hydrophobic materials in nature

Hydrophobic molecules (or hydrophobes) repel bodies of water and, owing to the fact that hydrophobes are non-polar, they attract other neutral molecules and non-polar solvents. Natural hydrophobes include alkanes, fats and oils.

Full Answer

What makes something hydrophobic?

In nature, the hydrophobic surface can be seen on lotus leaves or its scientific name Nelumbo nucifera. In 1992, lotus leaf was introduced as “lotus effect” that then became an icon for superhydrophobicity and self-cleaning properties.

What are examples of hydrophobic substances?

Jun 03, 2020 · Additionally, abrasion exposes underlying materials and may change the local nature of the surface from hydrophobic to hydrophilic 19, resulting in the pinning of water droplets to the surface. It ...

Which substance is hydrophobic?

A contact angle greater than 90 degrees is said to be hydrophobic and more than 150 degrees superhydrophobic. This hydrophobic nature is mimicked from the lotus leaf, and is also known as the “lotus effect.” Clothes with this hydrophobic behavior are included in self-cleansing textiles.

What compounds are hydrophobic?

Jul 09, 2019 · Hydrophobic molecules are nonpolar. When they are exposed to water, their nonpolar nature disrupts hydrogen bonds between water molecules, forming a clathrate-like structure on their surface. The structure is more ordered than free water molecules.

What materials are naturally hydrophobic?

Natural hydrophobes include alkanes, fats and oils. Hydrophobic materials are often used to remove oil from water, manage oil spills, and chemical separation processes that require the removal of non-polar substances from polar compounds.22-Nov-2012

What is the most hydrophobic material?

He says the team took inspiration from the lotus leaf – one of the most hydrophobic (water-repelling) surfaces known – which is actually made up of a hierarchy of double structures on the microscopic and nano scales.16-Dec-2015

What is an example of a hydrophobic surface in nature?

The most famous example of natural superhydrophobic surfaces are lotus leaves (Nelumbo nucifera), which are characterized by θw > 150°, ultra-low water adhesion (ultra-low H and α) and self-cleaning properties [15] (Fig. 2).

What surfaces are hydrophobic?

Hydrophobic surface is a surface that has the ability to repel water [1]. The term hydrophobicity was derived from two Greek words that are hydro that means water and phobos that means fear; thus, hydrophobic surfaces can be define as material that tend to repel with water.

What are hydrophobic materials?

Hydrophobic substances are composed of non-polar molecules that repel bodies of water and attract other neutral molecules and non-polar solvents. Examples of these molecules are alkanes, oils and fats in general.26-May-2021

What plants are hydrophobic?

Surfaces that repel water, like the leaves of the Colocasia plant, are called hydrophobic.30-Sept-2016

Is paper a hydrophobic material?

The highest hydrophobicity (29.57%) was found to be in paper discs coated with epicuticular wax extracted with benzene from the adaxial surface of Calotropis procera. Easy biodegradability and an eco-friendly nature make paper a very good packaging material for food as well as non-food items.

What is hydrophobic fabric?

This type of material resists water penetration with extremely low absorbency and high stability. Hydrophobic nonwovens are used for products that are intended to provide a dry barrier, while withstanding moisture. Some fibers, such as polyester, naturally have hydrophobic characteristics.02-May-2019

Is plastic hydrophobic?

During healthcare and pharmaceutical product development, hydrophilicity is a crucial factor in determining the product performance limits, and a challenge that porous plastic manufacturers face is that plastic polymers are naturally hydrophobic; that is, liquids bead up on the surface and do not form strong ...09-Jul-2021

What animals are hydrophobic?

Surface living animals such as the water strider typically have hydrophobic feet covered in small hairs that prevent the feet from breaking the surface and becoming wet. Another insect known to walk on the water surface is the ant species Polyrhachis sokolova.

Is table salt hydrophobic or hydrophilic?

Some of the most common examples of hydrophilic substances are sugar, salt, starch, and cellulose. Hydrophilic substances are polar in nature.23-Jul-2021

Is butter hydrophobic?

Butter is one of the examples of lipid that is non-polar (do not contain charge). It does not get solublizes in water because it is hydrophobic...

Are fish scales hydrophobic?

