to 5 micron range, fewer than 20 particles (adders) were added to etched substrates which are substantially below what was achieved in previous processes in this field trail.

For more details read the complete article “Advantages of HF-Last Etching and IPA Drying in One Chamber” to learn more about Modutek’s IPA vapor dryers. Call Modtuek at 866-803-1533 or send an email to Modutek@modutek.com if you have questions or would like to get a free consultation.

[thegallivantersart]

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[novikovaleksandrdye]

Application and characteristics of leveling agent in coatings

The leveling agent is a common surface active agent, and the leveling agent plays a great role at the interface. Next, the Yincai editor will talk about the application and characteristics of leveling agents in coatings.

The leveling agent is a common surfactant, and the leveling agent plays a great role at the interface. Next, the 258 platform editor will talk about the application and characteristics of leveling agents in coatings.

leveling agent is a kind of surface active agent that people often use and are familiar with. It is called a surfactant, not because of its structure, but because of its role at the interface. It has limited compatibility with resin solvents, and is squeezed out to the air/liquid interface to play a surface active role. The surface tension of the coating is in a balanced state, and the surface defects caused by the difference in surface tension are overcome.

The role of leveling agent in coatings

There are many shortcomings and shortcomings in the performance of coatings, which cannot be solved by using resins, pigments, and solvents alone. Use some additives. Leveling agent is an indispensable one of these additives.

Anti-shrinkage

Shrinkage on the surface of the coating film is a common problem. The reason for shrinkage is the imbalance of surface tension. The material that produces shrinkage has a lower surface tension than the coating film, and is called shrinkage donor. The surface tension of the coating film is higher than that of the shrinkage cavity donor body, which is called the shrinkage cavity acceptor. The reasons can include the following:

① When several resins are mixed together, they can be compatible or even form a transparent coating film when the solvent is matched properly. However, when the solvent is not properly matched, some resin will precipitate during the solvent volatilization process, resulting in colloidal particles that become shrinkage donor bodies.

②The pollution of external objects, low-energy floating objects in the air, and silica gel particles in the drying tunnel fall on the surface of the coating film.

③The paint is mixed with materials with low surface energy such as insoluble oil, silicone oil, rubber particles and other materials.

④The surface tension of the substrate is unbalanced, and some places are contaminated by substances with low surface energy or the surface energy of the substrate is too low.

⑤ Add substrate wetting agent to coatings containing pigments or matt powders that have not been treated with wetting dispersant, then substrate wetting agent will be adsorbed to the surface of exposed particles, and shrinkage donor body will be formed. Such maladies often occur in water-based matt paints.

A good way to overcome shrinkage is to use a substrate wetting agent combined with a silicone-based surface condition control agent. Some primers do not need or cannot use leveling agents, and the substrate wetting agent alone can achieve the purpose of anti-cratering. For example, SP-998 low foam wetting agent.

Anti orange peel, prevent color blooming, prevent light leakage and blooming

The root cause of these ills is the imbalance of surface tension between the surface layer and the lower layer of the coating film due to solvent volatilization, the lower layer is low and the upper layer is high. In addition, the density of the surface layer is greater than that of the lower layer. The lower layer of solvent-rich paint pushes it to the surface by surface tension, and gravity causes the surface layer of paint to sink, which creates a sinking, expanding, and rising eddy motion. The result is a hexagonal grid with irregular edges. Call it the "Benal" vortex. The new solvent-rich paint at the center of the grid has a low surface tension and pushes it toward the edge, where it accumulates to form a small mound, which is orange peel. This movement can also cause differences in color and pigment content. This is the main reason that causes the color paint to bloom, and the uneven arrangement of the sub-powder of the matt paint causes light leakage and matting.

Marangoni movement is the main source of these ills. As long as the surface tension of the coating film is reduced, the underlying paint cannot be pushed to the surface, and the above-mentioned ills cannot be produced. Therefore, it is a good way to add organic silicon leveling agents that can control the surface state and reduce the surface tension. For example, Bocheng Chemical's SP-934, SP-953 and so on. Te If the silicone additives cannot solve the problem, then consider choosing organic fluorine additives. But pay attention to cost and foam stability.

prevent ripples

Waviness is also caused by uneven surface tension. But pay attention to whether it is facade spraying or flat spraying. In plane spraying, the coating film drying speed is uneven, and the surface tension of the fast-drying area is higher than that of the slow-drying area. At this time, the surface tension will push the paint in the slow-drying area to move to the fast-drying area, resulting in ripples in the left and right directions. This can be solved with a silicone-based leveling agent that reduces surface tension. But when the facade spraying produces up and down ripples, it is better not to use a leveling agent that reduces the surface tension to solve it, otherwise it will become more and more serious.

This is because the paint falls, and the surface tension underneath is higher than the surface tension above, so the paint is pushed from the bottom to the top, and the gravity sinks, which produces up and down ripples. The more you add a leveling agent that lowers the surface tension, the more you depend on the surface tension below, the stronger the upward pushing force and the stronger the ripples. A good way is to add a leveling agent that does not reduce the surface tension.