They found that for their fish scales, the static contact angle for water in air is less than 10°, which changes to 58° on removal of the mucus layer – thereby still having the fish scales hydrophilic for water in air medium.12-Dec-2014

Are metals hydrophobic?

Analysis shows that polycrystalline silver, gold and copper are hydrophobic metals. However it is stressed that this conclusion for silver, gold and copper refers to heterogeneous crystalline surfaces, while for other sp metals the hydrophilicity refers to relatively homogeneous surfaces.

Why a surface is hydrophobic?

A hydrophobic surface is a water repelling, low surface energy surface that resists wetting. Moisture contact angle measurements will classify a surface as hydrophobic when the contact angle of the water droplet exceeds 90 degrees.

Is water hydrophobic?

Water and oil famously don't mix: the term hydrophobic (water-fearing) is commonly used to describe substances that, like oil, do not mix with water.30-May-2002

Material Properties of Hydrophobic Materials

A material’s surface can react either in a hydrophilic (water-loving) or a hydrophobic (water-hating) manner.

How to Make a Hydrophobic Material

Hydrophobic materials can be created using two methods. The simpler method is to coat a surface with wax, oil, or grease. The other is using nanoengineering to help create a unique, nanopatterned textured surface. The nanopatterns consist of small bumps that have a width of 10 µm.

New Innovations

The new hydrophobic material or superhydrophobic material that was created by a team of MIT nanomaterial scientists and mechanical engineers is said to be 10,000 times more hydrophobic than current hydrophobic surfaces. MIT’s superhydrophobic materials are set to revolutionize the efficiency of fossil fuel power plants.

Sources and Further Reading

Gary graduated from the University of Manchester with a first-class honours degree in Geochemistry and a Masters in Earth Sciences. After working in the Australian mining industry, Gary decided to hang up his geology boots and turn his hand to writing.

Photocatalytic nanomaterials for air purification and self-cleaning

Muhammad Shahid Rafique, ... M. Shakil, in Nanotechnology and Photocatalysis for Environmental Applications, 2020

Biocompatibility, Surface Engineering, and Delivery of Drugs, Genes and Other Molecules

Typical hydrophobic surfaces expose their methyl (–CH3 ), methylene (–CH 2− ), methoxy (–OCH 3 ), or trifluoromethyl ester (–OCF 3) groups toward the surroundings.

Functionalization of Graphene Oxide via Gamma-Ray Irradiation for Hydrophobic Materials

Buong Woei Chieng, ... Zainal Abidin Talib, in Synthesis, Technology and Applications of Carbon Nanomaterials, 2019

Upconversion nanoparticles

Alternatively, hydrophobic surface ligands on the UCN surface after most syntheses, like OA, can be directly modified to hydrophilic by a Lemieux–von Rudloff reagent. The double bond between C9 and C10 in the unsaturated oleic acid can be oxidized to azelaic acid and nonanoic acid [145 ].

Application of Polymer-Based Composites

The polluted surfaces of insulators may have a different mechanism of flashover as follows [2,55]:

Engineering Fundamentals of Biotechnology

L. Giorno, ... E. Drioli, in Comprehensive Biotechnology (Second Edition), 2011

Potential Applications and Perspectives

Graphene aerogels are a promising candidate for super hydrophobic surfaces because of their intrinsically high surface area, high porosity, low bulk density, and nonpolar carbon structure. The super hydrophobicity of the graphene aerogel was demonstrated for the first time by Lin et al. [22].

Abstract

The aqueous electrocatalytic reduction of CO 2 into alcohol and hydrocarbon fuels presents a sustainable route towards energy-rich chemical feedstocks. Cu is the only material able to catalyse the substantial formation of multicarbon products (C 2 /C 3 ), but competing proton reduction to hydrogen is an ever-present drain on selectivity.

Main

Figure 1a shows a theorized sustainable energy cycle propagated through the storage of renewable energies as CO 2 -derived fuel. Such a process would provide relief to numerous environmental concerns, both current and impending 1, and curtail dependency on fossil fuel.

Hydrophobic Cu dendrite preparation and characterization

Cu dendrite scaffolds were grown using previously reported aqueous electrodeposition procedures, which produced hierarchical architectures with both micro- and nanoscale features (Supplementary Fig. 1) 29, 30. Powder X-ray diffraction measurements confirmed the structure to be metallic Cu (Fig.