[audiopedia2016]

What is MARANGONI EFFECT? What does MARANGONI EFFECT mean? MARANGONI EFFECT meaning - MARANGONI EFFECT definition - MARANGONI EFFECT explanation. Source: Wikipedia.org article, adapted under http://ift.tt/yjiNZw license. The Marangoni effect (also called the Gibbs–Marangoni effect) is the mass transfer along an interface between two fluids due to surface tension gradient. In the case of temperature dependence, this phenomenon may be called thermo-capillary convection (or Bénard–Marangoni convection). Since a liquid with a high surface tension pulls more strongly on the surrounding liquid than one with a low surface tension, the presence of a gradient in surface tension will naturally cause the liquid to flow away from regions of low surface tension. The surface tension gradient can be caused by concentration gradient or by a temperature gradient (surface tension is a function of temperature). As an example, wine may exhibit a visible effect called "tears", as shown in the photograph. The effect is a consequence of the fact that alcohol has a lower surface tension than water. If alcohol is mixed with water inhomogeneously, a region with a lower concentration of alcohol (greater surface tension) will pull on the surrounding fluid more strongly than a region with a higher alcohol concentration (lower surface tension). The result is that the liquid tends to flow away from regions with higher alcohol concentration—along the tension gradient. This can also be easily demonstrated by spreading a thin film of water on a smooth surface and then allowing a drop of alcohol to fall on the center of the film. The liquid will rush out of the region where the drop of alcohol fell. The Marangoni number, a dimensionless value, can be used to characterize the relative effects of surface tension and viscous forces. A very detailed mathematical treatment of this from the point of view of the Navier–Stokes equations and the equations of thermodynamics can be found in the first third of Subrahmanyan Chandrasekhar's Hydrodynamic and Hydromagnetic Stability originally published in 1961 by Oxford, and republished by Dover in 1981. Under earth conditions, the effect of gravity causing density-driven convection in a system with a temperature gradient along a fluid/fluid interface is usually much stronger than the Marangoni effect. Many experiments (ESA MASER 1-3) have been conducted under microgravity conditions aboard sounding rockets to observe the Marangoni effect without the influence of gravity. Research on heat pipes performed on the International Space Station revealed that whilst heat pipes exposed to a temperature gradient on Earth cause the inner fluid to evaporate at one end and migrate along the pipe, thus drying the hot end, in space (where the effects of gravity can be ignored) the opposite happens and the hot end of the pipe is flooded with liquid. This is due to the very weak Marangoni effect within a mixture of almost identical surface tensions which is normally masked by the fluid's inertia due to gravity. The effect of the Marangoni effect on heat transfer in the presence of gas bubbles on the heating surface (e.g., in subcooled nucleate boiling) has long been ignored, but it is currently a topic of ongoing research interest because of its potential fundamental importance to the understanding of heat transfer in boiling.

[modutek]

How Marangoni Drying Produces Superior Surface Conditioning for Wafer Processing

In the final step of silicon wafer processing, wafers often have to be cleaned, rinsed, and dried. They must be free of any contamination or water marks. Contamination in silicon wafers leads to defects in the next processing steps or to high failure as the impurities negatively impacts their quality. IPA drying using the Marangoni drying effect results to dry silicon wafer surfaces without leaving any residues or water marks.

Modutek's standalone IPA vapor dryer is ideal for this drying procedure. There, the IPA vapor is introduced at the top of the drying tank. The Marangoni drying effect takes place -- since the IPA has a lower tension surface than water, it introduces a surface tension gradient where it interfaces with the water on the wafer surface. As a result, the water flows away from the surface of the wafer, leaving it completely clean and dry, with no watermarks whatsoever. The departing water, meanwhile, carries the impurities or particles that are suspended within it.

Modutek's IPA vapor dryer consists of a wide cabinet built of polypropylene construction which is fitted with Teflon (including its valves and tubes). Operation can be controlled by the menu on the touch screen. The dryer options include PVC construction, a manual lid, and a quick dump feature. Modutek can also customize the dryer to meet customer specifications.

Modutek's IPA vapor dryer is cost-effective and can be incorporated in a wet bench process without the need to add drying transfer steps. Read our complete article “How Marangoni Drying Produces Superior Surface Conditioning for Wafer Processing” to learn more about Modutek’s Marangoni drying. You may also contact us at Modutek@Modutek.com if you would like additional information.

[modutek]

Modutek's IPA Vapor Dryer, or Marangoni Drying, is a viable alternative to other drying processes. If you want to learn more contact us at 866-803-1533

Modutek's IPA Vapor Dryer, also called Marangoni Drying, is an alternative for semiconductor manufacturing. Read this http://www.modutek.com/discover-the-advantages-of-moduteks-ipa-vapor-dryer/

[modutek]

Modutek's IPA Vapor Dryer, or Marangoni Drying, is a viable alternative to other drying processes. If you want to learn more contact us at 866-803-1533

Do you know about the advantages of the Modutek IPA Vapor Dryer? You can learn more about it by reading this article.

[modutek]

Using a Marangoni Drying system, more commonly called IPA Vapor Dryer, is the current gold-standard drying method in semiconductor manufacturing and related industries. Modutek Corporation’s free standing IPA Vapor Dryer system uses one standard gallon bottle...

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[modutek]

Discover the advantages of the Modutek Corporation IPA Vapor Dryer, also known as Marangoni Drying, by visiting http://www.modutek.com/products/wet-processing-equipment/ipa-vapor-dryer/