Catalytic activity of hydrophobic and wettable Cu dendrites

Figure 3a shows the LSV of the hydrophobic dendrite and equivalent wettable dendrite in a CO 2 -saturated CsHCO 3 electrolyte (0.1 M, pH 6.8).

Conclusion

In summary, a hydrophobic coating of long-chain alkanethiols on dendritic Cu, with no further modification, led to a drastic increase in the CO 2 reduction selectivity.

Methods

SEM images were performed on a SU-70 Hitachi FEGSEM fitted with an X-Max 50 mm 2 Oxford EDX spectrometer or a Hitachi S-4800 SEM.

Data availability

Raw data used in preparation of this manuscript is available to download at https://doi.org/10.7910/DVN/DSPZHE.

Abstract

The ability of superhydrophobic surfaces to stay dry, self-clean and avoid biofouling is attractive for applications in biotechnology, medicine and heat transfer 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

Main

Minimizing the contact area between liquid and solid is a widely used strategy to enhance superhydrophobicity; however, it results in fragile surface textures and poor resistance to wear 20.

Data availability

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Acknowledgements

We thank B. J. Yu, J. L. Yang, Y. Li. and G.W. Zhou for discussions, and J. L. Song for providing the samples of the conventional superhydrophobic surfaces.

Author information

Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, China

Ethics declarations

X.D., D.W. and R.H.A.R. are inventors on a patent application relating to the surfaces described in this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Polymer-Based Nanomaterials for Drug-Delivery Carriers

Hemant K.S. Yadav, ... Manar S. Debe, in Nanocarriers for Drug Delivery, 2019

Separation Technologies

Lars Hagel, ... Gail Sofer, in Handbook of Process Chromatography (Second Edition), 2008

Role of hydrophobicity in underwater adhesion

Sukhmanjot Kaur, ... Ali Dhinojwala, in Macromolecular Engineering, 2021

Analysis, Removal, Effects and Risk of Pharmaceuticals in the Water Cycle

Paola Verlicchi, ... Mustafa Al Aukidy, in Comprehensive Analytical Chemistry, 2013

Smart Coatings Against Corrosion

Vadym Kovalenko, ... Vassilis N. Stathopoulos, in Encyclopedia of Smart Materials, 2022

Application of laser technology

On-na Hung, ... Chi-wai Kan, in Sustainable Technologies for Fashion and Textiles, 2020

Thin film coatings and the biological interface

The surface hydrophobicity effect of mammalian cells has been less explored compared with other material surface features.

Examples of Hydrophobic Substances

Oils, fats, alkanes, and most other organic compounds are hydrophobic. If you mix oil or fat with water, the mixture will separate. If you shake a mixture of oil and water, the oil globules will eventually stick together to present a minimum surface area to the water.

How Hydrophobicity Works

Hydrophobic molecules are nonpolar. When they are exposed to water, their nonpolar nature disrupts hydrogen bonds between water molecules, forming a clathrate-like structure on their surface. The structure is more ordered than free water molecules.

Hydrophobic vs. Lipophilic

While the terms hydrophobic and lipophilic are often used interchangeably, the two words don't mean the same thing. A lipophilic substance is "fat-loving." Most hydrophobic substances are also lipophilic, but exceptions include fluorocarbons and silicones.

Chemical background

The hydrophobic interaction is mostly an entropic effect originating from the disruption of the highly dynamic hydrogen bonds between molecules of liquid water by the nonpolar solute forming a clathrate -like structure around the non-polar molecules.

Theory

In 1805, Thomas Young defined the contact angle θ by analyzing the forces acting on a fluid droplet resting on a solid surface surrounded by a gas.

Material Properties of Hydrophobic Materials

• A material’s surface can react either in a hydrophilic (water-loving) or a hydrophobic (water-hating) manner. To understand the behavior of a surface towards water, its contact angle (CA) has to be measured, which will provide information on the interaction energy between the surface and the liquid. The angle at which a liquid/vapor interface converges with a solid surface is know…

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How to Make A Hydrophobic Material

New Innovations

Sources and Further Reading